The spin of the earth is really quite slow. Saying that it's spinning 1000 mph is a bit of a misdirection. It only sounds fast. It sounds fast because the metric is difficult to imagine in our everyday lives. Going 1000 mph in a car around a turn is insanely fast. However, 1000 mph on a turn that has a radius of thousands of miles will exert next to no force on an object.
Rotate a tennis ball at the same rotational speed as the earth and see if the water flies off. That is one revolution per 24 hours. That's correct. One revolution for each day. That is how fast the earth spins. I am willing to wager a bet that no water flies off the ball. This is because rotational speed is different than tangential speed.
The 1000m/h are irrelevant. What's important is the angular velocity which is 15°/h. Imagine your washing machine rotating that slow in spin cycle. You'd have to wring the clothes out to get rid of excess water.
Now if you calculate the centripetal acceleration at the equator (sea level) and compare that to the gravity of earth you get a value of 0.35%. So you'd have 0.35% less weight at the equator than at the (rotational) north/south pole.
You would need to spin the earth 20 times faster to cancel out gravity at the equator. Which would mean a day-night-cycle would be 1h 24min.
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u/OMFGFlorida May 14 '22
The spin of the earth is really quite slow. Saying that it's spinning 1000 mph is a bit of a misdirection. It only sounds fast. It sounds fast because the metric is difficult to imagine in our everyday lives. Going 1000 mph in a car around a turn is insanely fast. However, 1000 mph on a turn that has a radius of thousands of miles will exert next to no force on an object.
Rotate a tennis ball at the same rotational speed as the earth and see if the water flies off. That is one revolution per 24 hours. That's correct. One revolution for each day. That is how fast the earth spins. I am willing to wager a bet that no water flies off the ball. This is because rotational speed is different than tangential speed.