|MadSci Network: Physics|
First, the human body doesn't feel speed. Traveling down the road at 60 miles an hour in a car feels no different that flying at 500 miles per hour in a 747. It may be noisier, but as long as the speed is constant, we don't feel it. But, even if we could feel it, the difference between the speed at the equator at midnight when the planet surface is moving with the orbit and the difference at noon when it's going against the orbit is tiny. Do the math: the earth's orbit around the sun has a radius of roughly 93 million miles. Multiply that times Pi to get the circumference. Dividing the circumference by 365 gives you the number of miles per day the earth travels along it's orbit. Divide that by 24 and you'll get a little over 33,300 miles per hour. And, the difference between 32,300 and 34,300 is only about 6% per day... or about a change of 0.00007% per second. Essentially, no change at all. If you could feel that, you would probably be sea-sick all the time, as what you'd feel just turning around would be a million times stronger.
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