tag:blogger.com,1999:blog-45268053977260514712024-03-14T02:58:13.890-07:00Integrated Science at HomeLooking at the broad themes that tie different science disciplines together.Kathy Cecerihttp://www.blogger.com/profile/18188872992635537080noreply@blogger.comBlogger29125tag:blogger.com,1999:blog-4526805397726051471.post-47415866839560161422012-10-31T18:50:00.001-07:002012-10-31T18:50:40.622-07:00My New Books -- Perfect for Families Who Love Science!<div class="separator" style="clear: both; text-align: center;">
<a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgWy90761aiWKMs-Ljr8M8ou7zWopnUWX0JVK_582c6XlgaV3W13Cj0pN3rbiNNLkfyI6OHY52EyTsLNJ6PCMxu4X8ltW4ktU3e2izx9bz1gcoAYsLp4DXfw0uG05_VxhKJ3b8OPKggp_KF/s1600/GeekMomBookCover400.jpg" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="320" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgWy90761aiWKMs-Ljr8M8ou7zWopnUWX0JVK_582c6XlgaV3W13Cj0pN3rbiNNLkfyI6OHY52EyTsLNJ6PCMxu4X8ltW4ktU3e2izx9bz1gcoAYsLp4DXfw0uG05_VxhKJ3b8OPKggp_KF/s320/GeekMomBookCover400.jpg" width="258" /></a></div>
<div class="separator" style="clear: both; text-align: center;">
<a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgadCmBqgfscxraVCn1kCLfq-_2P12jcXQFrYL4kDjWglu77LUTXuGKTC9lT4wqnZUo622YwHEnqpfaQ2Qq4JNjk7uhglZR7HMaznX38bYBIs0CEMD085G_qqhcMrEBUJBNMFOT-xcvVjkQ/s1600/Robotics_Cover+500px.jpg" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="320" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgadCmBqgfscxraVCn1kCLfq-_2P12jcXQFrYL4kDjWglu77LUTXuGKTC9lT4wqnZUo622YwHEnqpfaQ2Qq4JNjk7uhglZR7HMaznX38bYBIs0CEMD085G_qqhcMrEBUJBNMFOT-xcvVjkQ/s320/Robotics_Cover+500px.jpg" width="256" /></a></div>
This past year has been busy -- but the result has been TWO new books with tons of amazing science and other geeky projects for kids and families!<br />
<br />
<a href="http://amzn.to/OCLuLa" target="_blank"><i>Geek Mom: Projects, Tips, and Adventures for Moms and Their 21st-Century Families</i></a> is a new book from Potter Craft co-authored by me and the other editors of Wired.com's <a href="http://www.geekmom.com/" target="_blank">GeekMom</a> blog: Natania Barron, Corrina Lawson and Jenny Williams.Written primarily for moms who want to share their geeky interests with their kids, it includes fun activities like superhero costumes, math puzzles, snack food hacks, and science-y crafts, as well as a whole chapter of at-home experiments.<br />
<br />
<a href="http://amzn.to/PoqXEM" target="_blank"><i>Robotics: Discover the Science and Technology of the Future with 20 Projects</i></a>, a book for kids ages 9-12 from Nomad Press, is packed full of information about how robots work and contains "low tech/no tech" projects based on actual robotics research. No special tools or skills are needed to build any of the working robotics models in this book -- just ordinary crafts materials and recycled electronics parts!<br />
<br />
Both these books are available from Amazon or your favorite local bookstore. You can see sample projects and photos and read more about the books on my website <a href="http://www.craftsforlearning.com/" target="_blank">Crafts for Learning</a>, my <a href="http://www.facebook.com/amazingroboticsprojects" target="_blank">Amazing Robotics Projects Facebook page</a>, and on <a href="http://www.wired.com/geekmom/tag/geek-mom-book/" target="_blank">GeekMom</a> and <a href="http://www.wired.com/geekdad/2012/08/robots-everyday-stuff/" target="_blank">GeekDad</a>!Kathy Cecerihttp://www.blogger.com/profile/18188872992635537080noreply@blogger.com0tag:blogger.com,1999:blog-4526805397726051471.post-87934527519649090622012-06-15T20:59:00.000-07:002013-07-05T11:25:15.128-07:00The Transit of Venus and a Space Shuttle<div class="separator" style="clear: both; text-align: center;">
<a href="http://farm9.staticflickr.com/8144/7354539846_2e45516b5e_k.jpg" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="380" src="http://farm9.staticflickr.com/8144/7354539846_2e45516b5e_k.jpg" width="640" /></a></div>
<a href="http://www.geekmom.com/" target="_blank">GeekMom</a>, the blog I helped found and co-edit, has moved to Wired.com, where things are hopping! I've been so busy that science blogging has taken a back seat. But here's a quick update on some cool science things we've been doing.<br />
<br />
Above, I was lucky enough to be in New York City when the Space Shuttle Enterprise sailed from Long Island to New Jersey and onward to its final resting place on the Intrepid Museum in Manhattan. I wrote a bit more about the exciting event in <a href="http://www.wired.com/geekmom/2012/06/new-yorkers-turn-out-for-docking-of-a-space-shuttle-close-up/" target="_blank">a post on GeekMom</a>. <br />
<br />
And on June 5, the family pulled out the Galileoscope to view <a href="http://www.wired.com/geekdad/2012/06/get-ready-for-this-weeks-transit-of-venus/" target="_blank">the transit of Venus</a> across the face of the sun. Although it was cloudy most of the day, the skies did open long enough to let us project this great view of the disk of Venus against the sun. Note the sunspots as well. <br />
<br />
I'll continue to cross-post here, but for timely news about our science goings-on, please visit GeekMom! And if you're interested in news about robotics (and my <a href="http://www.amazon.com/dp/1936749769/ref=as_li_ss_til?tag=craftsforlearning-20&camp=0&creative=0&linkCode=as4&creativeASIN=1936749769&adid=0QXQWXVHESYW7B03EXYQ" target="_blank">forthcoming activity book</a>), stop by the <a href="https://www.facebook.com/AmazingRoboticsProjects" target="_blank">Amazing Robotics Projects</a> Facebook page!Kathy Cecerihttp://www.blogger.com/profile/18188872992635537080noreply@blogger.com0tag:blogger.com,1999:blog-4526805397726051471.post-66156795598521750102012-05-19T22:00:00.005-07:002012-06-15T20:41:27.487-07:00More Galileoscope Viewing -- The Sun and Venus<table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto; text-align: center;"><tbody>
<tr><td style="text-align: center;"><a href="http://blog-admin.wired.com/geekmom/wp-content/uploads/2012/05/Crescent-Venus.jpg" imageanchor="1" style="margin-left: auto; margin-right: auto;"><img border="0" height="320" src="http://blog-admin.wired.com/geekmom/wp-content/uploads/2012/05/Crescent-Venus.jpg" width="304" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">The crescent of Venus, refracted by Earth's atmosphere. Image: Kathy Ceceri</td></tr>
</tbody></table>
<br />
<br />
My <a href="http://www.wired.com/geekmom/2012/05/view-eclipse-safely/" target="_blank">post on GeekMom today </a>includes a photo of a crescent Venus. I was surprised and thrilled to see it when I peeked through the telescope!<br />
<br />
And I failed to mention in the post that as I was setting up the telescope, I saw a good-sized meteor fall straight down! It was an amazing night for viewing.<br />
<br />
If you're in the path of the eclipse tomorrow, go out and take a look (but safely). And next month, almost everyone will get to watch Venus make a transit across the face of the sun. Exciting!Kathy Cecerihttp://www.blogger.com/profile/18188872992635537080noreply@blogger.com2tag:blogger.com,1999:blog-4526805397726051471.post-52851039351520569062012-05-16T05:09:00.002-07:002012-05-16T05:10:38.837-07:00Still Working on Robotics...<div class="separator" style="clear: both; text-align: center;">
<a href="http://www.craftsforlearning.com/images/Robot%20Hydraulic%20Arm%20300px.jpg" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" src="http://www.craftsforlearning.com/images/Robot%20Hydraulic%20Arm%20300px.jpg" /></a></div>
Where have we been? Still watching <a href="http://www.amazon.com/dp/B000MR6DVQ/ref=as_li_ss_til?tag=homeintegratedscience-20&camp=0&creative=0&linkCode=as4&creativeASIN=B000MR6DVQ&adid=094TN5YMN70E2C6WKAMD" target="_blank"><i>The Joy of Science</i></a>, and still working on the Robotics book and various accessories, such as a Teaching Guide.<br />
<br />
If you'd like to see what we're up to during this busy time, come visit my <a href="https://www.facebook.com/AmazingRoboticsProjects" target="_blank">Robotics Facebook Fan</a> page (you don't have to be a member of Facebook to see it) and <a href="http://www.geekmom.com/" target="_blank">GeekMom</a>, now on Wired.com!<br />
<br />
And you can see photos and videos of many of our robotics projects and read about my programs for schools, libraries and museums on my website <a href="http://www.craftsforlearning.com/Robotics%20Program.htm" target="_blank">Crafts for Learning</a>.Kathy Cecerihttp://www.blogger.com/profile/18188872992635537080noreply@blogger.com0tag:blogger.com,1999:blog-4526805397726051471.post-83169427353186825902012-03-12T18:26:00.002-07:002012-03-12T18:29:32.718-07:00Sunspot Update<div class="separator" style="clear: both; text-align: center;">
<a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEh2lSVg5CzK0p4D4bclGBnZIZXj2mujx9uc3nrLPQc008GCtI34YSUd5yK8WeNlghyphenhyphenjxbVlZVjW0M3qg37sDkY-9-RUkL4T9Q9a5g_cBw30SX5_QuOUZaVVjKYLmMnb2TDRYg9HKszHdBY/s1600/Sunspots3-12.JPG" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEh2lSVg5CzK0p4D4bclGBnZIZXj2mujx9uc3nrLPQc008GCtI34YSUd5yK8WeNlghyphenhyphenjxbVlZVjW0M3qg37sDkY-9-RUkL4T9Q9a5g_cBw30SX5_QuOUZaVVjKYLmMnb2TDRYg9HKszHdBY/s1600/Sunspots3-12.JPG" /></a></div>
It was another sunny, warm day today, so I took the telescope outside to look for sunspots again. This time, I used photo paper to try to get a smoother surface for the projected image. I also made a collar for the telescope out of black foamboard to make the image easier to see and photograph. Unfortunately, the telescope itself was pretty shaky today, so the only really clear photo I got was this one, which is at enough of an angle to distort the circle of the sun.<br />
<br />
Something else I was curious to see was whether <a href="http://integratedscienceathome.blogspot.com/2012/03/sunspots.html">the big sunspot from yesterday</a> had moved with the sun's rotation. I think it is, indeed, a little closer to the left edge of the sun. What do you think?<br />
<br />
<div class="separator" style="clear: both; text-align: center;">
<a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiry2BMQ1ME79zlXs0X62h3bItcvvCKD-Ob1jI2v8qWxq4sxfFykyMrksj8VxFveTNvYwE0iybMU69IxzT5HBbqQy6WTmnDJjPFqsx9bT4w4D0lQcHL3kLjc2fYl0IL2ysH_7sp5sowwnk/s1600/Sunspot+Best450px.JPG" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="640" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiry2BMQ1ME79zlXs0X62h3bItcvvCKD-Ob1jI2v8qWxq4sxfFykyMrksj8VxFveTNvYwE0iybMU69IxzT5HBbqQy6WTmnDJjPFqsx9bT4w4D0lQcHL3kLjc2fYl0IL2ysH_7sp5sowwnk/s640/Sunspot+Best450px.JPG" width="580" /></a></div>
<div class="separator" style="clear: both; text-align: center;">
</div>
<br />
If you look closely, you can also make out two sunspots that were not visible yesterday. They are on the right side, just above and below the height of the large spot on the left, and lined up one above the other. <br />
<br />
Considering I didn't have to leave my front porch to do this celestial viewing, I think it's pretty awesome!<br />
<br />Kathy Cecerihttp://www.blogger.com/profile/18188872992635537080noreply@blogger.com0tag:blogger.com,1999:blog-4526805397726051471.post-69173470156733140312012-03-12T06:14:00.002-07:002012-03-12T18:20:11.247-07:00Sunspots!<div class="separator" style="clear: both; text-align: center;">
<a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEj_XIik_1KTZT1T1sOLT2pys7IPDiyr33glq0-ApUUM99jBNk1HtW9nInSlq-hSJ0joYdcFKswuwNg1HJsufgv5PPeneaZIvlJHXs9YAEsi8akxAjcKaoKtQ6R2AOYlogRfQfFD5poeAUs/s1600/Telescope2.JPG" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="320" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEj_XIik_1KTZT1T1sOLT2pys7IPDiyr33glq0-ApUUM99jBNk1HtW9nInSlq-hSJ0joYdcFKswuwNg1HJsufgv5PPeneaZIvlJHXs9YAEsi8akxAjcKaoKtQ6R2AOYlogRfQfFD5poeAUs/s320/Telescope2.JPG" width="316" /></a></div>
<br />
Last year we tried and failed to use our <a href="http://www.blogger.com/blogger.g?blogID=4526805397726051471#editor/target=post;postID=2054823295603937738">Galileoscope</a> to see sunspots. There were two problems: there were no sunspots to see that day, and we had the telescope pointed the wrong way!<br />
<br />
With news of the massive solar flares heading towards Earth this past week, I decided to give it another try. I read over the directions on <a href="http://spaceweather.com/sunspots/doityourself.html">spaceweather.com</a> again and corrected our mistake with the setup. Success! <br />
<br />
<div class="separator" style="clear: both; text-align: center;">
<a href="http://www.geekmom.com/wp-content/uploads/2012/03/Sunspot-Best450px.jpg" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="320" src="http://www.geekmom.com/wp-content/uploads/2012/03/Sunspot-Best450px.jpg" width="290" /></a></div>
<br />
Go to my blog post on <a href="http://www.geekmom.com/2012/03/sunspot-gazing-at-home/">GeekMom</a> to see how we did it.Kathy Cecerihttp://www.blogger.com/profile/18188872992635537080noreply@blogger.com0tag:blogger.com,1999:blog-4526805397726051471.post-44749678316319823082012-03-07T09:16:00.000-08:002012-03-12T18:19:45.161-07:00Grains of Salt and the Formation of Planets<iframe allowtransparency="true" frameborder="0" height="360" id="dit-video-embed" scrolling="no" src="http://static.discoverymedia.com/videos/components/dsc/f69336034bb17007dc86585e282f4752efc04455/snag-it-player.html?auto=no" width="640"></iframe>
<br />
We've been watching the Discovery Channel series <a href="http://www.amazon.com/dp/B004QSQMG8/ref=as_li_ss_til?tag=homeintegratedscience-20&camp=0&creative=0&linkCode=as4&creativeASIN=B004QSQMG8&adid=18BYKR8KFSSGY6PHNS6D"><i>How the Universe Works</i></a>. While a bit light on content and a tad repetitious, it also features amazing animations and lots of actual images we hadn't seen before.<br />
<br />
One of the most interesting factoids involved a casual experiment on the International Space Station that solved the mystery of how planets form. Watch the clip above to find out!Kathy Cecerihttp://www.blogger.com/profile/18188872992635537080noreply@blogger.com0tag:blogger.com,1999:blog-4526805397726051471.post-46023670923660398572012-02-21T21:08:00.000-08:002012-03-12T18:19:08.164-07:00Michio Kaku and Physics of the Future<div class="separator" style="clear: both; text-align: center;">
</div>
<div class="separator" style="clear: both; text-align: center;">
<a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgCG-lgrhSSSYP7je6ODoIQew0PXPTBdUFtn3VwXRL1rzLPXxRy5v5v08yC7IH_Y4z2Qxe6AZqHqNF_Kpan2FbIm97J62tGIQu08vZX1v1WHEeFz6j2a9cpiRc7LOIbZrTjmfzjRRN_hOg/s1600/MichioKaku2.jpg" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="391" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgCG-lgrhSSSYP7je6ODoIQew0PXPTBdUFtn3VwXRL1rzLPXxRy5v5v08yC7IH_Y4z2Qxe6AZqHqNF_Kpan2FbIm97J62tGIQu08vZX1v1WHEeFz6j2a9cpiRc7LOIbZrTjmfzjRRN_hOg/s400/MichioKaku2.jpg" width="400" /></a></div>
<div class="separator" style="clear: both; text-align: center;">
<br /></div>
It's been a while, but with my oldest son safely off at college, my 16 year old and I are starting to pick up where we left off in The Joy of Science. The last couple lectures have dealt with the universe, galaxies and black holes. And since the DVD series, while wonderful, is now rather old, I thought we should supplement it with something more recent.<br />
<br />
The newest and most highly rated documentary series I could find was <a href="http://www.amazon.com/dp/B004QSQMG8/ref=as_li_ss_til?tag=homeintegratedscience-20&camp=0&creative=0&linkCode=as4&creativeASIN=B004QSQMG8&adid=18BYKR8KFSSGY6PHNS6D"><i>How the Universe Works</i></a> from the Discovery Channel. The writing seems a tad light compared to the PBS series we are used to, but the animations and actual footage are stunning. As a visual learner myself I just rejoice when an animation makes it possible to grasp some concept that would be impossible to picture from a description on a page.<br />
<br />
We've only seen two episodes, but both have featured someone I had heard of but never seen before: physicist <a href="http://mkaku.org/home/?p=988">Michio Kaku</a>, one of the developers of string theory. And it just so happened that the Times Union featured <a href="http://www.timesunion.com/living/article/Physicist-author-Michio-Kaku-s-new-book-offers-a-3337181.php">an interview with Kaku </a>in advance of his appearance at UAlbany. I thought it would be fun to run down there and attend the free lecture.<br />
<br />
The topic was advanced physics -- mainly nanotechnology, in which <a href="http://cnse.albany.edu/Home.aspx">UAlbany</a> and the surrounding area are beginning to specialize. Kaku called the area "ground zero" for nano research. Still, even with the TU article, I was surprised to find that the ballroom on the Albany campus was standing room only. I counted more than a 1,000 people in the room. And amazingly, my son and I managed to find seats right up front.<br />
<br />
<div class="separator" style="clear: both; text-align: center;">
<a href="http://www.amazon.com/dp/0307473333/ref=as_li_ss_til?tag=homeintegratedscience-20&camp=0&creative=0&linkCode=as4&creativeASIN=0307473333&adid=18FTMAX4H7D9NX9AP5C3"></a><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjj3_5i-ZHapg4TJDAfAKp967_xc-0M4Db6OFHa_4wjzxkp3pxRbdwJ8xBmxuSOCnRGVSaxzP3ovK8Dvrr46aIHhpBwebSOq7O5cq8X9ElKGvmqsBIZi9PS18j02WW1JbEuz4QwQNwXSAM/s1600/physics_of_the_future_kaku1.jpg" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="320" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjj3_5i-ZHapg4TJDAfAKp967_xc-0M4Db6OFHa_4wjzxkp3pxRbdwJ8xBmxuSOCnRGVSaxzP3ovK8Dvrr46aIHhpBwebSOq7O5cq8X9ElKGvmqsBIZi9PS18j02WW1JbEuz4QwQNwXSAM/s320/physics_of_the_future_kaku1.jpg" width="209" /></a></div>
<br />
Kaku presented some of the ideas from his new book, <a href="http://www.amazon.com/dp/0307473333/ref=as_li_ss_til?tag=homeintegratedscience-20&camp=0&creative=0&linkCode=as4&creativeASIN=0307473333&adid=0TFGDEFXY2QFWJ6YM8C3"><i>Physics of the Future</i></a>. The lecture was interesting, even if some of the "future" technologies are already here (a phone that will make dinner reservations for you -- I believe it's called Siri) or seem as likely as the jetpack we were all promised back when I was a kid. Underscoring the reality of what "could" be with what probably "will" be was the primitive projection system in the ballroom, which made it hard for Kaku to show a video clip after his Power Point presentation. Looking around the room during the lecture at the rattling curtains and the chandeliers hanging scarily askew -- looking like they hadn't been updated since I went there 35 years ago -- it made me wonder how this country can try to take the lead in technology when our infrastructure is allowed to crumble. <br />
<br />
Still, it was a fun jaunt, the lecture was entertaining, and although we decided not to battle the crowds to buy a book and get it autographed, I think I will try to borrow a copy from the library as soon as I get the chance.<br />
<br />
My favorite takeaway from the evening came with the last question: Asked what he thought was the most important discovery of the last few years, Kaku pointed out that every science textbook which claims that everything in the universe is made of atoms was wrong. In fact, he said, atoms only account for 4 percent of the universe. The rest is made up of dark matter and dark energy. Sitting there following the discussion, I felt that it was a validation that I made the right choice when I decided that our study of physics would focus on the latest discoveries rather than rehashing Newton's Laws yet again.Kathy Cecerihttp://www.blogger.com/profile/18188872992635537080noreply@blogger.com0tag:blogger.com,1999:blog-4526805397726051471.post-38875848077145081472012-01-08T14:44:00.000-08:002012-03-12T18:18:16.857-07:00We've Been Building Robots...<div class="separator" style="clear: both; text-align: center;">
<a href="http://a5.sphotos.ak.fbcdn.net/hphotos-ak-ash4/375308_247519681964580_235676506482231_631950_1845519857_n.jpg" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="320" src="http://a5.sphotos.ak.fbcdn.net/hphotos-ak-ash4/375308_247519681964580_235676506482231_631950_1845519857_n.jpg" width="256" /></a></div>
If you've been wondering where we went, the past few months have been spent developing projects for two book projects. One is an activity book for ages 9-12 about Robotics. You can see some of them on the <a href="http://www.facebook.com/pages/Robotics-Discover-the-Science-and-Technology-of-the-Future-by-Kathy-Ceceri/235676506482231?sk=wall">Facebook fan page</a> I created. (A companion blog is forthcoming.)<br />
<br />
The other book is a joint project with the other editors of <a href="http://www.geekmom.com/2011/10/geekmom-to-become-a-book/">GeekMom</a>! I'll post more news of that as it develops.<br />
<br />
<br />Kathy Cecerihttp://www.blogger.com/profile/18188872992635537080noreply@blogger.com0tag:blogger.com,1999:blog-4526805397726051471.post-67458527785353918142011-08-28T09:51:00.000-07:002011-08-28T09:51:56.647-07:00More Integrated Science<iframe allowfullscreen="" frameborder="0" height="390" src="http://www.youtube.com/embed/W1xbk7M1yIo?rel=0" width="480"></iframe><br />
The Ceceri family will be continuing our study of Integrated Science this year, but with one less student. John III is now off at <a href="http://www.rit.edu/">Rochester Institute of Technology</a>, where he is in the <a href="http://games.rit.edu/">Interactive Games and Media</a> program.<br />
<br />
As a going-away present, I made him this great fish tank, using <a href="http://www.wired.com/geekdad/2011/08/genetically-modified-pets-your-kids-will-love/">genetically-modified fluorescent GloFish</a>. Watch the video to see what happens when you turn on a blacklight!<br />
<br />
The mini-aquarium I put together is a project I've written about before on Home Biology. Here are the <a href="http://www.geekmom.com/2011/08/diy-mini-aquarium/">instructions</a>, which I ran on GeekMom last week. <br />
<br />
Keep watching this space for more labs related to the Joy of Science video series. We'll also be trying out some electronics projects as I work on a new children's activity book about robotics. I'm looking forward to another fun year!Kathy Cecerihttp://www.blogger.com/profile/18188872992635537080noreply@blogger.com0tag:blogger.com,1999:blog-4526805397726051471.post-69044450796050541782011-06-17T12:29:00.000-07:002011-06-17T12:38:24.193-07:00Foam Plate Speakers<div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhcVMYV_LiSoGripdpzGuv_3kVRmAXGarEYwGWMCOPk-OAr6CdYBkpvtQLxpdxEKz80RPfHTUjo5RrhLbsBgCVnMGyoSPR9Vl07obKI9XKlTghnLoVTAW5rlnLxt7eAhHXQ3F1hP62sN6A/s1600/101_1824.JPG" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"> </a></div><div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgMQKW4iS5umYQnGFRO2h6RnHhMcJwCICc0pvY7F8MHVSna-d94vv3gci3V1m3P9X8zz-wEbZe658gASXqLZH7REywhTLhwOcPF-1ppozlOpN1PsL2jL6qRmANq1yJD7G70-icc0FtGxSA/s1600/101_1829.JPG" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="213" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgMQKW4iS5umYQnGFRO2h6RnHhMcJwCICc0pvY7F8MHVSna-d94vv3gci3V1m3P9X8zz-wEbZe658gASXqLZH7REywhTLhwOcPF-1ppozlOpN1PsL2jL6qRmANq1yJD7G70-icc0FtGxSA/s320/101_1829.JPG" width="320" /></a></div><br />
For science this week, we decided to experiment more with audio devices. (The episode of <a href="http://www.amazon.com/dp/B0010L578S?tag=homeintegratedscience-20&camp=213381&creative=390973&linkCode=as4&creativeASIN=B0010L578S&adid=05RZD1T1QMMCF7SKB3Z8">The Joy of Science</a> we had just watched was about properties of matter, including magnetism, and mentioned that speakers worked because magnets changed shaped.) Since we had already <a href="http://integratedscienceathome.blogspot.com/2011/01/powered-by-radio-waves.html">built a radio</a>, this time we built a speaker. The speaker was much easier to make and much less elaborate than the radio, and we were able to have it working in about a half-hour. Despite requiring some fine-tuning, we were able to get it to work very well.<br />
<br />
This simple and elegant project was designed by <a href="http://www.josepino.com/?homemade-hifi-speaker">Jose Pino</a>. You can see it being made in this Make Magazine <a href="http://www.youtube.com/watch?v=EIbzQ_8-aaM&feature=player_embedded">YouTube tutorial</a>. <br />
<br />
We didn't test our speaker out with our foxhole radio, because the volume is so low on both devices. Instead we used an mp3 player. But we plan to try our homemade radio with the speaker sometime in the future.<br />
<br />
<br />
<a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhklp1cVsqJjj9KNwPwC3i4Bhh-TIaza5m8a8Bbz9w3ilSnLGssIsPhJNUr-oJK2GMVSqd8h6pzUTvaaf73OdoNDl0fHk96ffi_0B0VygXyKLdXIpOwaZLzSOelOQ6Wp7XkwP5zcEWf2_8/s1600/101_1816.JPG" imageanchor="1" style="clear: right; float: right; margin-bottom: 1em; margin-left: 1em;"><img border="0" height="213" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhklp1cVsqJjj9KNwPwC3i4Bhh-TIaza5m8a8Bbz9w3ilSnLGssIsPhJNUr-oJK2GMVSqd8h6pzUTvaaf73OdoNDl0fHk96ffi_0B0VygXyKLdXIpOwaZLzSOelOQ6Wp7XkwP5zcEWf2_8/s320/101_1816.JPG" width="320" /></a><b>Materials:</b><br />
<br />
A foam plate<br />
Two strips of paper <br />
Two business cards (we just cut an index card in half for this)<br />
Tape<br />
A hot glue gun<br />
Magnetic copper wire (Jose Pino recommends using AWG 32)<br />
Neodymium magnets<br />
An audio plug<br />
A piece of cardboard<br />
<br />
1. We started by rolling one of the strips of paper over the magnets. We then taped the roll closed, being careful not to tape it to the magnets.<br />
<br />
2. Next, we rolled the other strip of paper around the first strip, and taped it closed. We cut this strip a little less wide than the first. This made the outer strip stick out a bit more than the inner one.<br />
<br />
<a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiqb1RfQMaal1dF2ncdO4IJNoii2LWGk2p2Ol-4LA8uGyHYgaEViNEE1N5oSk3HKMSqIP67pfPnJraNUc3UVaAWWCGmhYBjOPKmNpxFXlg3LFgPXS0U2JS5xVwFk3MwdLF4tiB3jp0Vb4c/s1600/101_1823.JPG" imageanchor="1" style="clear: left; float: left; margin-bottom: 1em; margin-right: 1em;"><img border="0" height="176" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiqb1RfQMaal1dF2ncdO4IJNoii2LWGk2p2Ol-4LA8uGyHYgaEViNEE1N5oSk3HKMSqIP67pfPnJraNUc3UVaAWWCGmhYBjOPKmNpxFXlg3LFgPXS0U2JS5xVwFk3MwdLF4tiB3jp0Vb4c/s200/101_1823.JPG" style="cursor: move;" width="200" /></a>3. Keeping the magnet inside the tubes of paper, we coiled the copper wire around it, using about 50 turns. Leave a few inches of copper wire uncoiled on each end.<br />
<br />
4. We then pulled the magnet out of our paper, along with the inner strip (we made it wider so that it would be easier to pull out.)<br />
<br />
5. Discarding the inner strip, we then hot-glued the outer to the bottom of the foam plate, being careful to have it in the center.<br />
<br />
6. Next, we hot-glued the magnet to the cardboard. After that, we folded the business cards in an accordion shape, we glued them to the bottom of the plate, one on each side of the coil. We then put hot glue on the bottoms of the cards, and glued them to the cardboard base, making sure that the coil would go over the magnet.<br />
<br />
7. We tested the wires by touching the ends to either end of a battery. This is what happened:<br />
<br />
<object height="390" width="480"><param name="movie" value="http://www.youtube.com/v/XNLCsRR8Yn0?version=3&hl=en_US&rel=0"></param><param name="allowFullScreen" value="true"></param><param name="allowscriptaccess" value="always"></param><embed src="http://www.youtube.com/v/XNLCsRR8Yn0?version=3&hl=en_US&rel=0" type="application/x-shockwave-flash" width="480" height="390" allowscriptaccess="always" allowfullscreen="true"></embed></object><br />
<br />
<a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgeCTvwiwGOBE7WMFY1w0sXlqB5BphEXi-XM_k56LneslfiwobGgBDb352PyNY2u6s5mrmJIPH5EHOajE9QYWJcJR42L9EnrOQb2qSXavuPwh1i_V0o2VpnwmJzfeXZHDTUk9U7X5RLFoU/s1600/101_1825.JPG" imageanchor="1" style="clear: right; float: right; margin-bottom: 1em; margin-left: 1em;"><img border="0" height="213" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgeCTvwiwGOBE7WMFY1w0sXlqB5BphEXi-XM_k56LneslfiwobGgBDb352PyNY2u6s5mrmJIPH5EHOajE9QYWJcJR42L9EnrOQb2qSXavuPwh1i_V0o2VpnwmJzfeXZHDTUk9U7X5RLFoU/s320/101_1825.JPG" width="320" /></a><br />
<br />
8. To connect our speaker to a sound system, we needed an audio plug. We got one by cutting the end off a cheap set of earbuds from the dollar store. FIrst we had to sand off the coating from each end of the copper coil wire and strip the rubber insulation from the ends of the audio plug. Because the earbuds were stereo, we needed to connect one wire from each earbud to each of the copper coil wires in order to hear both sides. (We're not sure that worked well, though.)<br />
<br />
9. Finally, we plugged the audio wire into a music device. We found that MP3 players worked the best.<br />
<br />
<object height="390" width="480"><param name="movie" value="http://www.youtube.com/v/uWf2Iib2iKc?version=3&hl=en_US&rel=0"></param><param name="allowFullScreen" value="true"></param><param name="allowscriptaccess" value="always"></param><embed src="http://www.youtube.com/v/uWf2Iib2iKc?version=3&hl=en_US&rel=0" type="application/x-shockwave-flash" width="480" height="390" allowscriptaccess="always" allowfullscreen="true"></embed></object><br />
<br />
<b>How it Works:</b><br />
<br />
The speakers operate largely on the same principle as the piezoelectric earpiece we used in our radio experiment. The coil serves as an electromagnet. It receives electrical currents from the audio plug, which gives it either a stronger or weaker attraction to the magnets. This causes the foam plate to bounce up and down, creating sound vibrations.Kathy Cecerihttp://www.blogger.com/profile/18188872992635537080noreply@blogger.com0tag:blogger.com,1999:blog-4526805397726051471.post-55811805193962660802011-05-23T11:49:00.000-07:002011-05-23T11:49:22.328-07:00More Plasma Fun<div class="separator" style="clear: both; text-align: center;"></div><iframe allowfullscreen="" frameborder="0" height="390" src="http://www.youtube.com/embed/wWWoi6Ve37s?rel=0" width="480"></iframe><br />
<br />
We had so much fun playing with our <a href="http://integratedscienceathome.blogspot.com/2011/05/plasma-fourth-state-of-matter.html">plasma ball</a>, we decided to try making some plasma of our own! According to <a href="http://www.youtube.com/watch?v=_ux8nSWmAz0&feature=related">YouTube</a>, this is easy to do if you have (a) a microwave and (b) a grape. This experiment was about the most exciting thing we have ever tried in our kitchen. Here's how to do it:<br />
<br />
<div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEj8PKbm-mcbcIXvpih2C8M7LHdDlNN9mCH6PdOetHKFGZgYzI0V7e7y5zkT6CSYcWcPWl5kxEVNYoPMRh_YW3yPBuhY8xPHezUnWqfYF3-sYJA7CrctcsBd0bq7Zu4FqkhN9ov28OwVVko/s1600/Grape+Plasma+Blob.jpg" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="266" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEj8PKbm-mcbcIXvpih2C8M7LHdDlNN9mCH6PdOetHKFGZgYzI0V7e7y5zkT6CSYcWcPWl5kxEVNYoPMRh_YW3yPBuhY8xPHezUnWqfYF3-sYJA7CrctcsBd0bq7Zu4FqkhN9ov28OwVVko/s400/Grape+Plasma+Blob.jpg" width="400" /></a></div><div class="separator" style="clear: both; text-align: center;"></div><br />
<div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgYNnmovAr7iFBlYA96GFF-pQN6XYqcmXa8vx6EmewV3mVWkMAUKACekV7z2D73zw8cDk_gk1BxiyYGhNRuZLjo_rxIGLKQPYdpf0WDAUzzHno_-3IQu7xXKFiCyoC2VaxhHYgznkmkfF4/s1600/Grape+Plasma+Materials.JPG" imageanchor="1" style="clear: right; float: right; margin-bottom: 1em; margin-left: 1em;"><img border="0" height="257" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgYNnmovAr7iFBlYA96GFF-pQN6XYqcmXa8vx6EmewV3mVWkMAUKACekV7z2D73zw8cDk_gk1BxiyYGhNRuZLjo_rxIGLKQPYdpf0WDAUzzHno_-3IQu7xXKFiCyoC2VaxhHYgznkmkfF4/s320/Grape+Plasma+Materials.JPG" width="320" /></a></div><b>Materials</b><br />
<ul><li>large juicy grape</li>
<li>knife</li>
<li>microwave-safe plate</li>
<li>microwave-safe tall heavy glass, preferably tapered (like a beer or coke glass)</li>
</ul><ol><li>Cut a grape in half across the middle. Take one half and cut the long way, leaving a bit of skin to hold the halves together. </li>
<li>Open up the halves and place grape on a small plate. Remove the rotating turntable in the microwave. Place the plate in the microwave. </li>
<li>Turn off the lights. Set the microwave for 5 seconds (but stand by to hit "Stop" when needed). You should see sparks and a puff of “flame.” That is the plasma.</li>
</ol><br />
<div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhNGh-30Z0G8ZSHV-MGAyHbbDB7Lf1VpfqdQuJJ44lnBiUREVZeds84CHME6-drU8jM7IJS-K8bx_fI3a8qRPuOCEisg54fh2VITXftknVwNbPHulW-IvOv_SLp0XaObQqHJXEqJCgw0C8/s1600/100_1699.JPG" imageanchor="1" style="clear: left; float: left; margin-bottom: 1em; margin-right: 1em;"><img border="0" height="213" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhNGh-30Z0G8ZSHV-MGAyHbbDB7Lf1VpfqdQuJJ44lnBiUREVZeds84CHME6-drU8jM7IJS-K8bx_fI3a8qRPuOCEisg54fh2VITXftknVwNbPHulW-IvOv_SLp0XaObQqHJXEqJCgw0C8/s320/100_1699.JPG" width="320" /></a></div><br />
Here's something even cooler: To make a kind of <a href="http://tesladownunder.com/JacobsLadder.htm">Jacob's Ladder</a>, cover the grape with the glass. Make sure the glass is sturdy, or <a href="http://www.youtube.com/watch?v=mNXAYTqVZW0">it may break</a>! Set the microwave for 5 seconds (but stand by to hit "Stop" when needed). You should see blobs of plasma rising in the glass over and over.<br />
<br />
<iframe allowfullscreen="" frameborder="0" height="390" src="http://www.youtube.com/embed/r6XhRpTBLFE?rel=0" width="480"></iframe><br />
<br />
Here's an explanation of how a microwave creates plasma from <a href="http://www.thenakedscientists.com/HTML/content/kitchenscience/exp/grape-plasmas/">Naked Scientists</a>:<br />
<blockquote>A microwave oven heats up food using microwaves - these are electomagnetic waves that cause electric current to move back and forth between the two halves of the grape. This current is concentrated in the piece of skin between the two, which will heat up and dry out. The current then has to move through the air, creating a spark. </blockquote><br />
<blockquote>The spark is created when the electric field rips electrons off atoms. These can then move freely and carry electric current. A gas with free electrons and positive ions is also known as a plasma. This plasma conducts electricity and can absorb microwaves. Sometimes the plasma gets big enough to absorb enough microwaves to keep growing.</blockquote><br />
And from <a href="http://www.physicsforums.com/showthread.php?t=189942">Physics Forums</a>:<br />
<blockquote>There's two clean grape surfaces that are separated by a fraction of a millimeter near the corner of an air wedge. The electric field between the grape portions at the tip of the wedge is large enough to cause breakdown in the air gap, making a plasma ball there.</blockquote>Kathy Cecerihttp://www.blogger.com/profile/18188872992635537080noreply@blogger.com2tag:blogger.com,1999:blog-4526805397726051471.post-66946206234945372122011-05-05T07:36:00.000-07:002011-05-05T07:36:23.968-07:00Plasma: The Fourth State of Matter<div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhiZB1THRbkgZTjNqlIFtlMB9CewCa_Xm2p-xoMF7tD9KYNe0F6yEajgjBupCrTwDMwXJPSN_JCtr6S9JmRo2PFalzfiTuOUxmeFD7F-h5J7pt9VKk-QmAdDGHi0JzftXLwaMmCYgj6RJE/s1600/Penny+Spark.JPG" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="320" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhiZB1THRbkgZTjNqlIFtlMB9CewCa_Xm2p-xoMF7tD9KYNe0F6yEajgjBupCrTwDMwXJPSN_JCtr6S9JmRo2PFalzfiTuOUxmeFD7F-h5J7pt9VKk-QmAdDGHi0JzftXLwaMmCYgj6RJE/s320/Penny+Spark.JPG" width="270" /></a></div><br />
This week's episode of The Joy of Science was about States of Matter. Most people are familiar with three: solid, liquid, and gas. But there is a fourth state of matter: plasma.<br />
<br />
Plasma is a gas-like field made up of charged atomic particles – negative electrons and positive ions (atoms which have lost some of their electrons, and so have an excess of positrons). As they move, these particles generate electricity and magnetic fields. Plasma requires low pressure and extremely high temperatures. On Earth, plasma only occurs naturally in the form of lightning, polar auroras, and extremely hot flames. However, plasma is actually the most common state of matter in the universe, since it makes up stars and other celestial bodies, as well as the space in between.<br />
<br />
Plasma was first identified in 1879 by Sir William Crookes, who called it "radiant matter." It can be created artificially by running an alternating electric current through certain types of gas in vacuum tubes. This “knocks electrons” off the atoms inside. <br />
<br />
In this experiment, we decided to use a <a href="http://www.amazon.com/dp/B0000945JQ/ref=as_li_ss_til?tag=homeintegratedscience-20&camp=213381&creative=390973&linkCode=as4&creativeASIN=B0000945JQ&adid=05S4AWMARHQG5A1XM7E9">plasma globe</a> to observe some properties of plasma. A plasma globe is a type of lamp that you can buy in a novelty shop, museum gift shop, or through a science supply house. Inside the glass bulb of the plasma globe is a <a href="http://www.teslasociety.com/teslacoil.htm">Tesla coil</a>. This creates a plasma field of electrically charged particles, which look like small tendrils of lightning.<br />
<br />
<div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEg70TEbhdF7SqecS2O3Ql-GDTWqGKbfOAxfEWjAX_tSXsR-085pL12RX_1RaZZ0kyPzHczvxTE_bHjIajvOMDsIAxgxEyE0dazKqqiZ-27tynzbJ6RHo83KB5wGW1b807PpsvgivMDrGH4/s1600/Plasma+Ball+Materials.JPG" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="267" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEg70TEbhdF7SqecS2O3Ql-GDTWqGKbfOAxfEWjAX_tSXsR-085pL12RX_1RaZZ0kyPzHczvxTE_bHjIajvOMDsIAxgxEyE0dazKqqiZ-27tynzbJ6RHo83KB5wGW1b807PpsvgivMDrGH4/s320/Plasma+Ball+Materials.JPG" width="320" /></a></div><br />
When we turned the plasma globe on and touched the glass, the tendrils of lightning concentrated at the spot that was touched. Touching it in more than one place at the same time created several points of concentration. Our plasma globe also had a setting that made it react to sound waves. We put mp3 speakers next to it and watched it flick on and off in relation to the music. Interestingly, it was more affected by frequency (how high or low the note was) than to volume. It reacted very strongly to particular notes and not at all to others. This reminded us of seeing the band <a href="http://www.arcattack.com/">ArcAttack</a> at <a href="http://makerfaire.com/newyork/2011/">Maker Faire NY</a>. ArcAttack creates music using giant Tesla coil-driven <a href="http://en.wikipedia.org/wiki/Plasma_speaker">plasma arc speakers</a>.<br />
<br />
<object height="390" width="480"><param name="movie" value="http://www.youtube.com/v/Kij1HA6JAto?fs=1&hl=en_US&rel=0"></param><param name="allowFullScreen" value="true"></param><param name="allowscriptaccess" value="always"></param><embed src="http://www.youtube.com/v/Kij1HA6JAto?fs=1&hl=en_US&rel=0" type="application/x-shockwave-flash" width="480" height="390" allowscriptaccess="always" allowfullscreen="true"></embed></object><br />
<br />
The first experiment we did was to hold different kinds of unplugged light bulbs near the globe. As described on the Plasma Ball experiments page on the <a href="http://uw.physics.wisc.edu/%7Ewonders/PlasmaBall.html">Wonders of Science website</a> from the University of Wisconsin, some electrons from inside the globe travel through the glass to the light bulbs. <br />
<br />
<div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEi8cMYgAfInXQ_1RbBrTpBHGkT6UUcjd_0g4Yniq4mP-kx98mLo7arbU3ajYA59RlFZD81ZWpgKeRCrsbcP4Qo1Uy99eD5GgRB3eFDEQEgiZrak45TLo8wLRk4h54GesJZPTH1mIqSLqwg/s1600/Fluourescent+tube.JPG" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="263" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEi8cMYgAfInXQ_1RbBrTpBHGkT6UUcjd_0g4Yniq4mP-kx98mLo7arbU3ajYA59RlFZD81ZWpgKeRCrsbcP4Qo1Uy99eD5GgRB3eFDEQEgiZrak45TLo8wLRk4h54GesJZPTH1mIqSLqwg/s320/Fluourescent+tube.JPG" width="320" /></a></div><br />
Inside the bulbs are gas molecules. In fluourescent bulbs, molecules of mercury vapor become excited by the energy of the charged particles bombarding them from the plasma field. Electrons in the mercury atoms make a quantum jump to a higher energy level (or shell) around the atom's nucleus. When they return to their previous energy level, the extra energy is given off in the form of light. When they are plugged in, fluourescent tubes also operate by creating plasma fields out of the mercury gas.<br />
<br />
We got good results with fluorescent and neon lights, above and in the videos below. We also tested Halogen and Xenon bulbs, but were unsuccessful.<br />
<br />
<object height="390" width="480"><param name="movie" value="http://www.youtube.com/v/jw5wytTZ5dc?fs=1&hl=en_US&rel=0"></param><param name="allowFullScreen" value="true"></param><param name="allowscriptaccess" value="always"></param><embed src="http://www.youtube.com/v/jw5wytTZ5dc?fs=1&hl=en_US&rel=0" type="application/x-shockwave-flash" width="480" height="390" allowscriptaccess="always" allowfullscreen="true"></embed></object><br />
<br />
<object height="390" width="480"><param name="movie" value="http://www.youtube.com/v/WbUnBl2WJic?fs=1&hl=en_US&rel=0"></param><param name="allowFullScreen" value="true"></param><param name="allowscriptaccess" value="always"></param><embed src="http://www.youtube.com/v/WbUnBl2WJic?fs=1&hl=en_US&rel=0" type="application/x-shockwave-flash" width="480" height="390" allowscriptaccess="always" allowfullscreen="true"></embed></object><br />
<br />
Our second experiment was more elaborate. First, we balanced a penny on the top of the globe. Next, we took another penny, and close to the penny balanced on the dome, but not touching it. As in the first experiment, some electrons from the plasma field traveled through glass and were carried by the penny on top as an electrical current. The penny was able to carry a current because they are made out of a conductive material, copper. Holding a second penny above the first drew the electricity throught the air, creating a tiny spark. You can just barely see the spark in the photo below; in the video you can see and hear the tiny crackle as the pennies spark.<br />
<br />
<div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhVSw2lMCJ8drkDExmAhyy1osSVx6mAMOQ08QeM-IGTsoVHuXnYEVWgd2dRjox_x69-3UKUejMHaBws4m1KqV4GtyHVJVWsZvq0O2UCZEbBgUNRH7Df3pPJKf1zmtY2okb_ld0Q1wRM4sQ/s1600/Penny+Spark+Closeup.JPG" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="223" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhVSw2lMCJ8drkDExmAhyy1osSVx6mAMOQ08QeM-IGTsoVHuXnYEVWgd2dRjox_x69-3UKUejMHaBws4m1KqV4GtyHVJVWsZvq0O2UCZEbBgUNRH7Df3pPJKf1zmtY2okb_ld0Q1wRM4sQ/s320/Penny+Spark+Closeup.JPG" width="320" /></a></div><br />
<br />
<object height="390" width="480"><param name="movie" value="http://www.youtube.com/v/WItt1JgniBQ?fs=1&hl=en_US&rel=0"></param><param name="allowFullScreen" value="true"></param><param name="allowscriptaccess" value="always"></param><embed src="http://www.youtube.com/v/WItt1JgniBQ?fs=1&hl=en_US&rel=0" type="application/x-shockwave-flash" width="480" height="390" allowscriptaccess="always" allowfullscreen="true"></embed></object><br />
<br />
<br />
We also tried sending sparks to our fingers. We found that, if we weren’t grounded, we could send a spark from the penny to one of our fingers without feeling a shock!<br />
<br />
Stay tuned for more exciting plasma experiments in the second part of our report on States of Matter!Kathy Cecerihttp://www.blogger.com/profile/18188872992635537080noreply@blogger.com0tag:blogger.com,1999:blog-4526805397726051471.post-5008430762267878682011-04-25T08:20:00.000-07:002011-04-25T08:20:00.124-07:00Isolating DNA -- a long polymer chain<div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhUq6DAtLZkx-EQ3qSBFQ0LMJDdEj2oTooGRQDHY95n5_EDSrfGK5BVxf-9loHUwv7jv1HnPvdpeb5hucnfxrQhWzZB_Ik4HUueqT2o0NnMYfxjO9XtuJ01EHQkFS_EQDIg69aFssNep7M/s1600/DNA+Strand+Closeup.jpg" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="231" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhUq6DAtLZkx-EQ3qSBFQ0LMJDdEj2oTooGRQDHY95n5_EDSrfGK5BVxf-9loHUwv7jv1HnPvdpeb5hucnfxrQhWzZB_Ik4HUueqT2o0NnMYfxjO9XtuJ01EHQkFS_EQDIg69aFssNep7M/s400/DNA+Strand+Closeup.jpg" width="400" /></a></div>DNA, which stands for Deoxyribonucleic acid, is made up molecules known as nucleic acids. These were first identified by Swiss physician and biologist Johannes Friedrich Miescher in 1869, who called them “nuclein” because they were found in the nucleus of the cell. Every type of life form known contains nucleic acids, in the form of DNA or RNA (ribonucleic acid).<br />
<br />
Oswald Avery received the Nobel Prize in 1943 for confirming that DNA carried genetic information. Each strand of human DNA is divided into 23 pairs of chromosones, which in turn contain hundreds or thousands of genes. Genes record information in the form of chemical codes about how to build the proteins and other molecules which make up living organisms. <br />
<br />
DNA is one of the longest type of polymers, or chains of molecules. Strands of human DNA are 6 feet long. In 1950, scientist Rosalind Franklin used X-ray crystallography to find that DNA is made up of two long polymers, or chains of molecules, twisted into a shape called a double helix. In 1953, James Watson and Francis Crick discovered that the strands were connected by crossbars, like a ladder. They won the Nobel Prize in 1962 for uncovering DNA’s structure.<br />
<br />
<br />
Isopropyl (rubbing) alcohol (70 or 91 percent)<br />
Clear plastic cups<br />
Plastic spoons<br />
Small plate (preferably disposible)<br />
Drinking water<br />
Salt<br />
Dish soap <br />
Blue food coloring (optional)<br />
<br />
<div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgSChZqQUAiSRSz9BMSRb_Yue8Tqc9CUbegQqjEpr-prMf9p0RNk548YiKbDvfRZxi4kG35qztEOg8XWtG4nP_szxI4bVZ9zb9F5Z7QjuiWVOPJ8pM9ksy0_S89TJqwiGeN4rhX02yWfbM/s1600/101_1652.JPG" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="213" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgSChZqQUAiSRSz9BMSRb_Yue8Tqc9CUbegQqjEpr-prMf9p0RNk548YiKbDvfRZxi4kG35qztEOg8XWtG4nP_szxI4bVZ9zb9F5Z7QjuiWVOPJ8pM9ksy0_S89TJqwiGeN4rhX02yWfbM/s320/101_1652.JPG" width="320" /></a></div><br />
Step 1: Chill the alcohol<br />
Place the bottle of alcohol in the freezer to chill while preparing the next steps. (Do not leave in long enough to freeze!)<br />
<br />
<br />
Step 2: Gather the DNA <br />
In the plastic cup, mix ¼ teaspoon of salt in 1/4 cup of water. Swish the salt water around in your mouth for a minute, making sure it reaches the inside of your cheeks. Spit all the water back in the cup. Do not swallow! (If you prefer, you can also use Gatorade, which is sweeter.)<br />
<br />
Cells from the inside of your cheek mix with the salt water and are carried away when you spit. Above is a photograph of cheek cells under a microscope. You can see the nucleus inside each cell. <br />
<br />
<div class="separator" style="clear: both; text-align: center;"></div><div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjQekVeXZhJUApWw_AU8kablAZ_vIUoBQdw1dQB-Ts4qqTiIwtsvYpWWIho9585J0cVtyHrLRzFG8EYzYntfDr9QdO3ipQ63p9d2u17H0sYDgHRJ9BHQXnXpb0i4fQbP1rKgvXtD4FydCk/s1600/101_1648.JPG" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="320" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjQekVeXZhJUApWw_AU8kablAZ_vIUoBQdw1dQB-Ts4qqTiIwtsvYpWWIho9585J0cVtyHrLRzFG8EYzYntfDr9QdO3ipQ63p9d2u17H0sYDgHRJ9BHQXnXpb0i4fQbP1rKgvXtD4FydCk/s320/101_1648.JPG" width="213" /></a></div><br />
Step 3: Release the DNA from your cheek cells<br />
Put a drop of dish soap on the plate. Touch the spoon to the soap, and then dip it in the cup of salt water. Gently stir once or twice. Cells are contained within membranes that are made up of fats. The soap solution breaks down the fat molecules, just like soap breaks down grease on your dishes, and releases the contents of the cell. <br />
<br />
<div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjKaTRVEQjpw004_LK_n7Qrb-1_wDKEH-45-Uc8gYBRY_fISgD004TaBYBBPbq0l5RAGh3KXiSPI_Wo-piq1rY8_AN7bAwwwaaMX4fKNYzxTnTqfpbus8jFwAY2RfO2rVWAxvlHxTjcfNw/s1600/101_1663.JPG" imageanchor="1" style="clear: left; margin-bottom: 1em; margin-right: 1em;"><img border="0" height="213" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjKaTRVEQjpw004_LK_n7Qrb-1_wDKEH-45-Uc8gYBRY_fISgD004TaBYBBPbq0l5RAGh3KXiSPI_Wo-piq1rY8_AN7bAwwwaaMX4fKNYzxTnTqfpbus8jFwAY2RfO2rVWAxvlHxTjcfNw/s320/101_1663.JPG" width="320" /> </a></div><div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjXXHuJVuUB3QjVW_U7dh_J7zKQTSPKPjJcD71x1j94zLumMEknAoJJKGHO5xLn-GJYIhy13dCw9oyNK60T4wYROqeZtyFXfR06d-Nfq-Rij_HOKXL1DeSjoQ2OxHKMxU-_oju8YHDdZMM/s1600/101_1655.JPG" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="213" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjXXHuJVuUB3QjVW_U7dh_J7zKQTSPKPjJcD71x1j94zLumMEknAoJJKGHO5xLn-GJYIhy13dCw9oyNK60T4wYROqeZtyFXfR06d-Nfq-Rij_HOKXL1DeSjoQ2OxHKMxU-_oju8YHDdZMM/s320/101_1655.JPG" width="320" /></a></div><div class="separator" style="clear: both; text-align: center;"><br />
</div><br />
Step 4: Add the alcohol<br />
Remove the alcohol from the freezer. Pour about a quarter of a cup into a second plastic cup. If desired, add a drop of blue food coloring to make the alcohol easier to see. Stir until evenly mixed. Take the salt water cup and tilt to one side. Hold the cup of alcohol up so that the lip touches the tilted cup. SLOWLY pour a little alcohol down the inside of the cup so that it floats on top of the salt water without mixing. Continue until there is about an eighth of an inch of alcohol on top of the salt water.<br />
<br />
<div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEj3FTkMV6Lhz_5JlmkGTjatRsIFRohoyj2ZFniAt8zGOoAGBn0fxC-dCpEG6r12plPFRkm8MfRv105594Tom1aBSXvxKAHyVG7lAfAgeEomJYPPh4kv5BRhBXAW0HVB6ZwgKKnBaF3rhrM/s1600/DNA+strand.jpg" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="348" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEj3FTkMV6Lhz_5JlmkGTjatRsIFRohoyj2ZFniAt8zGOoAGBn0fxC-dCpEG6r12plPFRkm8MfRv105594Tom1aBSXvxKAHyVG7lAfAgeEomJYPPh4kv5BRhBXAW0HVB6ZwgKKnBaF3rhrM/s400/DNA+strand.jpg" width="400" /></a></div><br />
Step 5: Watch the DNA strands appear<br />
Wait a few minutes and you will see long strands or clumps of a sticky white substance start to come together in the alcohol layer. This is the DNA from thousands of cheek cells in the salt water. The DNA cannot dissolve in the chilled alcohol, so it precipitates out (comes out of solution as a solid).<br />
Variation: If you want to remove the DNA to look at it through a microscope, dip a toothpick into the alcohol layer and twirl it to gather up the sticky DNA. Place on a glass microscope slide. You can also save the DNA in a small clear container with a little extra salt water. Keep tightly covered.<br />
<br />
More information:<br />
<br />
http://tang.skidmore.edu/pac/mtm/DNA/index.html<br />
www.nespal.org/oziasakinslab/edout/AnimalDNAExtraction.pdf<br />
http://www.vampirewear.com/dna.html<br />
http://nature.ca/genome/05/051/0511/0511_m204_e.cfm<br />
http://www.californiasciencecenter.org/Education/GroupPrograms/HomeSchool/docs/DNA.pdfKathy Cecerihttp://www.blogger.com/profile/18188872992635537080noreply@blogger.com1tag:blogger.com,1999:blog-4526805397726051471.post-63567100746308496682011-04-12T14:21:00.000-07:002011-04-13T17:35:26.344-07:00Splitting Saltwater<iframe allowfullscreen="" frameborder="0" height="390" src="http://www.youtube.com/embed/UrfkfcmzRe4?rel=0" title="YouTube video player" width="480"></iframe><br />
<br />
Last week we watched an episode of <a href="http://www.amazon.com/dp/B0010L578S?tag=homeintegratedscience-20&camp=213381&creative=390973&linkCode=as4&creativeASIN=B0010L578S&adid=05RZD1T1QMMCF7SKB3Z8"><i>The Joy of Science</i></a> dealing with elements that have an affinity for one another, like sodium and chlorine. In the great Theo Gray book <a href="http://www.amazon.com/dp/1579127916/ref=as_li_ss_til?tag=geekdadklc-20&camp=213381&creative=390973&linkCode=as4&creativeASIN=1579127916&adid=12PDAQ0Q6KPH3ZY2RZ72" mce_href="http://www.amazon.com/dp/1579127916/ref=as_li_ss_til?tag=geekdadklc-20&camp=213381&creative=390973&linkCode=as4&creativeASIN=1579127916&adid=12PDAQ0Q6KPH3ZY2RZ72"><i>Mad Science</i></a>, he shows that combining sodium and chlorine to make your own salt <a href="http://www.popsci.com/node/3243" mce_href="http://www.popsci.com/node/3243">results in quite a bang</a>.I was looking for other interesting sodium-related YouTube videos when we came across <a href="http://www.youtube.com/watch?v=OoIuDPI5GQs">one that showed a cool way to split salt</a> into its component elements.<br />
<br />
Above you can see our version of the experiment. What we did is explained below.<br />
<br />
<div class="separator" style="clear: both; text-align: center;"></div><div class="separator" style="clear: both; text-align: center;"><img border="0" height="266" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgjoXHaZvdtZALv5x1B8z3FcpeJxUehsWBKAKBJagF6y-qpWkqFbxHb_tFU6AhoWRoar35Uydq9DNNSoFYfOpXlo_pngUJkpKHQzxryDwI4L__toMZsxehoeRgSicxJvJP9KVXgXZnZcWU/s400/Saltwater+Setup.JPG" width="400" /></div><br />
<br />
<br />
Saltwater Electrolysis<br />
<br />
Materials:<br />
<br />
-Salt<br />
-One 9-volt battery<br />
-Two spoons<br />
-A medium-sized glass bowl<br />
<br />
<br />
<br />
<div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgtuZnywUxXYoKVkr_JpyK-7fLSL3QtGLVDBmJsyv5v6qEAh19jYLKY-pOP6hSjBNKsq5SZcXkUaBWG-KgvtsBaIYZIdM8o8-LRB5JzxPrg5EY3DsXMgr5AUEjLZQmArsrOaQU_X2cNhn8/s1600/101_1627.JPG" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="266" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgtuZnywUxXYoKVkr_JpyK-7fLSL3QtGLVDBmJsyv5v6qEAh19jYLKY-pOP6hSjBNKsq5SZcXkUaBWG-KgvtsBaIYZIdM8o8-LRB5JzxPrg5EY3DsXMgr5AUEjLZQmArsrOaQU_X2cNhn8/s400/101_1627.JPG" width="400" /></a></div><br />
<div class="separator" style="clear: both; text-align: center;"></div><br />
Steps:<br />
<br />
1. Fill the bowl with warm tap water, and stir in a spoonful or so of the salt.<br />
<br />
<br />
2. Place the two spoons in the water, being careful not to let the two spoons touch each other.<br />
<br />
3. Hold the ends of the two spoons to the battery connectors, one spoon on each connector.<br />
<br />
<br />
<div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiy9UirJqrLSix8imkZsU2ko-hUQtrnEH4fj2WyKy59GUIi2JuIkUiw_DWfbPeobjTMsrpsC5V1XlXjQxCjHmOYYje_SlLvqFMNCLx6P0ntEEXfR1fa2bMOLl1aLKfX5bLHA1YUlAV61yE/s1600/Yellow+Water.JPG" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="333" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiy9UirJqrLSix8imkZsU2ko-hUQtrnEH4fj2WyKy59GUIi2JuIkUiw_DWfbPeobjTMsrpsC5V1XlXjQxCjHmOYYje_SlLvqFMNCLx6P0ntEEXfR1fa2bMOLl1aLKfX5bLHA1YUlAV61yE/s400/Yellow+Water.JPG" width="400" /></a></div><br />
<br />
4. Within a few seconds, you should see tiny bubbles coming off of the spoons. You will also notice what looks like smoke coming off the water.<br />
<br />
5. After holding them in a minute or so, you should be able to see the water begin to turn murky yellow.<br />
<br />
6. After several minutes, the water starts to turn dark green.<br />
<div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEikC4m88lo3toTp9HMFqQPVCTmlvRTv8ddspqexccopMdMtndKiu5wt-0UftRoyqlZn6BzAXaeo1YFBLUuCLV8GmQI7MUOBh_e13fdmgMNuAMgQsl6CZwGSz3E1YUd9zBQc8LVyl0fAV-A/s1600/Green+water.JPG" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="327" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEikC4m88lo3toTp9HMFqQPVCTmlvRTv8ddspqexccopMdMtndKiu5wt-0UftRoyqlZn6BzAXaeo1YFBLUuCLV8GmQI7MUOBh_e13fdmgMNuAMgQsl6CZwGSz3E1YUd9zBQc8LVyl0fAV-A/s400/Green+water.JPG" width="400" /></a></div><br />
<br />
Here is an explanation of what's happening (from the <a href="http://aquarius.nasa.gov/electrolysis.html">NASA Aquarius website</a>):<br />
<br />
<blockquote>In chemistry, electrolysis is a method of separating bonded elements and compounds by passing an electric current through them. An ionic compound, in this case salt, is dissolved with an appropriate solvent, such as water, so that its ions are available in the liquid. An electrical current is applied between a pair of inert electrodes immersed in the liquid. The negatively charged electrode is called the cathode, and the positively charged one the anode. Each electrode attracts ions which are of the opposite charge. Therefore, positively charged ions (called cations) move towards the cathode, while negatively charged ions (termed anions) move toward the anode. The energy required to separate the ions, and cause them to gather at the respective electrodes, is provided by an electrical power supply. At the probes, electrons are absorbed or released by the ions, forming a collection of the desired element or compound.<br />
<br />
One important use of electrolysis is to produce hydrogen. The reaction that occurs is 2H2O(aq) → 2H2(g) + O2(g). This has been suggested as a way of shifting society towards using hydrogen as an energy carrier for powering electric motors and internal combustion engines. Electrolysis of water can be achieved in a simple hands-on project, where electricity from a battery is passed through a cup of water (in practice a saltwater solution or other electrolyte will need to be used otherwise no result will be observed). Electrolysis of an aqueous solution of table salt (NaCl, or sodium chloride) produces aqueous sodium hydroxide and chlorine, although usually only in minute amounts. NaCl(aq) can be reliably electrolysed to produce hydrogen. Hydrogen gas will be seen to bubble up at the cathode, and chlorine gas will bubble at the anode.</blockquote>According to<a href="http://en.wikipedia.org/wiki/Electrolysis_of_water">Wikipedia</a>, this is the formula for the chemical reaction taking place:<br />
<br />
<blockquote>2 NaCl + 2 H<span style="font-size: xx-small;">2</span>O → Cl<span style="font-size: xx-small;">2</span> + H<span style="font-size: xx-small;">2</span> + 2 <a href="http://en.wikipedia.org/wiki/Sodium_hydroxide">NaOH</a></blockquote><br />
That means, two sodium chloride molecules (which is the salt) plus two <a href="http://en.wikipedia.org/wiki/Dihydrogen_monoxide_hoax">dihydrogen monoxide</a> molecules (also known as water) becomes one chlorine molecule, one hydrogen molecule, and two molecules of sodium hydroxide (which is also known as lye). So in our experiment, the bubbles were hydrogen, the "smoke" coming off the water was chlorine gas, and the yellow color of the water was the sodium, in the form of lye.Kathy Cecerihttp://www.blogger.com/profile/18188872992635537080noreply@blogger.com2tag:blogger.com,1999:blog-4526805397726051471.post-69992682334000755362011-04-01T09:35:00.000-07:002011-04-02T19:17:19.237-07:00Observing Energy Levels of Electrons Using a Cereal Box<div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjRfR3ISZItp0uDWbWhaBe6wG6rTWD4F-w7Y0pFI-379okTbGtZ52xWQeHxPzV00uDh5z2r0T9LHXjx1zRuCbPtUbYRg9tHsZtPgM0OZumasQ5mmNvkepZMp3pDuFbTuxXdGtRQ8QyLtnw/s1600/Spectrascope+Interior.JPG" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="176" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjRfR3ISZItp0uDWbWhaBe6wG6rTWD4F-w7Y0pFI-379okTbGtZ52xWQeHxPzV00uDh5z2r0T9LHXjx1zRuCbPtUbYRg9tHsZtPgM0OZumasQ5mmNvkepZMp3pDuFbTuxXdGtRQ8QyLtnw/s320/Spectrascope+Interior.JPG" width="320" /></a></div><br />
In our most recent episode of <i>The Joy of Science</i>, Dr. Hazen describes observing energy levels of electrons and atoms using a Spectroscope. So, for science this week, we decided to make a <a href="http://stereo.gsfc.nasa.gov/classroom/spectroscope.shtml">Spectroscope out of a cereal box</a> and diffraction grating glasses. We used it to look at different light sources.<br />
<br />
<br />
<div style="margin-bottom: 0in;">Spectroscopy is the study of light-matter intersections. By using a spectroscope, scientists make a record of the light intensity over a range of wavelengths. Each element produces its own spectrum, and many new elements were discovered by this method. <a href="http://www.ipac.caltech.edu/outreach/Edu/Spectra/spec.html">Astronomers use spectroscopy</a> to figure out the composition of stars and whether they are moving towards or away from the earth.</div><br />
<br />
<div style="margin-bottom: 0in;">The way spectroscopes work is by breaking light up into its different wavelengths. The light can be viewed through a filter (as we did in this version) or reflected off an object's surface (as we did in a version we made a few years ago; see below). </div><br />
<div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjmNDo0qYGM7piG8ATtd_FnyOuM_CgW_Ru_x3q27eBiVQGvT2LwpeaQ405FowdjhSPIjqCf6sfZfudTIjJAxT7go6_44U6EFAO67ZbbxAwcah1YwKRjxlKLZ8-ejZ3Qgs50tujo9zGNlsk/s1600/Cereal+Box+Spectrascope.JPG" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"></a></div><br />
<table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto; text-align: center;"><tbody>
<tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEglNH7QYH5IVh9d7AMrjtKAVFi9qt5FXD_j5kMQI7Tpw5pI_EZlcONV2o4AlEtWJWHfFZXF3ewW4xD4kRy6ESQ9WOkoQ-VOqx2JeekiSGZQXUbC_bkz7szArS4fEVHC7PQSUoQpD8E6qew/s1600/Rainbow+Viewer+Kitchen+Light.JPG" imageanchor="1" style="margin-left: auto; margin-right: auto;"><img border="0" height="272" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEglNH7QYH5IVh9d7AMrjtKAVFi9qt5FXD_j5kMQI7Tpw5pI_EZlcONV2o4AlEtWJWHfFZXF3ewW4xD4kRy6ESQ9WOkoQ-VOqx2JeekiSGZQXUbC_bkz7szArS4fEVHC7PQSUoQpD8E6qew/s320/Rainbow+Viewer+Kitchen+Light.JPG" width="320" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">This photo was shot using the diffraction grating glasses <br />
before we taped them to the Spectroscope.</td></tr>
</tbody></table><br />
<a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEj4P9Gth46Wi11uAec0p5rFyQSRMNWyG3jvsM3BGQAx8KotEzzLmJSJqa6hcHTYtjFLaxAjUhUgkdaEOdiy8a0km3rXDuDdDkFnETCyVdgJCN__NjeMsaIm6NfuZYuQLXYu7JG4InkLHoE/s1600/Holographic+Glasses.JPG" imageanchor="1" style="clear: right; float: right; margin-bottom: 1em; margin-left: 1em;"><img border="0" height="96" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEj4P9Gth46Wi11uAec0p5rFyQSRMNWyG3jvsM3BGQAx8KotEzzLmJSJqa6hcHTYtjFLaxAjUhUgkdaEOdiy8a0km3rXDuDdDkFnETCyVdgJCN__NjeMsaIm6NfuZYuQLXYu7JG4InkLHoE/s320/Holographic+Glasses.JPG" width="320" /></a><br />
For our diffraction grating, we took a pair of <a href="http://www.amazon.com/dp/B0014EAYB6/ref=as_li_ss_til?tag=homeintegratedscience-20&camp=213381&creative=390973&linkCode=as4&creativeASIN=B0014EAYB6&adid=0N6RB0J2TN3B34C7F0M2">cardboard holographic glasses</a> and cut them in half. We made two Spectroscopes, so we used one half for each one.<br />
<br />
Next we took the cereal box, placed the diffraction grating on top, and outlined it using a sharpie. We made marks to indicate where the actual lens was. Then we opened the flaps and cut a hole the size of the lens in the cereal box.<br />
<br />
We then taped the cereal box flaps closed and taped the grating over the opening.<br />
<br />
<a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjmNDo0qYGM7piG8ATtd_FnyOuM_CgW_Ru_x3q27eBiVQGvT2LwpeaQ405FowdjhSPIjqCf6sfZfudTIjJAxT7go6_44U6EFAO67ZbbxAwcah1YwKRjxlKLZ8-ejZ3Qgs50tujo9zGNlsk/s1600/Cereal+Box+Spectrascope.JPG" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="213" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjmNDo0qYGM7piG8ATtd_FnyOuM_CgW_Ru_x3q27eBiVQGvT2LwpeaQ405FowdjhSPIjqCf6sfZfudTIjJAxT7go6_44U6EFAO67ZbbxAwcah1YwKRjxlKLZ8-ejZ3Qgs50tujo9zGNlsk/s320/Cereal+Box+Spectrascope.JPG" width="320" /></a><br />
On the opposite side of the box from the grating, we made a mark and cut a very narrow slit. During our first attempt at the spectroscope, we made the slit wider than recommended. We fixed this by taping a piece of card stock over the slit and cutting through that. However, a different set of directions suggested using a wider slit, so we also tried taking photos with the original slit as well.<br />
<br />
<table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto; text-align: center;"><tbody>
<tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjn5jYYsHHRWzOuWHjcgDhCnHC-EZWIGlXGJ5OB5rcRZb-RktyQAva-_UsoBDtP2J73P6ymmrl4SKwJWsue7fzZpPX9kPWpAoFPoeYw_P0-T1AGYn2PRZYrZvlXXfilYh5es6z7OkFjvp0/s1600/Fluorescent+light.JPG" imageanchor="1" style="margin-left: auto; margin-right: auto;"><img border="0" height="400" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjn5jYYsHHRWzOuWHjcgDhCnHC-EZWIGlXGJ5OB5rcRZb-RktyQAva-_UsoBDtP2J73P6ymmrl4SKwJWsue7fzZpPX9kPWpAoFPoeYw_P0-T1AGYn2PRZYrZvlXXfilYh5es6z7OkFjvp0/s400/Fluorescent+light.JPG" width="353" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">Fluorescent light, using wider slit.</td><td class="tr-caption" style="text-align: center;"><br />
</td></tr>
</tbody></table><div class="separator" style="clear: both; text-align: center;"></div><br />
<br />
After completing it, we took some photos by holding the camera up to the grating, and pointing the Spectroscope towards a light. The result was the photo shown at the top of this post.<br />
<br />
<table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto; text-align: center;"><tbody>
<tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEg6x6N8oxyEnph033i3UVU1cXxduyUP9XR5K-k-WoymC_G-PDq3F7PCEuEDJTVIUnnvfkSWUKk3sS8ksnsnwvRJQ8_5Y5WvIiLYFYRzF4hjTKK2hfmJ-8hihOGwEWrhQGSilarC0aokk7w/s1600/Fluorescent+spectrum.JPG" imageanchor="1" style="margin-left: auto; margin-right: auto;"><img border="0" height="234" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEg6x6N8oxyEnph033i3UVU1cXxduyUP9XR5K-k-WoymC_G-PDq3F7PCEuEDJTVIUnnvfkSWUKk3sS8ksnsnwvRJQ8_5Y5WvIiLYFYRzF4hjTKK2hfmJ-8hihOGwEWrhQGSilarC0aokk7w/s400/Fluorescent+spectrum.JPG" width="400" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">Detail of fluourescent light spectrum</td></tr>
</tbody></table><div class="separator" style="clear: both; text-align: center;"></div><br />
Here is a cropped version of the photo above, showing the bright lines of higher intensity at different wavelengths. Scientists use this kind of spectrum to analyze what elements are present in a light source. Our grating was not as high a resolution as a real Spectroscope, so it was harder to use. Our spectrum is more an approximation.<br />
<br />
For more precision, you can try the directions for a <a href="http://sci-toys.com/scitoys/scitoys/light/spectrograph/spectrograph.html">homemade high-resolution Spectroscope</a> from Simon Field at SciToys.com. A few years ago, we made his version of a <a href="http://homechemistry.blogspot.com/search?q=spectroscope">Spectroscope using an old DVD</a>. (It's also in his book, <a href="http://www.amazon.com/gp/product/1556525206?ie=UTF8&tag=homechemistry-20&linkCode=as2&camp=1789&creative=9325&creativeASIN=1556525206">Gonzo Gizmos: Projects & Devices to Channel Your Inner Geek.)</a><br />
<br />
Here's a site with really nice photos taken with a <a href="http://www.cs.cmu.edu/%7Ezhuxj/astro/html/spectrometer.html">cereal box/CD</a> type spectroscope.Kathy Cecerihttp://www.blogger.com/profile/18188872992635537080noreply@blogger.com0tag:blogger.com,1999:blog-4526805397726051471.post-88409009137565153612011-03-07T12:28:00.000-08:002011-03-28T08:13:34.320-07:00Proving Atoms Exist with Brownian Motion<object height="297" width="475"><param name="movie" value="http://www.youtube.com/v/6VdMp46ZIL8?fs=1&hl=en_US&rel=0"></param><param name="allowFullScreen" value="true"></param><param name="allowscriptaccess" value="always"></param><embed src="http://www.youtube.com/v/6VdMp46ZIL8?fs=1&hl=en_US&rel=0" type="application/x-shockwave-flash" allowscriptaccess="always" allowfullscreen="true" width="475" height="297"></embed></object><br />
In 60 BC, the Roman poet Lucretius published a poem entitled <i>De rerum natura</i>, or <i>On the Nature of Things</i>. Its contents were mostly philosophical, focusing on themes of life, death, love, the soul, and such. However, the first two sections of the six-book poem were focused on a very different subject matter: atoms. The poem read:<br />
<blockquote>“Observe what happens when sunbeams are admitted into a building and shed light on its shadowy places. You will see a multitude of tiny particles mingling in a multitude of ways . . . their dancing is an actual indication of underlying movements of matter that are hidden from our sight. It originates with the atoms which move of themselves [i.e., spontaneously]. Then those small compound bodies that are least removed from the impetus of the atoms are set in motion by the impact of their invisible blows and in turn cannon against slightly larger bodies. So the movement mounts up from the atoms and gradually emerges to the level of our senses, so that those bodies are in motion that we see in sunbeams, moved by blows that remain invisible.” </blockquote>This is a phenomenon called <a href="http://brink%20is%20an%20upcoming%20futuristic%20fps%20from%20bethesda/">“Brownian Motion</a>,” named after Botanist Robert Brown. Although it was Albert Einstein that finally described the physics behind this, it was named after Brown because of his being the first to test this theory by observing pollen grains bouncing off of water molecules. But it was ultimately Einstein who brought this to the attention of the physics community, and in doing so, proving the existence of what we now think of as atoms and molecules.<br />
<br />
We decided to reproduce Brown’s experiment, adapting directions from <a href="http://www.rmcain.com/pageserver.mv?BYNDDec00DWBrown%20">Dave Walker</a>.<br />
<br />
<a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiel_glAlt3Yy5MQa9ZWPW1hDFQDsIGNiJlXv15R5GbbDAX8AVm6iJFXPfttrbOEI1R_Bfou7ly_QNXnIEDXg251DrZ4W8Q1xASX_IRsxmpK92Hr0IvhGqiFRqC_UWmpSTnY1loGXOvnX8/s1600/Brownian+Set-up.JPG" imageanchor="1" style="clear: right; float: right; margin-bottom: 1em; margin-left: 1em;"><img border="0" height="273" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiel_glAlt3Yy5MQa9ZWPW1hDFQDsIGNiJlXv15R5GbbDAX8AVm6iJFXPfttrbOEI1R_Bfou7ly_QNXnIEDXg251DrZ4W8Q1xASX_IRsxmpK92Hr0IvhGqiFRqC_UWmpSTnY1loGXOvnX8/s320/Brownian+Set-up.JPG" style="cursor: move;" width="320" /></a><br />
What you need:<br />
<ul><li>student microscope with 200X or 400X magnification</li>
<li>milk (we used 2%)</li>
<li>microscope slides and coverslips</li>
<li>thin needle or wire</li>
<li>water (preferably distilled, although we used tap water)</li>
<li>Vaseline petroleum jelly (optional)</li>
</ul>To prepare the slide:<br />
<br />
1. Place a very small drop of water in the middle of the slide (use a dropper).<br />
<br />
2. Dip the needle in the milk, then dip and stir in the water drop. We picked up a drop in the eye of the needle and stirred it with the needle almost flat in the water drop.<br />
<br />
3. Gently lower the coverslip onto the diluted milk drop.<br />
<br />
4. Make sure no water is near the edge of the cover slip. This is important to ensure you observe Brownian motion and not liquid movement caused by evaporation).<br />
<br />
5. Optional: To make a slide that lasts longer, seal the coverslip on with a thin line of Vaseline to minimize evaporation.<br />
<br />
<table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto; text-align: center;"><tbody>
<tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEj1mhvhAQDGMwK1P-_M1w8YS3lObd3S3qp08TSkgo4a5nuJlyGwNrxfbCrTYjlB3KpNuzAOFeM5CbJkt7u2Qa1FF9E3pP03nWZZ-3JU_9qPKXV0atvGBExQRXTzPI7_rWiZ4fmlFaYhXck/s1600/101_1529.JPG" imageanchor="1" style="margin-left: auto; margin-right: auto;"><img border="0" height="266" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEj1mhvhAQDGMwK1P-_M1w8YS3lObd3S3qp08TSkgo4a5nuJlyGwNrxfbCrTYjlB3KpNuzAOFeM5CbJkt7u2Qa1FF9E3pP03nWZZ-3JU_9qPKXV0atvGBExQRXTzPI7_rWiZ4fmlFaYhXck/s400/101_1529.JPG" width="400" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">Still photo of fat molecules taken with standard microscope and point-and-shoot camera.</td></tr>
</tbody></table><br />
We tried this experiment with both our <a href="http://www.amazon.com/gp/product/B0002HLKI2?ie=UTF8&tag=craftsforlearning-20&linkCode=xm2&camp=1789&creativeASIN=B0002HLKI2">computer microscope</a> and our <a href="http://howto.wired.com/wiki/Take_Microphotographs">standard microscope</a>. Although we were unable to get decent pictures with either microscope, we were able to see decent results with the basic microscope.<br />
<br />
We placed a droplet of water on a glass slide, and then, using a pin, we placed a smaller droplet of milk (we used 2% instead of whole) inside the water. We then placed a coverslip over the droplet, and sealed it with vasoline. The first few times we did this, we were unable to observe, or even locate the water droplet with our computerized microscope. However, after a few tries, we found that making adjustments to the experiment (such as not using vasoline and placing smaller droplets on the slide) were effective, allowing us to at least see the water. Switching from the computerized microscope to our lower-tech but more high-powered microscope produced much more positive results. The higher magnification allowed us to actually observe the Brownian Motion of the milk fat particles bouncing off the water molecules.<br />
<br />
<iframe allowfullscreen="" frameborder="0" height="390" src="http://www.youtube.com/embed/3eCth6oYpUU?rel=0" title="YouTube video player" width="500"></iframe><br />
<br />
We also decided to test a simplified version of Brown’s experiment by dropping food coloring into a large bowl of water. While this was not as precise as the milk experiment, observing the cigarette smoke-like movements of the dye was more effective at demonstrating Brownian Motion. Above, you can see a video of a similar experiment, conducted by <a href="http://www.geekmom.com/">GeekMom</a> writer Kay Holt and her son Bastian.<br />
<br />
Other resources: <br />
<br />
<a href="http://en.wikipedia.org/wiki/Brownian_motion">Wikipedia </a><br />
<a href="http://www.einsteinyear.org/facts/brownian_motion/">Einstein Year</a><br />
<a href="http://galileo.phys.virginia.edu/classes/109N/more_stuff/Applets/brownian/brownian.html">University of Virginia</a><br />
<a href="http://blogs.discovermagazine.com/80beats/2010/05/21/refuting-einstein-in-4-easy-steps-physicists-measure-brownian-motion/%20">Discover Magazine</a>Kathy Cecerihttp://www.blogger.com/profile/18188872992635537080noreply@blogger.com0tag:blogger.com,1999:blog-4526805397726051471.post-70229623202040594952011-02-17T09:00:00.000-08:002011-04-02T19:17:36.500-07:00Powered by Radio Waves<div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiqVcHpLlrWPiDpuAWDGouGp7OCBxGjvpUbjPA2GfNU9JnMZnS3sht1KgPI_lZz_SuI1cZtor5foapBbh8XkJqmGcFFTVe6MKmhu34f4_AUgVDSP3l1npuAkmielFsBQu0HewXlhesChI4/s1600/101_1373.JPG" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="640" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiqVcHpLlrWPiDpuAWDGouGp7OCBxGjvpUbjPA2GfNU9JnMZnS3sht1KgPI_lZz_SuI1cZtor5foapBbh8XkJqmGcFFTVe6MKmhu34f4_AUgVDSP3l1npuAkmielFsBQu0HewXlhesChI4/s640/101_1373.JPG" width="425" /></a></div><br />
In WWII, ally POWs invented some ingenious devices while imprisoned. One of the most resourceful and impressive of these was something called a crystal radio. Fairly straightforward and simple to make, these devices harnessed local materials using an impressive amount of understanding of scientific principles, and made them into a working radio set. While not always successful, these “foxhole” radios, as they were called, would pick up German and occasionally even British stations if they were carefully made. As impressive as anything else made by the POWs of the day, these foxhole radios are still made by Boy Scouts and hobbyists. <br />
<br />
We chose this project to demonstrate electrical currents and radio waves. Our first attempt was met with limited success. However, after several tries, we were able to get a (faint but audible) radio signal. We ended up using a magnetic copper wire stretching over fifty feet as our antenna, which sacrificed historical accuracy, but it was nonetheless successful.<br />
<div class="separator" style="clear: both; text-align: center;"></div><div class="separator" style="clear: both; text-align: center;"></div><br />
<div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhCzx027JGQkQBoPnJ6_3cNTew042SyEKMOIRjKALNnmm9tMy_loDOpAwkhLseQn7_DYF5BN8H8aNb2Oy88qwEdKS5ySYqHN6HZznxghUzmc0em6Pzgeie1Frwq2GRclc83DurvJp5qjlo/s1600/Radio+Kit.JPG" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="161" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhCzx027JGQkQBoPnJ6_3cNTew042SyEKMOIRjKALNnmm9tMy_loDOpAwkhLseQn7_DYF5BN8H8aNb2Oy88qwEdKS5ySYqHN6HZznxghUzmc0em6Pzgeie1Frwq2GRclc83DurvJp5qjlo/s400/Radio+Kit.JPG" width="400" /></a></div><div class="separator" style="clear: both; text-align: center;"></div><br />
<br />
The first design we used was based off of the radio in a <a href="http://www.youtube.com/watch?v=skKmwT0EccE">Make Magazine video</a>. We were able to pick up static, but the signal was too weak to pick up actual stations. After a day or so of tooling with it, we decided to start from scratch, using the instructions and parts supplied in the <a href="http://www.amazon.com/dp/1886978034?tag=homeintegratedscience-20&camp=213381&creative=390973&linkCode=as4&creativeASIN=1886978034&adid=1T5D1RW63ZS9VG13ENZY">Science Wiz Inventions kit</a>. After some modifications to the original design (like adding a fifty-foot antenna) we were able to pick up fairly clear signals. The clearest we were able to pick up (<a href="http://albanymagic.com/">Albany Magic 590 AM</a>) turned out to be coming from a station 25 miles away from us, in Latham, NY.<br />
<br />
Some other resources we used:<br />
<ul><li>MAKE Magazine's Foxhole Radio project with <a href="http://www.youtube.com/watch?v=skKmwT0EccE&feature=player_embedded">video</a> and <a href="http://cdn.makezine.com/make/wp_foxholeradio.pdf">PDF plans</a> </li>
<li>The site <a href="http://sci-toys.com/scitoys/scitoys/radio/radio.html">SciToys </a>offers several versions of increasing difficulty.</li>
<li>YouTube has many videos of foxhole radios, including this one of <a href="http://www.youtube.com/watch?v=Gj7yk4qZKOg&feature=related">a Tunable Foxhole Radio</a> built by 10-year-old based on these plans from <a href="http://gizmodo.com/024255/retro-ww2-foxhole-radio">Gizmodo</a></li>
<li>A project to <a href="http://www.tompolk.com/crystalradios/buildinginstructions.htm">make radios with fourth-graders</a>, including printable guides for building </li>
<li>The website <a href="http://www.crystalradio.net/">Crystal Radio</a> has lots of information, including a page to help you <a href="http://www.crystalradio.net/beginners/trouble.shtml%20">trouble shoot </a>and test the parts of your radio. </li>
</ul><br />
Here is a video of our radio in action, followed by explanation of its parts:<br />
<div style="text-align: center;"><br />
</div><iframe allowfullscreen="" class="youtube-player" frameborder="0" height="390" src="http://www.youtube.com/embed/B9XKHvTGUs8?rel=0" title="YouTube video player" type="text/html" width="480"></iframe><br />
<br />
<div style="text-align: center;"><u><b>Parts of the Radio</b></u></div><br />
<div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEi_IPph57SNRRxmZy5SLKyjOzjASupclzFef2qJILc3Gbl8-D_VCVRlh0cDAXVHw87PNDvZepLLNfUTsj_2l8FENhM_t2t56ezWaJdsRP_WTwdn-oCuQNocnMKUpQB_paclPtn3sgLKWqc/s1600/Antenna+Stairs.JPG" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="213" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEi_IPph57SNRRxmZy5SLKyjOzjASupclzFef2qJILc3Gbl8-D_VCVRlh0cDAXVHw87PNDvZepLLNfUTsj_2l8FENhM_t2t56ezWaJdsRP_WTwdn-oCuQNocnMKUpQB_paclPtn3sgLKWqc/s320/Antenna+Stairs.JPG" width="320" /></a></div><b>Antenna - 50+ foot wire strand</b><br />
Our antenna was fairly simple. We bought a length of magnetic copper wire, about fifty feet or so, and hung it around the entire house, starting in the mud room on the first floor and traveling up the stairs to the master bedroom on the second. The longer the antenna is, the clearer its signal seems to be. The antenna serves to convert electromagnetically radiated radio waves into electrical current, making them able to be conducted by the inductor.<br />
<br />
<div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjWIK_eKBvu-B869GmCN5v8vAEvfmHlda1dIbwtZi1dheJQZMy4a4s759Gy7rJJqpObcJearfVK1DdPg0MIlice_mbmrtNPJ7-KuItqqdqPyAagtrqAjO9-PVBfKD9e-RaajsVd3BYkOnE/s1600/Coil.JPG" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="168" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjWIK_eKBvu-B869GmCN5v8vAEvfmHlda1dIbwtZi1dheJQZMy4a4s759Gy7rJJqpObcJearfVK1DdPg0MIlice_mbmrtNPJ7-KuItqqdqPyAagtrqAjO9-PVBfKD9e-RaajsVd3BYkOnE/s400/Coil.JPG" width="400" /></a></div><b>Inductor - The coil of copper wire</b><br />
We made out inductor out of about a hundred turns of copper wire wrapped around a cardboard toilet roll former. Our inductor serves alongside our variable capacitor as what is called a tuning circuit. Since the inductor conducts electricity, once the antenna converts the radio waves into electrical currents, the inductor can transmit the currents to the capacitor. However, since the inductor is coiled, the current must travel the coil, and thus travels slower than it would if the inductor was a straight piece of wire connected to the capacitor. The slower current allows the capacitor to tune to specific radio stations.<br />
<br />
<div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhBOL1E82cOXtQ96n9GXl2U7h7fgYi7qD_RJSbpzNHqvWyQKcvyUxqi9Yo00O_AnC0xrV8W3GWgy7KIM3hEE82FqNs1XdSch6oT0px_HaiZ8qWnuvAcqjAjk1TnEfvMjEB6cmBOeLrIzG4/s1600/Radio2.JPG" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="320" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhBOL1E82cOXtQ96n9GXl2U7h7fgYi7qD_RJSbpzNHqvWyQKcvyUxqi9Yo00O_AnC0xrV8W3GWgy7KIM3hEE82FqNs1XdSch6oT0px_HaiZ8qWnuvAcqjAjk1TnEfvMjEB6cmBOeLrIzG4/s320/Radio2.JPG" width="242" /></a></div><br />
<b>Variable Capacitor - The aluminum foil-covered tubes</b><br />
Our capacitor was made by taking a long cardboard tube and wrapping smoothed aluminum foil around half of it. We then took a smaller piece of aluminum foil (again smoothed) and wrapped it around a wider piece of paper. Finally, the paper and aluminum foil were wrapped around the half of the cardboard tube covered in aluminum foil. This, once hooked up to the rest of the radio, serves as our variable capacitor, or tuning capacitor. This, when combined with the aforementioned inductor, creates a tuning circuit. The capacitor is designed to store electrical charge. However, it is only possible for charge to be stored in the spot that the aluminum foil wrapped around the paper, called the slider, overlaps with the foil on the tube. Moving the slider up and down can either increase or decrease the amount of charge stored in the capacitor. The capacitor allowed us to change which radio station was being picked up by changing the amount of electrical charge stored in the capacitor.<br />
<br />
<div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgtJlKcN7cYcLFyu8PhDH0UyvhOGD1tIci8dcc3pc_udmSyMbLrr9RFWQILoDSrcZtrzA-eZKHAxiA0VUAft_Cxnp419Yx-dH64jYwuD_vEd8B-DAXo4vSQ8nOo5QboaDg2hS1GazeIOsM/s1600/Razor+Blade.JPG" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="155" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgtJlKcN7cYcLFyu8PhDH0UyvhOGD1tIci8dcc3pc_udmSyMbLrr9RFWQILoDSrcZtrzA-eZKHAxiA0VUAft_Cxnp419Yx-dH64jYwuD_vEd8B-DAXo4vSQ8nOo5QboaDg2hS1GazeIOsM/s320/Razor+Blade.JPG" width="320" /></a></div><br />
<b>Diode - The germanium crystal OR "blued" razor blade and safety pin "cat's whisker"</b><br />
In our different attempts at the radio, we ended up using two different diodes. Our first was a traditional foxhole diode using a razor blade and a “<a href="http://en.wikipedia.org/wiki/Cat%27s-whisker_detector">cat’s whisker</a>” made from a safety pin and a sharpened pencil stub. The point of the pin was stuck into the end of the pencil through the exposed graphite (the "lead"). The safety pin was then attached to the base with a thumbtack and partially straightened so that the lead pencil tip touched the razor. <b> </b><br />
<br />
<br />
Most directions call for a blade that had been “blued,” or given an oxidized coating to protect it against rust. You are able to blue a blade simply by heating it up in a flame of some sort. We tried a box cutter blade that had spots of rust (oxidation) on it, but couldn't get it to work. Then we built a second radio and used the germanium crystal (see below). After we got that to work, we substituted a razor blade from a scraper that was blued in the flame of our gas stove. Both the blued part and the "white" unheated lip of the razor worked to some extent. The white part produced loud static, but on the blued part we could just barely tune in a station.<br />
<div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgm-iqvZdvo47Ohxg2RmFm-f1nhfQj_tYaqvY4oWBYbLMlbaErihfKE3ZpGXqSWDZICbcnpJXn7jcyL7PCa97e95ho3by9rfzIaqUwJ3vjQkqVcPvz2TKugJjochAnRz3Z8g4lu0Bq05Eo/s1600/Gm+Diode.JPG" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgm-iqvZdvo47Ohxg2RmFm-f1nhfQj_tYaqvY4oWBYbLMlbaErihfKE3ZpGXqSWDZICbcnpJXn7jcyL7PCa97e95ho3by9rfzIaqUwJ3vjQkqVcPvz2TKugJjochAnRz3Z8g4lu0Bq05Eo/s1600/Gm+Diode.JPG" /></a></div><br />
For our second design, we used a germanium crystal diode that came in the kit. Both versions of the diode serve to force the signal to only travel forwards, thus converting it from alternating current to direct current. It also serves to filter out anything other than the strongest parts of the signal, called "peaks." This allows us to tune the signal to various stations using the capacitor and to convert the signal into sound.<br />
<br />
The germanium diode works much better and is easier to use than the razor blade diode. (We later we went back to the first radio and got that one to work with the germanium diode as well.) Some sources we found state that moving the cat whisker on the razor blade is another way to tune the radio, but that needs to be verified.<br />
<br />
<div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjqZW3ry1OmOip-VaZ_mnPhGKlY4_JbtgIubEZ4ZgWq-NrhyRHJPdXtQJq7QSrk3LL9_H2VKQoXoF7QNx4-D_fxQoSc1ARsso2XYFGhPs_xSAW5Ku7TiQKJEM6BMWo9nK1iY3Hd9D2yFkk/s1600/Ground+wire.JPG" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="320" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjqZW3ry1OmOip-VaZ_mnPhGKlY4_JbtgIubEZ4ZgWq-NrhyRHJPdXtQJq7QSrk3LL9_H2VKQoXoF7QNx4-D_fxQoSc1ARsso2XYFGhPs_xSAW5Ku7TiQKJEM6BMWo9nK1iY3Hd9D2yFkk/s320/Ground+wire.JPG" width="288" /></a></div><b>Ground - The cold water pipe</b><br />
Our ground was fairly simple. In both versions of the radio, we took a wire and attached it to the cold water pipe in our bathroom sink, making sure that the exposed metal wire at the end of the otherwise insulated wire touched the metal pipe. The ground, of course, allows the electrical current to flow through the radio. While exceedingly simple, it is perhaps one of the most important parts of the radio.<br />
<br />
<div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgDL4MCMIOXvNF7s_RH3h7sTMPm8tHYY0XgW3AS8B9EdGrPfNvnJfmHiyFjNo61JP3zosmbezBOSUVkmk25E5WLQUzdvzvz5FLkhX0Mr3wziOuyNfvk-vLz9L0Xjpu-FfwmolZvFW1mmak/s1600/Earpiece.JPG" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgDL4MCMIOXvNF7s_RH3h7sTMPm8tHYY0XgW3AS8B9EdGrPfNvnJfmHiyFjNo61JP3zosmbezBOSUVkmk25E5WLQUzdvzvz5FLkhX0Mr3wziOuyNfvk-vLz9L0Xjpu-FfwmolZvFW1mmak/s1600/Earpiece.JPG" /></a></div><br />
<b>Speaker - piezoelectric earphone </b><br />
The most important, however, is doubtless the last part, the earphone. The earphone is a fairly basic piezoelectric earpiece, attached to the ground and the capacitor. Inside the earpiece (ours came in the kit, but you should be able to find one in a hobby store) is a copper wire coiled around a magnet. As the current flows through the coiled wire it creates an electromagnet. Also inside the earpiece is a transducer, or diaphragm, with iron embedded inside of it. As the current flows through the coil, it causes the magnet inside to grow stronger or weaker, depending on the peaks of the signal. Its attraction to the diaphragm also grows stronger or weaker. This causes the diaphragm to vibrate in accordance with the signal, producing sound vibrations.<br />
<br />
(Thanks to Anthony for researching and writing up this post!)Kathy Cecerihttp://www.blogger.com/profile/18188872992635537080noreply@blogger.com1tag:blogger.com,1999:blog-4526805397726051471.post-72356826260699718122011-02-01T17:33:00.000-08:002011-02-02T08:36:39.897-08:00Maxwell's Equations for Dummies<div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgPv_l_bXe3Hc6FvuDslHmK3C_mPQsvsw6NypwZA82VzFYJskttN83a6iNeESXR0JOf0UJ_ZCGW31jI0pxCInTPtVh8WT9lGSURzQVxdlktpYeAY8jhTJwwkoASZVgQEkS2c2TBHsU7gmU/s1600/MaxwellComic.jpg" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="132" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgPv_l_bXe3Hc6FvuDslHmK3C_mPQsvsw6NypwZA82VzFYJskttN83a6iNeESXR0JOf0UJ_ZCGW31jI0pxCInTPtVh8WT9lGSURzQVxdlktpYeAY8jhTJwwkoASZVgQEkS2c2TBHsU7gmU/s400/MaxwellComic.jpg" width="400" /></a></div><br />
We are working on a post about our lab on radio waves that will be ready soon. In the meantime, I wanted to make a note of a website I found when looking for an explanation of Maxwell's Equations (mentioned in the "Joy of Science" lecture on electromagnetic radiation) that we could understand without the math. This explanation comes from a site called <a href="http://www.irregularwebcomic.net/1420.html">Irregular Webcomic</a>, the creation of <a href="http://www.dangermouse.net/">David Morgan-Mar</a>, an astrophysicist and former science teacher in Australia. <br />
<blockquote><a href="http://en.wikipedia.org/wiki/Maxwell%27s_equations">Maxwell's equations</a> are a set of four equations that describe the relations between <a href="http://en.wikipedia.org/wiki/Electricity">electricity</a> and <a href="http://en.wikipedia.org/wiki/Magnetism">magnetism</a>. Written more neatly, they look like this: <br />
<div class="center"><img height="180" src="http://www.irregularwebcomic.net/annotations/annot1420a.gif" width="210" /> </div>To understand the mathematical notation here, you need to know vector calculus. I believe, however, that anyone can understand Maxwell's equations, and why they are so important and amazing, if they're explained clearly enough. </blockquote>Morgan-Mar even spells out the connection between Maxwell's equations and radio waves:<br />
<blockquote>From this breakthrough have come countless other discoveries about the nature of light, as well as its sibling electromagnetic waves: radio, microwaves, infrared and ultraviolet, x-rays, and gamma rays. All these forms of radiation are made of electric and magnetic fields, moving through space at the speed of light, exactly as described by Maxwell's equations. We now know that radio waves, for example, can be generated by switching an electric current on and off at high speed. The electrons in the wires wiggle back and forth, creating wiggling electric fields, which create magnetic fields, and so on - the overall effect being radio waves. And radio waves in turn wiggle the electrons in your radio or TV antenna, creating electric currents that various electric circuits turn back into sound and pictures. </blockquote>I enjoyed browsing around Morgan-Mar's site, including his pages celebrating <a href="http://www.dangermouse.net/lego/">LEGO</a> and <a href="http://www.dangermouse.net/media/picard.html">Star Trek</a>. I suggest you take a look.<br />
<br />
Update: My kids tell me that everyone on the Internet has already heard of <a href="http://www.irregularwebcomic.net/">Irregular Webcomic</a> except me. Ah well.Kathy Cecerihttp://www.blogger.com/profile/18188872992635537080noreply@blogger.com1tag:blogger.com,1999:blog-4526805397726051471.post-82816644934437435172011-01-13T16:46:00.001-08:002011-01-13T21:13:38.157-08:00Bending Light<div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgTzsNsXy2lB93xJ_x_TK2tFKqO9MJMzy8GSZArIKnyZ4fXmfY0eA7i68Ne_sjJfbUfTvX-Mu4qFhCpLZ8tGayEQt6BzX6soGhiaLaxFZLPLJChVopobHN_3YF4Tq_AuTbXBs4vUylcQ3g/s1600/Bending+Light.JPG" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="640" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgTzsNsXy2lB93xJ_x_TK2tFKqO9MJMzy8GSZArIKnyZ4fXmfY0eA7i68Ne_sjJfbUfTvX-Mu4qFhCpLZ8tGayEQt6BzX6soGhiaLaxFZLPLJChVopobHN_3YF4Tq_AuTbXBs4vUylcQ3g/s640/Bending+Light.JPG" width="425" /></a></div><br />
Lecture 14 of <a href="http://www.amazon.com/dp/B0010L578S?tag=homeintegratedscience-20&camp=213381&creative=390973&linkCode=as4&creativeASIN=B0010L578S&adid=0P6GDTSWSC931DKRTSMF">The Joy of Science</a> describes the properties of Electromagnetic Radiation, including light. Light waves can be made to bend as they pass through substances of different densities, like air and water.<br />
<br />
One experiment I always wanted to try was using a stream of water like a <a href="http://media.corning.com/flash/opticalfiber/2006/timeline/timeline_index.html">fiber optic cable</a> to bend light. We saw a demonstration of this at the <a href="http://www.cmog.org/dynamic.aspx?id=5722">Corning Museum of Glass</a> last summer. The exhibit at Corning got cool effects by varying the stream of water from a steady flow to drops.<br />
<br />
Our version was made using an empty soda bottle and a laser pointer. It works best at night, or in a room that can be darkened. Here is what we did:<br />
<br />
<div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjGu8RzzDFzfb4cKNVWApRNbaG-Mt3-X-JQ8L8_ozutPQaQAwFr7zLeJKMIFKj5CBByzLLzdA6FEtFuaIilrghxpU6FDZ3ubjk-etw4L2NWONns9OzK46d5kdABnhlN6k4FSJR5I9fQ5Q8/s1600/Bending+Light3.JPG" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="341" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjGu8RzzDFzfb4cKNVWApRNbaG-Mt3-X-JQ8L8_ozutPQaQAwFr7zLeJKMIFKj5CBByzLLzdA6FEtFuaIilrghxpU6FDZ3ubjk-etw4L2NWONns9OzK46d5kdABnhlN6k4FSJR5I9fQ5Q8/s400/Bending+Light3.JPG" width="400" /></a></div><b>Materials:</b><br />
<br />
laser pointer (I got a couple different kinds from the supermarket, about $6 each)<br />
stand for laser pointer (we tried poking it through a foam cup and laying it on a stack of coasters) <br />
rubber band <br />
clear empty soda bottle with cap<br />
water<br />
milk<br />
permanent marker<br />
metal skewer<br />
flame <br />
masking tape<br />
sink<br />
<br />
<ol><li>Fill the bottle with water and put a few drops of milk in to make it slightly cloudy. You can also try mixing in a little powdered milk or corn starch.</li>
<li>Wrap the rubber band around the laser pointer so it is pressing the "on" button continuously.</li>
<li>Set up the laser pointer so it is lying horizontally about 3 or 4 inches from the surface of the counter. Put it next to the bottle and adjust until you see the line of light passing through the milky water.</li>
<li>With the marker, make a dot where the light beam touches the far side of the bottle. Pour out all the water.</li>
<li>Heat the metal skewer in the flame (such as a stove burner) until it is very hot. Use the tip to melt a small hole in the soda bottle at the dot.</li>
<li>Cover the hole with a piece of masking tape. Put the cap on tight.</li>
<li>Fill the bottle again with milky water. Place it on the counter next to the sink. Set up the laser pointer so it is aimed through the bottle at the hole. Take the tape off to see if the light hits the hole. (The water won't come out until you loosen the cap -- try it!)</li>
<li>When everything's arranged, loosen the cap until you get a stream of water pouring into the sink. Adjust the light or walk around the bottle until you can see the light in the curved stream of water.</li>
</ol><br />
<object height="385" width="480"><param name="movie" value="http://www.youtube.com/v/Eu1U4c-1238?fs=1&hl=en_US&rel=0"></param><param name="allowFullScreen" value="true"></param><param name="allowscriptaccess" value="always"></param><embed src="http://www.youtube.com/v/Eu1U4c-1238?fs=1&hl=en_US&rel=0" type="application/x-shockwave-flash" allowscriptaccess="always" allowfullscreen="true" width="480" height="385"></embed></object><br />
<br />
<b>What's Happening?</b><br />
<br />
The laser beam is "trapped" inside the water because of <a href="http://www.physicsclassroom.com/class/refrn/u14l3b.cfm">Total Internal Reflection</a>. As the light tries to pass from the more-dense water to the less-dense air, it bends. (This is called refraction.) At a certain point the light bends so much that it is bounces off the surface of the water. (This is called reflection.) In the narrow column of water, the light wave continues bouncing off the boundaries of the stream of water but cannot pass through into the air.<br />
<br />
The same principle applies with a piece of glass or plastic fiber optic cable. We have some lying around somewhere. I'd like to try using it in an art project, but with LED bulbs instead of lasers....Kathy Cecerihttp://www.blogger.com/profile/18188872992635537080noreply@blogger.com0tag:blogger.com,1999:blog-4526805397726051471.post-48042837633751082382010-12-27T08:00:00.000-08:002010-12-27T08:00:00.064-08:00The No-Frog Battery<div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjtT6O1Qot7zSdesqsrZ6ruUh-dJ9ILQvZw9ATcuxsLD7T17oXFB7i_NAyVSLcKt4a9qioirY_niIz6Ro5unq9hv4BQhaH7wEOUndpXZ3YhxU0E-mgYSULZf8soxAMggVRE8N4sTD7esOI/s1600/Cu+Al+foil+test.JPG" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="266" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjtT6O1Qot7zSdesqsrZ6ruUh-dJ9ILQvZw9ATcuxsLD7T17oXFB7i_NAyVSLcKt4a9qioirY_niIz6Ro5unq9hv4BQhaH7wEOUndpXZ3YhxU0E-mgYSULZf8soxAMggVRE8N4sTD7esOI/s400/Cu+Al+foil+test.JPG" width="400" /></a></div><br />
In Lecture 12 of <a href="http://www.amazon.com/dp/B0010L578S?tag=homeintegratedscience-20&camp=213381&creative=390973&linkCode=as4&creativeASIN=B0010L578S&adid=05RZD1T1QMMCF7SKB3Z8">The Joy of Science</a>, Prof. Robert Hazen tells the story of the first electric battery. In 1799, Alessandro Volta was the first person to devise a way to chemically generate electricity <a href="http://www.ccrane.com/library/frog-legs.01.20.03.aspx">without the use of frogs</a>. I decided to try this experiment at home.<br />
<br />
<table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto; text-align: center;"><tbody>
<tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhmT26CElPZYcAaS97vWAGlxG1cck6b_ofmD_0LP4OaE7exBZwY0XtsAG40O0TMLkAEZKHwBzdmpWKhCUZGhLmuWBX1sdbYBMGq_b6HYlbin99fPqjiQXdZ-UT51ZaKNt_PITVSxIJmhaA/s1600/frogs.jpg" imageanchor="1" style="margin-left: auto; margin-right: auto;"><img border="0" height="276" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhmT26CElPZYcAaS97vWAGlxG1cck6b_ofmD_0LP4OaE7exBZwY0XtsAG40O0TMLkAEZKHwBzdmpWKhCUZGhLmuWBX1sdbYBMGq_b6HYlbin99fPqjiQXdZ-UT51ZaKNt_PITVSxIJmhaA/s400/frogs.jpg" width="400" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">Luigi Galvani and his wife Lucia discovered that <a href="http://batterydictionary.com/2009/02/09/volta-galvani/">dissecting frog legs</a><br />
with a scapel near an electrostatic generator caused the muscles to jump.</td></tr>
</tbody></table><br />
We had tried to make a <a href="http://www.hilaroad.com/camp/projects/lemon/lemon_battery.html">Lemon Battery</a> back when we were doing chemistry. <a href="http://homechemistry.blogspot.com/2008/01/lemon-battery-take-1.html">We were not successful</a>. I was all ready to go out and buy a bag of lemons and try again, when I came upon this <a href="http://www.instructables.com/id/The-micro-Lemon-Battery-reusable-1-hour-of-led-l/">Tiny Lemon Battery Instructable</a>. The author shows many different ways to create what one commenter dubbed "nano-batteries" using the bare minimum of materials and only a few drops of lemon juice. Since I had a bottle of lemon juice in the fridge, and the other materials were easily scrounged from our science and art supplies, we were able to make a few different types of batteries in the course of a morning -- two of which actually worked!<br />
<br />
<b>Method One: Copper and Aluminum Foil Batteries</b><br />
<div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhk3SYK5PjIV2ULyp3-nzcPrlAQx3b5TvHqEBRc0zpcLs21wie4srELUfP6dxA7VZ-Mq7ahlfzlAVIW0eQoApprW-wP9hH8rnqRPb-_elGtprWSDG0NyvWsbEGrq4xUaJAODpWqsrVMlCY/s1600/Foil+materials.JPG" imageanchor="1"><img border="0" height="266" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhk3SYK5PjIV2ULyp3-nzcPrlAQx3b5TvHqEBRc0zpcLs21wie4srELUfP6dxA7VZ-Mq7ahlfzlAVIW0eQoApprW-wP9hH8rnqRPb-_elGtprWSDG0NyvWsbEGrq4xUaJAODpWqsrVMlCY/s400/Foil+materials.JPG" width="400" /></a></div><br />
<b></b><br />
<u>Materials</u><br />
<br />
copper foil (available in craft stores)<br />
aluminum foil (from the supermarket)<br />
facial tissue (Kleenex)<br />
multimeter or voltmeter<br />
disposable plate (to work on)<br />
dish soap or lemon juice <br />
<div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgMbNkrqrtj104zPYRePcrUOZIkm0padyO-mnFbhCuquhX8nZKS2wVWq6IWwBpMe13XyI7nAMOqRetRoirbNcxPlnow0ZhufdxLfJH6IAa0jW8EXehYTEeI_66Qfq1OpM5fhlVcuO8JdZY/s1600/Foil+battery+dry.JPG" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="173" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgMbNkrqrtj104zPYRePcrUOZIkm0padyO-mnFbhCuquhX8nZKS2wVWq6IWwBpMe13XyI7nAMOqRetRoirbNcxPlnow0ZhufdxLfJH6IAa0jW8EXehYTEeI_66Qfq1OpM5fhlVcuO8JdZY/s400/Foil+battery+dry.JPG" width="400" /></a></div><br />
<ol><li>Cut a piece of copper foil about 1 inch by 2 inches.</li>
<li>Separate the tissue into layers. Cut a piece about 1 inch by 3 inches.</li>
<li>Cut a piece of aluminum foil about 2 inches square.</li>
<li>Layer the materials so that the aluminum foil is on the bottom, the tissue is in the middle, and the copper is on top. Fold the aluminum foil so that the edges wrap around the tissue and copper foil as shown above. This is your battery.</li>
<li>Place the battery on a plate. Soak the paper with either dish soap or lemon juice. (We tried one of each.)</li>
<li>With your voltmeter, measure the voltage generated by placing one terminal on the copper and one on the aluminum. We got up to half a volt of electricity from our primitive <a href="http://en.wikipedia.org/wiki/Galvanic_cell">Galvanic cell batteries</a>.</li>
</ol><br />
<b>Method Two: Copper and Zinc Wire Battery</b><br />
<div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhWMgkETMvZu1kMAUXgYZYartFiISUlfbdygW_X8a9OrqVJOw6nE8yXZAvvrpT7CTFHZEfUJLOcTyOJoKdT_wtkv39ypif0SGLhS81Wvvdmxqw7HJHyVF1DSpVGwLyPJgv1gg4YhVgYPSs/s1600/Cu+Zi+wire+cell.JPG" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="104" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhWMgkETMvZu1kMAUXgYZYartFiISUlfbdygW_X8a9OrqVJOw6nE8yXZAvvrpT7CTFHZEfUJLOcTyOJoKdT_wtkv39ypif0SGLhS81Wvvdmxqw7HJHyVF1DSpVGwLyPJgv1gg4YhVgYPSs/s320/Cu+Zi+wire+cell.JPG" width="320" /></a></div><br />
<u>Materials</u><br />
2 inch long piece of zinc-plated steel wire ("galvanized" picture-hanging wire works well)<br />
4 inch long piece of uncoated copper wire, as thin as possible <br />
a layer of Kleenex (see above)<br />
disposable plate<br />
lemon juice or dish soap<br />
<br />
<ol><li>Cut a piece of tissue about 1 1/2 inches long and 1/2 inch wide.</li>
<li>Wrap the tissue layer around the steel wire, leaving the ends uncovered.</li>
<li>Coil the copper wire around the tissue, being sure not to touch the steel wire inside. Make the coils as close together as possible without overlapping. </li>
<li>Soak the paper in lemon juice or soap as above and measure the voltage!</li>
</ol>The Instructables page has directions for several variations, which include making several batteries and attaching them in series to light an LED, and flower and animal "sculptures" which use lemon juice to light up attached LEDs using the same techniques. One variation which we tried but did not (yet) get to work was to make tiny batteries from coils of wire inside lemon juice-filled drinking straws sealed with hot glue. Although the cells we made looked right, we could measure no voltage from them. We'll write an update post when we've got a few more designs to show off!Kathy Cecerihttp://www.blogger.com/profile/18188872992635537080noreply@blogger.com0tag:blogger.com,1999:blog-4526805397726051471.post-43977185241613873202010-12-15T18:06:00.000-08:002010-12-24T13:57:40.834-08:00Second Law of Thermodynamics -- Keeping Butter Cool with Evaporation<div style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEg0zLhq2sjWjR8pijig1Iw6CCCSPDVN9X4kCCrb9jhtbIGJXTzmLvH5Ee9s9J4DXIgyFxHDM2pxs_xmwQMLxvNgZpVLlXbDCSeEFvQRBSWiYsnCnW5RDG4a3iYntD4tXWRZ7mAqOufev7M/s1600/All+cups.JPG" imageanchor="1" style="margin-left: auto; margin-right: auto;"><img border="0" height="170" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEg0zLhq2sjWjR8pijig1Iw6CCCSPDVN9X4kCCrb9jhtbIGJXTzmLvH5Ee9s9J4DXIgyFxHDM2pxs_xmwQMLxvNgZpVLlXbDCSeEFvQRBSWiYsnCnW5RDG4a3iYntD4tXWRZ7mAqOufev7M/s400/All+cups.JPG" width="400" /></a></div><div style="text-align: center;"><span style="font-size: x-small;">The setup. Left to right: the control, Anthony's experiment (The cup of butter was kept in wet sand,) and John's experiment, (The butter was put in a bowl of water, and covered by a ceramic pot and a cloth.)</span></div><br />
After watching <a href="http://www.amazon.com/dp/B0010L578S?tag=homeintegratedscience-20&camp=213381&creative=390973&linkCode=as4&creativeASIN=B0010L578S&adid=05RZD1T1QMMCF7SKB3Z8">The Joy of Science</a> lecture about the <a href="http://en.wikipedia.org/wiki/Second_law_of_thermodynamics">Second Law of Thermodynamics</a>, I decided to spend a week focusing on entropy. <a href="http://www.physics4kids.com/files/thermo_entropy.html">Entropy</a> is a concept that has always interested me, although I don't understand very well. I first read about it in a short story by <a href="http://www.amazon.com/dp/0316724432?tag=homeintegratedscience-20&camp=213381&creative=390973&linkCode=as4&creativeASIN=0316724432&adid=14NPBDS91KWHCQ6EV87E">Thomas Pynchon</a>, and then ran into it again when I saw Tom Stoppard's play <a href="http://www.amazon.com/dp/0571169341?tag=homeintegratedscience-20&camp=213381&creative=390973&linkCode=as4&creativeASIN=0571169341&adid=11VGKKN6263HKSNK0CF8">Arcadia</a>. But despite its interest for writers, it doesn't seem to have inspired a lot of popular science videos we could watch. The only mention I could find in the archives of what is now my favorite science show, <a href="http://www.pbs.org/wgbh/nova/">NOVA</a>, was a show about <a href="http://www.pbs.org/wgbh/nova/zero/">Absolute Zero</a>. Luckily, this topic proved to be interesting in its own right.<br />
The Teachers Guide for NOVA programs often contain good hands-on science activities. In this case, however, I thought the activity -- <a href="http://www.pbs.org/wgbh/nova/teachers/programs/3501_zero.html">using a thermometer to calibrate a homemade thermometer</a> -- was a tad lame. But a mention in the show about the discovery that evaporating chemicals could be used to produce refrigeration did catch my attention. I started Googling for safe classroom-type activities the kids and I could do to recreate the 1823 experiment by Michael Faraday, but perhaps without the potentially explosive chlorine.<br />
<br />
<table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto; text-align: center;"><tbody>
<tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgR1iRg808CQhOpn8MZMooTqTZ4CiQtOiQcBN2PmKiwhMBo-PRjhKaOC7abdkUwQ2mUsKx_eMyyf2tQnq3X5qWLxbeX-ohF309kD7OENZJa38JOiqWxyAZ58kSRHkC4iDr25RpXe3i4wKo/s1600/Thermometer.JPG" imageanchor="1" style="margin-left: auto; margin-right: auto;"><img border="0" height="320" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgR1iRg808CQhOpn8MZMooTqTZ4CiQtOiQcBN2PmKiwhMBo-PRjhKaOC7abdkUwQ2mUsKx_eMyyf2tQnq3X5qWLxbeX-ohF309kD7OENZJa38JOiqWxyAZ58kSRHkC4iDr25RpXe3i4wKo/s320/Thermometer.JPG" width="279" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">Taking the temperature of butter in a Butter Keeper</td></tr>
</tbody></table>And then it occurred to me that I could use the concept of a Butter Keeper -- a porous terracotta holder that keeps butter cool through water evaporation -- to achieve the same purpose. (Ironically, the type of Butter Keeper <a href="http://www.amazon.com/dp/B0001LFPCQ?tag=homeintegratedscience-20&camp=213381&creative=390973&linkCode=as4&creativeASIN=B0001LFPCQ&adid=0K3DJJMBEXANZ1V0HV59">which inspired this activity</a> actually keeps the butter cool by <a href="http://www.frenchbutterdish.com/FAQ.php">sealing out air</a>, not by cooling it!)<br />
<br />
We looked at some different types of <a href="http://www.chelseagreen.com/content/project-evaporative-cooler-box-draft/">evaporative coolers</a>, including a similar metallic evaporative cooler invented by a student when she was in high school. We then gathered some materials and tried making our own. Although we did get some cooling, the Butter Keeper works is most effective in hot, dry climates. Here are the directions for our experiments:<br />
<br />
<table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto; text-align: center;"><tbody>
<tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhYx-C3TEMr6CO9YrDrQsJsm8riSB7nLdYm1AeeRNyTDr258bmHyZbx_m2wllUnhbRyo1GU9BNS2e75HWDiflKfh8EjQuGgWbr4ZF1zBnWjSVGkGwMXPcfMsrxrQ5Vv8X5srEKUL6l3_D4/s1600/Materials.JPG" imageanchor="1" style="margin-left: auto; margin-right: auto;"><img border="0" height="239" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhYx-C3TEMr6CO9YrDrQsJsm8riSB7nLdYm1AeeRNyTDr258bmHyZbx_m2wllUnhbRyo1GU9BNS2e75HWDiflKfh8EjQuGgWbr4ZF1zBnWjSVGkGwMXPcfMsrxrQ5Vv8X5srEKUL6l3_D4/s320/Materials.JPG" width="320" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">The materials.</td></tr>
</tbody></table><br />
<b>Materials: </b><br />
<ul><li>room-temperature butter (we made a bowl of butter by whipping heavy cream; you could also soften some store-bought butter)</li>
<li>plastic wrap <br />
</li>
<li><a href="http://www.amazon.com/dp/B0021AEAG2?tag=homeintegratedscience-20&camp=213381&creative=390973&linkCode=as4&creativeASIN=B0021AEAG2&adid=15JMVWXBB4WJRE42FV75">digital food thermometer</a> (about $15)</li>
<li>terracotta flower pots</li>
<li>terracotta flower pot dishes</li>
<li>disposable bowls and cups</li>
<li>sand</li>
<li>cloth (we used a bandana)</li>
<li>water</li>
</ul><ol><li>Fill a small disposable cup with softened butter. Cover with plastic wrap </li>
<li>Use the food thermometer to punch a hole through the plastic wrap and take the temperature of the butter. </li>
<li>Use the materials on hand to design and assemble a Butter Keeper that will hold the cup of butter. The Butter Keeper should hold and absorb for an extended period. See the photos for ideas.</li>
<li>Place the cup of butter in the Butter Keeper. Place another cup of butter next to it as a control. Check the temperature of both cups at regular intervals to see whether the butter in the Butter Keeper is cooler than the butter sitting outside at room temperature.</li>
</ol><br />
<br />
<b>What We Did:</b><br />
<b> </b><br />
John built one using a cloth to wick up water from a dish holding the terracotta pot. This design was apparently used in <a href="http://www.britishpathe.com/record.php?id=19196">Great Britain</a> and <a href="http://www.pukeariki.com/Heritage/SpotlightontheHeritageCollection/id/185/title/butter-cooler.aspx">Australia</a> in the 20th century.<br />
<br />
<table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto; text-align: center;"><tbody>
<tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEic9r7ADxJks-WXiYaEW6X2E8oaBKhpef0wm0Eda-uLdjYigx-woH3E2D-PVCCDgo5Q5DoxdFonEF149YT0T-GnZT7gIYI8DNTUsJqlZ5NFzJpirSJ-MKO3kadQzw4q6-2bywz69NKzFDE/s1600/Cloth+pot+prep+2.JPG" imageanchor="1" style="margin-left: auto; margin-right: auto;"><img border="0" height="320" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEic9r7ADxJks-WXiYaEW6X2E8oaBKhpef0wm0Eda-uLdjYigx-woH3E2D-PVCCDgo5Q5DoxdFonEF149YT0T-GnZT7gIYI8DNTUsJqlZ5NFzJpirSJ-MKO3kadQzw4q6-2bywz69NKzFDE/s320/Cloth+pot+prep+2.JPG" width="316" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">The preparation of John's experiment. The cloth <a href="http://en.wikipedia.org/wiki/Wicking">wicked</a> the water up over the pot to keep it wet.</td></tr>
</tbody> </table><br />
<table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto; text-align: center;"><tbody><href="file: c:%5cdocume%7e1%5ca%5clocals%7e1%5ctemp%5cmsohtml1%5c01%5cclip_filelist.xml="" rel="File-List"><style>
<!--
/* Style Definitions */
p.MsoNormal, li.MsoNormal, div.MsoNormal
{mso-style-parent:"";
margin:0in;
margin-bottom:.0001pt;
mso-pagination:widow-orphan;
font-size:12.0pt;
font-family:"Times New Roman";
mso-fareast-font-family:"Times New Roman";}
@page Section1
{size:8.5in 11.0in;
margin:1.0in 1.25in 1.0in 1.25in;
mso-header-margin:.5in;
mso-footer-margin:.5in;
mso-paper-source:0;}
div.Section1
{page:Section1;}
-
</style></href="file:></tbody></table><table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto; text-align: center;"><tbody>
<tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhK9-dbWbPwRogEUe7qX8KWgv5yaZfLZyj6Nmri9kRau2mO7IgMS3p6KEjhHVzNxi7RlMBKFlODf9vvAhQNF4fJeL1pUHv5NFwWFSyh_Q8UG_gh2AJnNbcERuUYO0iRI68Sqoaz71F6iVk/s1600/Cloth+pot+prep+1.JPG" imageanchor="1" style="margin-left: auto; margin-right: auto;"><img border="0" height="236" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhK9-dbWbPwRogEUe7qX8KWgv5yaZfLZyj6Nmri9kRau2mO7IgMS3p6KEjhHVzNxi7RlMBKFlODf9vvAhQNF4fJeL1pUHv5NFwWFSyh_Q8UG_gh2AJnNbcERuUYO0iRI68Sqoaz71F6iVk/s320/Cloth+pot+prep+1.JPG" width="320" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">John's experiment.</td></tr>
</tbody> </table>Anthony used a smaller container set into a terra
cotta pot filled with sand and then dampened. That version comes from
Africa, where it is known as a <a href="http://practicalaction.org/?id=zeerpots">zeer</a>,
and is used to keep produce fresh in areas where electricity is
unavailable.
<table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto; text-align: center;"><tbody>
<tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiZoM_J106CETOAkrhVSoAfLCa1XuzmBIMmrYAqb18ce1ncF7HtVeSKrUdWsD5KddjCXM5Ov_6fg2BzNGhB7-7P5Cj6zWFx-h_OujUu3nI1xC0Rw0RYlJta59Vk0u7dFGW9l0WZITB3crM/s1600/Sand+pot+prep.JPG" imageanchor="1" style="margin-left: auto; margin-right: auto;"><img border="0" height="213" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiZoM_J106CETOAkrhVSoAfLCa1XuzmBIMmrYAqb18ce1ncF7HtVeSKrUdWsD5KddjCXM5Ov_6fg2BzNGhB7-7P5Cj6zWFx-h_OujUu3nI1xC0Rw0RYlJta59Vk0u7dFGW9l0WZITB3crM/s320/Sand+pot+prep.JPG" width="320" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">The setup for Anthony's experiment. </td></tr>
</tbody></table><table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto; text-align: center;"><tbody>
<tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgcTpoCZsqjEg5FgJ95EtpOsoA31PE6FgutpA9UCQWG3KWyFktuGsi6-fHXK55WrfUYOEc7Ct-UszjJEeZogj4OjDy2z3wfPK-kNZ-f9gAhIqP4Pfyq7tMtiCeA8IU1AzPSyAAMtPqCR3c/s1600/Sand+pot+prep2.JPG" imageanchor="1" style="margin-left: auto; margin-right: auto;"><img border="0" height="286" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgcTpoCZsqjEg5FgJ95EtpOsoA31PE6FgutpA9UCQWG3KWyFktuGsi6-fHXK55WrfUYOEc7Ct-UszjJEeZogj4OjDy2z3wfPK-kNZ-f9gAhIqP4Pfyq7tMtiCeA8IU1AzPSyAAMtPqCR3c/s320/Sand+pot+prep2.JPG" width="320" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">The sand in this experiment serves the same purpose as the cloth in John's.</td></tr>
</tbody></table><b> What Happened:</b>
We assembled the Butter Keepers and set them out on a bench, next to an unprotected cup of butter. We kept the pots wet by periodically refilling the bowls as needed. When we started, the butter was 65 degrees. Within a few hours it had decreased to 62, while the control cup was at 70. While not a gigantic difference, it does show a noticeable drop in temperate, from both the un-refrigerated control and the actual room temperature. After a few days the butter did begin to smell bad, and we ended the experiment. Note: Our first thermometer, from Wal-Mart, died soon after we started. We bought a slightly better version from an upscale cooking equipment store, which worked fine.Kathy Cecerihttp://www.blogger.com/profile/18188872992635537080noreply@blogger.com0tag:blogger.com,1999:blog-4526805397726051471.post-20548232956039377382010-12-03T15:07:00.000-08:002010-12-24T13:57:48.035-08:00Our Galileoscope<div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEigEYtB-i0v-8P9Boe7xsBWE56WbEfjIins5gWI2pbWShTqifOaMOBg6iViHIBbc_5cygVHCFENLSDjTssUH1bH9XBjSithxr3mCs3Zv4QtnF_x6oiBa62N8q7DYzDwJ4bsnPD5pOH3sIM/s1600/Moon3.JPG" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="340" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEigEYtB-i0v-8P9Boe7xsBWE56WbEfjIins5gWI2pbWShTqifOaMOBg6iViHIBbc_5cygVHCFENLSDjTssUH1bH9XBjSithxr3mCs3Zv4QtnF_x6oiBa62N8q7DYzDwJ4bsnPD5pOH3sIM/s400/Moon3.JPG" width="400" /></a></div><div class="separator" style="clear: both; text-align: center;"></div><br />
In Lecture 3 of The Joy of Science, Prof. Hazen talks about how <a href="http://en.wikipedia.org/wiki/Galileo_Galilei">Galileo</a> used his telescope to explore the heavens, and was the first to observe the craters of the moon, sunspots, and Jupiter's moons. (In the process upsetting medieval European society by suggesting that the celestial bodies were not "perfect.")<br />
<br />
We happened to have on hand a reproduction of Galileo's telescope, the <a href="https://www.galileoscope.org/gs/">Galileoscope</a>. This inexpensive instrument was designed for student use during the <a href="http://www.astronomy2009.us/">International Year of Astronomy</a> in 2009. Although it claims to have decent lenses, it is very lightweight and doesn't come with a stand, which makes it hard to use. We had never really used it, but this seemed like a good time to try again.<br />
<br />
First, we set up the telescope for <a href="http://spaceweather.com/sunspots/doityourself.html">projecting sunspots</a> on a piece of paper. (NEVER point a telescope at the sun!) Unfortunately, after checking <a href="http://spaceweather.com/">SpaceWeather.com</a>, we found that we had picked a day that the sun really did have no spots! However, we were able to see the disc of the sun. We will have to try this experiment again.<br />
<br />
<br />
<div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEj7NMV6xSdnH1642PLVLxVIRyZXbKe31y0q7Owz9QqFQEOpFWvYqhXRGEHp7JnOSUAHHJCjRgwump__lL4YJEb8qWwgk_JyaWtQmoTpmgSXdvXWyLmbTjh3QqCvl7aeEz33iC3mbsrwFPM/s1600/Set+up.JPG" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="320" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEj7NMV6xSdnH1642PLVLxVIRyZXbKe31y0q7Owz9QqFQEOpFWvYqhXRGEHp7JnOSUAHHJCjRgwump__lL4YJEb8qWwgk_JyaWtQmoTpmgSXdvXWyLmbTjh3QqCvl7aeEz33iC3mbsrwFPM/s320/Set+up.JPG" width="302" /></a></div><br />
<div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEj4Whg8_yVVESC_DweADY5mxaAh0qGG2FD-bHXIdAIDb1yS6U3_0CM-fxx9zUQQSEnqHJJrXP634gvheAnVznr0c1DbgkoXAPVxHgfYdvkQnbz-n0BF0UKIPW6dtLAqKap0QF_C5VbMfj4/s1600/Sun+image.JPG" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="266" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEj4Whg8_yVVESC_DweADY5mxaAh0qGG2FD-bHXIdAIDb1yS6U3_0CM-fxx9zUQQSEnqHJJrXP634gvheAnVznr0c1DbgkoXAPVxHgfYdvkQnbz-n0BF0UKIPW6dtLAqKap0QF_C5VbMfj4/s400/Sun+image.JPG" width="400" /></a></div><br />
A few weeks later on a particularly cool crisp night, I noticed that Jupiter was clearly visible near the almost-full moon. I set up the Galileoscope on our front lawn. The moon and Jupiter were so bright that they could be observed even with the streetlights shining. I had never seen the moons of Jupiter through a telescope before, but they were clearly visible in the Galileoscope. The four Medici moons were lined up horizontally, three to the left of Jupiter and one to the right. About a month later, with the conditions almost the same, I pulled the telescope out and took another look. This time the line of moons was tilted down towards the left, and there were two moons on either side of Jupiter.<br />
<br />
<div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgT2AODnMkjORG-ix-qMXRQanPGab3nXEzUUh7YhaxJQ506GaCf9vCz-MVMbWQSioQuqMP_8Y6jrEvtkCSZIoLaFHNiW4TNoAE6xHUmEyA_lb8Zcq5UKDnzR17oBuLtjollYnJel5vDsLw/s1600/800px-Jupiter-moons.jpg" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="191" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgT2AODnMkjORG-ix-qMXRQanPGab3nXEzUUh7YhaxJQ506GaCf9vCz-MVMbWQSioQuqMP_8Y6jrEvtkCSZIoLaFHNiW4TNoAE6xHUmEyA_lb8Zcq5UKDnzR17oBuLtjollYnJel5vDsLw/s320/800px-Jupiter-moons.jpg" width="320" /></a></div><br />
I was unable to take any photos of Jupiter with my little digital camera. (The image above is from <a href="http://en.wikipedia.org/wiki/Moons_of_Jupiter">Wikipedia</a>.) So instead I pointed the Galileoscope at the moon and took some photos of it. The craters of the moon can be seen along the right edge. To get the photo, I held the set the camera for landscape (so the focus would be infinity) and held the lens a little bit away from the eyepiece. I lined up the image of the moon on the screen and then shot the photo. Pretty nice, right?<br />
<br />
<div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhv55p1qTxoR7qIfpVwkARRfGe8_Qe8KAQeO6p2090HffBn2hb-5yXhgmROuO4dv6X8iOrpRiZ7uEVW7K1V55qLeoUYYOi5ghBCfS1qWc7b4O8DHosd0uQ_lZibkIvlLg99XM7dDDjzGIc/s1600/Moon2.jpg" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="265" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhv55p1qTxoR7qIfpVwkARRfGe8_Qe8KAQeO6p2090HffBn2hb-5yXhgmROuO4dv6X8iOrpRiZ7uEVW7K1V55qLeoUYYOi5ghBCfS1qWc7b4O8DHosd0uQ_lZibkIvlLg99XM7dDDjzGIc/s400/Moon2.jpg" width="400" /></a></div><br />
We also watched Bertoldt Brecht's play <a href="http://www.amazon.com/dp/B0000TPABA?tag=homeintegratedscience-20&camp=213381&creative=390973&linkCode=as4&creativeASIN=B0000TPABA&adid=04PERHR75KTDCB91WE4T">Galileo</a>, which I have seen performed live. It does a good job of showing the conflict between the scientist and the Church. A good book for younger kids, which we read many years ago is <a href="http://www.amazon.com/dp/0374470278?tag=homeintegratedscience-20&camp=213381&creative=390973&linkCode=as4&creativeASIN=0374470278&adid=087PX0WVXDN1X6T98NYM"><i>Starry Messenger</i></a> by Peter Sis. That is the title of a work by Galileo, which was part of a museum exhibit we saw called <a href="http://tang.skidmore.edu/index.php/slideshows/view/id:3/page:10">A Very Liquid Heaven</a>. I was very impressed with the large meteorite (below) which was part of the combination art and science exhibit.<br />
<br />
<div class="separator" style="clear: both; text-align: center;"><img border="0" height="320" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiEYMfoyOWaEwQN_Sv-BdOkQk_L03Dwj-jxcrP_TAOrgwh7XVUwEIPi-i1WOmrznb8g0MoIOuf7_-UfLWW3nMEr4AzGx3w1MTufn2YjsOAEsUCtWojCFvbozts2ZhOaizJAmvP02soesD4/s320/Tang+Meteorite.jpg" width="295" /></div>Kathy Cecerihttp://www.blogger.com/profile/18188872992635537080noreply@blogger.com0tag:blogger.com,1999:blog-4526805397726051471.post-16760036311899700222010-11-30T08:44:00.000-08:002010-12-24T13:57:53.183-08:00Magnets and Declination<div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgFELaYm8k7qSE1zQ9ueEuJGPBXv3dpAT_Nf27au3-qut8LaUrA3xekDiAPg_8C1kKu6BbWOpFkuZCHIEsEYtMeL9leVHmlkFcoELaVd6DmT37lvywZYKQ2z1SVdpxlaYF2eXIRLiSW_74/s1600/Floating+Cork.JPG" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="213" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgFELaYm8k7qSE1zQ9ueEuJGPBXv3dpAT_Nf27au3-qut8LaUrA3xekDiAPg_8C1kKu6BbWOpFkuZCHIEsEYtMeL9leVHmlkFcoELaVd6DmT37lvywZYKQ2z1SVdpxlaYF2eXIRLiSW_74/s320/Floating+Cork.JPG" width="320" /></a></div>In <i>The Joy of Science</i>, Lesson 11: Magnetism and Static Electricity, Robert Hazen explains that the Earth is itself a giant magnet. In the Northern Hemisphere, the north end of a compass will point down towards the magnetic North Pole. He described an experiment by Robert Norman in his book <i>The Newe Attractive</i> which showed the declination by floating a magnetized needle in a piece of cork in a container of water. By shaving away the cork, Norman got the needle to float below the water's surface so that it's dip toward the Pole could be seen.<br />
<div class="separator" style="clear: both; text-align: center;"><iframe allowfullscreen='allowfullscreen' webkitallowfullscreen='webkitallowfullscreen' mozallowfullscreen='mozallowfullscreen' width='320' height='266' src='https://www.blogger.com/video.g?token=AD6v5dwO5wkmRwiOx4DEO75G4hHmGLPGceMUDvZRHbSIZwoiw6O_OiiI_29rEOwu3-pWASRupW4nwoQg_EiO9GGPcA' class='b-hbp-video b-uploaded' frameborder='0'></iframe></div><br />
We tried to recreate Norman's experiment from Hazen's description using a needle and a straightened paper clip as the magnetic pointers, and real and artificial cork and pieces of a Styrofoam cup as the floatation device.We did get the needle to point on a north-south axis. But it was hard to tell if the needle dipped, because the angle would change depending on where the cork was.<br />
<br />
There's another description of <a href="http://www.practicalphysics.org/go/Resources_15.html">Norman's experiment</a> at <a href="http://www.practicalphysics.org/">Practical Physics</a>. And <a href="http://books.google.com/books?id=9JHyM0JCCAsC&pg=PA57&lpg=PA57&dq=experiment+cork+water+magnetic+declination&source=bl&ots=zRKT9pjr3v&sig=Kg0GLRrnUfMZxFTAFkmKmHkG3bM&hl=en&ei=pCb1TLryKcSclgebqNmnBg&sa=X&oi=book_result&ct=result&resnum=1&ved=0CBMQ6AEwAA#v=onepage&q=experiment%20cork%20water%20magnetic%20declination&f=true">Safe and Simple Electrical Experiments</a> (viewable through Google Books) gives some alternate ways of observing the declination of the needle. You can find the <a href="http://en.wikipedia.org/wiki/Magnetic_declination">magnetic declination</a> for your position at <a href="http://www.ngdc.noaa.gov/geomagmodels/struts/calcDeclination">NOAA's Geophysical Data Center</a>.Kathy Cecerihttp://www.blogger.com/profile/18188872992635537080noreply@blogger.com0tag:blogger.com,1999:blog-4526805397726051471.post-13430036105691787122010-11-17T08:36:00.000-08:002010-12-24T13:57:57.757-08:00First Law of Thermodynamics: Heating Sand by Shaking It<div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgwUD8KAZ98vPFcMY6xjfI45oM28HsTpy0yj4phyGhaEa3lZPIEuY2FKvvpSjUdryyDVEnFbZo5RMUQetbuC6GmeMOFj0bG3LZlGrhvgwlgH7KWBp_Su2TkXQugVTCapa1_V1DZutOB1j4/s1600/101_1123.JPG" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="320" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgwUD8KAZ98vPFcMY6xjfI45oM28HsTpy0yj4phyGhaEa3lZPIEuY2FKvvpSjUdryyDVEnFbZo5RMUQetbuC6GmeMOFj0bG3LZlGrhvgwlgH7KWBp_Su2TkXQugVTCapa1_V1DZutOB1j4/s320/101_1123.JPG" width="213" /></a></div><br />
The first law of thermodynamics says that the total amount of energy in a closed system remains constant. There are many different forms of energy, and energy can shift from one form to another. So the total amount of energy in a closed system is the sum of all the different forms of energy added together.<br />
<br />
To test this principle, we measured the temperature of sand in a Styrofoam cup.This experiment was suggested by Professor Robert Hazen in his video course <a href="http://www.amazon.com/dp/B0010L578S?tag=homeintegratedscience-20&camp=213381&creative=390973&linkCode=as4&creativeASIN=B0010L578S&adid=05RZD1T1QMMCF7SKB3Z8"><i>The Joy of Science</i></a>. In his video, he used a jar of sand. However, we decided to use insulated cups so we didn't have to open it to measure the heat. We first measured the sand's temperature, then we sealed the cup, shook it for about five minutes, and measured the sand again. The sand's temperature actually changed from 65 degrees Fahrenheit to 68 in just the five or so minutes we shook it.<br />
<br />
Materials:<br />
<br />
2 disposable insulated cups (we used Styrofoam)<br />
masking tape<br />
sand<br />
and a food thermometer (the kind with a sharp metal probe.)<br />
<br />
Procedure:<br />
<ol><li>Pour the sand into one of the cups until it is about three-quarters full. </li>
<li>Measure the temperature of the sand.</li>
<li>Place the empty cup on top of the cup with the sand on it. Tape them together.</li>
<li>Shake for five minutes.</li>
<li>Poke the thermometer's probe though the top of one of the cups. Measure the temperature again. You should see the temperature go up a few degrees.</li>
</ol>What Happened:<br />
<br />
Shaking the sand is a form of kinetic energy. The friction of the sand particles rubbing against each other converts the kinetic energy to heat energy. Some of the kinetic energy also converts into the energy of sound waves, which you can hear while you shake the sand.Kathy Cecerihttp://www.blogger.com/profile/18188872992635537080noreply@blogger.com1