Dear Jack,

We can obtain a definition of 1 'second' in this modern era by using the monochromatic wavelength of light emitted by certain atoms, but original definitions of time were always based upon the regular movement of the heavens.

The use of 24 hours is fairly arbitrary, but it does allow for things like 15 degrees of rotation per hour, which is quite useful.

However, most people are not too interested in what time Orion rises, since they plan their day from morning to evening, so a system based upon the Sun rising is what we use for our everyday clocks and watches.

The difference of about four (mean solar) minutes between 24 mean solar hours and 24 sidereal hours is caused by the stars going around slightly quicker than the Sun.

In the heliocentric model, these two times are attributable to different components of the World's movement, whilst the Sun and stars are effectively fixed.

In the geocentric model, the difference is caused by the Sun going 'backwards' around its path, taking 12 months to get all the way round, whilst the path rotates nightly with the heavens.

Regards,

Neville

www.GeocentricUniverse.com

-----Original Message-----
From: jack.lewis@xxxxxxxxxxxx
Sent: Sun, 11 Nov 2007 09:32:13 -0000

Dear Neville,

I have a question regarding the rotation time.

The World takes 23h 56m 4.091s to rotate once about its axis. From where do we get a measurement of time that is not related exactly to the time of the Earth's rotation? Whys is there a 4 min. difference. This has always been a puzzle to me.

 

Jack