The sun revolves around the earth..?

Question

According to Einstein there is no absolute motion, only relative motion, so couldn't we as well say that the sun revolves around the earth?

Answer 1

nopes

because you will encounter the h**l, trying to support (mathematicaly) the crazy orbits of the sun and the other planets putting the earth in the center

that was the problem of earlier astronomers

since keppler and newton, that matter is solved

sun is steady (relatively to the planets) and the planets move

Answer 2

Jeff said it for me. See his answer.

Answer 3

You can describe the motions for Earth/Sun by saying the the Earth is the center, this cinematics.

You may even use the Moon.

By in terms on dynamics, the forces involved in the motions, you must use the Sun as the center.

Answer 4

Yes, you can -- you can choose any center of the system you'd like.

However, from the practical standpoint it is not convenient. If you chose Earth as the point, than the Sun will indeed be rotating around us. But then the orbits of the rest of the planets in the solar system will become irregular (again, relative to Earth).

We chose the sun to be the center because then observed phenomena are easier to fit into the known laws.

Answer 5

You can choose any reference frame.  If you choose Earth as the reference point for the motion of all other objects, you can say that the Sun (and the whole Universe) is revolving around the Earth.  The only problem is that the maths required to describe the different motions (planets, etc.) gets more complicated.  It's easier and more convinient from the mathematical standpoint to describe the motion of the planets (including Earth) using the Sun as the reference point, or to describe the motion of the Solar System using galactic center as the reference point.

Answer 6

um, no.

Answer 7

Put something in front of you at the right side. Turn towards the right. The object will appear to be moving towards the left as if it is going around you. But you are the one turning. So motion is relative. It depends on how you view it.

Answer 8

well then what about the other planets? how can the sun be revolving around them too?

Answer 9

actually the answer given about technically they are both revolving around each other is about the closest you'll get with out starting a massive amount of orbital mechanics calculations.

If you get down to it though Einstein had a theory.. that 'theory' is called Relativity, as he's stated himself though if he could prove every part of it, it wouldn't be a 'theory' it would be 'fact'. When you get into orbital mechanics, you have to look at a LOT of items, for a start an object orbiting another object is in 'free fall' by rights, it's traveling with enough speed in 1 direction to start at point A and return to point A while being pulled towards the object it's orbiting (in this case the sun) so it's 'falling' towards the sun at the same time as it's 'Pushing' itself away from it this gives us our 'orbit'. Now does the sun orbit around the earth? technically speaking from raw maths yes you can argue that depending on your frame of referance.

But as pointed out that frame of referance is against what you'd logically do, because the Sun is:

A. the larger body.

B. The larger mass

C. has more objects in motion around it.

It is generally agree'd upon that the following happens:

1. The moon orbits the earth.

2. The earth in turn orbits the Sun (Yet the moon also orbits the sun, because it's in earth orbit).

3. The Sun orbits the Center of the Milkyway

4. The Milkyway orbits the Center of the Galaxy (presumably).

The problem with the argument that the sun revolves around the earth is that from that frame point, you can NOT calculate the orbits of the other plants in the solar system based on Physics, simple as that.. because you would have to use the referance for EVERY object in the solar system, if the sun Orbits the earth then the moon orbits the earth then Mars orbits the earth etc etc etc etc..

However if you look at it this becomes increasingly harder to model mathematically, or even using physics, because of other laws beyond Einsteins Theory of Relitivity. These laws being those of Gravity, Inertia etc.

Even Einstein gives way to Newton ;).

Answer 10

I wouldnt say that the sun is revolving around earth completly. I think that we just say that the sun revolves around the earth for a means to educate basic understanding.

Answer 11

the earth's orbit around the sun is not an inertial frame of reference, so special relativity doesn't apply.

Answer 12

You're oversimplifying Einstein.

Relativity deals with the equivalence of inertial frames, in particular the constancy of the speed of light in all inertial frames regardless of the velocity of that frame.

That's really a statement about the laws of physics, but not a statement about how physics plays out in the Universe.

In fact, the Universe does have a well-defined "rest frame"---the one in which the Cosmic Microwave Background is maximally isotropic.  In that frame, the Earth goes around the Sun, and not the other way around.

Answer 13

Yes - you can - relative to you it does revolve around the earth.

Answer 14

Of course you can.  But the Sun would be spinning around really fast.  That's because the rotating Earth is not an inertial reference frame.  You could use it, but you'd have to compensate for it in the math, and it would be messy.

Even if you stop the Earth rotating, the Earth in it's orbit isn't an inertial reference frame.  It's accelerating on it's way around the Sun. You could use it, but you'd have to compensate for it in the math, and it would be messy.

Answer 15

First of all, for describing any motion, there should be a reference frame.What Einstein meant was that how a viewer sees a motion depends on where he is(the reference frame).We specify something to be at rest and view all things relative to it. As we see from the Earth,the sun revolves round us from west to east.Doesn't it!!!! But it is of little importance in astronomy or for any practical purpose because from Earth, the motion of other planets is too complicated.Making sun the reference frame simplifies things too much.

Answer 16

technically, you dont have to bother with Albert, the Sun and the Earth revolve around a barycenter.  Basically, they revolve around each other.

<edit>

I hate you, Robert!

Answer 17

It all depends what you want to do with the model.

However, what Einstein meant is that there does not exist a fixed frame of reference from which absolution motion can be measured.  

Now, it would appear that the Cosmological Microwave Background radiation could provide such a background.  Relative to the CMB, our Galaxy is moving at 400 km/s in a particular direction (roughly: RA = 14h DEC=-30).  Since the CMB is an artefact created at a precise moment in the entire universe, it should appear perfectly isotropic, whatever the motion of the observer.

Since it doesn't, it provides a background against which we can measure motion.

The CMB is deemed to be the result of an expanding universe;  Einstein did not believe that the universe was expanding, so he would have overlooked this possibility (he did later correct his "blunder" as he called it).

Still with Einstein:  like Newton's theory, Einstein's theory still has the effect of gravity depend on the mass of an object.  When two objects are involved, the most precise model is based on having both bodies orbit their common centre of mass (barycentre)

Since the Sun is 332,946 times the mass of Earth, then Earth's orbital movement around the barycentre is 332,946 times faster around the Sun, than the Sun's orbital movement around the barycentre.

So, in general, a model having Earth orbit the sun will be far more useful than one where the Sun orbits Earth.

Despite that, there are some calculations where it turns out easier to set the model the "wrong way around".  The two that I am familiar with (having studied them) are celestial navigation -- as used on ships for example -- and tide predictions.

In the first, it is much easier (mathematically) to set up the entire universe as if it were rotating around the eye of the observer (this forces one to consider Earth as immobile).  The reason that works is that the model is designed to compare what the observer... err... observes (with a sextant) with what the observer should have observed, had she been at the estimated position.

In the second case, there are two tricky parts to the calculations:  the prediction of the tidal height and the behavior of the bulge as it approaches a coast.  The first part is done by considering everything as fixed (nothing moves), then (in order to keep the calculations simple) we first move the Moon around Earth (and see what happens), then the Sun.  Then we combine the two movements and study the behavior of the resulting wave.

Then we calculated what happens when something gets in the way of the wave.

Answer 18

Actually, the Earth and the Sun are revolving around each other.  The center of this revolution is the center of mass of the Sun-Earth system.  However, since the Sun is so massive, that center of mass is actually within the Sun, giving the illusion that the Earth revolves around the Sun.

As to Einsteain, it is true that there is no absolute motion and you question is valid in Special Relativity in the absence of force and acceleration (constant inertial frame).  However, there is force and acceleration in the Earth-Sun system and we have to use General Relativity (non-constant inertial frame).  There is no argument that the Earth is experiencing a larger force from the Sun and experiencing the higher acceleration also.  This makes us the ones who are moving and not the Sun.

Answer 19

no....

Answer 20

The sun has not orbitted Earth since the days of Ptolemy.  

It was Copernicus, I think, who first proved that Earth orbits the sun.

The relative motion is the same.

Answer 21

NO.  The answer is simple.  Relativity relates to inertial frames, or frames of constant velocity.  Rotational and orbital movement are not inertial frames that you can define other objects as relative to because they are ACCELERATING.  Orbital motion implies centripetal acceleration.

Even if there was no sun and the earth was orbiting circles around nothing, you would detect this movement and could identify the invisible center of orbit due to the centripetal acceleration of the earth--which is relative to the body that is accelerating.  

Your argument only works for motion in a straight line.  If the sun was moving in a straight line to the west past the earth, then you could just as easily say that the earth is moving in a straight line to the east past the sun.  If one of them stops and turns around, you cannot equivalently say that the other one stopped and turned around in the other direction.  You can't say that because the one that turned around had to accelerate to do it, and the other body did not experience acceleration.  Look up the twin paradox--When one twin leaves on a spaceship at a relativistic speed and returns later on, he is younger than his twin left behind.  It was a paradox in special relativity because it seems like whoever is older would depend on which frame of reference you use.  The catch is, in order to return, one twin must accelerate to turn around, and therefore the other twin cannot be considered from his frame of reference anymore.  Or as general relativity explains, acceleration has its own effect on time dilation etc., which is relative to the acceleration and not to an outside frame of reference.

Constant velocity can only be defined relative to another body of constant velocity.  Acceleration and orbital motion, however, can be defined relative to the body accelerating and not to any other body.   The Earth is definitely orbiting around the Sun and not the other way around.

Answer 22

Wrong !!!

Answer 23

No , because it happens to be relative to us.

Answer 24

I think Aristotle and Ptolemy beat you to it by about 2500 years, but it has been disproven repeatedly.  It just doesn't work when you consider the movements of the other planets in the Solar System.  

The Earth-centered Universe of Aristotle and Ptolemy held sway on Western thinking for almost 2000 years. That being said, Aristarchus, a much under appreciated astronomer of the 3rd century BC, proposed a heliocentric model of the Earth's motion. But it was not until the 16th century, when the idea was reintroduced by the Polish astronomer Nicolai Copernicus (1473-1543) that the idea began to attain a broader appreciation.

In astronomy, the geocentric model of the universe is the theory that the Earth is at the center of the universe and the Sun and other objects go around it. Belief in this system was common in ancient Greece. It was embraced by both Aristotle and Ptolemy, and most Greek philosophers assumed that the Sun, Moon, stars, and naked eye planets circle the Earth.

The geocentric model held sway into the early modern age; from the late 16th century onward it was gradually replaced by the heliocentric model of Copernicus, Galileo and Kepler. Today, geocentric cosmology survives as a literary element within alternate history science fiction.

The modern heliocentric model of the universe was proposed by Nicolaus Copernicus in the mid 1500's in his work De revolutionibus orbium coelestium. It addressed many of the problems associated with the geocentric model such as the multitude of epicycles required to describe planetary motion. Heliocentrism is the belief that the Sun is the center of the solar system or universe. While some of the ancient civilizations in India and the Middle East had proposed the heliocentric model before, Copernicus' discovery set the groundwork for the modern view of the universe.

In Copernicus' heliocentric model, there are seven theories he presents:

There exists more than one center of the universe.

There is a center of the universe near the sun.

The planet Earth is not the center of our universe.

The scale of distances between the Earth and the Sun is miniscule compared with the astronomical distances between Earth and the stars in the sky.

The Earth revolves around the sun, thus causing the annual cycles in solar activity that we witness.

It is the Earth's own rotation that causes the stellar landscape to shift every night.

Any retrograde motion, previously explained by epicycles, is in fact caused by the differing orbital velocities of planets around the sun.

Copernicus did not publish his work until 1542.

Despite the basic truth of his model, Copernicus did not prove that Earth moved around the Sun. That was left for later astronomers. The first direct evidence came from Newton’s laws of motion, which say that when objects orbit one another, the lighter object moves more than the heavier one. Because the Sun has about 330,000 times more mass than Earth, our planet must be doing almost all the moving. A direct observation of Earth’s motion came in 1838 when the German astronomer Friedrich Bessel measured the tiny displacement, or parallax, of a nearby star relative to the more distant stars. This minuscule displacement reflects our planet’s changing vantage point as we orbit the Sun during the year.

Answer 25

You've misunderstood his point. He doesn't mean motion is what it looks like to us human. The earth is still revolving around the sun, even if it doesn't look that way to us. By relative motions, for example, he means that the earth's revolution is relative to the sun.

Another illustration: The earth is rotating at thousands of kilometers per hour, but we do not feel it; we are moving with it.