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Prog47
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Let's say a single human exits the atmosphere? Why doesn't he orbit the Earth like the moon does? Why does he drift in space instead?
He doesn't drift in space. He falls back on earth. If he leaves a spaceship, he has all the orbital velocity the spaceship has, so he stays near the spaceship. It's the same thing as if you jump up and down in a train. You land on the place where you jumped off. If he leaves Earth with the right velocity and angle, he could orbit earth.Prog47 said:Let's say a single human exits the atmosphere? Why doesn't he orbit the Earth like the moon does? Why does he drift in space instead?
fresh_42 said:He doesn't drift in space. He falls back on earth. If he leaves a spaceship, he has all the orbital velocity the spaceship has, so he stays near the spaceship. It's the same thing as if you jump up and down in a train. You land on the place where you jumped off. If he leaves Earth with the right velocity and angle, he could orbit earth.
Doesn't that kind of depend on which way he was pointing - and how fast they were spinning when he let go?OscarCP said:Well: no, that can't happen like that and is a major flaw in the movie that, after all, is about "gravity."
Instead of falling down after letting go of her, he would quite slowly drift away while turning round and round the space station, in plain sight from the place where she finds refuge thanks to his sacrifice.
I'm sceptical that you could learn physics from a Sandra Bullock movie. That said, I don't think I've actually seen one.OscarCP said:Do you remember "Gravity"? The 2013 movie where two astronauts, played by Sandra Bullock and George Clooney
I know it's off topic to the OP, but this brief interview with Gravity's science adviser, Kevin Grazier, suggests accurate orbital mechanics was not a motivator for the plot:OscarCP said:...is something I would put the blame squarely on the movie makers and their science adviser(s), or on how little the former care about the advice of the latter...
Humans do not naturally orbit the Earth because they do not have enough speed or force to counteract the pull of Earth's gravity. Objects in orbit must travel at a speed of approximately 17,500 miles per hour to stay in orbit.
No, humans cannot orbit the Earth without assistance because they do not have the physical capabilities to reach the required speed and escape Earth's gravity on their own. They need the help of powerful rockets and spacecraft to achieve orbit.
Orbiting and falling to Earth are two different things. While both involve the force of gravity, orbiting requires the object to have enough speed and force to constantly fall towards Earth while also moving forward at a fast enough speed to stay in orbit. Falling to Earth, on the other hand, is when an object loses its speed and momentum and is pulled down by gravity to the Earth's surface.
Yes, humans can orbit other celestial bodies besides Earth. In fact, humans have orbited the Moon and have sent spacecraft to orbit other planets such as Mars, Venus, and Jupiter. The same principles of speed and force apply for orbiting other celestial bodies as well.
Technically, there is no limit to how high humans can orbit the Earth. However, the higher the orbit, the faster the speed and greater the force needed to counteract the pull of gravity. There is also the risk of being outside of the Earth's protective atmosphere, which can expose humans to harmful radiation. Most human-made satellites and spacecraft orbit the Earth at an altitude of a few hundred miles.