Sunday, October 07, 2007

A Quick Take on Geocentrism

This past week's Jewish Press had a letter from Amnon Goldberg, of Sefad, Israel, advocating geocentrism as the Torah-true view of cosmology. He relies on Mach's Principle (something that has never been fully accepted by the scientific community) to make the point. He states:

Mach’s Principle shows that a universe going around the Earth every 24 hours will produce exactly the same effects as Foucault’s Pendulum, Coriolis forces, earth bulge, weather patterns etc., as an Earth rotating in its axis every 24 hours.

Now, I'm not going to claim that I fully understand Mach's Principle, but one of the main problems I have with it is this:

The Andromeda Galaxy is the closest galaxy to the Milky Way. It lies aproximately 2.5 million light-years away from us. If one maintains that the entire universe rotates around the earth every day, that means that the Andromeda Galaxy would speed along, making a 15.7 million light-year journey every day (circumference = pi * diameter)*. That results in a speed *much* faster than the speed of light. And objects that are even further away would have to travel even faster to make it around the earth every day. To me, a rotating earth sounds much more reasonable.

The Wolf

(*Yes, I know the path that the galaxy would take would be an elipse and not a circle -- I just used the formula for the circumference of a circle as an approximation.)

14 comments:

Orthoprax said...

No need to go so far out, nearby Pluto would already be going faster than light.

Orthoprax said...

In any case that Amnon guy just pretends to know science since he totally misconstrues the Michelson-Morley experiment and thereby undermines the basis behind Relativity - on which the entire concept of equivalent coodinate systems depends.

He's eating his own tail.

Steve said...

Someone was commenting on a site that promotes geocentricity a while back. The claim of the geocentrist is that if the Earth was realling travelling through space at the speed it does, its atmosphere would be stripped away.

Therefore it is the sun that must be moving around the Earth. Of course, how the sun's outer atmosphere wouldn't be stripped away is still a mystery. I calculated it out and it would be travelling some ridiculous speed.

zach said...

Wow, two wackos on one page - Yaakov Stern and Amnon Goldberg!

Lubab No More said...

Great point! The geocentrics never bother to try and explain the physics of it all. They just borrow what they think helps their case and then ignore the rest.

TheAnswer said...

Good argument, assuming Einstein was correct about the speed of light. :)

I am interested in what he claimed at the end

"The Maharal, the Baal HaTanya, the Ma’aseh Tuviyah, the Mateh Dan, R. Yonoson Eibeshutz, R. Nachman of Breslov, the Sefer Habris, the Lubavitcher Rebbe, etc., were all familiar with the theory of Copernicus, yet rejected it in favor of the geocentricism of the Tanach and Chazal."

I would love to see how these luminaries dismiss the Copernican arguments. Anyone have source references by any chance?

cipher said...

I've only heard of the Rambam dealing with it (and rejecting the Copernican view), although I haven't read the treatise and I'm not familiar with his argument.

Apparently - according to my Chabadnik nephew and what little I've read online - the Rebbe's argument was this: Since Einstein, we know that there's no such thing as absolute position (because they're willing to accept scientific conclusions when it works to their advantage), therefore, it makes as much sense to say that the Sun revolves around the earth as it does to say that the earth revolves around the Sun. Further, according to my nephew, some Lubavitch guy got a PhD in astronomy and supposedly has supplied them with the requisite physics. This is as much as I know, and it's enough to aggravate me every time I think about it.

BrooklynWolf said...

cipher,

So how come he hasn't published his findings and collected his Nobel Prize yet? :)

Saying that the sun goes around the earth because there is no fixed position is akin to saying that the house is turning you (and the entire planet along with you) when you screw something into your wall.

The Wolf

Zach Kessin said...

while there is not exactly such a thing as absolute position there is relative position. The earth moves around the sun. The Earth's orbital radius is about 150,000,000 km, the sun moves almost not at all. The sun's mass is also several hundred thousand times more massive than the earth. So if you take Newton's laws of motion (which you should) then there is only one solution that makes sense. And it doesn't involve the earth standing still.


As for the Rambam and Coppernicus it should be pointed out that the Rambam lives about 400 years before Coppernicus.

Anonymous said...

OK, time for the quick physics review. This must be gone through every time this topic comes up on a frum blog.

Relative motion between two objects is indistinguishable only in non-accelerating reference frames. Basically this means constant speed in a straight line. Rotational motion is by definition an accelerating reference frame, the constant angular acceleration is what keeps the rotating object in orbit. If there were no angular acceleration, the object would go off in a straight line.

If you don't understand this, please go study some physics. There are many free courses online.

Orthoprax said...

Anon,

"Relative motion between two objects is indistinguishable only in non-accelerating reference frames. Basically this means constant speed in a straight line. Rotational motion is by definition an accelerating reference frame, the constant angular acceleration is what keeps the rotating object in orbit. If there were no angular acceleration, the object would go off in a straight line."

So? That doesn't mean that the relative coordinate systems are not equally valid. All it requires is the proposition of (much) larger fictitious forces which effect the rest of the universe rather than smaller ones that only would effect stuff on Earth.

You could do physics just as well with either assumption.


Wolf,

"Saying that the sun goes around the earth because there is no fixed position is akin to saying that the house is turning you (and the entire planet along with you) when you screw something into your wall."

That's correct, though it's actually the screw causing the turning, not the house. It is mathematically valid and there's no way to prove one perspective to be more correct than the other. As far as I can be concerned, the universe does literally revolve around me. :)

Anonymous said...

o-prax:

Just because you can mathematically translate from one relative coordinate system to another does not mean that that translation has any physical meaning. Given two objects moving in a non-accelerating reference frame, either object can be the coordinate reference point and describe the physics of the system correctly. That's what it means when I stated 'Relative motion between two objects is indistinguishable only in non-accelerating reference frames.'
The reference points are physically symmetrical. This is not the case in accelerating reference frames, even though you can translate the math from one reference frame to another, it does not follow that that translation describes the physical system correctly.

A good introduction would be Richard Feynman's 'Six Easy Pieces' and 'Six Not So Easy Pieces', where he explains, in layman's terms, the concept of symmetry in physical law.

Orthoprax said...

Anon,

"This is not the case in accelerating reference frames, even though you can translate the math from one reference frame to another, it does not follow that that translation describes the physical system correctly."

Then it's a difference without distinction. If the math works then the math works and you cannot prove one reference frame more correct than another.

The only differences you will experience in an accelerating reference field as opposed to an inertial reference field is the addition of fictitious forces. But you can just as easily say the fictitious forces are working on the universe at large and not on the chosen reference field.

If you're spinning in a circle and you let go of a ball, you will see it fly away from you. Mathematically you can say that's due to the fictitious centrifugal force from your spinning - or you can say that the rest of the universe's spinning around you created a fictitious pulling force on the ball. You cannot prove one more valid than the other.

-suitepotato- said...

I never thought the day would come I would be more googly-eyed over a Jewish blog post's reply content than Geometrodynamics which I don't recommend those with hernias to take off the shelf much less read.

In any case, if the geocentrist POV makes no rational sense for the fundamentalist Christians on TV, why would it make any more sense from Israel directly? You could waste time cataloging the statistically likely animals, bugs, demons, etc. to have been around at the time of Noah and then extrapolate for food and water needs for so many days and nights, and figure out given what we know of structural capabilities of wood and ancient ship building, how much wood would be needed and that there wasn't enough in all of the entire middle east to do it and probably Asia Minor either.

Good topic for an otherwise unoccupied moment though.