Gravity contradicting Relativity?

Im having a bit of trouble understanding Newton's Law of Gravity. Newton states that if you change the distribution of matter in one region of space, the change in the gravitational field would be felt instantaneously everywhere else in the universe. Not only does this mean that you could send signals faster than light, but it also requires an Absolute or Universal Time which has been abolished in favor of Relativistic Time. This seems to contradict the idea of relativity does it not?

For example, what would happen if our sun suddenly collapsed in on itself in a matter of seconds. Since it takes seven minutes for the light from the sun to reach our earth, does this mean that the effect of our sun collapsing should be felt, as a gravitational event, at least seven minutes later as well. Does gravity travel faster than light?

[bobman0330]

No. Newton's Law of Gravity is wrong. General Relativity is right. Or at least righter.

[GuyOnTilt]

Read the next chapter.

GoT

[Lestat]

I believe Einstein's theory of relativity solves for this by showing space as a fabric which actually becomes warped by matter.

Under the theory of relativity if the sun were to collapse, we would not immediately fly off into space. It would indeed take 7 minutes for us to know about it. Thus, gravity does not travel faster than the speed of light.

[Unabridged]

newton's model says gravity travels instaneously, GR says it travels at the speed of light

some evidence for gravity moving at the speed of light
http://www.universetoday.com/am/publish/speed_of_gravity.html

[tolbiny]

"For example, what would happen if our sun suddenly collapsed in on itself in a matter of seconds."

As long as the total mass of the sun and the distance from the earth to its center remained unchanged we wouldn't feel any change in gravatational effects would we?

[daryn]

[ QUOTE ]
"For example, what would happen if our sun suddenly collapsed in on itself in a matter of seconds."

As long as the total mass of the sun and the distance from the earth to its center remained unchanged we wouldn't feel any change in gravatational effects would we?

[/ QUOTE ]

correct

[Cooker]

Of course Newtonian Gravity and General Relativity disagree. That is why we needed GR in the first place, because Newtonian Gravity didn't work as well as we would like. General Relativity works much better. GR is a theory of Gravity and has thus far been well verified by observavtion, it simply is different than the Newtonian Theory of Gravity (which is in disagreement with many observations, but is usually OK for most purposes).

Newtonian gravity simply is not a relativistic theory -- it lacks certain required symmetries. Since it is well known that the universe seems to respect relativity, you should quickly come to the conclusion that Newtonian gravity, in certain situations, is guaranteed to give you the wrong answer -- and this is in fact what happens. If you try to send a space probe to the outer planets using Newtonian gravity alone, you will miss your target.

A surprising fact, however, is that Maxwell's equations (electromagnetism) were fully relativistic decades before relativity was understood as an underlying physical principle.

lol, are you talking about "A brief history of time"?

[Trantor]

[ QUOTE ]
[ QUOTE ]
"For example, what would happen if our sun suddenly collapsed in on itself in a matter of seconds."

As long as the total mass of the sun and the distance from the earth to its center remained unchanged we wouldn't feel any change in gravatational effects would we?

[/ QUOTE ]

correct

[/ QUOTE ]

This is the correct answer only because the effects of the collapse, which relativity indicates would be present, are so minute as not to detectablelt be the human body.

In classical mechanics (newtonian gravitational theory) the gravitational field would not change.