OK Go is a band that’s a bit hard to define; Wikipedia lists them as “American alternative rock” which is possibly the least specific adjectival phrase I can think of (besides maybe “mostly carbon-based”).
They make ridiculously catchy songs, and are better known for their quirky and astonishing videos. Maybe you saw the one they did for “Here It Goes Again” where they do synchronized treadmill calisthenics. Or maybe “The Writing’s on the Wall”, which I featured on the blog, because of my love of optical illusions.
Well, rejoice! They’ve just released a new video, and they have honestly outdone themselves. This is truly amazing, so I’ll just let you watch it first before I talk about it! Behold, “Upside Down and Inside Out”:
Ha! See? I told you. Delightful.
So what did you just see?
As the video claims, they didn’t use wires or green screen for this. What they used was… SCIENCE!
Or in this case specifically, PHYSICS. They filmed this video on an airplane capable of making steep arcs up and down in the air, over and over again. Near the top of the arc, the only forces acting on the plane are gravity and air resistance. The engines are cut back and the plane pitched to an angle that exactly compensates for air resistance, leaving only gravity acting on the plane.
The plane then follows a ballistic trajectory, governed only by Earth’s gravity. The plane continues up, tops out, and then starts to fall. A few seconds after that the engines are throttled up, the plane pulls out of the dive, levels off, and it’s ready to start again.
During those briefs seconds around the top of the arc, the plane and all the objects inside it are freely accelerated* by gravity at the same rate, so to anyone inside, they feel weightless! If you hold up a ball in front of you and let go, it’ll appear to float there. Really you’re just all traveling along the same ballistic trajectory, but your body will feel like it’s freely falling.
And that’s the trick to this video! They built a mock airplane cabin inside of a Russian Ilyushin-76 airplane (flown by the Russian S7 airlines), and filmed it as the plane made a series of arcs. So when you see them floating around weightless, well, that’s no trick. Except a trick of… SCIENCE.
But there’s so much more going on than just that!
For example, the weightless periods in this particular flight lasted about 27 seconds. That’s about the most you can do in this case. And the price you pay to be weightless at the top of the arc is to pull out at nearly twice the force of gravity. That happens pretty suddenly, going from 0 to 2 gs rapidly. Everything falls to the floor of the cabin, and if you’re not ready for it, you will too.
So how did they record a video that’s much longer than 27 seconds? I asked exactly this of Damian Kulash, the lead singer and guitarist for OK Go, and he told me what they did. It’s quite clever.
First, they created each “scene” that they could do in the weightless time allotted. Given the tempo of the song, each scene is 21 seconds long. They then performed the routine slightly slower (at 21/27 = 78 percent of the actual speed), then sped it up in post-processing! This also eliminates another issue: In zero-g, it just looks like everything has been slowed down, like it’s been faked. Speeding up the footage gets rid of that problem.
Mind you, this entire video was done in one continuous shot! They didn’t cut and redo any scenes; it was filmed in one take in the order you see it. At the end of each scene they braced for the feeling of gravity to come back, waited it out, then started the next scene once everyone was weightless again. After they were done, they edited out the parts with them standing there, then used a morph to smooth over the transitions. Those jumps are hard to notice, actually. See if you can spot them! Hint: There are six of them.
Amazing.
Some of the choreography (most notably with the “stewardesses”; I loved that retro bit, especially since I once had a car the exact color of their uniforms) looked like it could only have been dreamed up in weightlessness, so I also asked him how the heck they planned this.
It turns out they did it in several steps. They planned as much as they could, then booked a week of test flights (six flights in total) in Russia to try things out. They came back home, worked out the details, then went back to Russia for a week of six more flights to rehearse, then a week of eight flights to record it.
Easy, right? Yeah, not so much. Besides the amazingly detailed choreography, they had to deal with… well human digestive issues. There’s a reason NASA calls its zero-g astronaut training aircraft the Vomit Comet. I asked Kulash about this, and he told me, “… yes, lots of puking.” But apparently that was only at the beginning, and after a while they all got used to it (with the help of some anti-nausea medication).
They are made of sterner stuff than I am. I flew on a fighter jet for my show Bad Universe a few years ago, and while the high acceleration didn’t bug me (in fact I enjoyed it), the transitions are what killed me; going from one g to four in a fraction of second destroyed my middle ear. I was sicker than I ever have been in my life (though I’ll brag I didn’t throw up… but it was a very, very near thing).
But what OK Go did? Geez, I’d throw up every piece of food I ever ate in my entire life. Kudos to them.
I also loved the scene with the balloons at the end. They spent a lot of time in stores looking at products that might behave in funny and odd ways in weightlessness, and popping balloons filled with liquid was a stroke of genius. The patterns the liquid makes once the balloons are popped are like lessons in hydrodynamics. It’s beautiful.
Like the illusion-based “The Writing’s On the Wall” video, “Upside Down and Inside Out” is like a lesson in perception, as well as one in physics. I can see high school science teachers using this video to get their students to think differently about motion, forces, and even on how to plan something on this scale; creating experiments in physics is much like planning a video like this.
You might say… they fall along the same trajectory.
My congratulations to the band and their crew, and my thanks to Kulash for contacting me about it. Getting an email from an artist you admire, much like lowering the effect of gravity, is a really great way to put a bounce in your step.
* In physics, deceleration is just a negative acceleration, so we tend to just call it all “acceleration”; if you’re slowing down then you’re being negatively accelerated or accelerated in a different direction.
from Bad Astronomy http://ift.tt/1QbVhIy
via IFTTT
沒有留言:
張貼留言