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[–] 10 points 1 year ago* (16 children)

theyd also need something to protect them from the friction and resulting heat of air brushing by at terminal velocity tho, i assume?

oh no wait, im making it too realistic

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  • [–] 13 points 1 year ago (14 children)

    Terminal velocity for a human is not fast enough to cause air to heat up. You'd probably get frostburn instead.

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  • [–] 18 points 1 year ago (6 children)

    If you're jumping from a space station then you'd be traveling at orbital velocity when hitting the atmosphere which is plenty fast enough to generate heat.

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  • [–] 7 points 1 year ago (5 children)

    Unless the space station is not orbiting. Maybe it's a mobile one like the Desthstar.

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  • [–] 6 points 1 year ago (4 children)

    ... the death star orbits. The timer for the rebels to blow it up in a New Hope was how long its orbit would take to clear the moon in its path to the rebel base. The battle of endor was fought over the new death star in orbit over the moon.

    Yes, the death star is capable of warp, but that just puts it into orbit over different things.

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  • [–] 3 points 1 year ago* (last edited 1 year ago) (3 children)

    Yes it orbits in the movies, that doesn't conflict with anything I said. I'm describing a scenario where it doesn't (which doesn't happen in the movies).

    A space station with the ability to achieve orbital speeds on it's own power means it can also negate orbital speeds, before you jump off. And presumably regain them afterwards, if it doesn't want to also plummet down to the planet.

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  • [–] 2 points 1 year ago (2 children)

    Your example was for a space station that doesn't orbit and you used the death star for that, which does orbit. Does that make sense to you? Cause it's baffling me

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  • [–] 4 points 1 year ago* (1 child)

    No, it was not an example of a station station that doesn't orbit. It was an example of a mobile space station. I agree it would be baffling to read my comment that way.

    Here is a rewording if that helps: You could jump off of a station station without worrying about orbital velocity if it wasn't orbiting. To have a space station that doesn't orbit, it would have to be a space station with engines, so that it can cancel that velocity. For an example of a station station that has engines, you can look at the Death Star.

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  • [–] 1 point 1 year ago*

    Oh! That's the confusion. The Death Star wouldn't be able to cancel out is orbital velocity in any meaningful time frame, but I get what you're saying. Its engines are tiny compared to its size.

    It's comparable to saying the ISS is a mobile space station because it can use the engines on the Soyuz to adjust its orbit (in terms of thrust to weight, not mechanics, since the Death Star has its own engines)

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  • Heating on reentry is actually due to compressing the air in front of you, not friction. Falling from orbitall height will absolutely cause you to heat up the air in front of you, even as the air paassing you by is doing you no harm.

    Though, if you smash into the atmosphere at orbital speeds, it's probably going to do you some harm as it tries to force you back down to TV.

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  • [–] 2 points 1 year ago (5 children)

    Hold up. Didn’t some guy drop balls off a roof to show that things fall at the same speed?

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  • [–] 9 points 1 year ago (3 children)

    So, yes and no. Acceleration due to gravity impacts all objects equally. With no air resistance, on earth, everything speeds up at 9.8m/s/s. But, that "no air resistance" is a big asterisk. This is why, say, parachutes work. It's also how we get terminal velocity. Often misinterpreted as "how fast you'd have to go to die from a fall" it's actually "how fast you need to go before the drag from your air resistance is a force greater than or equal to gravity"

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  • [–] 3 points 1 year ago (2 children)

    Right. That all makes sense. So the air resistance is what is also causing it to heat up. I still don’t see why a person wouldn’t do that.

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  • [–] 12 points 1 year ago (1 child)

    So, multiple options here. Skydivers regularly hit terminal velocity, as fast as they'll go in atmosphere, before pulling their chutes. At these speeds, heat from friction isn't enough to worry about. Once again though, if you're coming down from space, that "in atmosphere" asterisk goes away. If you're dropping from a satellite, you're going at speeds necessary to orbit, and you don't have anything slowing you down until you hit the atmosphere. Suddenly your terminal velocity is way lower than infinity, and the friction you're feeling from the atmosphere is INTENSE, rapidly turning that speed into heat

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  • [–] 4 points 1 year ago*

    I recently had this explained to me, terminal velocity is falling versus the force of the air pushing back on you, right? In vacuum you just keep accelerating, in atmosphere the air pushes back against you falling, limiting your speed

    That force follows the rule that force (of air pushing back) is equal to acceleration (9.8m/s/s) times mass

    So different weights fall at different speeds.

    Half of the replies to me when I said what you said were

    Idiot, f=ma

    Or similar

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