Unfortunately, the destruction is so fast you don’t see it. Begging for a high-speed camera.
h/t @drskyskull
Category Archives: Video
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.
The Vanishing Train
Vanishing train defies space and time
It’s a model train like no other: when it enters a tunnel, it seems to defy the properties of space and time. But of course, what you’re seeing is just an illusion. Do you know what the trick involves?
Doesn’t seem like there’s enough space to have a curved and slanted track, but that may be because one thinks it needs to be carried out within a small space. The train takes almost as much time to emerge from the tunnel as to go around the track, so I don’t think it’s a perspective illusion of the tunnel being longer than it appears. My guess is that there’s a second track below the table. The train enters, veers right and down slightly and follows a large loop below the table, re-emerging inside the tunnel.
Burn, Baby, Burn!
You Owe Me 15 Grand, Pal
Pretty neat what happens when she reverses the polarity halfway through…
I'm Still Not Ashamed
I’ve already explained that I’m not embarrassed about this — it’s tied in with something Sean mentions around the 10:30 mark: you really don’t have to worry about this in order to do quantum mechanics. Apart from the embarrassment bit, I don’t think I have much (if any) disagreement with any other point. This is good stuff.
Pole Dancing — With Quadrocopters
Video: Throwing and catching an inverted pendulum – with quadrocopters
As you can see in the video embedded above, at the end of Dario’s thesis two quadrocopters could successfully throw and catch a pendulum.
Many of the key challenge of this work were caused by the highly dynamic nature of the demonstration. For example, the total time between a throw and a catch is a mere 0.65 seconds, which is a very short time to move to, and come to full rest at, a catching position.
Another key challenge was the demonstration’s high cost of failure: a failed catch typically resulted in the pendulum hitting a rotor blade, with very little chance for the catching quadrocopter to recover. A crashed quadrocopter not only entailed repairs (e.g., changing a propeller), but also meant recalibration of the vehicle to re-determine its operating parameters (e.g., actual center of mass, actual thrust produced by propellors) and restarting the learning algorithms.
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)