# Galileo and a rotating earth

1. Feb 14, 2013

### Thecla

Galileo tried to convince church leaders of the correctness of the Copernican Theory. He had difficulties because the leading thinkers of his day couldn't believe in the rotation of the earth on its axis. They thought that a spinning earth would be easily felt and the earth must be stationary.
In normal day to day life we don't feel the earth rotating. Could we ever "feel" the rotation of the earth if it rotated on its axis every 24 minutes instead of 24 hours? I am not talking about how the evolution of life on earth would be different or the weather patterns would be different if it rotated much faster, but pure mechanics of doing things. like walking down the street or driving a car. Is there any rotational speed that would throw people off the earth's surface, like a child thrown from a merry-go-round, if the earth rotated faster?

2. Feb 14, 2013

### Drakkith

Staff Emeritus
At that rotational speed I'm not sure the Earth would be able to hold itself together. At a minimum it would be horribly deformed into an oblate spheroid and there would be a very large difference between the force of gravity felt at the poles with that felt near the equator, with the latter being much less than the former.

3. Feb 14, 2013

### cepheid

Staff Emeritus
Yeah, and it corresponds to about 17 rotations per day (or greater), if I did my math right.

Edit: at the equator, I mean.

4. Feb 14, 2013

### phinds

Hey, don't be talking about my gut like that !

5. Feb 14, 2013

### Drakkith

Staff Emeritus
How your gut holds together under those stresses is one of the great unsolved mysteries in science. I vote for dark matter. You eat everything.

6. Feb 15, 2013

### xAxis

Even if the earth retained its shape, we would definitely feel it. Our angular velocity would be 60 times greater, and centrifugal force is proprtional to the square of it.
Average person from far north of the USA would lose about 7 kilograms just by traveling to New York.

Last edited: Feb 15, 2013