Naked Science Forum

Non Life Sciences => Physics, Astronomy & Cosmology => Topic started by: Astronomer_FB on 12/02/2009 13:04:36

Title: Why does the tilt of the Earth not change or move?
Post by: Astronomer_FB on 12/02/2009 13:04:36

Hi I was wondering why does the tilt of the earth not change?  The  Sun pulling on the Earth and the moon helping at times shouldn't the tilt change at the least bit?  Does Jupiter have any effect or is it to far away?

Title: Why does the tilt of the Earth not change or move?
Post by: dentstudent on 12/02/2009 13:14:19

The earth does wobble on its axis. It was discussed recently in this post:

http://www.thenakedscientists.com/forum/index.php?topic=19997.0

Welcome to the forum, by the way! All questions are welcome. Well, nearly all. Some. A few. Very special ones. In fact, please check before you post anything else. JOKE!!!!!

Enjoy the forum!

Title: Why does the tilt of the Earth not change or move?
Post by: Astronomer_FB on 12/02/2009 20:06:53

Quote from: dentstudent on 12/02/2009 13:14:19

The earth does wobble on its axis. It was discussed recently in this post:

http://www.thenakedscientists.com/forum/index.php?topic=19997.0

Welcome to the forum, by the way! All questions are welcome. Well, nearly all. Some. A few. Very special ones. In fact, please check before you post anything else. JOKE!!!!!

Enjoy the forum!

thanks but I was talking about going from 23.5 degrees to  something else like 35 degrees or something.  I did realize  that the earth wobbles on its axis.

Title: Why does the tilt of the Earth not change or move?
Post by: Soul Surfer on 12/02/2009 23:27:40

Over extremely long periods (ie long with respect to the orecession of the equinoxes in 26,000 years)  the earth's axis angle dooes vary a bit (but I can't remember how much at the moment)  but it does not topple completely because the presence of the moon pulling on the oblate earth tends to stabilise the earth's  axis.  without the moon more extreme variations would be possible

Title: Why does the tilt of the Earth not change or move?
Post by: Damo the Optics Monkey on 13/02/2009 00:41:36

Here (http://www.uwgb.edu/DutchS/pseudosc/flipaxis.htm) is an interesting article about this topic.

Title: Why does the tilt of the Earth not change or move?
Post by: Astronomer_FB on 13/02/2009 11:00:28

Quote from: Damo the Optics Monkey on 13/02/2009 00:41:36

Here (http://www.uwgb.edu/DutchS/pseudosc/flipaxis.htm) is an interesting article about this topic.

Nice article thanks it help answer my question pretty well.

But what about when the order of the sun moon and earth are  : Sun Moon Earth shouldn't that be alot of gravity pulling on it what is holding the Earth back besides its own gravitational resistance, the way I see it is it is 2 against 1 why doesn,t the team of 2 win.

Title: Why does the tilt of the Earth not change or move?
Post by: yor_on on 14/02/2009 22:59:05

Very nice article Damo:)

Title: Why does the tilt of the Earth not change or move?
Post by: Damo the Optics Monkey on 25/02/2009 11:17:50

Thank you :)

In answer to your next question - and this is thinking out loud... as the gravitational force (which would cause a wobbling wobble) decreases by the distance squared and as the moon's mass is considerably smaller than Earth's - the effects are quite negligible on the Earth's axis.

This formula:  F = GMm/r^2

Mind you, it is a different story when it comes to the oceans and possible earth-crust tides.

But this is the ramblings of a tired teacher who got beaten by a giggly 7 year old