Can someone answers this question of mine?

inf1nity

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Well Galileo was punished by the church for teaching that the sun is stationary and the earth moves around it. His opponents held the view that earth is stationary and the sun moves around it.

So if the states of rest and motion are determined only by the frame of reference and the relative velocity between the observer and the object, and if absolute motion has no meaning, then are the two viewpoints not equally correct and equally wrong?
 
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Markbnj

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I don't know much about physics, but however you slice it the earth is actually in orbit around the sun, not the other way around.
 

yuchai

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Aug 24, 2004
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I think when they say that the sun or Earth is "stationary" it is based on the frame of reference of the solar system, which makes only 1 of the statements wrong.
 

Lean L

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I don't know much about physics, but however you slice it the earth is actually in orbit around the sun, not the other way around.

Laws of physics disagree with that. Everything is relative so they are both right with only two frames of reference.
 

Markbnj

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Laws of physics disagree with that. Everything is relative so they are both right with only two frames of reference.

Ok, so in one frame of reference the earth is in orbit about the sun, and the forces that generate that motion are well understood: gravity, mass, momentum. In the other frame of reference, what mechanics account for the orbit of the sun around the earth?
 

Tweak155

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Sep 23, 2003
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Laws of physics disagree with that. Everything is relative so they are both right with only two frames of reference.

One of them is wrong because they limited themselves to 2 frames of reference. Used the wrong construct to reach an answer. That is called ignorance, not accurate.
 

Tweak155

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Ok, so in one frame of reference the earth is in orbit about the sun, and the forces that generate that motion are well understood: gravity, mass, momentum. In the other frame of reference, what mechanics account for the orbit of the sun around the earth?

Because if we stood on the earth and looked at the sun, it goes "up and down". So the assumption is the Sun is going around the earth but really the earth is spinning.
 

olds

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I don't know much about physics, but however you slice it the earth is actually in orbit around the sun, not the other way around.
Please! Next your going to try to tell me that Earth isn't flat!
 

jaedaliu

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Feb 25, 2005
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Didn't bother to google it, but I think the real disagreement wasn't which was circling the other (Sun and Earth) but what was the center of our solar system? Earth or Sun? They knew about the other planets had to circle about something, and disagreed on that.

Didn't Galileo get his pardon a few years ago?
 

Lean L

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Ok, so in one frame of reference the earth is in orbit about the sun, and the forces that generate that motion are well understood: gravity, mass, momentum. In the other frame of reference, what mechanics account for the orbit of the sun around the earth?

The earth is immensely massive and the sun is hollow. With only two frames of reference that could still be valid.

While I agree that limiting the frames is a form of ignorance it really does create some interesting opportunities to learn and take on abstract ideas. I've seen a model of the terrestrial system (get it?) where they had all 9 planets (at the time) and the sun orbiting the Earth. The placement of all the planets still lined up perfectly with the seasons. I'm sure there can be a whole course taught about this.
 

Tweak155

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The earth is immensely massive and the sun is hollow. With only two frames of reference that could still be valid.

While I agree that limiting the frames is a form of ignorance it really does create some interesting opportunities to learn and take on abstract ideas. I've seen a model of the terrestrial system (get it?) where they had all 9 planets (at the time) and the sun orbiting the Earth. The placement of all the planets still lined up perfectly with the seasons. I'm sure there can be a whole course taught about this.

That's hot :wub:
 

Markbnj

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Because if we stood on the earth and looked at the sun, it goes "up and down". So the assumption is the Sun is going around the earth but really the earth is spinning.

One of many reasons why I am no good at physics: I insist on believing in a single, objective reality. In that reality the earth is _actually_ orbiting the sun, regardless of what might _appear_ to be happening from other perspectives and frames of reference. I further insist that there is no objective reality in which the sun is orbiting the earth, again regardless of appearances.
 

Kadarin

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Well Galileo was punished by the church for teaching that the sun is stationary and the earth moves around it. His opponents held the view that earth is stationary and the sun moves around it.

So if the states of rest and motion are determined only by the frame of reference and the relative velocity between the observer and the object, and if absolute motion has no meaning, then are the two viewpoints not equally correct and equally wrong?

Both viewpoints are technically wrong. The earth and sun orbit around a common center, which due to the relative masses of the earth and sun happens to exist inside the sun. This movement is also affected by the existence of the other planets, so actual orbital paths are a bit more complex.
 

Markbnj

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Both viewpoints are technically wrong. The earth and sun orbit around a common center, which due to the relative masses of the earth and sun happens to exist inside the sun. This movement is also affected by the existence of the other planets, so actual orbital paths are a bit more complex.

An even better answer, I agree. But for all practical purposes the popular description is accurate. Is the point around which the two bodies orbit actually different from "the center of the sun?" Does the earth make the sun wobble? Probably does to some micro-infinitesimal extent.
 
Feb 25, 2011
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An even better answer, I agree. But for all practical purposes the popular description is accurate. Is the point around which the two bodies orbit actually different from "the center of the sun?" Does the earth make the sun wobble? Probably does to some micro-infinitesimal extent.

Watching stars wobble is one of the ways we spot extrasolar planets.
 

Murloc

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Well Galileo was punished by the church for teaching that the sun is stationary and the earth moves around it. His opponents held the view that earth is stationary and the sun moves around it.

So if the states of rest and motion are determined only by the frame of reference and the relative velocity between the observer and the object, and if absolute motion has no meaning, then are the two viewpoints not equally correct and equally wrong?
Nope, because the simpler solution that explains a set of data is the one that should be kept by scientists, see occam's razor.
Without this rule it's more difficult to make scientific progress.
Galileo's theory explains everything with less exceptions and rules, while the ptolemaic vision requires complicated stuff such as retrograde motion etc.
Physics buried that model forever though, and showed that galileo's is an approximation.
 
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Lean L

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No. In neither frame of reference does the sun revolve around the earth.

Rather pointless don't you think to just state that and leave it as is?

Both viewpoints are technically wrong. The earth and sun orbit around a common center, which due to the relative masses of the earth and sun happens to exist inside the sun. This movement is also affected by the existence of the other planets, so actual orbital paths are a bit more complex.

Truth. In this case it's negligible as you would not see it in either of those frames of reference.

Now that I think about it, it makes sense that Galileo was disregarded for so long. What compelling evidence did he have at the time? One of the biggest arguments (parallax movement of the stars) he could not prove since we didn't have precise enough instruments to measure it yet. We take it for granted what we learn in science class. How many people question matter or atoms? Yet can it not be conceivable that it might be disproved in the future?
 

phucheneh

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Jun 30, 2012
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i dont think anything in the universe is truly stationary

The Earth and Sun rotating around the galactic core doesn't make it any less true than the one is still orbiting the other.

Frame of reference is practically a non-sequiter.

IF YOU USE YOUR CAR AS A FRAME OF REFERENCE, THE HIGHWAY DRIVES DOWN YOU! MAGIC!