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Author Topic: Is space elastic?  (Read 821 times)

Offline mxplxxx

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Is space elastic?
« on: 14/10/2016 02:51:15 »
Given that space is expanding at present and maybe contracting at some time in the future is it possible it is elastic?
« Last Edit: 14/10/2016 09:04:06 by chris »


 

Offline PmbPhy

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Re: Is space elastic
« Reply #1 on: 14/10/2016 05:39:50 »
Given that space is expanding at present and maybe contracting at some time in the future is it possible it is elastic?
No. The term elastic is defined only as it pertains to a physical material, of which space is not.
 

Offline mxplxxx

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Re: Is space elastic?
« Reply #2 on: 15/10/2016 08:23:30 »
Pretty weak answer PmbPhy give that there is a lot of activity on physics forums regarding this question:). Doesn't Einstein postulate that space is elastic. I.E. a particle moving into an area of space displaces that space space which springs back when the particle moves on?
 

Offline PmbPhy

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Re: Is space elastic?
« Reply #3 on: 15/10/2016 09:35:11 »
Quote from: mxplxxx
Pretty weak answer PmbPhy ...
If this is the way that you respond to people trying to help (i.e. by being so rude) when you disagree with the response you get (due to your ignorance of the subject matter) then why on Earth would I want to try helping you again?

The fact is that people like yourself are merely trying to find people to agree with your flawed grasp of the subject. If you actually have a real desire to know the truth about it then you'd contact a well known expert in the field such as my friend Dr. Oyvind Grøn
See: http://www.mn.uio.no/fysikk/personer/vit/ogron/   
From that website you can get his e-mail address and write to him. In the mean time you can see part of his body of work by looking up the textbooks he's written or go to the American Journal of Physics website and search for his papers. This will demonstrate that he's an expert in the field. You can also write to other relativists. I'm a relativist who disagrees with the nonsense you just posted but since I disagree with you you chose to be rude. Take my advice and don't be rude to the other relativists that you e-mail, should you take up my challenge.

I'm curious - Can you think of any reason why you wouldn't contact an expert in e-mail? I hope you don't refrain from doing so by assuming that such people are selfish and as such choose not to help others who contact them?

Quote from: mxplxxx
...is a lot of activity on physics forums regarding this question:).
Lol!! So what? The fact of the matter is that almost all members of such discussion forums have absolutely no idea what they're talking about when it comes to this subject whereas I have a very solid understanding as reflected by my interactions and discussions with experts in the top of these fields.

Quote from: mxplxxx
Doesn't Einstein postulate that space is elastic.
No. Absolutely not.

Quote from: mxplxxx
I.E. a particle moving into an area of space displaces that space space which springs back when the particle moves on?
That statement makes no sense as worded. Are you claiming that space is "displaced" because a particle moves into it and "springs back" when it moves out of it?? What utter nonsense. First of all there is no meaning to what you refer to as space being displaced. And the term "particle" is used to refer to objects whose mass is so small that it doesn't affect the curvature of spacetime.

And space doesn't "displace" (especially since that term is undefined in relativity). Matter "curves spacetime". Lookup what that means.

Since you were so rude in your response don't expect any help from me in the future or to read anything you post again.
 

Offline mxplxxx

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Re: Is space elastic?
« Reply #4 on: 15/10/2016 10:33:53 »
Quote from: mxplxxx
Pretty weak answer PmbPhy ...
If this is the way that you respond to people trying to help (i.e. by being so rude) when you disagree with the response you get (due to your ignorance of the subject matter) then why on Earth would I want to try helping you again?

The fact is that people like yourself are merely trying to find people to agree with your flawed grasp of the subject. If you actually have a real desire to know the truth about it then you'd contact a well known expert in the field such as my friend Dr. Oyvind Grøn
See: http://www.mn.uio.no/fysikk/personer/vit/ogron/   
From that website you can get his e-mail address and write to him. In the mean time you can see part of his body of work by looking up the textbooks he's written or go to the American Journal of Physics website and search for his papers. This will demonstrate that he's an expert in the field. You can also write to other relativists. I'm a relativist who disagrees with the nonsense you just posted but since I disagree with you you chose to be rude. Take my advice and don't be rude to the other relativists that you e-mail, should you take up my challenge.

I'm curious - Can you think of any reason why you wouldn't contact an expert in e-mail? I hope you don't refrain from doing so by assuming that such people are selfish and as such choose not to help others who contact them?

Quote from: mxplxxx
...is a lot of activity on physics forums regarding this question:).
Lol!! So what? The fact of the matter is that almost all members of such discussion forums have absolutely no idea what they're talking about when it comes to this subject whereas I have a very solid understanding as reflected by my interactions and discussions with experts in the top of these fields.

Quote from: mxplxxx
Doesn't Einstein postulate that space is elastic.
No. Absolutely not.

Quote from: mxplxxx
I.E. a particle moving into an area of space displaces that space space which springs back when the particle moves on?
That statement makes no sense as worded. Are you claiming that space is "displaced" because a particle moves into it and "springs back" when it moves out of it?? What utter nonsense. First of all there is no meaning to what you refer to as space being displaced. And the term "particle" is used to refer to objects whose mass is so small that it doesn't affect the curvature of spacetime.

And space doesn't "displace" (especially since that term is undefined in relativity). Matter "curves spacetime". Lookup what that means.

Since you were so rude in your response don't expect any help from me in the future or to read anything you post again.

Sorry to have offended you PmbPby. Personally I try and roll with the punches, that way future possibilities are left on the table. You will be tempted to keep answering my questions cos they are so interesting:).

"Displaced"  and "springs back" as in "space is a fluid" a concept that seems seems to be getting more and more traction with physicists.
 

Offline evan_au

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Re: Is space elastic?
« Reply #5 on: 15/10/2016 13:27:42 »
Quote from: mxplxxx
Given that space is expanding at present and maybe contracting at some time in the future...
One of the possible solutions of Einstein's General Theory of Relativity is that the universe may have sufficient density (and insufficient velocity), so that it expands, slows, stops, reverses, and collapses inwards, to a "Big Crunch".

Observations last century suggest that the density of the universe is fairly close to the value that would allow it to expand indefinitely - at least to the accuracy that astrophysicists believe they can measure.

More recent observations deduce the presence of Dark Energy, which seems to be accelerating the expansion of the universe. If this continues, the universe will not start contracting. It won't return to a Big Crunch, and may in fact suffer a Big Rip...

Quote
is it possible (space) is elastic?
An ideal elastic material follows Hooke's Law - if you stretch it to twice it's original length, the force required will double.

When you have masses in space, if you double their distance, the force between them will decrease by a factor of 4. This is defined by Newton's law of universal gravitation (or Einstein's General Relativity, if you want to be more accurate on cosmic scales).

So the behavior of ideal elastic materials is quite different from the behavior of masses in spacetime.
 

Offline Nilak

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Re: Is space elastic?
« Reply #6 on: 16/10/2016 18:08:30 »
If you compress spacetime the energy required is proportional to the compression magnitude.
 

Offline evan_au

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Re: Is space elastic?
« Reply #7 on: 16/10/2016 21:31:20 »
Quote from: Nilak
If you compress spacetime the energy required is proportional to the compression magnitude.
Please describe how you do this.
Also how you apply the energy and measure the energy involved.
 

Offline Nilak

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Re: Is space elastic?
« Reply #8 on: 17/10/2016 06:50:07 »
Quote from: Nilak
If you compress spacetime the energy required is proportional to the compression magnitude.
Please describe how you do this.
Also how you apply the energy and measure the energy involved.
One way is to use a particle collider to accelerate say protons. This will increase their mass and then spacetime compression will manifest as a gravitational force.

Another way is by bringing a heavy mass object wich we can attribute a potential energy equal to the energy of a collection of photons with the same motion mass.
 

Offline mxplxxx

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Re: Is space elastic?
« Reply #9 on: 20/10/2016 23:45:08 »
Of course if you stretch something, something must do the stretching. This could be achieved in the case of space by photons which end up at the edge of the universe. Space doesn't necessarily have to follow Hooke's Law because it is not a material.
 
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Offline jeffreyH

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Re: Is space elastic?
« Reply #10 on: 21/10/2016 00:15:03 »
Space contains objects but is not itself an object. Since it has no material presence it cannot have the property of elasticity. There is energy in the vacuum which must occupy space. Virtual particles may well exhibit properties that could be confused with elasticity. The action of dark energy on this vacuum energy may give the impression that space is elastic.
 

Offline Nilak

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Re: Is space elastic?
« Reply #11 on: 21/10/2016 06:05:00 »
In my opinion, umtil we have a complete theory, we can't say with great certainty, that doesn't have a sort of elasticity.
 

Offline yor_on

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Re: Is space elastic?
« Reply #12 on: 25/10/2016 13:26:10 »
Space is a 'geometry' that shows no resistance, and no friction. That's why objects keep moving indefinitely in it. It is also expected to be part of a 'field' as it can create pair productions of particles, more or less 'spontaneously'. The geometry though is what defines it and as there is no way, I know of, to 'compress' a absolute vacuum? It's a weird thing, necessary but weird.

« Last Edit: 25/10/2016 13:28:39 by yor_on »
 

Offline mxplxxx

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Re: Is space elastic?
« Reply #13 on: 26/10/2016 23:28:23 »
Of course if you stretch something, something must do the stretching. This could be achieved in the case of space by photons which end up at the edge of the universe. Space doesn't necessarily have to follow Hooke's Law because it is not a material.

And it seems to makes sense that the stretched universe contains energy that is elastic in nature. Possibly dark energy!
 

Offline zx16

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Re: Is space elastic?
« Reply #14 on: 27/10/2016 01:03:02 »
Isn't there a variant of "Godwin's Law" operating here, ie  - the longer the discussion goes on, someone will eventually mention "Dark Energy"
 

Offline mxplxxx

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Re: Is space elastic?
« Reply #15 on: 27/10/2016 04:42:29 »
Isn't there a variant of "Godwin's Law" operating here, ie  - the longer the discussion goes on, someone will eventually mention "Dark Energy"
Fascist swine:).
 

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Re: Is space elastic?
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