This video from NASA (via physorg.com) includes a nice little section showing the movement of charged particles (cosmic rays) through the Sun’s magnetic field. What’s really neat, is that the Voyager spacecraft (now 33 years old) have discovered magnetic bubbles at the edge of the solar system that make the particles dance a little. It’s a wonderful application of the basic principles of electricity and magnetism.
Author: Lensyl Urbano
The Art of Specimen Preservation
After the joy of playing around with microscopy and staining last fall, it’s no surprise that someone has taken the science of staining and specimen preservation and turned it into art.
Iori Tomita has done an amazing job at making visible the internal organs of the specimens.
Using a method that dissolves an animals natural proteins, Tomita is able to preserve these deceased animals with striking detail–highlighting the finest and most delicate skeleton structures.
To further enhance the visual appeal of these ornate skeletons, Tomita selectively injects different colored dies into hard bones and soft bones to create a 3-d effect. Without the addition of the dye, the animals remain translucent.
— Michael (2010): New World Transparent Specimens Turns Preservation Into Modern Art
Tomita’s website has some excellent photographs, and there appear to be two books available from Amazon.com.jp. More pictures can be found online here and here. Lisa Stinson at Wired has more pictures and details on the method.
Storm: Life is Precious
I try not to post things with anything approaching obscene language, but sometimes, as in this piece, called “Storm” by Tim Minchin, it’s a small part in the service of a much bigger, more significant idea. Anyway, this one might not be for the kids.
Squid Dissection
To follow up my own attempts at a fish anatomy lesson, I asked the people at the Gulf Coast Research Lab’s Marine Education Center to include a dissection in their program for our Adventure Trip. They chose squid.
Squid are nice because they’re mostly soft tissue and the organs are fairly easy to identify. They’re also quite charismatic, which piqued the students’ interest. These squid were going to be used as bait, so I didn’t feel too badly about using them for science.
Once again, our guide, Stephanie, was an excellent teacher. A good time was had by all, even though it was a bit gruesome.
I would have liked to have a little more time to draw some diagrams, but I don’t think my students would have had the patience. It was the Adventure Trip after all, and they’d much rather spend the time outside.
As for the future, I like this note about squid dissection:
… this … is a tactile experience. You may want to explore this aspect through sensory activities, written descriptions, poetry, and/or artwork. Encourage students to experience the many textures found inside and outside the squid’s body. Moving fingertips along the suckers is suggested as well – the suckers do not scrape or hurt if you are gentle with them.
–Center for Educational and Training Technology, Mississippi State University: Squid Dissection
This quote comes from a Mississippi State website, which also has a great set of calamari recipes in addition to dissection instructions. I’m always in favor of an interdisciplinary approach; food-preparation rather than purely dissection.
Finally, the University of Buffalo’s Biology 200 class has some excellent, labeled pictures, for reference.
Variations on a Theme
In seeking their identity, adolescents try out a wide variety of different personas. These are often closely associated with changing appearance and style. What I find interesting is how the different styles increasingly cross cultures and other traditional divides (like race). This is evident in Ari Versluis and Ellie Uyttenbroek’s photographic series Exactitudes.
There’s something sad about the loss of local cultural uniqueness to globalization; it’s a bit similar to the feeling you get when you hear about another interesting species becoming extinct. Curiously, however, when Versluis and Uyttenbroek tile together photographs of different people from the same subculture striking identical poses, they not only highlight the similarities between very different people, but also the minute variations that individuals employs to make the subgroup’s “uniform” their own.
All 128 pictures sets are thought provoking and worth a look. I think they would make useful subjects for students to reflect on (though, warning, there is a little nudity in one of the sets).
(via Brain Pickings)
The Uses of Rare Earth Elements
Tiny quantities of dysprosium can make magnets in electric motors lighter by 90 percent, while terbium can help cut the electricity usage of lights by 80 percent.
–Lifton (2010): The Battle Over Rare Earth Metals
There has recently been a bit of a furor over the fact that, currently, China produces 90% of the world’s rare earth metals. Special properties of these elements are making them extremely important in a lot of high-tech and alternative energy technologies.
Fiber-optic cables can transmit signals over long distances because they incorporate periodically spaced lengths of erbium-doped fiber that function as laser amplifiers. Er is used in these laser repeaters, despite its high cost (~$700/kg), because it alone possesses the required optical properties.
–Haxel et al., 2005: Rare Earth Elements—Critical Resources for High Technology
The rare earths are so chemically similar that they’re lumped together in one corner of the periodic table, which is why they have not been used a lot until now. Only recently has their influence on elecromagnetic systems been discovered. Wikipedia has a good list of the elements with some of their uses.
Many people are worried about one country controlling so much of a single resource, especially since China cut its export quotas earlier this year. Fortunately, rare earth metals are found in places other than China, and, as the demand continues to outstrip supply, it’s just a matter of time for high prices to to bring more mining and recycling projects into production.
Government and Geology in Nashville
Earlier this spring, we had an excellent immersion trip to Nashville. The primary purpose was to visit the capitol and meet with Memphis’ State Representative Mark Kernell.
But we also had time to visit the Abintra Montessori School in Nashville (who returned the visit last month), and have an excellent hike along a limestone-bedded stream in Montgomery Bell State Park. The hike, however, was not without some controversy.
Shilo and Pickwick Immersion
The Shiloh National Battlefield is only a couple hours east of Memphis (or west of Nashville), and its proximity to Corinth, MS, and a state park with a hydroelectric dam, make it an excellent place for an immersion trip during the cycle when we study the U.S. Civil War and electromagnetism. Two years ago, on a couple beautiful, sunny days in the middle of spring (early April), almost on the anniversary of the battle, we made the trip.
We drove over on a Tuesday morning, and since our very nice cabins at Pickwick Landing State Park were not quite ready yet, we ate the lunch we’d brought with us at a picnic shelter on the park grounds. The choice of picnic shelter number 6 was serendipitous, because not only was it beautifully located, but just down the hill, at the edge of the water, is an excellent outcrop of fossiliferous limestone.
After unloading at the cabins, we took a short, afternoon drive to see the hydroelectric dam.
The next morning we hiked along the Confederate line of advance during the Battle of Shiloh.
It was a relatively long hike, but useful in that it allowed students a feel at least for the scale of the battle, and the conditions the soldiers endured. There was also a nice museum at the end, with an interesting video and an excellent demonstration from one of the park rangers (you need to book an appointment ahead of time).
Finally, on Thursday morning, on our way back to Memphis, we stopped at the Civil War Interpretive Center in Corinth, Mississippi. The museum is excellent, especially the Stream of American History, which is abstract enough that it makes a great puzzle for students to figure out.
The map below shows the locations of the stops, and has links to the posts about each stop.
View Shiloh Immersion in a larger map