Naked Science Forum
Non Life Sciences => Physics, Astronomy & Cosmology => Topic started by: Spacetectonics on 15/01/2013 07:07:36
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Q1) If we release an apple it falls to the ground,but what about earth atmosphere? does it follows the gravity(space-time curvature)?
Q2)The circumference of the Earth at the equator is 25,000 miles. The Earth rotates in about 24 hours. Therefore, if you were to hang above the surface of the Earth at the equator without moving, you would see 25,000 miles pass by in 24 hours, at a speed of 25000/24 or just over 1000 miles per hour.
But it does not work that way for a chopper standing still above my house?why!!How gravity grab us sidewise when we are not on the surface?!(considering Space-time Curve) ::)
Cheers
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Q1) If we release an apple it falls to the ground,but what about earth atmosphere? does it follows the gravity(space-time curvature)?
Yes. Note: Don’t confuse gravity with spacetime curvature. They are not the same things.
Q2)The circumference of the Earth at the equator is 25,000 miles. The Earth rotates in about 24 hours. Therefore, if you were to hang above the surface of the Earth at the equator without moving, you would see 25,000 miles pass by in 24 hours, at a speed of 25000/24 or just over 1000 miles per hour.
But it does not work that way for a chopper standing still above my house?why!!How gravity grab us sidewise when we are not on the surface?!(considering Space-time Curve) ::)
Because the Earth and the atmosphere move together as the earth rotates about its axis. Partly because the Earth drags the atmosphere along with it and partly because the atmosphere has momentum itself and it keeps moving because nothing is opposing its momentum.
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The helicopter, your house and the air are all attracted towards the center of the Earth.
If the helicopter is 1 mile above your house (above the equator) with GPS auto-pilot, over 24 hours it will travel 25,003 miles, or just over 1000 miles per hour.
The helicopter and atmosphere (on a still day) start off with the same initial velocity as the ground, so the helicopter doesn't have to accelerate by 1000 miles per hour to sit above your house.