Tuesday, August 5, 2008

Testing Physics

Um, yeah. There's really no way to display this picture without giving away that I went skydiving this past weekend, is there?

Basically, this is something that I've wanted to do even back in New Zealand, but we just never got around to it. A few other students here in the program were keen on going, though, so we joined up and finally did it halfway towards Sacramento from the Bay Area. Mind it was $100 for a tandem jump from 13,000 feet, which is a relative steal as far as these things go...
Our motley crew, waiting for the plane to take us up. Mind I didn't notice at the time that I was the only one of us with a purple harness; this was only pointed out to me later...

It should also be noted that it turns out that the sort of people who decide to be professional skydivers are really the sort to get excited upon the word that they're ferrying a bunch of students working at the SETI Institute. As in they get very much into the joke of which one of them we've come to take away, and appreciate responses like "sorry, we're only looking for intelligent life..." and "I could tell you the truth [about aliens], but then I'd have to kill you."

Which raised the obvious question in my mind of why exactly people who professionally do SETI and people who professionally skydive are probably considered mildly crazy (probably in slightly different ways, but not much), and why at the same time you would trust someone society at large considers a bit crazy to jump out of an airplane with you and make sure you land safely. But I digress...
On the ride up- the guy sitting in front of me was the guy who took all the pictures you see here (I ordered them, seems kind of silly to go skydiving and not have pictures!) and the guy behind is the guy who operated the parachute and all that... This plane btw was a little one, just big enough to hold 15-20 people, and we were sitting crammed in on two benches by the window like they do in WWII movies.

And because it's inevitable to be asked, no, I really wasn't scared at all- there might have been a bit of a "huh, I'm actually going to do this" thought when the plane was taking off but I never gave it another thought since.

To be honest, I am almost worried sometimes about my inability to get scared about things a lot of people get really freaked out about. This started when I was in New Zealand last year, where I never thought I could do bungy jumping but ended up realizing that rationally there's nothing to be scared of. You know the physics and how it works, you know the statistics of something happening, so why be afraid?

Skydiving is, to me, the same idea- you are about twenty times more likely to die in a car accident than jumping out of a plane and you know the physics works, so what is there to be afraid of? Just a simple kinematic equation is all.

(Yes, I realize I'm essentially saying something along the lines of learning physics helped me master my fears. I don't think that was the intended consequence, but it's definitely a nice one.)
So for anyone who is curious, in my experience it is a lot easier to skydive versus bungy jump. This is because first of all you don't have much time to think in skydiving- they open the door and everyone hops out in pretty quick succession- and because unlike bungy jumping the ground is really, really far away so that instinct of "maybe this isn't the best idea" doesn't cut in as much. Even better, in skydiving once you hit ~50 mph (terminal velocity is 120 mph when you're on your tummy) the wind resistance makes you feel like you have some weight, meaning after about a second you don't even feel like you're falling. You're just... floating, I guess, which was so great that I spent the entire time alternating between laughing and grinning like an idiot.

One cool thing I really liked about all this by the way is how we did some sort of backflip on the way out, meaning I spent the first few seconds watching the plane go away. Per my frame of reference, however, it felt like I wasn't moving, so I watched the plane go up and away at an odd angle all the while thinking "huh, that's mighty interesting!" And then I got even more excited, as it was by far the best demonstration of relative reference frames I have ever experienced and physics has destroyed any chance I have of thinking normal things even when falling out of an airplane at a hundred twenty miles an hour.
Falling. It was the most absolutely lovely sensation. In fact, he photographer spent some time towards the end trying to get me to do a thumbs up or some other gesture for photographic purposes, but honestly I was only vaguely wondering who the hell this guy was and what he wanted because I wasn't even bothering to pay attention to anything more than the moment. There's just too much to process... Now I'm told if you go skydiving again it's a lot easier to figure out what's going on the second time, but we're going to ignore that line of thought because my mom still has yet to progress beyond saying "I'm glad you survived."
Parachute deployed! This is a rather abrupt stop- taking you from 120 mph to a less splattering descent is guaranteed to be- and I was frankly amazed that it was over that quickly. I was told that free fall lasts about a minute, but it definitely seemed much shorter.

And here's something that I only remembered later, on the ground, while rethinking everything. Somewhere along the way, probably right before the instructor deployed the parachute, he shouted in my ear, "do aliens exist, yes or no? I'm not pulling until you answer!!!" Such wonderful senses of humor, those skydivers... And fyi no, I didn't answer, as a. I wasn't processing what he was saying, b. it's not like he would've heard an answer due to the wind, and c. I was too busy smiling and laughing at the awesomeness known as skydiving.
Gliding through the sky, ho-hum. Still very awesome though, it lasts maybe three or four minutes and I got to steer the parachute. Pretty simple, you have two ropes, and you pull the one on the right to go right and the one on the left to go left. If you pull one of them really, really hard you go into this nice looping spiral, which is similar to the scale of a looping decent on a tall roller coaster. The only problem I had with the parachute part is your weight is essentially held entirely in check by the straps on your legs, which isn't the most comfortable thing in the world but is obviously necessary and doesn't last long so we'll let it slide.
Coming in for landing on the landing field. Landing is so gentle that we ended up standing (slight winds and you might end up sitting instead) and you're unsteady for a second or two on your feet until you remember how to deal with real ground again.

So that is skydiving, or at least the best description I can possibly give of it. I must say explicitly though, in case it wasn't clear, that skydiving is wonderful and you all should most definitely go do it when you have the chance. Trust me on this. After all, you'd trust the astrophysics student who searches for aliens and goes skydiving on the weekends, wouldn't you?


steven said...

way cool!

one question: it looks an awful lot like ohio from the air. any give-a-ways that you weren't back in the midwest?

Yvette said...

The fact that I know I'm still in California and most of the fresh produce you eat was grown here? ;-)

No really, California's different because they don't grow the standard soybeans and wheat or whatever but rather tomatoes and grapes etc. That and off in the distance at the way beginning you could see the fog rolling in from SF Bay, I noticed it before jumping.

Anonymous said...

This was certainly GREat, but I could think of hearing something about what you are doing that was even GREater, or even the GRE a test.

But do keep having fun

Anonymous said...

They sure got a great shot of your butt in that one close to the plane. ;)