What's the Fabric of space made out of?

Every creationist I have ever spoken to (other than buzsaw) speaks of a universe with an origin in time.Those who put this origin within ten thousand years or less reject just about the whole edifice of science; including cosmology with its 13.7 billion years since the Big Bang singularity.Otherwise, old earth creationists have welcomed the Big Bang model, for its implications of the origin in time for the universe. There is some criticism of the model from within the scientific community, but over recent decades it has become more and more marginalized as evidence for the Big Bang model continues to accumulate. The funny thing is that what little rejection remains is mostly from atheists who have a strong philosophical objection to the Big Bang, precisely because it involves an origin in time; and they object to this as a creationist notion.Many intelligent design creationists have also welcomed the fine tuning argument, which is particularly strong in Big Bang cosmology.This is a minor point; buzsaw is welcome to advocate his particular theological notions for what kinds of universe are consistent with his God; but he is a very unusual intelligent design creationist! You have misunderstood this one. It's complicated. I do not say "consists of"; but rather say that there is no such thing as empty space, because the "vacuum" turns out to be seething with virtual particles. Buzsaw is probably referring to the posts where he cited papers about the interstellar medium, and confused this notion with the virtual particles notion. I pointed out this mix-up in the discussion.I don’t think space consists of anything in particular, and the term fabric is a metaphor which that I consider rather misleading.Unfortunately the search facility is not working; otherwise I would have pointed you to the posts in which this was discussed. That’s a pretty good statement.Cosmological redshift is the major line of empirical evidence for expansion. There are some alternative ideas, some of which correspond to a tired light model. Some of the tired light models involved the reddening of light due to interactions with particles, or other more exotic interactions. The tired light model has been disproved by supernova light curves, and the particle interactions model for tired light has also been disproved by resolutions available for high red shift objects. There are still a few people trying to defend this model, but it is now quite solidly falsified. The Grand Unified Theory (not Theorem), if we ever get such a thing, will basically be a model able to probe back into the very earliest times, even before 10^-47 of a second from the singularity, where a quantum theory of gravity is required. It’s not required to substantiate the basic facts of expansion, which are a fairly straightforward consequence of classical physics. Any grand unified theory will need to reduce to classical physics as a good approximation; just as Einsteinian physics reduces to Newtonian physics as a good approximation. This means any GUT will still need to continue to explain well established phenomena like elliptical gravitational orbits, relativistic dilation effects, and relativistic expansions of space.Cheers -- Sylas

TD1, maybe; but TD2, definitely not. Discussion on this point has been a bit confused, with irrelevancies about "infinity plus one". TD2 means energy tends to disperse and dissipate, which is a problem in infinite universe models. This has been done to death by various posters; not always very well it must be said.For the rest, I agree that your hypothesis is more reasonable than YEC. The latter. I am indeed saying that space is seething with virtual particles. They flash in and out of existance, all the time. Each individual virtual particle only lasts a very short time before being anihiliated again. But all of space is filled with them, so they occupy space, and space (vacuum) is not really empty.Cheers -- Sylas

No in both cases, as far as we can tell. At least, there is no reason to think any such thing. That's getting pretty deep. Andrei Linde, one of the world's foremost cosmologists, has speculated on such notions; and others even more weird than this. He has speculated that new inflationary domains could be forming right now, all the time, throughout space. For example, if an infinitesimal region inside your own body suddenly inflated into a whole new universe, you would not notice a thing; because it does not push any other spaces aside as it expands. In fact, Linde has speculated this is going on all the time; the mother of all multiverse models.It's just a speculation; and would be very hard to test. His major work is in inflationary cosmology, but the variation I mention above is not his major idea; just a side line of some strange things that might be going on.Interestingly, Linde is one of those atheists I mentioned early who seems to have philosophical concerns about an origin in time. However, he is also a first rate scientist. He is not particularly dogmatic on these matters; but he does seem to be in search of a way to get rid of the troubling origin to time implicit in cosmology, while still recogizing that all evidence at present clearly indicates that the universe as we know it expanded from conditions in which conventional physics becomes singular, about 13.7 billion years ago.He has done a long of stuff on chaotic inflation and eternal inflation which are a bit more relevant here. These also infolve new inflationary domains starting up all the time; but not within our already inflated domain.Cheers -- Sylas

Sort of. But we've established more than this, in physics. We've established that space has a geometry, and that the geometry of space is distorted by mass. To say "space is absolutely nothing but" the area in which things exist is probably missing a few subtleties.Cheers -- Sylas

I do appreciate it is difficult. One of the hardest things for some people to accept is simply that it does take so much time and study to understand the models and the data involved.Many people want their own intuitions and philosophical musings to have the same status as the physics they could learn about if they went a harder longer road of study. But life is not that easy. Ungrounded commentary is worthless. Trying to explain that the physics is complicated is sometimes taken as elitism; and I'm not sure how to deal with that.Mostly, I just don't worry. There are plenty of people genuinely interested in learning about this stuff; and I so I don't just blow them off with comments about it all being too hard. I explain, to the best of my ability, the bits and pieces I have managed to learn so far. I am also actively trying to learn more myself at the same time; getting to grips with the geometry and tensors required, at about the level of half way through an undergraduate degree majoring in maths and physics. I am working my way through The geometry of spacetime : an introduction to special and general relativity, by James J. Callahan (Springer, 2000).So no, I am not trying to "have things both ways". When you ask honest questions, I'll answer them to the best of my ability. If we ignore the rather off putting remarks about having it both ways, I will answer your implicit questions plainly as follows:Yes, the notion of space has subtleties. The major subtleties I am speaking of are that notions of distance and time are not the nice absolutes we are used to in normal experience. For example, you've heard that the circumference of a circle is 2*pi*r? Well, that is only an idealized result in Euclidean geometry. It turns out to be incorrect in real life, in the sense that the distance around a circle in space can be more than, or less than, 2*pi by its radius. The geometry of real space is not, in fact, Euclidean.We could explain more about this at many levels of detail. For a brief post, rather than a full lecture, it should be enough to point out that this is a feature of General Relativity; one of the most stringently tested scientific theories of physics, confirmed in countless experiments. Space has curvature. There is a subtlety for you, right there.Furthermore, this is not about particles. The virtual particles that occupy otherwise empty space are another matter entirely.So. Space does not consist of particles. Particles occupy space. But neither is space simply absolutely nothing but the void in which particles exist. It has other subtleties, like intrinsic curvature, and expansion over time, and so on; which are quite distinct from anything about particles.Now. Do you understand that this is nothing but me trying my damndest to explain some very difficult physics for you? Having it both ways indeed... cut it out buzsaw. I don’t deserve such remarks. No; this is YOUR problem, and a bad one. It is an observation, a discovery, that space has these unexpected attributes. This is not something that was dreamed up by physicists who had some kind of problem with your musings. Scientists developed this understanding BECAUSE THE EVIDENCE REQUIRES IT.We can describe how space expands, and how this is associated with mass and energy, and the experiments which prove the association, and much else besides. Science does not, however, have a private access to perfect truth. Of course there are still open research questions; on such things as the Higgs field, and the cosmological constant and quantum gravity and much else besides. None of this can give you the slightest comfort. It is profoundly irrational to just throw out everything we have discovered simply because there is still more to be found out. And yes, I do mean discovered. Not invented, not assumed, not ungrounded speculation. It is classic experimental physics, in the best traditions of scientific investigation of our world.Cheers -- Sylas

No. You are wrong. Gravity is the least well understood of the four fundamental forces in physics. However, we have made a fair amount of progress. That includes disproving the old notions of gravity from the nineteenth centurty and earlier in which gravity is merely a force on objects in a simple Euclidean space. Some of the consequences of the new gravity descriptions, which are most definitely demonstrated and modeled, include distortions of time and space; and curvature. Insofar as we can describe gravity, the best descriptions involved curvature of space.The very fact that space can be distorted shows that the simplistic model you are using is inadequate. You have already read plenty of stuff to explain this to you; I've written a fair bit of it myself. But you just don't understand it, and you apparently don't even understand that you need to learn a few basics to make sense in such a subject. You are absolutely resistant to education on this matter; and when you associate with with some kind of bizarre standard of fairness by which your random musings should be given equal respect with those of people who actually know a bit of physics, there are going to be some bad experiences involved.This is not about me reserving science to myself. I absolutely accept that there are many unanswered questions and real disputes in science. However, you are not yet at a level of basic comprehension for your comments to even be coherent, let alone sensible criticisms of well established physics.THAT is the main thing you need to learn before you can even start to make progress. Until you learn that you need to learn, you'll continue to be repeating howlers.Cheers -- SylasThis message has been edited by Sylas, 03-04-2005 20:52 AM

No, buz; you certainly do not have that much comprehension. And until you actually learn that you don’t comprehend you’ll never overcome your failures of comprehension.I have already said space is the region in which things exist; but that it has curvature in the sense of the geometry being non-Euclidean. I gave the example of Euclidean formulae for circumference of a circle being inaccurate in real life; that’s basically what curvature means. You appear to have closed your mind to that entirely, to the point where you don’t even hear the explanations you are being given. Progress and comprehension stops dead. It isn’t even at the level of real disagreement yet, just inability to comprehend.For example: you say you will only accept a definition which involves space consisting of something before you will accept the expansion or curvature of space.You’re out of luck then. The truth of the matter is that space does not need to consist of something for curvature and expansion to be meaningful. That is just an assumption you impose. Modern physics works just fine defining curvature and expansion and so on simply in terms of the metrics. A metric is a way of measuring separations of events in space and time. It’s all about the geometry.As for expansion; this means that distances in space increase over time. This can be a feature even of a completely empty space. At this point you are going to say illogical or no it isn’t, or something of that kind. Well, that opinion of yours deserves no respect at all, because you are so completely in the dark in actually comprehending physics or why you are so atrociously bad at it.Bottom line. Space does not consist of anything. Particles, and fields, and galaxies, and so on exist in space. Space is curved, in the sense that simple Euclidean geometry does not work. We can put a number on curvature, but that will require a lot of trickly tensor maths to give the full definition. At this level of definition here it should be enough to say that curvature means Euclidean geometry is inaccurate. Space expands, in the sense that separation distances between distant objects are increasing; faster than can be accounted for by any local motions. It’s all about geometry and metrics. All of this is stock standard classical physics, abundantly confirmed by many observations. The physics based on old Euclidean notions of a simple flat space have been amply disproved by those observations.Cheers -- Sylas

Skip many many irrelevant red herrings. We aren't stalled. Nearly everybody involved, me included, has been making progress. Even buz has been been making some progress. In a nutshell, because space has curvature. This is an observation. Since space has measureable properties, it is wrong to say it is "just" an area.Sylas

Geometry. Separations. Time. We measure with rulers and clocks, but we are not measuring any particular thing, so much as the space they occupy. If you have a circle, and find that the circumference is less than 2 * pi * the radius, what are you measuring? The circle is just an abstraction; a locus in space along which we place rulers. The measurement is a measurement of curvature of space itself; there is no other object involved. Saying that you have to use something to make the measurements is missing the point. The curvature you measure does not depend on how you make the measurements.The notion that we are measuring aspects of things in space rather than the geometry of space itself does not work out in practice.One obvious example is time dilation. We can measure the differences in clocks at different heights in a gravitational field. This is not property of the clock; but of the space that the clocks occupy; because it makes no difference what clock you use. We also measure the speed of light to be constant, regardless of local motions of the observer, and regardless of what rulers or clocks you use to measure it.The constancy of light speed gives a nice way to derive special relativity; which is not about geometry of space. However, it is a starting point for how you can define separations when the normal definitions change according to observers. Many folks have a pretty good grasp of special relativity; it is actually fairly easy.The problem comes with gravity. We can use special relativity to manage accelerations, and twin paradox, and barn pole paradox, and so on, all within one consistent framework of special relativity. But gravity upsets the matter. It turns out that the only way we have for dealing with it is a generalization called general relativity; which involves the geometry of space.There are some good introductions available, and I've cited a few of them. I might even try writing some of my own; but the ones already out there are better. Try, for example Foundations, by Greg Egan. Egan is, like me, an amateur; but a very good one. He is also a writer by profession (science fiction).Cheers -- SylasThis message has been edited by Sylas, 03-06-2005 20:32 AM

And thank you... though I did recommend this page, I found it difficult. It’s more advanced than many more simplified descriptions; and trying to follow it was a motivation for me to do more study using a full relativity textbook; a project on which I am still engaged.Without doing a full course in physics, we are going to have to settle for simplified non-technical descriptions; and that is true of Egan’s page as well, for all that he makes a good attempt at technical accuracy. The problem is that people skip over the maths; and look to the pictures, and think of space as being a rubber sheet or whatever; confusing the analogy with the reality.To some extent, you're going to have to take my word on it (and the words of others) that the non-technical descriptions we are giving can be filled in with more detail. Egan’s page is only an introduction. I have some more vague ideas for posts with more detail, and with a less maths, but it is hard work to make a short web article convey something useful to an interested amateur. I am also aware of how much more I still need to learn.You may reword your position how you like. But inevitably, because you don’t actually know much physics, and because you are in effect trying to set up alternatives to real science, your descriptions end up being wrong, and people who do know more physics will keep trying to point out the mistakes in various ways.Hard as it may be to accept, the conventional understanding of modern physics is that space itself can be distorted and curved. The attempts to explain observations as distortions or properties for the things occupying space turns out not to work well. It is a failed model.I'm sure we'll continue to answer questions and explain issues as best we can; and that we'll continue to point out that even better and more details answers can be found with the hard work of further study and lots of maths.Cheers -- Sylas

I responded to Message 63 in Message 66.I'm getting a bit fed up with this, frankly. Common sense isn't all that common, and logic is a disciplined way of drawing out the consequences of your initial assumptions.Science works not by logic, or common sense, but by careful examination of the natural world, and development of models or theories that put observation into a consistent explanatory framework. Some scientists have observed that it is deeply significant or surprising that this program works. There is no reason in principle why the universe should be describable in terms of simplified abstractions or natural laws; but there you go. It is a feature of the world, as far as we can tell, that there are deep basic regularities and consistencies, which allow us to use abstractions like natural law to describe how the world works.Some of the conclusions we derive conflict with common expections formed by normal experience. What this means, basically, is that looking very carefully at the natural world reveals details that enable us to give more accurate models than those we form just by intuition and common sense. Real sense recognizes this.Some folks... you, for example, buz... simply cannot accept the discoveries of science and want to set up their own common sense intuitions as an alternative and as a basis for rejecting stock standard conventional scientific discoveries. This is not logic.Your criticisms of science are uninteresting, because you don't really know what you are criticising, and are not able to express a coherent criticism that takes into account the empirical observations that are the foundations of science. You can get an internally consistent notion for an alternative universe of your own making... your own common sense, that is. But it fails to match the universe we live in, and which (from a theistic perspective) was made by God.Cheers -- SylasThis message has been edited by Sylas, 03-12-2005 21:02 AM

The measurement of space is essentially the measurement of distances. In modern physics, space is not necessarily Euclidean. One consequence is that if you draw a circle, and measure the radius and circumference, the ratio may not be pi. It is a property of the space, quite independent of whether or not there is a physical object in the shape of a circle, or just a mathematical abstraction for distances in spacetime.In modern physics, space and time are connected; we speak of spacetime since times and distances depend on how you look at it. The one thing which does not vary for observers is the "metric"; which is why we use it. Anyhow, to take an example where time and space are linked: consider an expanding space. This means that distances between things will increase as time passes. It is not a property of the things, but of the spacetime in which they exist. It is not local velocity because points at sufficiently large separations may separate faster than any local motion could compensate.All this has been explained before. It is not a measurement of the things in spacetime, but a measurement of spacetime itself. You can, in fact, speak of distances and curvature and so on in empty space; using Einstein's tensor. That gets a bit hairy, so to visualize it, it helps to imagine things in space. But it really is a property of the spacetime, not the things in it. To describe without objects, you are left with maths, and such things as the circle and radius. Just maths, and a metric for empty space to describe its geometry.You can't accept this? Fine. But that is how modern science represents the matter. It is not illogical. It may violate YOUR intuitions, but that is not something that is going to worry anyone except someone possibly your teacher; a position I decline to accept.Your description of what I am doing in the extract from message 63 is incorrect. You'll never understand it until you accept that I mean what I say.Spacetime has properties like curvature and expansion that are aspects of the spacetime itself. The consequences of curvature and expansion can be seen by looking at objects in space, but the models which represent what is seen do not treat this as aspects of the observed objects, but of the spacetime in which they exist. Older models, trying to capture this aspect of modern physics using velocity of objects and so on, are nineteenth century falsified models; useful as an approximation in some limited contexts but fundamentally inaccurate.The scientific models I am describing have a metric tensor for empty space, that represents things like curvature and expansion as intrinsic to the space.Cheers -- SylasThis message has been edited by Sylas, 03-13-2005 02:29 AM

(Stuffed up post.)This message has been edited by Sylas, 03-13-2005 16:12 AM

It's worth being careful about how this works. The major evidence for cosmological expansion is cosmological redshift; with the cosmic microwave background as a special case of extreme redshift. Buzsaw has previously acknowledged this. We don't measure space directly on the scales required to see expansion; we only observe things already out in space, and use them to infer distances and geometry.Now there are some alternative models for redshift; and buz has cited some of them. But they are failed models, falsified by the details of the evidence. There are still some isolated persons considering such models; but they are few and far between. The most credible attack on conventional models has been the attempt to show physical associations of high and low redshift objects; but even this has no real legs, since the evidence for associations is very weak; most astronomers think it is entirely coindidental alignments in the sky. This criticism also offers no alternative explanation; if confirmed it would also falsify scattering and tired light models.The alternative explanations for cosmological redshift are such things as "tired light" and scattering. These models are emphatically and decisively disproved by evidence such as the perfect blackbody sectrum of the CMBE (which rules out scattering) and the time dilation effects seen in supernova light curves (which rules out tired light AND scattering).The upshot is; we have a basic model for spacetime and gravity, called general relativity. This is tested eighteen ways from Sunday, and passes all tests with flying colors. This model involves a geometry on spacetime; curved space. The curvature of space is observed in various ways; most notably bending of starlight. The gravitational time dilation seen in satellites is also a kind of curvature.A consequence of the model is that spacetime on cosmological scales is dynamic; it either expands or contracts. The nice stable flat space fitting normal intuitions is an unstable solution to the equations. And we observe precisely the redshifts expected by a space expanding according to the general relativity.So expansion and curvature of space are scientific models, represented by the metric tensor defining the geometry of space itself without any reference to object in space; and connected with gravity by Einstein's equation and the Einstein tensor.We cannot measure space directly on scales beyond the solar system; we can only observe what objects are already out there and use them to infer distances and geometry. The observations are all consistent with the relativistic model, and they falsify all the alternatives like tired light or scattering.Scientifically speaking, it is an open and shut case.Cheers -- Sylas

NO. Sheesh, buzsaw, try to keep up. If anything, the majority view is the space is infinite, but the real majority view is that we just don’t know whether space is finite or infinite.I have said this right from the start; it was how I got into these absurd discussions.It doesn't bother me what you do with your vague metaphysical preferences for infinite over finite. I have been concerned here simply with the matter of the geometry of space, because this is something we DO know.Modern physics associates a geometry with spacetime; not with the objects within spacetime. It does this without proposing any material fabric or composition of spacetime.Space is curved. It expands. These features of the geometry of spacetime are very solidly established.Whether it is finite or infinite; bounded or unbounded; that we don't know. Several errors packed into this.First, there is the same old so-called problem of space needing something to expand into. This is not any kind of problem whatsoever. This is purely and simply a case of buzsaw being unable to shake some conventional assumptions about flat space. Expansion simply means that there are greater separations between things over time. You don't NEED anything to "expand into". This is one of the really fundamental things that needs to be comprehended.The only basis for thinking that you need to expand "into" something is sheer assertion. This is dressed up with phrases like: "It's logical" or "It's common sense". Sorry; but common sense is trumped by observed evidence, and logic is only a way of developing implications of your starting assumption. The assumption that expansion can only mean expansion into something is not "logic", but an assumption that turns out to be wrong.Second, the word "bounded" comes in here from nowhere. What makes you think the metrics are "bounded"? It certainly is not something I have ever said. The metrics for spacetime work just fine for an infinite universe. In fact, the simplest homogenous solutions for what we observe right now are for a spatially infinite universe.Third, you've got Feynman wrong. I've not listened to the lecture, but I've read some of his writings on this. The principles of expanding space and so on are quite understandable. It is quantum physics that Feynman singles out as something no-one understands.Here is a famous quote from Feynman (I cut and pasted from Light through the ages: Relativity and quantum era) My emphasis added. Quantum mechanics is really hard to visualize; but relativity is not. Relativity is still a classical theory; and you need to discard a few assumptions that are a barrier to buzsaw; but many physics students manage this just fine. A bit of reading, a bit of an open mind for new ideas, and even a total novice can develop a fair degree of understanding of relativity. Special relativity is easy; general relativity is harder, but still quite comprehensible. It is the general theory you need to understand curved spaces, and expanding spaces, and so on.Quantum mechanics and electrodynamics, however: fergeddaboutit. That's okay, it's your choice... and your loss. You have mistaken "common sense" for the naive intuitions we form in the absence of rigourous consideration of all the evidence. Real learning means discarding those assumptions when they turn out to be wrong; and you'll HAVE to do this because the real world does not match your intuitions. It still makes good sense, however, and it is still understandable (if we omit the quantum domain); but alas you've chosen to rule yourself out of contention.Cheers -- SylasThis message has been edited by Sylas, 03-13-2005 07:11 PM