Expert: Jayendra Upadhye - 3/29/2008

Question
I have came across some articles stating that the earth axis tilt has recently increased by an additional 26 degrees. How can I do my own calculations to verify if this in fact true or not.

Thanks,
Mark

Answer
Hi Mark,
Found this in the question pool.
I simply had to answer.

First of all, the source from where you got that info is NOT authentic.

Reasons:-
1 - The earh is a HUGE..HUGE..HUGE ball, even though we keep on hearing how "puny" it is compared to Jupe and Saturn and the sun.
It will take unbelievably TITANIC efffort to make it "wobble" / "Topple" by 26 degrees!

Such a wallop would kill off all life on earth and there would be a planet wide tsunami a few kilometers high!!

2 - The earth's axis indeed has a "wobble" from a wallop a few billion years ago, before life started, and also due to the interactions with the solar system. This gyrating which is called "precession of the equinoxes" is well known and regular feature and is well understood by scientists, who even predict which star will be polasris next!

This precession is however very slow lasting a few 1000's of years.
The hindu astronomers knew of it, and so did those from some really ancient cultures like egypt and Inca/mayas.

3 - To "Calculate", simply measure the ..
a - degrees above the northern horizon (if you are in the southern hemisphere), of the sun, at noon, or
b - degrees above the southern horizon (if you are in the northern hemisphere), of the sun at noon
.. at the two solstices!

No you dont have to wait for a whole year, last years observations are on the web if you search. (solar Azimuth related tables)..

The (difference in degrees)/2 =  measured will directly tell you the axial tilt.
The difference will come out 47 degrees.
And the tilt will be shown as 23.5!

regards
Jayen