Thread: Need help again - weirdness Relativity

1. Need help again - weirdness Relativity

OK, so someone was talking about a book called Copernicus and the Jews, which uses the point that just as the Church has misconstrued its understanding of the Solar System, it has misconstrued its understanding of our relation to the Jews - long story and off topic, I know.

But the hang-up here is a guy who uses relativity to defend geocentrism.

The Copernicus argument is a whole lot of garbage.

Assuming Relativity is accepted scientific law, then it is just as correct to say everything else revolves around the earth as it is to say the earth revolves around the sun.

According to Relativity, there is no preferred frame of reference. Every observer has an equal right to consider themself to be at rest.

Thus, it is equally correct to say that a train moves past the station, or that the station moves past the train. This example is not as unreasonable as it seems at first sight, for the station is also moving, due to the motion of the earth on its axis and its revolution around the sun. All motion is relative, according to Einstein. None of Einstein's basic assumptions was revolutionary; Newton had previously stated “absolute rest cannot be determined from the position of bodies in our regions.”
Also, Einstein even found the formulae to convert observations made from one reference frame, to that of another. for example, the inability of ancient scientists to mathematicly describe observations made from their own reference frame is a fault if the individuals ingorance or lack of mathematical language to portray that, and not a fault of the reference frame. In other words, the people just didn't know HOW to put it into mathematical terms. While it may be "easier" to describe a heliocentric model, it is no more accurate or correct than an earth centered model. According to both Newton and Einstein, the only thing that matters to the observer is just that: what they observe. According to Einstein, the laws of physics remain constant for every observer, but the measurements they make will depend on their own reference frame. From the sun's reference frame everything appears to revolve areound the sun, including the rest of the universe. From the Earth's reference frame everything appears to revolve around the earth, though admittedly many things don't appear to follow circles or ellipses. From the hub of the galaxy, everything in the universe appears to revolve around the milkyway, and so on. This is the consequence of relativity.

If person A and person B are standing 5 meters apart, facing one another. Person C walks between them on a path perpendicular to the line AB. From person A's point of view, person C is walking to the left. From person B's point of view, person C is walking to the right. Both people have an equal right to assume they are making the correct observation. If A and B want to effectively communicate observations they make, they must convert their ovservations to the other person's frame of reference, by rotating relative direction by 180 degrees.

Now if "A" is the sun and "B" is the earth, and "C" represents any other object in the universe, you can see how neither A nor B has exclusive rights to claim to be the correct reference frame. B does not make the same observations as A because B sees the events from a different point in space-time than does A. Both observations are correct, and given the proper formullae(provided by Einstein), you can convert from one to the other.

So the reality is, if you wanted to, you can actually do the math and make an earth centered model that accurately depicts the solar system without violating the laws of physics. it is a lot more complicated than the heliocentric model, but it is JUST as valid, and in fact, because we are IN the earth's frame of reference, the earth centered model is what we observe every day with our own eyes, and NOT the heliocentric model.

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I know there's a place where some people won't listen to anything . . . but what the best way to respond to this guy?

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Originally Posted by nebularain
But the hang-up here is a guy who uses relativity to defend geocentrism.

I know there's a place where some people won't listen to anything . . . but what the best way to respond to this guy?
He can use geocentric coordinates if he wants, but this freedom also extends to any number of other coordinate systems (e.g., barycentric coordinates for example). So, there isn't really anything special about geocentric coordinates. Who would argue that JPL should be using geocentric coordinates for calculating the mission parameters of a spacecraft orbiting (and landing on) Mars for example?

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The author is right in his main point, but not in the following:

The Copernicus argument is a whole lot of garbage.

Assuming Relativity is accepted scientific law, then it is just as correct to say everything else revolves around the earth as it is to say the earth revolves around the sun.

According to Relativity, there is no preferred frame of reference. Every observer has an equal right to consider themself to be at rest.
When Copernicus put forth his argument, there was no relativity theory to refute him. His description of the solar system was the closest to reality, available at the time. In fact, without heliocentrism, there would have been no relativity.

He's also wrong about the following:
So the reality is, if you wanted to, you can actually do the math and make an earth centered model that accurately depicts the solar system without violating the laws of physics. it is a lot more complicated than the heliocentric model, but it is JUST as valid, and in fact, because we are IN the earth's frame of reference, the earth centered model is what we observe every day with our own eyes, and NOT the heliocentric model.
We do not observe the Sun revolve around the Earth. That's an interpretation of what we observe.

4. A few words from The Bad Astronomer himself.

5. Barycentered relativity?

That author is out to lunch. The barycenter in the Sun-Earth-Moon system is deeply imbedded inside the Sun. So there is no question as to which goes around which. We observe the Sun passing overhead everyday, but there is nothing 'realtivistic' about that, since it is the Earth spinning on its axis that gives us that observable effect. If the Earth stood stock still, our Sun would be a fixed massive star in the sky, scortching one half of the planet.

6. Thanks for the responses and links!

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8. I'd pull out this quote:
While it may be "easier" to describe a heliocentric model, it is no more accurate or correct than an earth centered model. According to both Newton and Einstein, the only thing that matters to the observer is just that: what they observe.
This is all true, but note the whole point is that "easy" is as much a part of science as "accurate or correct". Science is not just about making calculations that stand up to predictions, it is also about understanding. Relativity embodies some deep ideas that make us feel like we understand our reality better, but it is not the be all and end all of that understanding. The fact is, some reference frames really do provide a simpler description of what is going on, and the rotating Earth is a classic example of this. Even more importantly, I would argue that the crux of the Copernican revolution is not that the Sun's frame is preferred over the Earth's, it is that the Earth is not special compared to other planets and other places in the universe. Indeed, all of modern cosmology is built on this principle, as is the justification for using spatial coordinates that move with the matter equally on large scales all over the universe. So the real problem with the geocentrist model as a way to understand our universe is its failure to recognize this important truth.

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