Gravity

What is it?

Originally posted by whodey
What is it?

Curvature of space-time.

Originally posted by DeepThought
Curvature of space-time.

Where do the gravitons come in? Are they responsible to the curvature?

Originally posted by DeepThought
Curvature of space-time.

Curvature of what?

What particles make up space and time?

Originally posted by whodey
Curvature of what?

What particles make up space and time?

Space is the underlying form that contains matter. That form is not fixed but can bend and like a hill or a crevice which controls how a rock rolls around it, space bends to control how matter moves through it and also how time flows. The deeper the gravity crevice, the slower time flows.

That has been proven in experiment after experiment. Now atomic clocks are so accurate they can tell the difference in the flow of time by the movement of one clock 1 meter higher than a second clock which had been at the same level.

As to what particles make up space and time, good luck with that one, news at 11. Strings, triangles, lots of hypotheses but no evidence yet.

Originally posted by sonhouse
Space is the underlying form that contains matter. That form is not fixed but can bend and like a hill or a crevice which controls how a rock rolls around it, space bends to control how matter moves through it and also how time flows. The deeper the gravity crevice, the slower time flows.

That has been proven in experiment after experiment. Now atomic c ...[text shortened]... good luck with that one, news at 11. Strings, triangles, lots of hypotheses but no evidence yet.

All this is probably true, but nothing more than observations and consequence of theory.

The most interesting question is - why?

Why "Space is the underlying form that contains matter."? Is it really a known fact that matter needs space? Is matter without space really impossible, (more than philosophicly)? Has anyone made any scientific work about this?

An answer that "it is what it is because that is the way it is" is not really better than the usual GDI-answer...

Originally posted by FabianFnas
All this is probably true, but nothing more than observations and consequence of theory.

The most interesting question is - why?

Why "Space is the underlying form that contains matter."? Is it really a known fact that matter needs space? Is matter without space really impossible, (more than philosophicly)? Has anyone made any scientific work about t ...[text shortened]... t is what it is because that is the way it is" is not really better than the usual GDI-answer...

We'd expect a quantum theory of gravity to have an intermediate responsible for carrying the force. That particle is called the graviton.

The rest of your point goes into extremely difficult territory, since we're running into issues regarding the problem of time. Space-time itself is a dynamic physical thing and without the presence of matter it's not clear that it would exist. In string theory space-time dimensions correspond to fields on the string world-sheet, so without the string there is no space-time.

Originally posted by whodey
What is it?

Gravity is the force caused by time dilation. Many people on this forum will tell you I don't know what I'm talking about but they are wrong. Gravity does not happen despite time dilation, it happens because of it.

The graviton is a hypothetical particle. Nobody knows if it really exists. Matter causes time dilation but nobody knows why. It is a mystery.

Originally posted by Metal Brain
Gravity is the force caused by time dilation. Many people on this forum will tell you I don't know what I'm talking about but they are wrong. Gravity does not happen despite time dilation, it happens because of it.

The graviton is a hypothetical particle. Nobody knows if it really exists. Matter causes time dilation but nobody knows why. It is a mystery.

Why would time dilation cause a particle's trajectory to deviate from a straight line?

Originally posted by Metal Brain
Gravity is the force caused by time dilation. Many people on this forum will tell you I don't know what I'm talking about but they are wrong. Gravity does not happen despite time dilation, it happens because of it.

The graviton is a hypothetical particle. Nobody knows if it really exists. Matter causes time dilation but nobody knows why. It is a mystery.

You seem to have a tough time finding a job for someone who is supposedly smarter than all the physicists.

Time dilation has nothing to do with gravity, or with "matter" per se. It follows from special relativity, which does not take gravity into account. It occurs because the laws of physics are presumed to be the same in all inertial frames of reference.

Originally posted by DeepThought
Why would time dilation cause a particle's trajectory to deviate from a straight line?

It is following the shortest path in time. Everything does.

Originally posted by KazetNagorra
You seem to have a tough time finding a job for someone who is supposedly smarter than all the physicists.

Time dilation has nothing to do with gravity, or with "matter" per se. It follows from special relativity, which does not take gravity into account. It occurs because the laws of physics are presumed to be the same in all inertial frames of reference.

"Time dilation has nothing to do with gravity, or with "matter" per se."

Havn't you heard of Gravitational time dilation?

Are you having a TOUGH TIME finding a job? I do know someone with a master's degree in physics that could not find a job in that field. Are you implying that all people with physics degrees are employed in that field?

Originally posted by Metal Brain
It is following the shortest path in time. Everything does.

What do you mean by shortest path in time?

Originally posted by DeepThought
What do you mean by shortest path in time?

Moving toward where time passes slower.

Originally posted by DeepThought
Curvature of space-time.

Time dilation causes curvature of space-time.

Saying curvature of space-time causes gravity is like saying low pressure areas are caused by curvature of the atmosphere. Do clouds move toward low pressure because of a curvature of the atmosphere?