[walterbell]

Thanks, this was interesting:

"The changes in the Earth’s orbital tilt and precession (or the wobbling motion) occur because of gravitational forces emanating from other bodies in the solar system. To understand exactly what happens, picture a spinning top when it is slightly disturbed. Just like a top, the Earth too wobbles slightly about its rotational axis. This tilt changes between roughly 22 and 25 degrees about every 41,000 years, while the precession varies on about a 26,000-year period. These cycles have been determined by astronomers and validated by geologists studying ocean sediment records. "

Are there any recommended references on this 26,000 year cycle?

[NathanKP]

Here is a pretty decent documentary about it: https://www.youtube.com/watch?v=2OVAkMrdeKI

[walterbell]

Thanks!