What is the fabric of space made of

[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?

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.

 

[Fra]

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

I think I loosely addressed this questions in my posts in this thread, though not perhaps explicitly.

If we reduce space to geometry, we can ask then "what is geometry made of". As I tried to imply, IMHO this is a relation between the observer and the observed. And thus ultimately a relation between matter and it's environment. In particular in the abstraction of the observers information about it's enviroment, and the "local picture" of the state of the world, that's implied by a systems information abount the remainder of the universe. In this information geometry can be defined as properties of information. See http://en.wikipedia.org/wiki/Information_geometry.

I maintain my personal opinon that empty space makes as little sense as does matter without space, and as does observations without observers.

I think this ultimate meaning of this apparently circular argument is difficult to get a grip on. It has taken me som time to acquire an intuitive understanding of this. But now I think it has a deep satisfactory beauty. The concept goes hand in hand with an evolutionary view of relations. All relations evolve, without fixed points.

The problem with a lot of normal info.geometry is that it's using a background. Like a notion of a background probability or universal entropy. But this can I think be improved. I think it's still an open question. But to me the choice of direction is clear.

/Fredrik

 

[Dale]

If we reduce space to geometry, we can ask then "what is geometry made of". As I tried to imply, IMHO this is a relation between the observer and the observed. And thus ultimately a relation between matter and it's environment.

I think you are essentially stating Mach's principle which is broadly accepted. However, the question "what is geometry made of" is loaded since it implies the conclusion that geometry is made of something. That said, I agree completely that in physics geometry describes the relationship between physical things (I wouldn't limit it to observers and the observed). This is the sense in which spacetime was created at the big bang and the sense in which the universe expands.

 

[Fra]

I think you are essentially stating Mach's principle which is broadly accepted. However, the question "what is geometry made of" is loaded since it implies the conclusion that geometry is made of something. That said, I agree completely that in physics geometry describes the relationship between physical things (I wouldn't limit it to observers and the observed). This is the sense in which spacetime was created at the big bang and the sense in which the universe expands.

Yes, "what geometry is made of" might be a strange question, but as I interpret it, is what's the physical basis for geometry? I mean, I think my deviation from what almost all physicists would agre on is: Geometry is an mathematical abstraction. Alot of people are not disturbed by the fact that even the laws of physics, stated as mathematical laws are abstractions. Some have no problem to see these laws as independent of the physical world. I have a problem with this.

The physical basis I refer to, that solves this, is basically part of the observer. It means that there is not really any universal, observer-independnet laws, because even relations between objects, needs to be related to by other systems. Ie. you can only relate to a relation.

This is why I personally think the idea of perfect universal symmetry as a means to look for unification is not as good guide as it perhaps was 100 years ago. Because the notion of symmetry itself, is relative. In say GR, the observer invariants are assumed to be eternal laws of physics, but it doesn't handle the fact of information exchange and representation and the fact that the knowledge about these laws, are constrained to parts of the system.

I've posted about my opinions in many other threads, and this isn't the best exposition but as I see it, this takes machs principle to another level. Not only is physics about relations, the point is that there are also only relations to the relations! There is no fixed reference to even described a relation. This is the B/I problem, taken to more than just spacetime, it applies to all laws and statements.

The interesting question isn't if space is made of wood or wool, but what the physical representation of the information, implied in the abstractions used (ie geometry etc). Clearly this abstraction is encoded somewhere, at minimum in the scientists brain.

I am essentially critizising a realist view of physical law. Even if we think of laws as relations, the consistency of reasoning doesn't hold if we think of knowledge about this physical law as a non-relation.

/Fredrik

 

[Fra]

in physics geometry describes the relationship between physical things (I wouldn't limit it to observers and the observed).

Of course I agree with this as well. My choice of "observer" was meant not as a limit, on the contrary, do I see the analogy between observation / observer, and relations / matter in physical systems. A physical system, is well qualified as "an observer" in my abstraction. Could be an atom for example.

So when I said observation, I have in mind a "physical observation", ie basically a physical interaction. To me there is a difference in tone here, since I like the information picture better. Communication, observation and physical interactions are to me different words for the same thing.

/Fredrik

 

[stevebd1]

In theory, the energy that makes up both matter and space combines at Planck dimensions, creating a quantum 'foam' supported by either Loop Quantum Gravity or strings so if matter/space was to collapse to Planck dimensions, it would be a combination of both matter and space rather than just collapsed matter in space. I can't remember where I read this but it does imply that space has a constitution. I have heard that virtual particles, while virtual, do contribute some kind of residual effect or wave that possibly supports the existence of space (I suppose this is backed up to some extent by the Casimir effect).

 

[ThomasT]

Originally Posted by ThomasT
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.

I don't see spacetime in the title of this thread.

planck wants to know the physical makeup of the fundamental medium. Nobody knows -- and if the fundamental medium is structureless, then nobody ever will know. We're limited to conjecturing quantum foam(s) or strings, etc., which are at least one step removed from a fundamental medium that might be called space itself.
It seems that questions regarding the fabric of space will always have to do with some sort of activity as far as we can be concerned.

 

[Dale]

I don't see spacetime in the title of this thread.

This is a rather trivial objection to my point. Space is just any arbitrary spacelike hyperplane of spacetime, it is still just the geometry of physics. I simply use the word spacetime because it concisely implies that the geometry is not Euclidean.

The point remains that spacetime is nothing more than the geometry of physics and has only geometric properties such as distances and angles. This view is a core part of all mainstream physical theories including Newtonian physics, relativity, and QM, and is supported by several centuries of experimental evidence.

 

[Mk]

No, space did not exist before the big bang, yes, it was created, along with everything else.

You say that like you are so sure.

 

[tiny-tim]

You say that like you are so sure.

(that was seventy-six posts ago! )

Maybe he was there! ​

 

[ronjanec]

I believe space is a static singular distinct physical entity. The seamless physical material that makes up the fabric of space is not made up or composed of any particles or things or is like a elementary particle or fundamental particle in it's compostion.

Because of it's no particle or thing composition the space entity could also exist on the smallest level or say between the nucleus of the atom and it's electron(s), eliminating the illogical nothing existing here. The space entity is also any vacuum existing anywhere or is what is left after someone removes the air from something.

How large is the space entity? If you look at this from a strictly scientific viewpoint it must be infinite and have no end(s).

 

[martin1223]

Spacetime is just the geometry of physics.

You can describe a geometric shape and curve it mathematically but space-time actually curves; it certainly has the characteristics of a thing. Is the Universe a thing if it was empty? I guess I am asking are dimensions things? What happens to space-time near a black hole?

 

[martin1223]

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..)

Why space-time is the dough, the basic thing in the universe curves and stretches out of existence into a black hole. Before the big bang, there was no-thing.

 

[jreelawg]

Nobody knows. Fabric of space time is a concept of general relativity, and doesn't really seek to answer that. If you notice the term space, which refers to measurements of distance and such, often called the metric, or the ruler. The concept is that distance and time are linked and both relative.

I think we will probably learn more about the nature and relationship of what it means for something to be something, and of what it means for something to have observable properties, and how it relates to what we cannot observe that fills the voids of what we can.

I just don't see why everything that exists ought to be observable? I am very open to the idea of things that may be closer to us and more fundamental than anything else which may be entirely unobservable. I suspect that if something is to be learned in this way, it will have to come from interpretation, and won't necessarily be verifiable mathematically.

I guess I'm talking about metaphysics which isn't looked upon highly of by many physicists and mathematical thinkers, and I think that this is due partially to lack of advancement in the subject. In the olden days, people tried to interpret the very limited knowledge they had and came up with various metaphysical theories. I have hopes that one day, after the LHC and other new age experimentation have been explored and as the pieces of knowledge begin to unfold, a modern interpretation of metaphysics will be the answer to the question, and will evolve over time getting clearer and clearer, until our understanding of the universe, space, time, and everything in between will be eventually be understandable by even the layman.

 

[tauon]

it's made of nothing at all.

 

[Sorry!]

it's made of nothing at all.

Oh really! What a fascinating remark, and where is your source for this cause I would love to read through it.

 

[tauon]

Oh really! What a fascinating remark, and where is your source for this cause I would love to read through it.

mathematics...

space is a mathematical framework of relations between objects, it is the distances between things and a web of geometric relations.
but mathematics is merely a concept, not something "physical".
ergo, space is merely a conceptual framework.

 

[Sorry!]

mathematics...

space is a mathematical framework of relations between objects, it is the distances between things and a web of geometric relations.
but mathematics is merely a concept, not something "physical".
ergo, space is merely a conceptual framework.

Oh, how interesting. Mathematics is your source for this. Well then, show me your mathematics to PROVE that space is nothing. Tut, tut now.

And yes it is going to have to PROVE that space is nothing because you've taken space out of the science realm where nothing is proven and brought it to the mathematical realm, where proofs exist.

 

[jreelawg]

mathematics...

space is a mathematical framework of relations between objects, it is the distances between things and a web of geometric relations.
but mathematics is merely a concept, not something "physical".
ergo, space is merely a conceptual framework.

Space is nothing but a concept, but what about the fabric of Space? That is an entirely different question then asking what space is. This is a question that is beyond mathematics. The answer to this is found through observation and interpretation, if possible at all. As it is, space is used as a tool to describe objects, how fast they are moving, how far apart they are, and how massive they are. People sometimes mistake the fact the relativity doesn't say anything about what the fabric of space time is, for a belief that nothing is there at all.

 

[jreelawg]

Imagine that there was a time not so long ago when man thought that the air was nothing. Even though we felt wind, and had to breath, nobody could explain what it was, and probably thought nobody ever could. I think there is a syndrome man gets when some sort of knowledge is out of his reach, we make something up, or deny the existence of, and close the case until a rebel proves us wrong. I think one day this will happen again.

 

[tauon]

Oh, how interesting. Mathematics is your source for this. Well then, show me your mathematics to PROVE that space is nothing. Tut, tut now.

And yes it is going to have to PROVE that space is nothing because you've taken space out of the science realm where nothing is proven and brought it to the mathematical realm, where proofs exist.

Oh, what a fascinating personality you have.
I already made my point, if you are unable to comprehend it that's your problem, especially since I feel like I'm talking to a bratty little kid who just lost his candy and now is pissed at everyone, but fine:

When I said that space is nothing I meant it in the sense that space is not a substance, that it is not something physical - physical like elementary particles are discrete physical "objects" (as I clearly pointed out in my second post). My reasoning for it was self-evident and simple: we never observe space outside of a mere relational construct between objects. And that relational construct we use is mathematics (especially in a scientific context, and not a colloquial one) - space is in a way, just mathematics.

But mathematics is not a physical substance - it is merely a concept, a collection of ideas (of course for the sake of brevity, I am oversimplifying the description of mathematics).

 

[Sorry!]

Imagine that there was a time not so long ago when man thought that the air was nothing. Even though we felt wind, and had to breath, nobody could explain what it was, and probably thought nobody ever could. I think there is a syndrome man gets when some sort of knowledge is out of his reach, we make something up, or deny the existence of, and close the case until a rebel proves us wrong. I think one day this will happen again.

Some guy in the early 1900s wrote papers about some sort of 'sea of negative energy' Dirac or something. Not accepted mainstream in physics though.

Space to me is just a concept therefore the question what is space made of, or even the fabric of space. Is begging the question. So the answer isn't 'nothing', at least I don't think... it's that such questions don't make sense.

It's like asking what is outside the universe. Some scientist might say 'nothing' but that is because it is beyond the scope of attainable knowledge so it is a pointless question.

 

[jreelawg]

It's like asking what is outside the universe. Some scientist might say 'nothing' but that is because it is beyond the scope of attainable knowledge so it is a pointless question.

Exactly, but there is a history of underestimating our scope.

I also don't like the term outside the universe. There is a limit to how far we can see, but that doesn't make what we can't see not part of the universe.

 

[tauon]

@jreelawg:

Occam's razor.
All physical facts can be described in terms of properties of objects and the relations between them.
Why should we suddenly introduce another object (a physical spacetime) when it is not necessary?

 

[Sorry!]

Exactly, but there is a history of underestimating our scope.

I also don't like the term outside the universe. There is a limit to how far we can see, but that doesn't make what we can't see not part of the universe.

Sure we may be underestimating our scope but until the time that we realize the potential we have been failing to see questions as such remain pointless. Space by definition is merely a concept and answering what it is made of makes no-sense.

 

[jreelawg]

@jreelawg:

Occam's razor.

That's an easy way out isn't it. So a fabric of space time doesn't exist because it isn't necessary to make calculations about objects. Is that what your getting at. What if you want to know if space time is something, and what it is, rather than how an object is behaving relative to another.

 

[jreelawg]

@jreelawg:

Occam's razor.
All physical facts can be described in terms of properties of objects and the relations between them.
Why should we suddenly introduce another object (a physical spacetime) when it is not necessary?

As I stated before, whatever the fabric of space time is, it may have components which exist and are by nature unobservable directly by physical instruments. Sometimes the words don't exist to try to explain such things. I don't know if something has to be physical as we know it to exist. As you state, physics isn't very concerned with things like this, and as I stated, it will be interpretive metaphysics of the future that best explain these "pointless" questions.

I am not suggesting changing the theory of Relativity, or anything, just expressing my belief that one day a more sensical understanding will be possible.

 

[nevagil]

My first thought is that it's made of the same stuff we are. Processed more or less. It makes me wonder how much space is in me in that particular form.
It feels good if I wave my hand thru it.


Meditate, don't medicate.

 

[Dale]

You can describe a geometric shape and curve it mathematically but space-time actually curves; it certainly has the characteristics of a thing. ... I guess I am asking are dimensions things?

This depends entirely on the definition of the word "thing". It is a semantic argument that is rather uninteresting.

What happens to space-time near a black hole?

It curves a lot.

 

[petm1]

I think of light as being the fabric of space, with the photon as the thread and matter the ball of yarn. That would make space the loom, time the the room, and you can believe in any weaver that you want. Sorry if this seems to simple but it made me smile when I thought of it.

I wrote this back in 08 in another thread but I still like it.

 

[tauon]

As I stated before, whatever the fabric of space time is, it may have components which exist and are by nature unobservable directly by physical instruments. Sometimes the words don't exist to try to explain such things. I don't know if something has to be physical as we know it to exist. As you state, physics isn't very concerned with things like this, and as I stated, it will be interpretive metaphysics of the future that best explain these "pointless" questions.

I am not suggesting changing the theory of Relativity, or anything, just expressing my belief that one day a more sensical understanding will be possible.

if as you say, the supposed "fabric" of spacetime is experimentally unobservable, than it is not falsifiable, hence not something science can address.
and if that's the case than pretty much any view stands, we could even say the fabric of spacetime is made of cosmic butterflies, or godly chocolate. evidently, I'm not a "fan" of "metaphysics".

also, I would like to clarify that I did not state that spacetime does not exist, but that it isn't a physical "substance", that it's merely a conceptual framework: it is [mathematical] relations between objects and events.