# Tag Info

7

I don't think the question can be answered because you don't say how the orbital energy is to be dissipated. However it's quite interesting to compare the orbital energy with the energy required to boil the ice. Let's suppose our ice supplied is aboard the International Space Station, so they are at an altitude of $h$ = 300km and moving at an orbital ...

0

There are two big problems with this question: Some kind of astronomical observation is needed. Imagine intelligent aliens living on a habitable exoplanet that has a very thick and very opaque atmosphere and that has a slightly higher value of g than our 9.80665 m/s2. The thick, opaque atmosphere means they cannot see the stars or even their sun. They ...

0

You could imagine this. Say you have a railgun on the moon (to avoid atmosphere) that fires a projectile at the spacecraft. The projectile bounces elastically off the spacecraft, transferring twice its momentum. If you are happy to accelerate in exactly the correct direction, it could return to the moon to be fired again. The momentum is transferred to ...

2

The issue here is that the initial momentum needs to come from somewhere. I suppose, if we could track the momentum of various things in space, we could "hitch a ride" from it. Like netting a comet or taking advantage of space debris striking the craft. That's a properly analogous situation to your basketball/skateboard system. However, you seem to be ...

1

There is actually such a mechanism that you're describing. The means to achieve that is through radiation pressure from light. This is called solar sail, and would achieve space exploration without having to expend proppelents for the main movement production.

1

Well most texts tell you that light is an EM wave and will give you an image of a sine wave and then they start to define things like frequency, amplitude etc., leaving you to think that EM waves are like that zig-zag thing on the graph. But actually in nature what oscillate are the fields. The E-field, i.e. a region around a charged particle. When a charged ...

1

With Regards to the Energy Conservation To turn a turbine requires energy. A turbine will convert the energy that is required to turn it (mechanical energy), into another form of energy (electricity). This is why there is resistance in turning a turbine; if there was no resistance and it produced energy, it would defy the law of conservation of energy. ...

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You want to put in joules and take out watts? Watts = joules/second. Done. As for friction, if it is turning in space, why is there any?

2

Check out this post over at NASA. It's directed towards kids but it gives a good overview. Most relevantly, "In space, batteries must work in both very hot and very cold conditions. They must withstand a lot of radiation from the Sun. They must work in a vacuum without leaking or blowing up! They must be rugged enough to withstand the severe vibrations ...

1

By way of analogy, think of what happens when you blow up a balloon and let it go. It spins around, goes this way and that. A balloon rarely goes straight, without spinning. The thrust from a balloon rarely goes through the center of mass. It rotates and translates. Because the thrust vector itself turns with the rotating balloon, the translation is not ...

0

Apparently it's better to ask questions only one-at-a-time on this site, but I understand why you did it like that; these are all related. Now, these are some really interesting questions, hopefully I can help you out (there's some interesting subtleties to consider due to the thrusters). Answer 1 If you fire only B, then it will rotate, and it will ...

3

People don't immediately compress because the body is more or less a pressure vessel. It's not a very good pressure vessel for dealing with vacuum, but it's something. It's your body's resistance to pressure that lets you do things like spray bodily fluids (from your mouth, or from your bladder, or from your arteries). When my wife was in labor with my son, ...

1

Then why do airlocks do this in movies? Good question. Why do space vehicles have wings in movies? Why do producers have all kinds of non-physical nonsense going on in scifi movies? The answer to these questions is simple: Because they make for such cool special effects. Don't take anything you see in a bad scifi movie as real. Real airlocks currently ...

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Permeability is Constant of negative energy. Its counterpart-permittivity- is Constant of positive energy. Interaction between both of them create a physical entity called SPACE-TIME geometry. It is this space-time geometry which makes the speed of light finite. Negative energy attracts inward and acts as glue to make the universe finite and positive energy ...

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Objects exiting the spacecraft have inertia - they will continue to move at the same speed as the spacecraft. There is nothing to slow them down enough to drop them out of orbit, so they remain orbiting the earth.

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