Of what does Space consist?

[skippy]

There are, right now, hundreds of theoretical physicists who have spent their entire adult lives trying to answer this question. There are three or four directions that they are following (Loop Quantum Gravity, String Theory (AKA M-Theory), Causal Dynamical Triangulations, Graphity &ct.). Some of them (e.g. String Theory) assume a preexisting void or "container space", others hypothesize an underlying structure (spin-foam, loops or graphs) which, WHEN VIEWED ON LARGE SCALES, give an intuition of a continuous spacetime. In any event, it is well to remember that physics and science in general CANNOT PROVE ANYTHING. Theories which have explanatory power are put forward and they stand until proven false. The General Relativity and the "Big Bang" currently have a lot of explanatory power and have yet to be proven wrong. If you accept it as an explanation, then it is the event which created all the physical space and time of our universe. To ask where it occurred or what came before or what is outside our (probably finite) space is as meaningless as asking "What is South of the South Pole?"

Skippy

Edited March 13, 2009 by skippy

[Plasmatic]

There are, right now, hundreds of theoretical physicists who have spent their entire adult lives trying to answer this question. There are three or four directions that they are following (Loop Quantum Gravity, String Theory (AKA M-Theory), Causal Dynamical Triangulations, Graphity &ct.). Some of them (e.g. String Theory) assume a preexisting void or "container space", others hypothesize an underlying structure (spin-foam, loops or graphs) which, WHEN VIEWED ON LARGE SCALES, give an intuition of a continuous spacetime. In any event, it is well to remember that physics and science in general CANNOT PROVE ANYTHING. Theories which have explanatory power are put forward and they stand until proven false. The General Relativity and the "Big Bang" currently have a lot of explanatory power and have yet to be proven wrong. If you accept it as an explanation, then it is the event which created all the physical space and time of our universe. To ask where it occurred or what came before or what is outside our (probably finite) space is as meaningless as asking "What is South of the South Pole?"

Skippy

Skippy,Poppers nonsense is not a proper foundation for physics."Falsificationism" is bankrupt scepticism.

[skippy]

Skippy,Poppers nonsense is not a proper foundation for physics."Falsificationism" is bankrupt scepticism.

I am totally unfamiliar with Poppers.

Just what do we do with theories that are proven wrong??? Put them to a vote???

What do we do with new theories which predict things the old theories can't? Put our heads in the sand?

Aristotle gave us earth, air, fire and water = PHYSICS.

Plasmatic thinks Aristotle was a really smart guy.

Therefore everything can be explained in terms of earth, air, fire and water.

Are you living in a parallel universe, or what.

Cheers, Skippy

[Steve D'Ippolito]

It's Karl Popper. (Plasmatic left out the apostrophe in "Popper's nonsense")

Popper basically believed you could never be certain your theory was right, but that you could be certain a theory was wrong once it had been falsified, i.e., something had turned up showing that the theory was wrong. Well, he was right about that last part: You can be certain a theory is wrong if some "inconvenient" fact contradicts it. The problem with Popper is that apparently this is the only way you can judge a theory. It's (tentatively) possibly true until you find some reason to dispute it. Now this alone has some bad consequences; I could posit that there are green men living a thousand miles underground (somehow resistant to the white-hot heat down there), and that would never be "falsified". Popper attempts to overcome this rather egregious shortcoming by claiming that a theory must be in principle falsifiable, i.e., there must be a way it can be shown to be wrong, if it is wrong. This is not ridiculously far from our concept of the "arbitrary." It's frustrating actually, this guy started from a skeptical base (not being able to know things with certainty) and came up with half of the notion of the arbitrary and some rules that are not bad rules--just woefully incomplete.

Like many modern philosophers there's a tiny bit of truth in what they are talking about, but then it is extrapolated to try to cover phenomena it shouldn't or is otherwise assumed to be the whole story, because of a skeptical world view or denial of the existence of consciousness (as with the "behaviorists").

Another big problem with Popperism is he basically recomments scientists come up with just any old hypothesis and test it; if it passes enough tests it becomes promoted to "theory". Just running an experiment to see what happens doesn't cut the mustard with him; he certainly wouldn't want you to tentatively induce a hypothesis and then test it.

[caveat: I have not read Popper directly but I have read some scientists' wors about the modern methodology they use and claim it came from Popper. If they are wrong to attribute that to Popper or my interpretation of their methods is wrong, then I am wrong about what Popper said.]

[Plasmatic]

I am totally unfamiliar with Poppers.

Just what do we do with theories that are proven wrong??? Put them to a vote???

What do we do with new theories which predict things the old theories can't? Put our heads in the sand?

Aristotle gave us earth, air, fire and water = PHYSICS.

Plasmatic thinks Aristotle was a really smart guy.

Therefore everything can be explained in terms of earth, air, fire and water.

Are you living in a parallel universe, or what.

Cheers, Skippy

You obviously are unfamiliar with the source of your earlier comments about proof.Your comments about Aristotle are arbitrary nonsense, not to mention straw men.

Look up POPPER AND AFTER by D. Stove.

[crizon]

Another assertion that it is simply wrong, that the person can't imagine it, and it doesn't make sense to him. If it doesn't even make sense to you, then you can't even evaluate it as right or wrong.

Imagining freezing the universe is easy. Imagine you are standing away from everything in the universe with a camera and are taking photographs. The camera is special in that it detects everything in the universe simultaneously. Each photograph is an example of what one sees if they "freeze the universe". The issue here is not whether this can be actualized by a human, but whether we can imagine it.

I think this statement shows most clearly that you don't understand what measurment and observing means. Your subject that is taking photos must be part of your system and is therefore not "frozen".

Also when you are talking about measuring 2 entities you need a subject first. You can't measure without interaction.

If it is not part of your system, it can never measure the system. That is _fundamental_. So that thought doesn't make any sense in a physical perspective. You might use it for a movie.

I didn't read all your posts in this forum but i think you did not understand what QM says about the relation of object and subject since i never saw you taking that into account in the right way. I suggest you read "dr bertlmanns socks".

Edited April 21, 2009 by crizon

[Grames]

I'm gad crizon dug up this old thread, I have something to say that is on topic.

Space is suffused with at least electric and magnetic fields. These are real in that they store and release energy and obey conservation laws. Electromagnetic waves transport linear momentum. The orbital angular momentum of an atom changes when it emits or absorbs a photon, thus by conservation the photons involved must carry angular momentum.

Fields have indefinite boundaries, but a definite value can be computed at every point with respect to a source. Fields from multiple sources obey the superposition principle, meaning they add linearly. Empty space has measurable properties called the permeability of free space and the permittivity of free space. Permeability (greek letter μ) is a measure of the ability of a magnetic field to propagate through that medium, permittivity (greek letter ε) is a measure of the ability of an electric field to propagate through that medium.

The speed of light c=1 ∕ √εμ for any medium, where ε and μ take on values for that medium.

Are fields entities? Well, a photon is routinely regarded as an entity which propagates, carries energy, transfers linear and angular momentum. But it is merely a pair of fields. Fields are entities.

Space is measurable attributes. Attributes are not separable from entities. Therefore space is an entity.

Edited April 21, 2009 by Grames

[aristotlejones]

Space is measurable attributes. Attributes are not separable from entities. Therefore space is an entity.

Thank you Grames for a succinct and comprehensive description of space that finally includes e-m fields, as the overwhelming observational evidence of the past 50 years demands. I have been struggling with theories of the electric universe/ plasma cosmology crowd, and your description brings me that much closer to an integrated understanding of the topic.

You might be interested in one of the resource sites on electric universe theory:

Thunderbolts at www.thunderbolts.info

Stay Focused,

<Φ>aj

Edited April 24, 2009 by aristotlejones

[DavidOdden]

Popper basically believed you could never be certain your theory was right, but that you could be certain a theory was wrong once it had been falsified, i.e., something had turned up showing that the theory was wrong.

Though that is just one of many undigested aspects of his crazy epistemology. Refutation depends there being a theory of the observation itself (for example a theory of how a gadget reflects "temperature" or "mass"), so if any observation is to actually refute a theory, the observation must actually be certain, which means the underlying theory of the measurement must be certain. But that is impossible. So for a consistent Popperian, refutation itself is possible only probablistically, depending on the extent to which you believe the foundational elements of your supposedly refuting observation.

[altonhare]

I think this statement shows most clearly that you don't understand what measurment and observing means. Your subject that is taking photos must be part of your system and is therefore not "frozen".

Also when you are talking about measuring 2 entities you need a subject first. You can't measure without interaction.

If it is not part of your system, it can never measure the system. That is _fundamental_. So that thought doesn't make any sense in a physical perspective. You might use it for a movie.

I didn't read all your posts in this forum but i think you did not understand what QM says about the relation of object and subject since i never saw you taking that into account in the right way. I suggest you read "dr bertlmanns socks".

You're the one who is not understanding. The purpose is to step back and ask what the universe would be like if we were omniscient. Then we draw deductions about what humans will observe in such a universe. If what we observe is consistent, this is support for the universe as we imagined it.

I'm gad crizon dug up this old thread, I have something to say that is on topic.

Space is suffused with at least electric and magnetic fields.

Replace the word "space" with any other word. If you claim X is "suffused" then I have a right to ask you what IS X? Then it is your responsibility to point to X. If unable to point to the actual X, you will at least have to show a picture or model. If you cannot fulfill this simple minimum condition, then "X" is a wildcard, a floating abstraction.

These are real in that they store and release energy and obey conservation laws.

What's 'a' field? I'm not asking for a description or a quantification, I'm asking you what IS it, paleface? I'm an ET.

Electromagnetic waves transport linear momentum.

Impossible. Motion cannot be transferred like an entity itself. Transfer itself involves motion. You're talking about the motion of motion.

We still need to see 'a' field/EM wave, so we can even know what's moving.

Fields have indefinite boundaries,

Then they are most certainly not entities.

Empty space has measurable properties

Empty: nothing

Are you saying space is nothing or that it is an enclosure, inside of which there is no entity present? Is space like a box?

Are fields entities? Well, a photon is routinely regarded as an entity which propagates, carries energy, transfers linear and angular momentum.

transferring motion? Moving motion? You've gotta be kidding me.

But it is merely a pair of fields. Fields are entities.

Point.

Space is measurable attributes.

Space is an attribute? And all this time I thought you were saying it was an entity!

Attributes are not separable from entities. Therefore space is an entity.

This is insane. This summarily converts all attributes into entities, a completely absurd notion.

[altonhare]

In response to criticisms of my denial of "instantaneous velocity" or in general "instantaneous change", especially as it relates to calculus, this person has written well on the topic and reflects a lot of my own thought:

http://milesmathis.com/are.html

[Krattle]

I think Harriman (sp?) said it well in his lecture on physics. When you look at an empty room, you ask, what are we going to do with all this space?

What you do is you arrange furniture in that space. But what you *aren't* doing is taking that "empty space" out of the room to make way for furniture. You're not saying, "let's get this darn space out of here so I can put some furniture in."

In other words, space is a concept of method. It just denotes the distances between entities, not an actual entity itself. So there is no "outer space" per se. No, there are just a plenum of entities.

And on the subject of infinity. There is actually infinity, of a type, but I'll state it this way. The number series is infinite; you can keep thinking of a larger number and never run out of numbers. But each number is still finite. Googolplex is huge, but finite.

Applied to "outer space," you can keep going and finding new things (so far we've looked 14bl ly out, no?), but no matter how far away you move from your starting point (the Earth), you'll always be a finite distance away. So, even though we've only seen 14 billion light years out from the Earth, that doesn't mean we've seen to the physical boundaries of the universe. There is no such thing as a boundary to the universe (it is everything). It probably just means indicates a limitation to our technology, or perhaps, when we look that far out EM radiation becomes to garbled to resolve it. (alternative explanation for microwave background perhaps?). What I find VERY, VERY interesting is that astronomers keep finding fully formed, gigantic galaxies 13.5 and 13.8 billion light years away, almost completely contradicting the Big Bang theory.

One more point: there should be no limit on how far back in time, how far away we can look. You can't say: oh, well we've only seen 14 billion light years out because beyond that point nothing has existed long enough for its light to reach us. Nonsense! You're now implying a beginning of all time, which can't exist. Of course there's stuff that existed 14 billion years ago, and even 25 billion years ago. We just haven't seen that far yet. Even if those entities had stopped existing, their light would still be traveling to us.

One thing I can say for sure, I completely disagree with the Big Bang theory as beginning of the universe. Only if you define universe as an incredibly limited entity within the realm of existence (i.e we exist within some kind of bubble) will I accept that theory. But otherwise, the idea that matter, energy, and time began at one point is utter nonsense and contradicts the basic axioms of existence and identity. Time cannot begin, matter and energy cannot be created. Time exists within the universe because the universe is everything. You cannot create energy and matter because that would necessarily imply creation ex nihilo. Congratulations, you just contradicted several Laws of Conservation and the basic axiom of all thought: existence exists.

[nanite1018]

Krattle, I can assure you that no scientist in the world believes the Big Bang was the beginning of existence. There are a number of suggestions for what it actually was (a collision between two universes, acting as a sort of reset for both, or the moment our universe split off from the interior of a black hole in another universe, or the point at which the universe suddenly inflated from a microscopic portion of an infinitely large space, or even some sort of loop in time where the universe creates itself, etc. etc. etc. etc.), but we don't really know. Every book I've ever read on the subject suggests that existence has been infinite, in some sense, and that the universe is not the only universe which exists in the whole of existence.

Scientists use the term "universe" in the limited sense of the visible universe and the matter/energy/space/time within it, the things we can interact with in some way, our space-time structure, etc. It does not, ever, mean "the whole of all that exists", something that seems to trip up Objectivists when discussing physics and cosmology. And since physics has this definition of universe, when they say the universe came into existence 14 billion years ago, they are saying that the world we see around us and interact with in some way came into existence 14 billion years ago, not that all existence "began" 14 billion years ago.

As for the question of space, I have trouble with it as well, since it isn't an entity, yet it seems as though certain theories treat it as if it was, relativity theory in particular. This is something I don't care for. I worked out the basic equations of special relativity by simply assuming that the speed of light is constant and that it is, at root, our measuring stick for everything (we're held together by electromagnetic fields, which are made of photons, so it is really the case). From there you get the contraction of space (as defined by the distance we measure) and the dilation of time and all the rest of the consequences. Certainly, we can talk of space contracting because its a simple way of discussing it, as a shorthand, by saying that the distances we measure between objects are changing in certain ways. Sometimes though it can get muddled, as when physicists discuss space being curved in general relativity, when in reality we are discussing the fact that light does not seem to travel in straight line in an accelerating frame.

Some ultimate theories of the universe get around this by positing a structure which makes up both particles and space itself, with particles being propogations of certain types passing from one "point" to the next according to certain rules. That is my understanding of loop quantum gravity for example. Others have hypothesized that "space" is actually some sort of entity, a brane, on which the particles are "tied", which is roughly a proposal from string theory. In any case however, from my encounters with other physics students and my professors, it seems that "space" is often treated like an actual entity, when it is not. And this can lead to rather unsatisfying results, in my opinion.

[Krattle]

Oh, don't misunderstand me. Note that I said this in my original post:

"Only if you define universe as an incredibly limited entity within the realm of existence (i.e we exist within some kind of bubble) will I accept that theory."

If we're actually talking about some yet unknown entity that's around 14 billion ly across, then that's quite acceptable. Just prove it. And it's fine that we don't know yet. There's no rush.

I do have problems with the expansion of space that is so often inferred from red shift, a premise that is an intimate part of BB theory. Once you start talking about space expanding (and now it's at an ever accelerating rate), you're treating space as an entity. It's hard to deny the theory of expansion because there haven't been any valid alternative explanations of red shift (that I've seen). Halton Arp has one, but it proposes quite a few extraordinary ideas. Still, I haven't thrown it out even if the scientific community has...

Exactly, relativity theory seems to treat space as an entity. For the longest time I had trouble understanding it until I realized that when it says space curves, it actually means that space curves. I just can't see that...if it's just "shorthand" then shorthand for what? What's going on if there isn't an entity called space that bends with the mass of the objects in it?

[nanite1018]

Exactly, relativity theory seems to treat space as an entity. For the longest time I had trouble understanding it until I realized that when it says space curves, it actually means that space curves. I just can't see that...if it's just "shorthand" then shorthand for what? What's going on if there isn't an entity called space that bends with the mass of the objects in it?

Well, since we measure space (i.e. distances) and time (distance in a different dimension) using light, if light's observed motion is affected by observing it from an accelerating reference frame. Think of it as if you were in a car, accelerating slowly, and sent out a little toy airplane. The plane would look like it was moving in a curve, from your point of view. Now, I am not well versed in the mathematics of General Relativity, not at all (only a 2nd year student), so I do not know if that is a legitimate way of thinking about it. It seems intuitively how it should work, and it fits with my earlier statements on how I derived Special Relativity (so I could make sense of it). If you measure space and time with light, and lights path looks curved (because it is influenced by gravity), then "space" is curved, in a sense.

[Jake]

I replied to a post of Thomas Miovas in a thread over in the Metaphysics and Epistemology section. My reply included a quote from Einstein, which sparked another reply. I don't want to hijack that thread more than I already have, and I've been meaning to post in this thread (one of my favorite on OO.Net).

I've been re-reading Relativity by Albert Einstein. I can't recommend this book enough if you want a good understanding of Special and General Relativity. It's written by the man himself and has a refreshingly logical flow. I have not read the edition of the book for sale on Amazon, and I'm dubious of the:

introduction, by science writer Nigel Calder, [which] guides the reader through the work section by section, even giving advice on which sections to skip, or at least not to worry about, if you can't "accompany Einstein through the forest of tricky ideas contained in this slim volume."

but it appears Einstein's (translated) content is un-molested.

Here's the quote:

In this edition I have added, as a fifth appendix, a presentation of my views on the problem of space in general and on the gradual modifications of our ideas on space resulting from the influence of the relativistic view-point. I wished to show that space-time is not necessarily something to which one can ascribe a separate existence, independently of the actual objects of physical reality. Physical objects are not in space, but these objects are spatially extended. In this way the concept "empty space" loses its meaning.

Italics original

Here is the response from 'A is A'; replies from me are new:

...there is no necessity, Objectivist or Physical, for something C to be between A and B just because A and B are not co-located. The attempt to fulfill such a false necessity leads to infinite regress.

I haven't read that thread you reference, but how can it lead to an infinite regress? Provided you keep out Zeno's paradoxes, there should be no infinite regress.

I can't state it better than DavidOdden did in posts #14 and #23.

I don't find Einstein's statement helpful. It eliminates a noun, space, and replaces it with an adjective, spatial.

No, it replaces "in space" with "spatially extended." If physical objects are in space, it means space exists independently of those objects as a sort of background into which the objects are placed and in which they move. Spatially extended means that light takes a non-zero time to reach one entity from another.

And the concept of distance is related to position or place more than it is to space.

The concepts 'position' and 'place' require a reference point (i.e. another entity). In Math, one uses the origin of a given basis as the reference point, but origins and bases are concepts of method, not physical entities. There is no absolute reference or primary entity of the universe. Any given entity only has a 'position' or 'place' in reference to, or as observed from, another chosen entity.

Exactly, relativity theory seems to treat space as an entity. For the longest time I had trouble understanding it until I realized that when it says space curves, it actually means that space curves. I just can't see that...if it's just "shorthand" then shorthand for what? What's going on if there isn't an entity called space that bends with the mass of the objects in it?

IMO, this is a major pitfall in writing layman's or popularized versions of modern physics. There is no natural requirement that fundamental physical events be easily visualized by everyday perceptual means. AFAIK, Einstein never said that space is a physical entity like a membrane which bends or stretches in the presence of mass/energy. I think the quote above shows that he did not believe space was an entity. That is just how it is usually described to people (like me) who don't know have all of the requisite mathematical skills to comprehend the theory at the proper level. Edited December 13, 2009 by Jake

[dream_weaver]

David Harriman stated in one of the lectures from ARI something to the effect of 'the key to understanding Einstein, is to keep in mind that he is describing the appearances of reality, rather than attempting to explain what reality is specifically.' Additionally, it was either he or Harry Binswanger that was not fond of the concept of 'space' but rather prefered 'place', further explaining that many mistake 'space' as an actual existant, rather than the location, size, etc., where an existant actually is transpiring.

[Grames]

No, it replaces "in space" with "spatially extended." If physical objects are in space, it means space exists independently of those objects as a sort of background into which the objects are placed and in which they move. Spatially extended means that light takes a non-zero time to reach one entity from another.

I understand better now what it means to say space does not exist. When I said in an earlier post that space was suffused with fields that was inaccurate. I think now it would be more accurate to say space was constituted of those fields. Space should not be interpreted as existing independently of everything and all fields as a background.