Faraday cages

@deepthought said
Do you want to give a reference to the paper where Einstein says that time dilation causes gravity?

The bending of space/time is time dilation. Do you dispute that?

@metal-brain said
The bending of space/time is time dilation. Do you dispute that?

I have two objections. The first we've covered ad nauseam. The second is that there are more degrees of freedom than that. For a simple model of a possible universe consider the product space RxS_3. The R is the time-like coordinate, S_3 is a three sphere. That has curvature everywhere, but any two stationary clocks will go at the same rate.

@DeepThought
You are talking way over his head.

@sonhouse said
@DeepThought
You are talking way over his head.

For an even simpler geometrical construction consider a circle. It's got curvature equal to the inverse of its radius - by definition - and doesn't involve time at all.

@deepthought said
For an even simpler geometrical construction consider a circle. It's got curvature equal to the inverse of its radius - by definition - and doesn't involve time at all.

Actually I should make that a sphere for technical reasons. One dimensional spaces do not have intrinsic curvature.

@DeepThought

When you say inverse of radius are you talking about relating the radius to the slope of the curve of the circle or sphere? It looks to me like a large radius = smaller numbers which makes it sound like slope numbers.

@sonhouse said
@DeepThought

When you say inverse of radius are you talking about relating the radius to the slope of the curve of the circle or sphere? It looks to me like a large radius = smaller numbers which makes it sound like slope numbers.

Imagine a graph of a function like x^2. Fit a circle into the minimum of the curve, the largest circle that one can snugly fit it has some radius r. The curvature is then 1/r. For a sphere the largest circles that fit into the sphere are the great circles so the curvature is just the inverse radius of the sphere. This is explained in the first section of the Wikipedia page on curvature.

https://en.wikipedia.org/wiki/Curvature#Precise_definition

@deepthought said
I have two objections. The first we've covered ad nauseam. The second is that there are more degrees of freedom than that. For a simple model of a possible universe consider the product space RxS_3. The R is the time-like coordinate, S_3 is a three sphere. That has curvature everywhere, but any two stationary clocks will go at the same rate.

Again, Curvature of space/time is just the inclusion of the other dimensions of space along with time. By saying time dilation causes gravity I am not omitting the other dimensions. You cannot have time dilation without the bending of space/time. By implying that it does, you are misleading everyone here.

The bending of space/time is time dilation. You cannot have one without the other. Your deliberate jargon does not change that.

@sonhouse said
@DeepThought
You are talking way over his head.

No, he isn't.
He just picked a fancy way of saying what I have been saying all along, time dilation is just one dimension. He is trying to say because the term "bending of space/time" is a more complete description I am omitting the other 3 dimensions when I say time dilation. However, it is an irrelevant point. Time dilation (from matter) always bends space. YOU CANNOT HAVE TIME DILATION ALONE WITHOUT THE BENDING OF SPACE/TIME. That is a fact!

What I have done is explain GR in the most concise way possible to help people understand. "Time dilation causes gravity". Very concise and straight forward.

Depthought's goal is the opposite. He wants to confuse you so you do not understand anything at all. He is doing that in an effort to save face at the expense of misleading everyone on this forum into thinking he understands something nobody else does. It is all about him. He is being completely narcissistic. If you understood you would know he is wrong.

"If you can't explain it simply, you don't understand it well enough."
- Albert Einstein

He either doesn't understand it well enough or he is desperately trying to hide his failure. Time dilation and the bending of space/time are the same thing. Denying it will not make it untrue. It is a denial of science though.

Ask any good professor educated in the field of GR and he will tell you I am right. Just because he is talking over your head do not project that onto me. He claimed to take issue with it and then continued to confirm everything I said! He merely did it in a way so you would not understand he was contradicting himself.

When people do not care if you understand what they are talking about that is probably the goal. Usually it is to hide their lack of understanding. In this case deepthought is trying to avoid admitting he is wrong like the plague and he is being shamelessly dishonest about it.

Go ahead. Ask a good professor. He will tell you I am right.

@deepthought said
Actually I should make that a sphere for technical reasons. One dimensional spaces do not have intrinsic curvature.

Dude, that is like saying electricity does not cause magnetism. I am also aware that can work the other way around, but I am not talking about that other inverse. Saying the bending of space/time causes time dilation is like saying electromagnetism causes electricity. Can you have electricity without magnetism? I realize electromagnetism is a more complete description of what is going on, but you cannot have one without the other. Same thing with time and space. They are linked. Time dilation is causing the curvature, or you could say it "is" the curvature. Don't take the causation too literally.

Now do you understand?

@metal-brain said
No, he isn't.
He just picked a fancy way of saying what I have been saying all along, time dilation is just one dimension. He is trying to say because the term "bending of space/time" is a more complete description I am omitting the other 3 dimensions when I say time dilation. However, it is an irrelevant point. Time dilation (from matter) always bends space. YOU CANNOT ...[text shortened]... eing shamelessly dishonest about it.

Go ahead. Ask a good professor. He will tell you I am right.

From your post above the one I am replying to:

Curvature of space/time is just the inclusion of the other dimensions of space along with time.

No, it is not. This sentence is virtually meaningless. The only meaning it can have is that adding extra dimensions to a time-like dimension creates a curved space-time. There is no reason that should be the case.

Time dilation and the bending of space/time are the same thing.

No they are not. Time dilation is a difference in the rate of two different observer's clocks. Curvature measures the difference of circumference around a closed loop from what one would expect on a plane. They are separate concepts.

From your post on the previous page (11):

Einstein already did that 100 years ago.

"That" being to argue that gravity is caused by time dilation. You've been arguing this on the basis of watching a popular science video but haven't checked what Einstein actually said in his original papers, despite claiming he supports your case.

He is being completely narcissistic.

Look in a mirror.

@metal-brain said
Dude, that is like saying electricity does not cause magnetism. I am also aware that can work the other way around, but I am not talking about that other inverse. Saying the bending of space/time causes time dilation is like saying electromagnetism causes electricity. Can you have electricity without magnetism? I realize electromagnetism is a more complete description of ...[text shortened]... u could say it "is" the curvature. Don't take the causation too literally.

Now do you understand?

Electromagnetism is no more or less complete than GR, in fact as a classical field theory it is entirely compatible with GR.

Saying the bending of space/time causes time dilation...

Ok., I'll accept this sentence, really we need to specify two observers whose clocks are running at different rates and sort out some technical points to either make them stationkeep or have comparable states of motion somehow, but it'll do.

Time dilation is causing the curvature

This on the other hand will not do. The presence of energy (i.e. matter) causes the curvature. I don't like "gravity is caused by time dilation" since I think concepts are getting mangled, this on the other hand is a mess. By "gravity" we mean the tendency for objects to fall in an already existing gravitational field.

The explanatory chain is:

1) Matter causes space-time to curve.
2a) Space-time curving causes clocks to run at different rates.
2b) Space-time curving causes objects to fall.

@deepthought said

Time dilation is causing the curvature

This on the other hand will not do.

I, and I am absolutely certain the vast majority of physicists, would agree that won't do.
That statement does indicate erroneous understanding to all of us that understand the physics and I would personally say, at least in the narrow context it was said, its also an abuse of the word 'causing'.

Also notice how he keep saying "space/time", as in "space or time", as opposed to "space-time" which is the correct term and doesn't mean "space or time" thus he repeatedly shows he has that misunderstanding. His thinking on physics is clearly very muddled and in many different ways.

@deepthought said
Electromagnetism is no more or less complete than GR, in fact as a classical field theory it is entirely compatible with GR.

Saying the bending of space/time causes time dilation...

Ok., I'll accept this sentence, really we need to specify two observers whose clocks are running at different rates and sort out some technical points to either make them stationk ...[text shortened]... ime curving causes clocks to run at different rates.
2b) Space-time curving causes objects to fall.

You are hopelessly dogmatic. ASK A GOOD PROFESSOR WHO SPECIALIZES IN THE FIELD OF GR AND YOU WILL FIND OUT I AM RIGHT.

@humy said
I, and I am absolutely certain the vast majority of physicists, would agree that won't do.
That statement does indicate erroneous understanding to all of us that understand the physics and I would personally say, at least in the narrow context it was said, its also an abuse of the word 'causing'.

Also notice how he keep saying "space/time", as in "space or time", as opposed ...[text shortened]... s that misunderstanding. His thinking on physics is clearly very muddled and in many different ways.

ASK A GOOD PROFESSOR WHO SPECIALIZES IN THE FIELD OF GR AND YOU WILL FIND OUT I AM RIGHT.