What is the fabric of space made of

[Phrak]

Distances and angles are merely adjectives. But space is a noun that has dimensional properties.

For more stuff-like, than property-like space, you might want to look at this thread.

https://www.physicsforums.com/showthread.php?t=281754"

 

[Chrisc]

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.

 

[Dale]

My apologies in advance for the boring and pedantic grammar instruction.

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]

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?"

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 occurring 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]

I think the reason why people are asking 'what space is made of?' is because of the intuitive perception that if something spatial 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]

I throw in some thoughts to fuel the fire.

I think the reason why people are asking 'what space is made of?' is because of the intuitive perception that if something spatial 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]

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 don't have any sense at all.

 

[Chrisc]

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 don't have any sense at all.

This sounds like a "theory" of mathematics that requires the "baggage" it denies to support it's claims.

 

[Dmitry67]

No, read the chapter "Physics from scratch"

 

[jambaugh]

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]

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]

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 occurring 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]

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]

Is fabric even the right word for space? fabric implies structure and AFAIK no one has found any structure to space.

 

[ThomasT]

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.

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).

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.

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.

3) Space is infinite.

 

[stevebd1]

An interesting overview from 'http://einstein.stanford.edu/content/relativity/qanda.html" )-


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]

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]

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]

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? :tongue:

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?

An interesting overview from 'http://einstein.stanford.edu/content/relativity/qanda.html" )-


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..)

 

[ThomasT]

Not really, because even in the tub of water with the vibrating frequency, you would still see the same number of particles.

Just to make sure we're on the same page here -- I'm not talking about atoms, etc. The analogy has to do with the standing wave patterns that you see in the tub when you make it vibrate at certain frequencies. The patterns that you see in the water might be considered analogs of atomic and subatomic particles of the Standard Model.

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.

In the analogy, you create more or different particles by changing the vibrational frequency.

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?

If a volume the size of a teaspoon had a mass equal to the Earth's mass, then it would be a very very energetic volume. In the vibrating water tub analogy, this is suggested as you increase the vibrational frequency of the tub. Anyway, I think it should work that way ... although I haven't actually done it.

I just need to know what that dough is made of.

It seems that we'll never be able to know that. But it might be possible to understand particles that we CAN observe in terms of vibratory phenomena.

If you Google "standing wave patterns in water" or just "standing wave patterns" you'll get lots of hits that illustrate this idea.

Here's one with some photos and illustrations:
http://blazelabs.com/f-p-wave.asp

(Note: I don't know if this is a crackpotty site or not. But, it was at the top of the search results and had some nice pictures. )

There's lots of pictures and movies and animations of standing wave pattern generation on the www.

Another way to generate different standing wave patterns is to sprinkle sand or some other particulate matter on the head of a drum and then set the drum to vibrating at different frequencies.

 

[Hurkyl]

There's lots of pictures and movies and animations of standing wave pattern generation on the www.

Another way to generate different standing wave patterns is to sprinkle sand or some other particulate matter on the head of a drum and then set the drum to vibrating at different frequencies.

Such as this one: . (There are some other neat videos that you can find browsing from here)

 

[WaveJumper]

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)

I never liked this assumption as it would place us in a universe that's even weirder than a non-local one. And I don't like to believe we are puppets on strings. As a matter of fact, i don't like any of those choices but would go with non-locality for the consistency with CI and it's "user-friendliness".

 

[Hurkyl]

And I don't like to believe we are puppets on strings.

 

[wolram]

Doe,s not space also allow objects to exist, all massive things are mostly space, if the space of the universe exists, but space is not in massive (things),(things) could not exist, so space must be some thing, part and parcel of a thing.

 

[ThomasT]

Such as this one: . (There are some other neat videos that you can find browsing from here)

Thanks Hurkyl, there are some REALLY cool videos there. I think some of this stuff does give good hints about the deep nature of reality. What do you think?

 

[planck]

Just to make sure we're on the same page here -- I'm not talking about atoms, etc. The analogy has to do with the standing wave patterns that you see in the tub when you make it vibrate at certain frequencies. The patterns that you see in the water might be considered analogs of atomic and subatomic particles of the Standard Model.

In the analogy, you create more or different particles by changing the vibrational frequency.

You're saying that space vibrates to create the mass or objects (3D) that we see as tangible?

 

[WaveJumper]

I meant if you reject counterfactual definiteness, you have to say that when one person talks to another then you still cannot conclude that one person's choices about what to say affected what the other person heard(at a very long long distance in a FTL fashion). If you reject counterfactual definiteness you have to conclude that what i write on this forum will not affect what readers will comprehend. You must reject all evidence of causal influence completely. The way i see this is just one step away from giving up free will.
I don't think it's logical that we can discard counterfactual definiteness just on one occasion(Bell's theorem) and keep it for use on all other occasions and thus not reject the rest of science.

 

[Fra]

I meant if you reject counterfactual definiteness, you have to say that when one person talks to another then you still cannot conclude that one person's choices about what to say affected what the other person heard(at a very long long distance in a FTL fashion). If you reject counterfactual definiteness you have to conclude that what i write on this forum will not affect what readers will comprehend. You must reject all evidence of causal influence completely. The way i see this is just one step away from giving up free will.
I don't think it's logical that we can discard counterfactual definiteness just on one occasion(Bell's theorem) and keep it for use on all other occasions and thus not reject the rest of science.

I donä' think I got understand your logic in this reasoning regarding the problem of giving up CFD. But a guess is that you are worried about the subjectivity, and thus a problem of establishing objective causations when there is no definite basis?

If this is what you mean I kind of agree, but that is not a problem for me. I think objectivity is emergent, as the subjective systems interact. So causal laws are also emergent IMHO. This does not contradict any level of FAPP causality.

C. Rovelli phrased this well in this Relational QM paper.

"Suppose a physical quantity q has value with respect to you, as well as with respect to me. Can we compare these values? Yes we can, by communicating among us."
-- http://arxiv.org/abs/quant-ph/9609002

Then the idea is that any real life "communication" is always a physical interaction. I like to think for myself as the emergence of objectivity, as an emergent of consensus among systems/observers, and this has similarities to a negotiation or equilibration process.

I apologize if I missed the point.

/Fredrik

 

[ThomasT]

You're saying that space vibrates to create the mass or objects (3D) that we see as tangible?

It's one possible unifying conceptual approach. Wave mechanics, harmonics, etc. Not the only approach, but one that has some support wrt stuff that we're able to see.

Nobody has a definitive answer for the question that's the title of this thread.

 

[planck]

It's one possible unifying conceptual approach. Wave mechanics, harmonics, etc. Not the only approach, but one that has some support wrt stuff that we're able to see.

Nobody has a definitive answer for the question that's the title of this thread.

I'm not sure if I could agree with the idea of waves creating reality because this would mean that:

1) space is matter and matter is space.
2) space manipulates our perception of the tangible, so it's our limited senses that account for the inability to distinguish between the two.

 

[ThomasT]

I'm not sure if I could agree with the idea of waves creating reality because this would mean that:

1) space is matter and matter is space.

Maybe there's a fundamental, seamless, undetectable, and hence immaterial, medium corresponding to your space from which a hierarchy of particulate media emerge and interact to form what we call ponderable matter.

2) space manipulates our perception of the tangible, so it's our limited senses that account for the inability to distinguish between the two.

There's certainly more to reality than we're able to directly sense. If there is a fundamental medium (space) and it's perfectly seamless, contiguous, non-particulate in it's undisturbed state, then, as far as we can be concerned, it's not a material thing. But, wrt material things that emerge due to disturbances in the fundamental medium (space), then we are sort of indirectly observing space after all.

All of this is just conceptual spitballing of course -- though some would argue that a wave theory of nature (including some sort of fundamental medium) might be heuristically more useful than the current trend wrt eventually developing a conceptually unified, more or less realistic, description of reality toward a true understanding of Nature. But I wouldn't bet on any of that happening. More than likely, imho, people will be having these same sorts of 'what if' discussions 500 years from now -- and we won't be very much closer to a unifying conceptual understanding of Nature than we are now.

Then again, it's fun to speculate and see connections and so on. Who knows maybe we'll stumble onto something. It's like the lotto in that the chance of success is ridiculously small, but it we don't play then we CAN'T win.

Good luck with your spatial musings.

 

[Dale]

Yes, I'm aware that the words distances and angles are nouns. I meant that distances and angles are adjectives in the metaphorical sense.

I certainly wasn't speaking metaphorical sense. Spacetime does not need anything other than geometric properties in order to "bend" etc. You need not suppose any material properties.

Nobody has a definitive answer for the question that's the title of this thread.

I do, and I already gave it:

Spacetime is just the geometry of physics.

 

[planck]

I certainly wasn't speaking metaphorical sense. Spacetime does not need anything other than geometric properties in order to "bend" etc. You need not suppose any material properties.

You cannot be so sure of what the fabric of space is made of, considering physicists themselves aren't sure. I am assuming that space is "something." I base this presumption on the idea that matter needs an environment to exist. And since the big bang is assumed to have given birth to this matter, I would also assume it gave birth to the medium that it will coalesce in. So when I asked what is "something" made of, you replied, "something is made of nothing." It may be nothing, in which case space (vacuum, void, empty space, ether, etc.) had always existed even at T=0

 

[planck]

It looks like it turns out richard feynman may have an answer to my question. And his theory of Quantum electro-dynamics supposes that my "empty space" acts as an active conduit between dimensions/states...in a virtual, particle infested, quantum foam.

So for those of you who are claiming that empty space is "nothing" or just geometry, have some explaining?

 

[Dale]

You cannot be so sure of what the fabric of space is made of, considering physicists themselves aren't sure.

What a silly objection, of course I am not sure. We are talking about science, not religion or politics. There isn't anything "sure" in science.

So when I asked what is "something" made of, you replied, "something is made of nothing."

I never said any such thing, I always said that spacetime is the geometry of physics. Geometry is not nothing, it is just not a material "thing" (i.e. it has no material properties, only geometrical ones).

It looks like it turns out richard feynman may have an answer to my question. And his theory of Quantum electro-dynamics supposes that my "empty space" acts as an active conduit between dimensions/states...in a virtual, particle infested, quantum foam.

So for those of you who are claiming that empty space is "nothing" or just geometry, have some explaining?

You do not understand QED and spacetime. QED is a background dependent theory (which is one of the big problems in modern physics). In QED the "quantum foam" that you mention is not space, it is what happens in otherwise empty space. In all modern theories spacetime is simply the geometry of physics.