What is the fabric of space made of


by planck
Tags: fabric, space
Chrisc
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Jan2-09, 10:28 AM
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Quote Quote by tiny-tim View Post
ah …

so what is the recommended spin-cycle?

and should the dark matter be on a separate spin?
There is no fabric of space, mass is the "fabric", woven from the
Warp(space) and Weft(time) that is the geometry of GR.
That's why space is Warped when there is no time Weft you silly wabbit.
DaleSpam
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Jan2-09, 10:31 AM
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My apologies in advance for the boring and pedantic grammar instruction.
Quote Quote by planck View Post
Distances and angles are merely adjectives. But space is a noun that has dimensional properties.
No, "distances" and "angles" are nouns. The noun "distances" can be paired with a definite article "the distances" whereas adjectives cannot (e.g. "the red") and can be paired with an adjective "large distances" whereas a verb cannot (e.g. "large see"). Try the sentences: "The distances increased" and "The angles summed to 270º".
ThomasT
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Jan3-09, 01:14 AM
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Quote Quote by planck View Post
You would have a vibrating tub of water. But nonetheless, you would still have a tub of water where the medium would still consist of water.
The experiment I suggested illustrates one way to approach the issue that you brought up, "you can also fit a supermassive amount of particles in it also. Why is that possible?"

Quote Quote by planck View Post
Also, I'm not entirely sure about how exactly this would apply, but couldn't space be a higgs field?
That's a mathematical model. What space IS, in reality, is anybody's guess. My guess is that any volume is pervaded and permeated by all sorts of wave activity -- and that the medium or media in which that wave activity is occuring is what space IS. Maybe all detectable particulate media are byproducts of some fundamental seamless medium. Is that what you're wondering about? This stuff will remain speculative even if it's a logical extension of what's known.

I don't understand your other questions.
Dmitry67
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Jan3-09, 05:06 AM
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I think the reason why people are asking 'what space is made of?' is because of the intuitive perception that if something spacial is not made of something, it does not have a structure to support itself and collapses.

This is 'wired' (hardcoded) in our brain like the Neuton mechanics. Just compare, time and space are almost the same things but people ask about space 'what it is made of'? and regarding time they tend to ask different questions like 'is time actually moving'? etc.

This example illustrates that the 'requirement' that 'space must consist of something' to exist is nothing more then a naive vision based on our everyday experience and so called 'common sense reasoning'

When something is too abstract to deal with it in our everyday life people do not ask such questions, for example, people do not ask 'what energy is made of'? For the pure energy people somehow accept that it can just exist, without being consists of anything else.
Fra
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Jan4-09, 08:27 AM
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I throw in some thoughts to fuel the fire.

Quote Quote by Dmitry67 View Post
I think the reason why people are asking 'what space is made of?' is because of the intuitive perception that if something spacial is not made of something, it does not have a structure to support itself and collapses.
This isn´t such a bad rational as it might first seem. I think it suggest an answer.

What are questions made of? What supports a question? All questions is based on premises, necessary for the very formulation of the question. Questions don´t float in space, that depend on questioners, and I personally often thing of the essence of a question, as a property of the state of the questioner.

The original example of two hands beeing a boundary of the void. The question of what is the void, is pretty much the same question as what is the relation between the hands? or the distributed boundary? would it be possible to even pose the question of what is the void between the hands if the hands weren't there?

So the idea of pure space (pure gravity) is possible as strange as to ponder matter with no place to "sit". I often think of it as two sides of the same coin.

Olaf Dreyers, having some own ideas in "internal relativity" phrases it like this

"In our view, matter and geometry have a more dual role. One can not have one without the other. Both emerge from the fundamental theory simultaneously"
-- http://arxiv.org/abs/0710.4350

I guess what he says that there is little hope to find a consistent theory of say PURE gravity. Because the matter parts are required for consistency. I see this closely related to other obvious things, like that questions always live in a context. Measurements always live in context. The idea of ponder measurements, without an observers is to me the weirdest of all.

So my conclusion is that to ask what is spacetime is inseparable from the question what is matter, and how matter relates to itself.

So the question of what matter "is" in the mechanical sense might be a bad choice of question, but I would suggest the answer closest matching the question is that geometry is simply a state of matter. Then again, we are lead to ask what is matter. And they are related in an evolving relation.

/Fredrik
Dmitry67
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Jan4-09, 10:35 AM
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Quote Quote by Fra View Post
So the idea of pure space (pure gravity) is possible as strange as to ponder matter with no place to "sit". I often think of it as two sides of the same coin.

Olaf Dreyers, having some own ideas in "internal relativity" phrases it like this

"In our view, matter and geometry have a more dual role. One can not have one without the other. Both emerge from the fundamental theory simultaneously"
-- http://arxiv.org/abs/0710.4350
Interesting, but I am a fanatical adept of another religion :)

http://arxiv.org/abs/0704.0646
The Mathematical Universe
Authors: Max Tegmark

Let me give you some quotes regarding the subject we discuss (but it is much better to read the whole article):

All these theories have two components: mathematical equations and “baggage”, words that explain how they are connected to what we humans observe and intuitively understand.
<skipped>
However, could it ever be possible to give a description of the external reality involving no baggage? If so, our description of entities in the external reality and relations between them would have to be completely abstract, forcing any words or other symbols used to denote them to be mere labels with no preconceived meanings whatsoever. A mathematical structure is precisely this: abstract entities with relations between them.
<skipped>
The ERH implies that a “theory of everything” has no baggage.
2. Something that has a baggage-free description is precisely a mathematical structure.
Taken together, this implies the Mathematical Universe Hypothesis formulated on the first page of this article, i.e., that the external physical reality described by the TOE is a mathematical structure
So all these questions like "Does time actually flows? What space is made of? What is a vacuum? What is matter?" these questions are all about the "baggage" so in the ultimate sense they dont have any sense at all.
Chrisc
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#43
Jan4-09, 11:00 AM
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Quote Quote by Dmitry67 View Post
So all these questions like "Does time actually flows? What space is made of? What is a vacuum? What is matter?" these questions are all about the "baggage" so in the ultimate sense they dont have any sense at all.
This sounds like a "theory" of mathematics that requires the "baggage" it denies to support it's claims.
Dmitry67
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#44
Jan4-09, 12:25 PM
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No, read the chapter "Physics from scratch"
jambaugh
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Jan4-09, 02:35 PM
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Quote Quote by planck View Post
What is space itself made of? i.e. if you take both your hands and put them in front of you--parallel to your shoulders, what is the empty space between your hands made of.

Is this space just a void? Did this area of space between your hands exist before the big bang. And if it didn't, didn't this space need to be created?
My view is that space is not a physically existent object so the question is meaningless. Space is our conceptualization of the relationships (with regard to interaction) of physical objects/systems. It is no more real (and no less essential) than say abstract numbers.
Fra
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Jan4-09, 09:02 PM
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Quote Quote by Dmitry67 View Post
Interesting, but I am a fanatical adept of another religion :)

http://arxiv.org/abs/0704.0646
The Mathematical Universe
Authors: Max Tegmark
I've read that paper before. Interesting, but I don't see the clear utility of the abstraction he advocates.

Put shortly, my main general objection is that he is focusing on the so called birds view (also called the external view). This is to me, a way of reasoning that is old, I tried it and it didn't work for me This external reality, as seen from a fictive omnipresent and unconstraint observer (the "bird") is an abstraction that IMHO lacks physical motivation.

I favour the opposite, I consider the intrinsic view to be the scientifically motivated one. I see the external views to be emergent, but always in evolution.

I think that since Tegemark is unlikely to actually find and nail such an external view and moreover to communicate it to his fellow frog scientists, his choice is focus is totally akward to me. He seems to be an extreme reductionist. I am probably more like those solipsists that will reject his ERH.

My reason for rejection is that the hypothesis seems to me to lack utility unless that external mathematical structure is found. His hypothesis doesn't as far as I see help in finding it. Therefore I question the utility of his hypothesis.

/Fredrik
planck
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Jan5-09, 05:33 AM
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Quote Quote by ThomasT View Post
The experiment I suggested illustrates one way to approach the issue that you brought up, "you can also fit a supermassive amount of particles in it also. Why is that possible?"

That's a mathematical model. What space IS, in reality, is anybody's guess. My guess is that any volume is pervaded and permeated by all sorts of wave activity -- and that the medium or media in which that wave activity is occuring is what space IS. Maybe all detectable particulate media are byproducts of some fundamental seamless medium. Is that what you're wondering about? This stuff will remain speculative even if it's a logical extension of what's known.

I don't understand your other questions.
I'm not entirely sure what you are trying to illustrate with the vibrating tub of water, then. I'm correlating the water in the tub to being the medium in which objects in the tub are able to move in--much like the space I'm talking about.

So if space is merely "nothing," as some on this thread are suggesting. Then, wouldn't it be safe to assume:

1) Space had always existed, much like a solid-state, even before the big bang.

2) The big bang only introduced matter/energy into the universe.

3) Space is infinite.
Dmitry67
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#48
Jan5-09, 08:58 AM
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Quote Quote by planck View Post
1) Space had always existed, much like a solid-state, even before the big bang.
2) The big bang only introduced matter/energy into the universe.
3) Space is infinite.
For the spacetime of our universe (a brane) answers are:
1. no
2. no
3. probably yes

For the 'bulk' space
1. yes
2. n/a
3. yes
wolram
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Jan5-09, 09:15 AM
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Is fabric even the right word for space? fabric implies structure and AFAIK no one has found any structure to space.
ThomasT
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Jan5-09, 02:00 PM
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Quote Quote by planck View Post
I'm not entirely sure what you are trying to illustrate with the vibrating tub of water, then. I'm correlating the water in the tub to being the medium in which objects in the tub are able to move in--much like the space I'm talking about.
Yes, the water is the analog of your space (or at least some media component of it), and depending on the vibrational frequency you see more or different particles, or more energetic wave behavior and more complex wave interaction -- different interference effects. I was just suggesting one approach to how a given volume could hold more and more particles. Just spitballing -- my two cents.

Quote Quote by planck View Post
So if space is merely "nothing," as some on this thread are suggesting.
Or maybe there is a fundamental (seamless and therefore undetectable, fapp nothing) medium, from the agitation of which a hierarchy of detectable disturbances and media emerge, and it's some sort of mixture of all that that pervades and permeates the spatial volume defined by the boundary of our universe (if it has a boundary ... I think it's reasonable to assume that it does ... but who knows).

Quote Quote by planck View Post
Then, wouldn't it be safe to assume:

1) Space had always existed, much like a solid-state, even before the big bang.
Not necessarily safe , but it does seem reasonable to assume some sort of fundamental medium that our universe is a disturbance in.

Quote Quote by planck View Post
2) The big bang only introduced matter/energy into the universe.
It seems reasonable to assume some humongous initiating disturbance that shook up the existing medium and imparted a humongous amount of kinetic energy.

Quote Quote by planck View Post
3) Space is infinite.
stevebd1
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#51
Jan5-09, 04:51 PM
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An interesting overview from 'Special & General Relativity Questions and Answers' from the Gravity Probe B website (Credit to Naty1 for posting the link in this thread)-


If space exists, what is it?

This is the single most important question in modern physics. Einstein himself said that so far as his general relativity is concerned, space (actually space-time) and the gravitational field are the SAME THINGS. We see it as something that is empty because, in modern language, we cannot see the quantum particles called gravitons out of which it is 'manufactured'. We exist much like the raisins in a bread, surrounded by the invisible but almost palpable 'dough' of the gravitational field. In many respects there is no difference between the field that we are embedded in and the apparently solid matter out of which we are made. Even at the level of quarks, over 95 percent of the 'matter' that makes up a 100 kg person is simply locked up in the energy of the gluonic fields out of which protons are fashioned. The rest is a gift from the way quarks and electrons interact with a field called the Higgs field which permeates space. We are, really and truly, simply another form of the gravitational field of the universe, twisted by the Big Bang into a small family of unique particle states.
WaveJumper
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Jan5-09, 05:35 PM
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Quote Quote by stevebd1

If space exists, what is it?

This is the single most important question in modern physics.


Some 40 years ago James Bell proved that space is non-local. This is the best answer you could currently get about the ontology of space(though I must admit, it's probably not what you expected to find).
Hurkyl
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Jan5-09, 05:51 PM
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Quote Quote by WaveJumper View Post
Some 40 years ago James Bell proved that space is non-local. This is the best answer you could currently get about the ontology of space(though I must admit, it's probably not what you expected to find).
Firstly, James Bell proved an inequality that must be satisfied by a certain kind of theory. Empirical verification that the inequality was violated came later.

Secondly, the 'certain kind of theory' involved several different assumptions. That the inequality is violated means that one of those assumptions has to be given up -- but there is nothing to say which assumption has to be given up. (e.g. you could retain locality by giving up counterfactual definiteness)
planck
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Jan6-09, 01:14 AM
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Quote Quote by DaleSpam View Post
My apologies in advance for the boring and pedantic grammar instruction.No, "distances" and "angles" are nouns. The noun "distances" can be paired with a definite article "the distances" whereas adjectives cannot (e.g. "the red") and can be paired with an adjective "large distances" whereas a verb cannot (e.g. "large see"). Try the sentences: "The distances increased" and "The angles summed to 270º".
Yes, I'm aware that the words distances and angles are nouns. I meant that distances and angles are adjectives in the metaphorical sense.

Is this the physics forum or the english forum?


Quote Quote by ThomasT View Post
Yes, the water is the analog of your space (or at least some media component of it), and depending on the vibrational frequency you see more or different particles, or more energetic wave behavior and more complex wave interaction -- different interference effects. I was just suggesting one approach to how a given volume could hold more and more particles. Just spitballing -- my two cents.
Not really, because even in the tub of water with the vibrating frequency, you would still see the same number of particles. If you added more to the water, even something extremely dense, the water would be displaced. Space, on the other hand, is able to accommodate much more in a given cubic volume of space. I find this aspect of space extremely fascinating. The fact that the mass of the earth can be contained in a teaspoon, is beyond mind-boggling. How can space have these properties?



Quote Quote by stevebd1 View Post
An interesting overview from 'Special & General Relativity Questions and Answers' from the Gravity Probe B website (Credit to Naty1 for posting the link in this thread)-


If space exists, what is it?

This is the single most important question in modern physics. Einstein himself said that so far as his general relativity is concerned, space (actually space-time) and the gravitational field are the SAME THINGS. We see it as something that is empty because, in modern language, we cannot see the quantum particles called gravitons out of which it is 'manufactured'. We exist much like the raisins in a bread, surrounded by the invisible but almost palpable 'dough' of the gravitational field. In many respects there is no difference between the field that we are embedded in and the apparently solid matter out of which we are made. Even at the level of quarks, over 95 percent of the 'matter' that makes up a 100 kg person is simply locked up in the energy of the gluonic fields out of which protons are fashioned. The rest is a gift from the way quarks and electrons interact with a field called the Higgs field which permeates space. We are, really and truly, simply another form of the gravitational field of the universe, twisted by the Big Bang into a small family of unique particle states.
Exactly. It wouldn't be surprising if space, time, and gravitons all came together to create the space we're discussing. I just need to know what that dough is made of. (Please don't reply sugar, flour, yeast, egg, etc..)


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