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Post by theteacher on Mar 8, 2011 10:53:10 GMT -4
For as long as the rocket fires, that wall will continue to press on you and carry you along with the rest of the ship. Maybe it would be better to exchange "carry" with "accelerate"?
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Post by ka9q on Mar 10, 2011 9:49:37 GMT -4
For as long as the rocket fires, that wall will continue to press on you and carry you along with the rest of the ship. Maybe it would be better to exchange "carry" with "accelerate"? Either will do, I guess. I was trying to make the point that before the rocket is fired, you and the ship are both in free fall. You can float freely around the inside of the ship without necessarily coming in contact with the walls. But when the rocket fires, it will accelerate the ship and eventually the inside wall will hit you. If you didn't know that the ship was firing its rocket you might well believe that "gravity" has returned because that's exactly what the subjective experience would be like. You can't distinguish between a) sitting inside a sealed box motionless on the earth's surface and b) being inside that same sealed box somewhere in space as it is accelerated by a rocket engine with a thrust of one pound force per pound mass (or 9.8 newtons of force per kg of mass). Also, you cannot distinguish between a) floating weightless inside that sealed box somewhere in space and b) floating weightless inside that box in free fall near the earth. They would be distinguishable if 'b' ends with a rather sudden stop, of course. But that's what's so neat about an orbit -- there doesn't have to *be* that sudden stop. If you have enough horizontal velocity, you can free-fall indefinitely without ever actually hitting the earth.
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