Originally Posted by KC Fish
Absolutely, it's because we are used to it. Used to the atmospheric pressure that bears down on us at all times. We like to think that we'd be an equally proficient species in space. But the truth is that our human bodies don't do worth a shit in space without the Earthly physics affecting our bodies at all times. It's an underrepresented fact of space travel. The human body just goes to shit outside of Earth's atmosphere.
Not quite true. We are not "used to" the earths velocity. There is simply nothing to get used to. You can not feel
velocity. You can feel the vibrations from velocity and you can feel things running into you, but velocity itself you cannot. When you are in a car, you can feel the acceleration because acceleration you can feel. You can feel the wind against you if the windows open because that is basically just air molecules running into you. You can feel the physical bumps in the road that the car hits on the road.
Remember that velocity is relative. When you are saying that we are moving at some speed you have to have a point of reference. When you say The Earth spins at 1,000 mph you mean relative to the center of the earth. When you say that we hurl through space at 67,000 mph you mean relative to the sun. Also our solar system travels at about 560,000 mph around the center of the milky way. And the milk way hurls through the universe at some speed relative other galaxies. But it is all relative.
And to answer Literature's other question, if the earth were to magically stop spinning and we stopped with it, we would not feel any different walking around. There would be other serious effects of it (things like the oceans changing and change in the magnetic field of the earth) but we would not really notice a physical difference walking around.