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Author | Topic: What is "the fabric" of space-time? | |||||||||||||||||||||||||||
john6zx Member (Idle past 4820 days) Posts: 66 Joined: |
So you're effectively arguing that because space and time are not tangible, physical objects, that they cannot be used to describe natural phenomena? That is not my argument. I am saying, like you just did, that time and space are not tangible, physical objects. Since these things are not physical they do not exist physically and so do not bend, warp, or slow down. They are considerations that we have when observing motion and distance between objects. There are those things that exist physically in the world around us which we perceive to be real, and there are those things that we imagine, consider or create, (emotions for example) these things are just as real to us but are not things that exist out of us as some physical object. A rock for example exists whether we know about it or not. It is an object that exists on its own. Emotions, thoughts, considerations are not physical objects that exist in the physical universe, we create these things and so they are real in that respect. Our concept of space or time is just that, a concept. Space and time are not things that exist as an object or substance in the world outside of our ideas of them.
What are your emotions then? What are your feelings? What are your memories? What are your sensations? A thing need not be tangible to exist and affect things around it. Space is simply that, the medium in which matter exists, Emotions, feelings, memories, these are things that did not exist before you created them. If you feel a certain way, yes it is real to you and your manifestations of that feeling or emotion can be sensed by others by your expressions or actions, but they are not physical things that have always existed and will continue to exist after you have stopped creating them. The real physical objects that exist in the world outside of us have persistence, and will continue to exist after we take our attention off of them. Anyone can readily perceive those objects that exist in the world around us. Our memories, emotions and feelings could be said to only exist in our own personal world. The real things in the world around us are different than the real things that exist in our head. If space and time were real physical things that exist outside of our ideas or considerations of it, science would have said so by now. Space itself is not a tangible thing.
Newtonian physics are valid only within our physical universe. When the fabric of space-time is curved, our actual physical universe is curved, and Newton's laws work within that curvature. Newton's laws will not force an object to continue along a straight path unless that path is part of our universe, within which our physics make sense. Therefore, an object traveling along space-time will not require energy to follow a bend in it, because the bend is the only part of the universe that the object can travel upon. First of all, the concept of this space-time fabric is part of a theory and not established scientific facts. It is not a real physical thing. You are just stating what the General Theory if Relativity states, not observed phenomenon. It is one mans idea of a possible explanation for gravity. It has never been tested nor can it ever be tested.
No. When I say that a model explains what we see, you know as well as I do that what I mean is that a model explains the observable phenomena for which that model is created. The model of space-time explains the laws of physics and why they hold in our universe, and how Gravity works. However, our knowledge of Gravity is not complete, and there might need to be made some changes in our model to account for new information. You however, seem to have no idea what in the hell the model actually states, and yet are insistent on debunking it. A mathematical model can be of a real or imagined scenario. Just because something is shown in a mathematical model does not mean that it is a real world phenomenon. So no, the idea of space-time cannot be considered a real world explanation of gravity since it is just based on a theory, and not standard scientific observations. Space-time is not a real tangible thing so it cannot be used to describe real tangible occurrences. I know what the model states and I am not debunking the model, I am correcting you on your idea that the space-time model explains real world phenomenon, and that there is some real physical fabric that is warped by mass.
Jeezus Christ. You seem to have no idea what you're talking about. Time and space have existed since the Big Bang, and perhaps before. Really, so far you have only repeated things that you have read or were told. You do not think I am well informed on this subject. Lets see; is time defined as a real physical thing? No Is space defined as a real thing? No. If time and space exist as real physical things, then you have to ask what is their physical structure. In this universe, if something exists in the universe then it has a location. Time and space, if real physical things, would occupy a location. Tell me how you perceive these things called space and time. What senses do you use to know that they exist? Touch? Sound? Sight? (light is reflected off these things) Smell? Taste? Why do you personally think that time and space are real physical objects, when there is no evidence to support your view?
Just because we came up with terms for them later does not mean that they came into existence the moment we thought up what to call them. Surely, you can see what a ridiculous position you are implying. Re-read what I said here. You misread it.
I never said that time and space are real objects, only that they exist and that our current theories about space-time and the 4 fundamental forces of the universe predict and explain their existence. For the record. You are stating that time and space are not real objects. I agree, that is what I have been saying all along. You say that space and time are not real objects, yet they exist. Exist where? And in what form? You cannot have it both ways. Pick a stance and stick with it. Time and space are either real objects or they are not. That’s it. Those theories that you keep talking about are not empirical irrefutable rock solid observations that have been thoroughly scrutinized and tested. They are ideas on probable ways in which the universe works based on the idea that time and space are real physical objects. Without these ideas that space and time are real things the whole theory goes out the window. So these theories are based on terms that have been misused or misunderstood so as to support the theory. Time and space are not defined in any reference book as being real physical things, yet these theories are read by some people who think that time and space are real things and so the theory makes logical sense to them. “What a man believes upon grossly insufficient evidence is an index into his desires -- desires of which he himself is often unconscious. If a man is offered a fact which goes against his instincts, he will scrutinize it closely, and unless the evidence is overwhelming, he will refuse to believe it. If, on the other hand, he is offered something which affords a reason for acting in accordance to his instincts, he will accept it even on the slightest evidence. The origin of myths is explained in this way.”Bertrand Russell What are you getting on about? You seem to think that I believe that time and space are objects like a ball and some wooden cube that one can just pick up and play around with. Where in the hell did your reasoning go so wrong that you've come to think this? You have made statements that time and space are real, then you say they are not real. you tell me. do you think time and space are real physical things? If so then show me some evidence to back up your claim.
Again, I will emphasize that you understand this topic before you try and argue against it. Define the terms time and space and you will get a better understanding. My viewpoint on this topic is based on what references to these topics say. My viewpoint is backed up by standard references and observation. Where are you getting your understanding?
As it stands, none of your questions have been insightful, rooted in any modern cosmological theory, or even made sense. I am asking if you think time and space are real, you want it both ways. you know that there is no standard scientific reference that states that time and space are real physical things so this fact collides with your understanding of time and space causing some confusion on your part. That is why it does not make sense to you. All of my statements are based on facts and help clarify this subject. You have based your statements on repeating what you have misunderstood. If you define the terms time and space you will see that when you say space and time are real physical things you will see that this is not possible. If what I have said does not make any sense to you it is due to the fact that it goes against what you believe. Look up the terms time, space, theory, mathematical model, and see for yourself that what I have said makes perfect sense. You just need to clear up some misunderstandings in this subject.
You seem to be coming at the topic of cosmology from a philosopher's point of view without realizing that it is philosophy, not time or space that is a man made concept. I am coming at this topic with all of my terms defined per standard scientific references. This is a simple topic. Are space and time real physical things or not? that’s it. I say no, with references to back up my viewpoint, you want it both ways. You have said that space and time are real and then latter say that they are not real. Real simple question. Space and time are real physical things? Yes. No. This is not philosophy. Time and space are real physical tangible things or not. Get your favorite science dictionary and find out the answer. Simple as that.
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Silent H Member (Idle past 5819 days) Posts: 7405 From: satellite of love Joined: |
As ever, helpful yet adding further points of inquiry. But then again that is essentially the defining characteristic of science, right?
I'd possibly swing it around and say the Universe is simply how our perception sees the mathematics. It always sounds like a copout, but you really do need to get down and dirty with the fundementals to get so strong an impression.
Not to start the debate here, but as an explanation of my current thinking. I tend to view math as a prosthetic for the human mind to grasp what it cannot understand intuitively. Thus math is not the reality which our perception sees as the universe, but what we strap on to our perception to in some way see the universe as it is. But like I said, we don't have to debate that here...
consider distance - distance is merely a field that gives values assigned to pairs of points. So the distance say the Andromeda galaxy is away from you compared with your keyboard, is merely a case of a difference in a couple of values. There's no 'real' sense that Andromeda is way off in the Universe and the keyboard is next to you.
Okay, now you have to stop fucking with my mind (pardon the scientific jargon). Values do have meaning, right? How is there not a practical reality that my keyboard is next to me and Andromeda is far away, especially with the concept of a limited speed of light? Or is this to suggest that there is a difference between the universe and practical reality?
this is far beyond GR and definitely for another thread if you want to explore this further.
Yes, I would like to explore this further. Probably more than anything else at EvC, I would like to understand these concepts. However, I realize this puts a burden on you. If you feel you have the time and interest to walk me through it I will open a thread (probably Is it Science?). You can drop in as you can, and I will not expect immediate answers to any of my posts. But if this will likely strain your time in general, or our relationship as I suck knowledge from you like a very hungry intellect devourer, please let me know and I won't open that thread of worms.
except that even when energy is 'diffuse' it still has an associated mass.
Would I be correct in assuming an associated mass as if mass (equal in quantity with that energy) were spread "diffusely" over that same volume?
The masses in isolation experience no accelerations and simply trace out their path through time, following their purely time directed vectors. But near each other, their vectors are tipped by the space-time curvature generated by each other.
Let me try to restate... So two bodies start by simply moving through time, but when close to one another the c length vector each follow gets turned slightly (by the warping of space-time) from pure time, to both space and time. In this way a velocity is observed to begin in both bodies. As the curvature increases the vector turns more (aka vector follows curvature), and the resulting changes in velocity are the observed acceleration. I realize that there are no initial forces at a distance, however isn't it true that this activity of simply "following a vector" creates real momentum, which once those bodies meet gets converted into a real force, which then perhaps accelerates one or both bodies in a way that is real?
It doesn't - in orbit, your path winds around the centre.
In orbit, I get. But in the example of two bodies initially at rest, the path of acceleration is towards the center of the other, right? This next question is going to sound weird, but given your description of how this works, is it possible to create "isochronal" charts of space? This would be somewhat like weather maps or geologic maps with isobars and the like for elevation. These latter can be used to map out flows of air currents or water based on the difference between the high and low areas. In other words we get a good visual descriptions that allow accurate predictions of what will happen, without having to run mathematical equations. If movement is associated with mass, which is directly linked to different rates of time (so high and low "time pressure"), this would seem to be possible. Also, as rate of time does change, is there a minimum change in that rate which cannot be crossed? That is to say is rate of time change quantized? If this all sounds like gibberish, it may be a combo of ignorance or lack of adequate vocabulary. I'll take whatever spanking I deserve. h "Civilized men are more discourteous than savages because they know they can be impolite without having their skulls split, as a general thing." - Robert E. Howard
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cavediver Member (Idle past 3643 days) Posts: 4129 From: UK Joined: |
First of all, the concept of this space-time fabric is part of a theory and not established scientific facts. It is not a real physical thing. You are just stating what the General Theory if Relativity states, not observed phenomenon. It is one mans idea of a possible explanation for gravity. One man plus THE REST OF THE ENTIRE SCIENTIFIC COMMUNITY... how does one get so clueless? Surely you cannot produce anything more stupid than this?
It has never been tested nor can it ever be tested. Oh, I was wrong... much more stupid. GR has never been tested??? Have you arrived by time warp from 1915, by any chance? As I will never be tired of repeating, GR is one of the two most successful phsyical theories ever discovered. I would pick another subject to drivel on, if I were you...
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Admin Director Posts: 12995 From: EvC Forum Joined: Member Rating: 2.3 |
Hi John6zx,
I'm replying to you to request that you do one of the following:
The best example of what you're doing wrong is this:
john6zx writes: You are just stating what the General Theory if Relativity states, not observed phenomenon. It is one mans idea of a possible explanation for gravity. It has never been tested nor can it ever be tested. An error equally wrong in magnitude but in a religious context would be state unequivocally, "Jesus is Santa Claus." We wouldn't let an evolutionist repeat such wildly wrong statements in a religion thread, and we won't let a creationist do this in a science thread. The general theory of relativity has passed a number of very stringent tests. If you'd like to challenge those tests then that would be fine, as long as it's on-topic. But if you're just going to deny the tests were performed then that fits under the category of a violation of the Forum Guidelines, specifically:
Enforcement usually begins with a 24-hour suspension. Please, no replies. Edited by Admin, : Typo.
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johnfolton  Suspended Member (Idle past 5591 days) Posts: 2024 Joined: |
As an ex-'string theorist', neither do I feel that string theory is bollocks. But harping on about string theory, without a grasp of the fundementals IS bollocks. If string theory is correct and matter is not pointlike "then" the present belief (the status quo fundemental belief) that matter is pointlike is bollocks. String theory is based on the idea that the smallest known subatomic particles, such as electrons, are not really pointlike objects when viewed close up, but rather very small extended bits of "string." In fact they are so small that present-day experiments cannot distinguish them from points of vanishing size. This is a little awkward for physicists, who ultimately judge the validity of any new theory by whether it explains what we actually see in nature. At the moment there is no direct experimental evidence telling us that string theory is correct. This has always been its biggest weakness, and a target for skeptics. This is a clear sign of string theory's success: Once obscure and ignored, it is now attacked by some who believe it is being given more attention than it deserves. Why is it that string theory has become such a favoured paradigm? Have theoretical physicists deluded themselves? Have they been pressured by social forces to blind themselves to other possible theories? Is there a behind-the-scenes string-theory conspiracy that is propping up a pseudoscientific house of cards? Canada.Com | Homepage | Canada.Com
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cavediver Member (Idle past 3643 days) Posts: 4129 From: UK Joined: |
If string theory is correct and matter is not pointlike "then" the present belief (the status quo fundemental belief) that matter is pointlike is bollocks. **IF** string theory is correct and matter is not pointlike "then" the present belief (the status quo fundemental belief) that matter is pointlike is simply the low energy approximation to the deeper more fundemental theory. There is nothing bollocks about any of it On the other hand, the article you link to is very good, and well worth reading in its entirety.
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Son Goku Inactive Member |
Silent H writes:
Yes there is something similar in General Relativity, they're called the Penrose-Carter diagrams. A quick search on the net will give you a few images. It's also fairly easy to teach somebody how to read them, even if they haven't too much mathematical experience with GR. This next question is going to sound weird, but given your description of how this works, is it possible to create "isochronal" charts of space? This would be somewhat like weather maps or geologic maps with isobars and the like for elevation. These latter can be used to map out flows of air currents or water based on the difference between the high and low areas. In other words we get a good visual descriptions that allow accurate predictions of what will happen, without having to run mathematical equations. You mentioned the word "Isochronal". Just as isobars are surfaces of constant pressure, I'd imagine these would be surfaces of constant time, yes? If so, they're usually known as "spacelike hypersurfaces".
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cavediver Member (Idle past 3643 days) Posts: 4129 From: UK Joined: |
As ever, helpful yet adding further points of inquiry. But then again that is essentially the defining characteristic of science, right? Right
How is there not a practical reality that my keyboard is next to me and Andromeda is far away, especially with the concept of a limited speed of light? Even without going beyond basic relativity, this 'practical reality' is seriously screwed. Along the path taken by a photon leaving a star's surface in Andromeda and entering your cornea, there is literally zero space-time distance. However, we perceive that distance to be 2.2 million light years as we are not travelling with the photon.
If you feel you have the time and interest to walk me through it I will open a thread (probably Is it Science? Sure, that could be interesting.
Would I be correct in assuming an associated mass as if mass (equal in quantity with that energy) were spread "diffusely" over that same volume? Yes - mass and energy are really one and the same thing - mass is simply the measure of energy in the context of generating space-time curvature.
So two bodies start by simply moving through time, but when close to one another the c length vector each follow gets turned slightly (by the warping of space-time) from pure time, to both space and time. In this way a velocity is observed to begin in both bodies. As the curvature increases the vector turns more (aka vector follows curvature), and the resulting changes in velocity are the observed acceleration. Precisely
I realize that there are no initial forces at a distance, however isn't it true that this activity of simply "following a vector" creates real momentum, which once those bodies meet gets converted into a real force, which then perhaps accelerates one or both bodies in a way that is real? Yes - when the bodies collide, they will be accelerated off their free-fall path, but assuming they 'bounce' (rather than disintegrate) they will immediately enter new free-fall paths.
But in the example of two bodies initially at rest, the path of acceleration is towards the center of the other, right? If the bodies are non-rotating, yex. But if one is rotating, it will cause space-time to wrap around it, inducing a rotation to anything in its vicinity. This is known as frame-dragging and has been measured around the Earth. So here, the acceleration is directed inwards but around the body.
is it possible to create "isochronal" charts of space? Yes, as SG has mentioned. Carter-Penrose diagrams are the primary tool of the relativist in displaying the global properties of different space-times. However, we have to use other types of chart and diagram to display some properties, such as the frame-dragging mentioned above. There are some black holes on this page. However, when you say isochronal (and SG says spatial hypersurfaces), this is not a universally agreed surface of equal time, as there is no simultaneity in relativity - different observers will argue different spatial hypersurfaces of equal time.
Also, as rate of time does change, is there a minimum change in that rate which cannot be crossed? That is to say is rate of time change quantized? The time interval along a path between two events has a maximum, but the minimum is zero simply by taking a path at c for the entire path. Obviously some events cannot be connected with a path as they are space-like separated - e.g. now on Earth, and four minutes in the future at the Sun (the Sun is 8 light minutes away) As for a minimum quanta of time - possibly though not necessarily, but this is a whole new (much deeper) subject. Edited by cavediver, : No reason given. Edited by cavediver, : No reason given.
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randman  Suspended Member (Idle past 4898 days) Posts: 6367 Joined: |
In this universe, if something exists in the universe then it has a location. So you are defining physical as something that has a location? What if something has no definite location but merely the capacity to be or become in a specific location? Edit to add: it appears this should have been directed to someone else as I mistakenly hit the wrong reply button. Nevertheless, besides john, it would be interesting to see how you answer these questions. John seems to be claiming time and space are mere human descriptions and not physical things. Is that your view, and if so.....? Edited by randman, : No reason given.
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cavediver Member (Idle past 3643 days) Posts: 4129 From: UK Joined: |
So you are defining physical as something that has a location? Absolutely not
John seems to be claiming time and space are mere human descriptions and not physical things. Is that your view? Absolutely not "john" has adequately demonstrated a utter lack of any knowledge of this subject...
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Silent H Member (Idle past 5819 days) Posts: 7405 From: satellite of love Joined: |
Thank you SG...
It's also fairly easy to teach somebody how to read them, even if they haven't too much mathematical experience with GR.
That's what I figured could be done. It makes life much easier in geology/hydrology/meteorology. Less calculations produce many predictions which make it easy to understand what is happening, and most people can get it just by looking.'
You mentioned the word "Isochronal". Just as isobars are surfaces of constant pressure, I'd imagine these would be surfaces of constant time, yes? If so, they're usually known as "spacelike hypersurfaces".
I meant constant rates of time. I'm not sure if that is exactly the same as constant time. An example I could describe would be a line showing the time rate for those at the surface of the earth, and another at a level above the earth where satellites are at a different rate. From descriptions of how matter moves, one could "see" that something would naturally want to "flow" down the gradient from where the satellite was, to the earth. If that is like a spacelike hypersurface, while that is a cool name, isochronal is a bit shorter. h "Civilized men are more discourteous than savages because they know they can be impolite without having their skulls split, as a general thing." - Robert E. Howard
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Silent H Member (Idle past 5819 days) Posts: 7405 From: satellite of love Joined: |
Even without going beyond basic relativity, this 'practical reality' is seriously screwed. Along the path taken by a photon leaving a star's surface in Andromeda and entering your cornea, there is literally zero space-time distance. However, we perceive that distance to be 2.2 million light years as we are not travelling with the photon.
Ok, for photons I totally see your point. But for massive me, there really is a practical reality isn't there? I would never realistically reach the point of instantaneous travel, and for all practical reality distance is and distance seems... or at least it will take me a hell of a long time to reach Andromeda compared to this keyboard. On this idea. Is light then somewhat of a wormhole for photons? I know we want space-like wormholes, which is an instantaneous jump between locations in the same moment. But what you describe seems to be instantaneous jumps to a different time and location. The idea that there is no real distance rings to my ear like the description of movement through a wormhole.
However, when you say isochronal (and SG says spatial hypersurfaces), this is not a universally agreed surface of equal time, as there is no simultaneity in relativity - different observers will argue different spatial hypersurfaces of equal time.
I want to make sure to get something straight, while there would always be debates on when something occurred, or within how large a volume/area, everyone would agree on (measure the same) rate of time proceeding at any location, correct? For example if we have three ships zooming around at different angles and speeds to one another (some close to c, some not) When A and C look at B nearing a planet, while they would disagree on when B entered the planet's gravity, as well as how large B and the planet are, they would both predict the same rate of time going on within B as well as on the planet's surface, right? Or is there super-relativity? I'll look to start a new thread soon, so thanks in advance. h "Civilized men are more discourteous than savages because they know they can be impolite without having their skulls split, as a general thing." - Robert E. Howard
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randman  Suspended Member (Idle past 4898 days) Posts: 6367 Joined: |
Along the path taken by a photon leaving a star's surface in Andromeda and entering your cornea, there is literally zero space-time distance. However, we perceive that distance to be 2.2 million light years as we are not travelling with the photon. OK, interesting question. If there is no space-time distance, then why should we say it took x light-years to get here? In other words, when we say the universe is of a certain date, is that really valid? When the space was created that from that perspective, an old date was created, then the universe appears to be of a certain age. But in reality the time was created along with the space, right? Just thinking outloud and maybe should bring it up on another topic, but if space is being created, then certainly time is as well.
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Admin Director Posts: 12995 From: EvC Forum Joined: Member Rating: 2.3 |
randman writes: Just thinking out loud and maybe should bring it up on another topic... In case there's really doubt in your mind as to whether your query is on-topic, in my opinion it is very much on-topic. I don't know if CD or SG would agree, but the answer seems to me important to understanding the distinction between thinking about space and time separately, as we do in everyday life, versus thinking about space/time as a single concept.
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john6zx Member (Idle past 4820 days) Posts: 66 Joined: |
john 6zx wrote: "First of all, the concept of this space-time fabric is part of a theory and not established scientific facts. It is not a real physical thing. You are just stating what the General Theory if Relativity states, not observed phenomenon. It is one mans idea of a possible explanation for gravity."
cavediver wrote: One man plus THE REST OF THE ENTIRE SCIENTIFIC COMMUNITY... how does one get so clueless? Surely you cannot produce anything more stupid than this? You show me any scientific reference that states that this space-time thing is a physical thing. Go ahead. What observeable data backs up your claim that this space-time thing actually exists. In fact show me any reference that states time or space are real physical things. What observable physical phenomenon have you experienced that leads you to believe that space or time are real physical things. Put your money where your mouth is and give undeniable physical proof of the physical existence of space or time. Why do you believe that these two things are real physical things? Do not avoid the issue, just put this whole subject to rest by showing physical proof that is backed up by any standard reference books that states time or space are real physical things. The ball is in your court. GO!
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