3 ms·
Newtonian mechanics does not have absolute speed. We can only say A is moving at 5m/s relative to B. But Newton does have absolute acceleration. So we can say
by cuteboy19 5y ago
Newtonian mechanics does not have absolute speed. We can only say A is moving at 5m/s relative to B.
But Newton does have absolute acceleration. So we can say
A is accelerating at 5m/s² without even thinking of B.
Since a rotating body accelerates, we should be able to say that the earth rotates without even thinking of the sky.
The proof does exactly this. Looking at a gyroscope is sufficient to prove that the earth rotates. No need to look at the sky
- nyc111 5y agoBut the gyroscope looks at the sky, it points at the same star, right? This is how the proof works.
- cuteboy19 5y agoImagine that you live in a starless void. Could you still prove that the earth spins? Yes, simply point the gyroscope towards an arbitrary direction and repeat the same process as in the proof. If the earth doesn't spin, then the gyroscope would point at the same direction always. But if it does spin then it would show those circles.