Water Droplets In Orbit On the International Space Station 159
BuzzSkyline writes "Astronaut Don Pettit, who is aboard the International Space Station right now, puts charged water droplets into wild orbits around a knitting needle in the microgravity environment of the ISS. A video he made of the droplets is the first in a series of freefall physics experiments that he will be posting in coming months."
Re:All about energy (Score:5, Informative)
It's worth remembering that the V2 effort helped Germany lose WW2 - the energy needed to produce the fuel meant shortages of fuel for aviation and transport.
That is a LOL moment. If you're going to rewrite engineering history as part of tiresome environmental guilt trip prattle, don't do it on a website populated with engineers. Wrong both at the microscale in that A4/V2 didn't burn avgas or diesel or petrochemicals at all, wrong at the macroscale that every A4/V2 ever launched added together adds up to frankly not very much fuel. Those were relatively tiny SRBMs roughly similar performance to a modern MLRS not a thundering herd of saturn-5s.
fundamental physics research would simply awe the likes of Feynman ... if they were around to see it.
He didn't die that long ago, you know. Yes he chilled out with the manhatten project dudes as an extremely young man hanging with middle aged and old men. You may have missed he was on the Challenger loss commission in the 80s, etc. Even Dirac didn't die until the early 80s. If you want to surprise a physicist, find someone who croaked before WWII not a recently deceased.
I don't think they'll have a choice, though (Score:5, Informative)
I don't think they'll have a choice, though. The problems are that:
1. As Douglas Adams put it, "Space is big. You just won't believe how vastly, hugely, mind- bogglingly big it is. I mean, you may think it's a long way down the road to the chemist's, but that's just peanuts to space." So you'll need incredible speeds to get anywhere interesting even within one lifetime.
2. In that domain, Albert Einstein is the biggest mofo. He'll be a bigger pain in your dreams of space domination than Mace Windu.
Everyone has some half-baked solution like "well, just keep accelerating at 1g for a few years, and you'll be at 0.9c". What they don't think about is what kind of energy you need to keep doing that. Even fusion won't cut it.
At 0.9c, every gram of your ship packs enough kinetic energy as a 29 kiloton atom bomb. By comparison, the bomb dropped on Hiroshima was 15 kilotons. Even at near perfect efficiency, you'd need two of those to accelerate just one gram of matter to 0.9c.
If you want to do a round trip, you have to accelerate then decelerate in one direction, then accelerate and decelerate again in the other direction. So multiply by 4.
And that's with a cannon kind of a setup, so you only accelerate that one gram of matter, not also the rocket and fuel and whatnot. If you carry your own fuel and engines, you'll have to accelerate those too.
Doing it slowly or doing it fast, won't change anything. At the end of the acceleration period, each gram of your ship will still pack that much kinetic energy, so still that much energy will have gone into accelerating it.
Take your choice of realistic engine. Orion? If you took all the atom bombs ever made, they still wouldn't be enough to push even a modest capsule for a one way trip to a good habitable planet. Engine with uranium salts in water? Ditto, plus you now have to accelerate the water and the moderator bars too. Ion thrusters? Well, you still need that much energy piped into accelerating the ions. You'll still need a reactor that produces that much energy, and there just ain't enough uranium produced in the world for that.
The point is that even the next generation still ain't going anywhere. It doesn't matter if they want to push space travel or not, they're still not going to put a guy farther than maybe Mars. Unless some miraculous new source of energy is found -- note that even Star Trek essentially has infinite energy and stored as densely as antimatter -- the next generation is just tied to this rock as we are.
Re:Is this experiment about gravity or electricity (Score:4, Informative)
Orbit is usually associated with gravity but it can happen with any attractive force.