To the editor:

In response to the Dec. 21 “Proof Earth obits the sun,” I would like to thank the author for at least doing a response to a subject that seems to get very little thoughtful discussion; “Everybody just KNOWS that the earth goes around the sun-nuff said.” The author explains the Doppler effect quite well, and uses it to relate that the earth is moving away from the star for six months of the year and then towards the star during the other sic months as it travels around the sun once every year.

But here is another example of non-proof, mainly because the heliocentric and geocentric systems are geometrically equivalent. In the geocentric system, the sun orbits around the stationary earth, the remaining planets and all the stars orbit around the sun. All the stars are rotating around the earth once per day just as the sun is, but the sun is rotating around the earth slightly slower than the star field so that as sun and stars together orbit the stationary earth, you will see a certain star approach earth for six months and then start moving away from earth for the remaining six months. Therefore, in the “geocentric system” you would observe the same Doppler blue or red shifts that the author speaks of in his “heliocentric system.”

Picture yourself standing on a motionless earth looking out your window at 11 p.m. each night for a year to observe the stars. Line up a corner of the window with a tall object outside to observe a star in one of the 12 constellations in the zodiac. After about a month that constellation will be replaced by another one, say Aries by Taurus. After six months you will notice that star in Aries has been travelling away from you; but then will start travelling towards you as it circles behind you. After another six months have passed, it will have wheeled back to the original spot you had located it one year earlier.

A rough idea of this type of motion can be seen on U-Tube; search hypocycloid gearless speed reducers, use the “mekanizmalar” example for the animation. These mechanisms are used as final drive hubs in heavy equipment. Picture the flower shaped disc as the star system that is rotating around a center point — the “stationary earth”; Picture the small eccentric shaft near the center as the sun rotating around the earth. Of course the ratio is all wrong, but you get the general idea of how a star in the zodiac would progress around the earth during one year.

“Why do educators teach kids the earth moves around the sun when there really is no solid proof for it?”

Phil Drietz

Delhi