Top 10 Commander Chris Hadfield Videos from the ISS!
It goes to 11, since there’s a bonus video.
Category Archives: Other science
An Unfortunate Coincidence
I read Joe Hanson’s post The Evolution of Tyrannosaurus rex this morening (i.e. yesterday, relative to this appearing) about the correction of the posture of Mr. T as depicted in various media over the years.
[T]he tail-dragger myth persisted, and in 1988’s The Land Before Time (which, let’s face it, is where most of us first formed our images of dinosaurs) Sharptooth was frustratingly upright
I remember thinking that I’m not going to face it, because it’s quite possible our first glimpse of dinos, including an upright T. rex, was (as it was for me) in a movie was as a stop-action clip made possible by the wizardry of Ray Harryhausen.
And, later in the day, it was announce that Ray had passed.
So here’s a video, which includes an upright, posturically-incorrect, rexie, along with similarly-depicted Allosaurs, Ceratosaurs and Sceraptosaurs.
[A] compliation of every Ray Harryhausen animated creature in feature films, presented in chronological order.
Read the complete creature list at http://www.harryhausen.com
Look Very Closely
There's Antimony, Arsenic, Aluminum, Selenium …
Check out all three pages.
There's a Catch to This
Kill Thrill: Watch Animals Capture Their Prey in Slow-Mo
Animals use a variety of strategies to capture prey, some of which clearly kick ass (see the sniper-like archer fish, which spits at flies from underwater). But these strategies are even more awesome when scientists film them and produce super slow-motion replays, complete with awkward faces and outtakes. Here’s a gallery of some of nature’s finest prey-capture instant replays.
You Owe Me 15 Grand, Pal
Pretty neat what happens when she reverses the polarity halfway through…
Bursting Your Bubble Redux
Making Snowflakes
The Mystery of Magenta, and of Light Mixing
Interesting and fun, but about 35 seconds in he says that you can’t combine photons together, and that’s just plain wrong.
I know that you can’t mix photons together. So you can’t take a blue photon and a green photon and mix them together to get some other photon. That just doesn’t happen.
Except that it does. You have to do this in a nonlinear medium like certain crystals, but it can be done. It’s called sum frequency generation.
Energy is conserved, so in the example given a 2.5 eV (green) photon added to a 3 eV (blue) photon will result in a 5.5 eV photon, which will be ultraviolet. The addition is not what we see with our eyes, since that’s a different process.
A special case of this is where the two photons being added are the same frequency. This is called frequency doubling, and a common (amongst geeks, at least) example of this is a green laser pointer. The source inside of this is actually an infrared laser emitting at 1064 nm, which then passes through a doubling crystal to produce light at twice the frequency, or half the wavelength: 532 nm. (and cheap laser pointers may not filter the IR from the output, which can be a danger)