Water filters light. The more water that's above you, the more light is filtered out before it can reach your eyes. The deeper you go, the more this effect alters which colors you can see and how those colors appear
, writes Andrew David Thaler at Southern Fried Science. Even at a depth of just 5 meters, reds and oranges become difficult to distinguish from one another. — Maggie
Spotted at Comic-Con: Spectra, a series of well-done, smart comics about physics from the nonprofit American Physical Society. The art is great, the content is great, and leads to good, illuminating experiments you can do with household objects. They're free downloads, along with supplementary classroom materials, and you order signed hardcopies, too.
Spectra: Comic Books
Indispensable wisdom from the XKCDverse: "After falling from seven stories, the mass of bouncy balls would be moving at about 20 meters per second.... If you wanted to be sure of killing someone, you'd need 3,000,000 of them
—enough to fill a large room—to guarantee that the target would either be crushed to death by the impact or buried too deep to dig themselves out."
This is video of a talk given last year by David Dixon, assistant professor of math, science and engineering at Saddleback College in California. He used to work in the Physics Department at California Polytechnic State University, which, like many physics departments around the world, received loads of correspondence from non-scientists who thought they had come up with earth-shattering, game-changing hypotheses that needed to be shared.
Now, sometimes, laypeople come up with good ideas that should be explored. But many of these letters are better classified as the work of cranks — folks who had big ideas, cared deeply about those big ideas, but who were dead wrong ... and utterly impervious to the idea that they might be wrong.
Read the rest
Andy from the Royal Institution made a large, suspended Möbius strip out of rare-earth magnets, then cooled down an object until it became a superconductor, and set it levitating and running around the track. The result is amazing, plus Andy's explanation is cogent and fascinating. Plus, gravity-defying levitation!
Levitating Superconductor on a Möbius strip
Steve Mould, Britain's Brightest's "science guy," showed that if you put coil a 50' chain
of magnets in a jar and then casually toss out one end, the whole chain goes berzerk leaps and cavorts like an innocent colt on crystal meth, defying gravity and gravitas. In this video, Earth Unplugged gets Steve to explain what's really happening.
Amazing bead chain experiment in slow motion - Slo Mo #19 - Earth Unplugged
There is nothing wrong with adding ice to scotch,
writes Kevin Liu at Serious Eats. In fact, a little water can change the flavor profile of the drink for the better. What's more, chilling your scotch won't dampen down the aroma. A chilled drink won't be flinging off scent molecules left and right, but it will warm up enough from your hot breath to get the chemistry of scent where it needs to go — and to give you the flavor experience you want. — Maggie
In 1971, this ferret played a key role in the construction of particle accelerators at Fermilab's Meson Laboratory. As sections of vacuum chamber were connected together, Felicia would run through them, dragging a string. After she had carried the string all the way through, researchers would use the line to run a rag doused in cleaning solution through the long, narrow tubes.
Particle physics is seldom this adorable, and Felicia became a media star — until her retirement in December of 1971 (scientists replaced her with a vacuum-chamber-cleaning robot). She died the next year of an intestinal abscess. But her memory lives on.
Read about Felicia in the Fermilab archives
Thanks, Jennifer Ouellette!
Guidebook for the Scientific Traveler
, published in 2010 and written by Duane Nickel, promises to be a tour guide to chemistry and physics points of interest all across the United States. (Thanks Tim Heffernan!) — Maggie
The physics blog Skulls in the Stars has answers to your rainbow-related questions
. Among the fascinating things we learn here — each color in a rainbow represents the light reflected by a separate group of raindrops; skydivers can see circular rainbows; and the famous double rainbow
happens when light bounces off the inside of a raindrop not just once ... but twice. — Maggie
If you've ever spent much time in American farm country, then you've probably noticed that there's a strong tradition there of coating barns and outbuildings with red paint. Why?
Because nuclear fusion.
Okay, the actual answer is simply because red paint has long been a cheap color to buy. But, explains Google engineer Yonatan Zunger, there is some really interesting physics lurking in the background of that price point.
What makes a cheap pigment? Obviously, that it’s plentiful. The red pigment that makes cheap paint is red ochre, which is just iron and oxygen. These are incredibly plentiful: the Earth’s crust is 6% iron and 30% oxygen. Oxygen is plentiful and affects the color of compounds it’s in by shaping them, but the real color is determined by the d-electrons of whatever attaches to it: red from iron, blues and greens from copper, a beautiful deep blue from cobalt, and so on. So if we know that good pigments will all come from elements in that big d-block in the middle, the real question is, why is one of these elements, iron, so much more common than all of the others? Why isn’t our world made mostly of, say, copper, or vanadium?
The answer, again, is nuclear fusion.
You can read the full story on Zunger's Google+ page. In my experience, white is another really common barn color, due to the fact that whitewash — a paint made from calcium hydroxide and chalk (which is also calcium) — is way cheap, as well. Calcium is also one of the most abundant elements in the Earth's crust ... clocking in at number 5, right under iron in the top 10. I'm sure there's some different science that accounts for the high concentrations of calcium on our planet, but the same principal applies. Cheap paint is paint made with abundant (and easily accessible) elements. And abundant elements happen because of physics.
Image: Red Nebraska Barn, a Creative Commons Attribution No-Derivative-Works (2.0) image from 50779843@N03's photostream
Color is just a happy side effect of physics. So Canadian scientists are turning to The Canadian Light Source synchrotron, a particle accelerator in Saskatchewan, to help them figure out what color extinct duck-billed dinosaurs actually were. By putting a 70-million-year-old skull into the accelerator, they'll be able to figure out what molecules — from pigments to melanin-producing cells — are still present in the fossil. Francie Diep explains how it works at Popular Science
. — Maggie
Geoscientist Matt Kuchta explains why wet sand makes a better castle than dry sand — and what you can do to make your sand fortress even more impenetrable. Hint: The secret ingredient is window screens.
Honey, maple syrup, all those delicious gooey, gloppy things have some really interesting physics behind them, says Adam Becker at New Scientist. Viscosity alone can't explain the way strands of syrup stretch and drizzle as you pour them
. Instead, when we see a difference between pouring honey and pouring water, what we're really seeing is the effects of tiny ripples in the honey. — Maggie
The other night, Joshua Foer posed this question was posed to a table full of science journalists. Most of us started talking about friction, and/or possibly something to do with the little flanges on either side of a train wheel.
We were all wrong.
This is a Richard Feynman video, yes, but it's more about mechanics than physics. Turns out, you can learn a lot about how trains stay on the track by looking under your own car.