What is the universe expanding into?

I understand that the volume of existing reality, that is, the relationships between the celestial bodies, etc., has indeed increased.
But the concept of growth or expansion logically (or at least a priori) forces the existence of a medium in relation to which this process will take place.

You can of course do a thought experiment and try to rule out the existence of that “empty” medium within which space (and time?) supposedly expands, but if you rule out that medium you will paradoxically return to the assumption that it “exists” (as a possibility without which expansion could not even get underway).

Do you see a way out of this thought experiment?

I can only repeat what I wrote. I see no need for this (that there is a substrate, empty or not, at the expense of which the space expands)

Okay. I can't understand your reasoning for the claim but I don't want to continue this discussion.
I have a related question: Would you agree that Newton's bucket argument, insofar as it aims to prove the existence of absolute space (separate from man and his knowledge), is also aimed at proving the existence of the same “empty” medium that existed “before” the Big Bang (according to him)?

How does Newton relate to the explosion? I see no connection to the question of the medium.

Newton assumes that space is an entity separate from man and therefore absolute and he uses the Hadley argument to demonstrate this (and links it to his discussion of motion). His position is contrary to the position of Leibniz, for example (with whom he argued on this question) because he rejects the assumption that space is an “abstraction” from the relations of objects in space.
So far, I think you understand and agree.

From this, I think it follows that Newton opens the door to the fact that space was never “created” and in any case, it cannot expand. In other words, his argument shows that space is a necessary and constant medium (“eternal medium”).
Although Newton can insist and claim (according to his religious belief) that God created everything from nothing, that is, he “created” space as well. It seems to me that this insistence - if it comes from him - is arbitrary.

That is how I understand the bucket argument and its connection to my question.

The debate between Newton and Leibniz over Hadley's argument concerns the question of whether there is absolute space in the sense of empty space (free of objects). The question of whether motion, linear or rotational, can be defined in empty space. This has nothing to do with the question of the explosion and expansion of space. Whether space expands into a medium or without a medium, one can still ask whether it is absolute or not (in Hadley's sense).

I don't understand. After all, space also moves. At least in the sense that its edges are getting farther and farther away from the starting point at the beginning of the journey (the beginning of the explosion).
In any case, I can't understand what motion is that doesn't need a spatial medium that stands in relation to it.
As I understand it, Hadley's argument is trying to prove exactly this: not only is space absolute, but it is also a necessary medium, only in relation to which the concept of motion can be conceived.
Can you give me an example of the motion of an object that doesn't need a spatial medium?

The universe is everything.
This universe has volume, and the volume is increasing..
What exactly is actually happening? It is not clear. It is not clear what space itself is made of.
For example, if space is a lattice structure with a fixed distance between points, then you can imagine that more and more points are added to the lattice and this happens throughout space and thus its volume increases.

I can't give an example, and that's exactly why it's hard to imagine. You have to think about it non-visually. You're talking about the expansion of everything, and any example you can give could be the expansion of something. The closest thing is the inflation of a balloon, if you look only at the envelope (and not the volume). The parts that are added to the envelope area don't come from any two-dimensional edges. But I don't see any point in dwelling on the example, because you can argue about it. Think conceptually (not visually) and you'll see that there's no problem.

It might be helpful to think about the formation and development of language. Adding words doesn't come at the expense of anything. Again, there's no point in arguing about the example.

To Doron

You should first learn what a metric is. It is very difficult to imagine the concept of expansion without knowing what a metric is. The example of a balloon face is really the best, but it is not that successful because the balloon you know lives in a three-dimensional world and within it it expands (if conceptually it can also expand without such a world)

Precisely because it is not possible to give an example, I conclude about the special and necessary status of space, that is, that it cannot expand. In fact, the claim that it can expand seems to me meaningless. The concept of expansion forces a background substrate and in fact this substrate must be space itself (and thus a regression of space within a space within a space is created).
I also do not think that an appeal to metrics is relevant to my question. Metrics do not deal with an a priori metaphysical concept like the one in my question.

The correct verb in the Hebrew language that describes what is happening with the universe is to swell.
The universe is swelling.

Swelling, unlike expansion (and even expansion), does not involve anything external outside the object that is swelling.

I am not a professional physicist, but it seems to me that the claim is a little different. The claim of the expansion of the universe should be understood in light of Einstein's special theory of relativity. According to this theory, the presence of mass bends space and as a result causes light rays to move in a curved and not straight way. Think of it as a small hole created by a mass-bearing factor. Any such factor creates a hole in which waves cannot move straight but must move according to the configuration of the hole.

When we say that the universe is expanding, we are essentially saying that the initial point of mass that created a surrounding envelope of space within which light could move in a limited way, gradually expanded and began to move in a way that increased the universe, that is, the space within which light waves moved. This is the meaning of the expansion of the universe. Different mass factors moved away from each other in a way that expanded the space within which light rays move, and thus the universe expanded. What lies beyond the boundaries of the space within which light rays move? We have no idea. Our information is based on light rays and even light rays are limited by the space of mass. It is possible that if there were a factor with mass beyond the space of mass, space would expand to include it and then the light rays would provide us with the information about it. But for now, it seems that mass is limited to our universe.

So what is the space within which the universe has expanded? I don't know and we probably have no way of knowing. But when we say that the universe is expanding, we mean the expansion of the space within which the light rays move.

Ruling
The concept of “inflation” is logically related to the relation of the inflating object to some medium in relation to which it inflates. This medium is ultimately infinite space. Otherwise the concept has no meaning. If you think otherwise, I challenge you to give me an example of something that inflates without “something external”.

Y.D.
First of all, it seems to me that you are mistaken on a factual level regarding the role of special relativity. Special relativity does not deal with the question raised concerning the structure of space, its existence, or the effect of gravity on it, but rather deals with ways to measure speeds, distances, and periods of time. Physicists will come and correct me if I am wrong.

In essence, my argument about the concept of space (space) is not about the question of whether or not it is possible to know anything about it. I make a more radical claim: there is no meaning to the assumption that space was “created” and in any case there is no meaning to the claim that it is expanding. The fact that the balloon analogy doesn't work in my opinion is not because analogies are inherently partial and problematic. That is almost always true. The reason it doesn't work is because this analogy proves in my opinion the opposite of what the person proposing it intends to say.
Therefore, your need for information that light rays bring us also doesn't seem relevant to me. There is no data here that one day we might obtain and then we could re-formulate our opinion on the matter.

The concept of inflation describes something that happens to an object. Without reference to the thing at whose expense it inflates and is therefore closest to what happens with the universe.
But it is clear that in all the examples we know within the universe the inflation actually comes at the expense of another space.

This conceptual problem will not be solved through words but through the understanding that the examples you know from within the universe will not help you understand the issue.

The change should be a change of thought, not a verbal change.

Doron
I think your question is not about expansion but about the meaning of finite space.
Expansion presupposes some kind of finitude, but finitude does not necessarily presuppose expansion.
If you think it is possible to understand what a finite, limited space and a domain are even without expansion, then the concept of expansion is self-evident: now the distance measured within the boundaries is greater. Until now, between the boundaries we could insert four meter-long sticks, and now we can insert five meter-long sticks there. But you say that a non-infinite space must be located within a truly infinite space because it is impossible to define a boundary without referring to what is outside it. Do you agree?

And to be honest, a very nice comment.

Posek
You point out the inherent limitation of language to describe the concepts we are discussing, and in this you are right.
But if we have chosen to express ourselves and we believe that our words still have a certain weight, it does not follow that all claims are of equal value.
Your initial claim was that the more accurate verbal description is inflation. Now you are changing your position. Apparently you also think, like me, that there is some point in more accurate verbal claims.

Witstom
I did not understand most of what you said except for the last sentence, which summarizes my position well. Indeed, I argue that the concept of finite space, which I think we all believe in, conceptually swallows the existence of infinite space. Such a space cannot be created “out of thin air” or be destroyed.
If I am right, this should also shed light on scientific theories such as general relativity and the big bang theory.

To Doron

You surprisingly didn't understand the first part of Witstom (which shows how the concept of expansion does not require that space be located in some other space) and the second part (which you claim is what you said) you say yes. So you actually understand yourself……but in the end you are wrong. It is a philosophical discussion but it is a fact that the theory of relativity works and explains reality and it does not need a larger external space in which space-time resides. So maybe there is a larger external space or not but it is not needed to explain our reality. In such a case we say in a moment, paraphrasing Laplace's words: ” External space? – I do not need such an assumption …” (he spoke about God in physics). In other words, the monastic approach of reducing unnecessary assumptions has proven to be the most fruitful approach in physics.

Anyway, it's really strange and hard to get used to such a thought, but it's probably true. What happened here is that an auxiliary concept (space) that helped us describe movement (change in place) of physical entities (matter) as the norm of the real. became a reality (physical in itself). A kind of mathematical object that became physical. (There are other examples in physics of this (the vector potential of the magnetic field. The Bohm-Aharonov experiment). Of course, naturally, as a physical object, we ask where it lives, that is, we ask for a new space in which it will reside (and move). But there is none. It is who it is itself (it resides within itself). Incidentally, this also causes physical phenomena that seem to us to contradict the laws of nature. For example, the speed of expansion of this space in certain places in the universe (in galaxies far enough from us according to Hubble's law) is higher than the speed of light. And in fact, nothing else in nature (including light and various force fields) can move faster than the speed of light. According to your method, space could not move faster than the speed of light within the larger space (although this is not entirely necessary).

By the way, time also has a similar problem. We talk about movement in space-time (the four-dimensional space of time is one of its axes). And movement in time requires new time (here A”a to evade. They use a concept called self-time but it is not really “time” as we think of it). And this also causes a conceptual problem. And in general, one can ask about the Big Bang that occurred 14 billion years ago (in which our time was also “created”) what was before it? And the answer is that before it there was nothing (because before it there was also no time). The word “was” does not exist before the Big Bang. As such, this question is not asked at all in the first place (not only is there no answer to it, but it is not defined at all).

I haven't changed my position.
The word inflation is a better way to describe what's happening. Imagine you're inside a balloon that's inflating. All you see is that the volume of the balloon is increasing. That's what it means to inflate. When that happens, you don't have to think about "where is the balloon inflating?" but rather that its volume is increasing over time.

The term expansion doesn't fit this situation. It includes in the concept that there are certain areas to which it has expanded, meaning that it wasn't there before and now it is there. And that doesn't fit what's happening with the universe.

What's happening with the universe is that its volume is increasing. Space itself is inflating.

Emmanuel
With all due respect, but your argument is confused.
You note at the beginning that I myself distinguish between the scientific claim about space and the philosophical claim about it and that I have only recently addressed it.
But then, when asked to tell me where I went wrong on a philosophical level, you suddenly slide back into an argument in the name of science - a pragmatic argument according to which the theory of relativity “works” and that we “don't need this assumption (that space is infinite and does not expand). What is relevant about it working? Quantum mechanics also works (big time) and we are still arguing about its philosophical implications.
In any case, as long as we discuss the issue from a philosophical perspective, we need Abu Abu to assume the existence of such a platform.

And again: If you want to expose my mistake/failure, you must show why it is fundamentally conceptually implausible, philosophically speaking.

To Doron

That's exactly the point. Philosophically, nothing can be decided because nothing is up for testing. Science is a "mature philosophy". Apart from self-contradiction (or absurdities. Something that directly contradicts our experience. But then it's also a kind of science) you won't be able to find any error in any philosophical claim. And my argument is not pragmatic. It's completely theoretical. I'm talking about fertility. Fertility is an indication of truth. That's exactly the error in the "God of the Gaps" approach, for example. It wasn't fertile, unlike the other approach (i.e. closing the gaps through additional scientific research and if necessary finding a new reason to explain the gaps)

Just to clarify - the fertility I'm talking about is descriptive and explanatory fertility. Not technology. That is, my ability, through a particular claim, to explain additional phenomena that have not had (or that we haven't even imagined that they should have) an explanation until now, is what I mean by what I call the fertility of a claim.

Tov says a few minor things and one more important one. What you present here is a scientism that in my opinion is naive and confused: a paradoxical philosophical position that comes to undermine any philosophy whatsoever in the name of science. It is a position that defeats itself.

Your puzzling assertion that philosophical questions cannot be decided (except for certain reservations that you pose) is also factually incorrect. The history of ideas in general and of philosophical ideas in particular is full of decisions regarding countless questions, theoretical and practical. The decisions are not always justified, but factually there is no problem in principle with “deciding” in a reasoned and systematic manner.

Regarding fertility, I do not understand how a sharp distinction between philosophical discussion and scientific discussion (as I do) can suppress fertility in one of these areas. If you give an example, perhaps there is something to talk about.

But all of this is marginal to the main point of our discussion.
The main thing is that you yourself admit, despite your scientism, that philosophy has value in the area of identifying contradictions or absurdities. It seems to me that this is exactly what I tried to do here regarding the concept of space and its accepted interpretation in the Big Bang theory. It is not clear to me why you “allow” this discussion in principle but in practice avoid addressing the concrete claims that appear in it.

Posek
I think you are playing with words. In the example of the balloon, you insist on claiming that one does not need to think “where” the balloon inflates, but only to observe from within it, subject to what I actually see. And so is your claim regarding space.
Witstom already wrote here (and Hegel said it before him) that given the concept of a boundary, you have already crossed it in your mind. The example of the balloon envelope is ultimately an ostrich's move (like an ostrich's) - if I do not refer to something, it does not exist. But even that does not work. Even the ostrich that buries its head in the sand does so in the context of an external reality that it assumes and wants to “eliminate”.

First of all, I suggest you stop using the words “puzzled, naive, confused, scientism, paradoxical, self-defeating.” These are a lot of empty words that I am used to seeing used by fake and empty intellectuals. Words that cover up a lack of content. I do not believe in scientism, nor in kishkushism, nor in any ism. These catalogs are meaningless.

I also do not admit to anything. From the beginning, my discussion is entirely philosophical. I do not think that there are no decisions in philosophy because there really are decisions, only they are made on an observation that is, in any way, scientific. An observation of the subject being discussed. And this is what I am talking about as absurdities, for example (which are not paradoxes – contradictions – but situations that common sense – the observation of the eyes of reason – rejects). When I talk about indecisiveness in philosophy, it is either about metaphysical debates that lack information (air debates) or when it is clear that the arguing parties (or at least one of them) lack information. Or situations in which all sides of the debate have been exhausted and since then people have remained in their positions forever. In such a situation, there really will be no decision because there is a lack of information. And in the end, I argue that science is part of philosophy itself - it's just that it is a philosophy that works. I don't understand what is not understood. In my opinion, this approach of a space within another space is sterile. This is my basic feeling. If you show it interesting implications, then it won't be so. There is nothing to argue about here anymore. You think there is something here - go ahead and save the scientific world. Show that there is something and we will continue talking.

Well, regarding your linguistic suggestions (as well as your earlier suggestion that I pay in ”metrics”) I will consider and return an answer to you. If it is acceptable to you.

As mentioned, I think your position is inconsistent and I have provided relevant reasons for this from the relevant field (not from ”science”)

In general, I think my claim about space is true and I do not care whether it has practical implications or not.

What I do agree with you is that a large volume of the history of ideas is talk in the air.

As for my ability to save the scientific world… well, I do not wish the world any salvation from people like me.

No. That's exactly the point. Something that is barren means it's not true. Like the God of the Gaps. There's no proof that it's not true (that God is responsible for the explanatory gap). The God of the Gaps is an approach that has never been refuted. But it was barren. On the other hand, the alternative approach - every gap in science has an explanation from within science (and not outside of it. Like God) - has been proven to be fruitful. I don't have an example at the moment, but there are many. Go ahead and ask (even Newton sinned with this. Here's an example. How does the universe not collapse in on itself due to gravity? He claimed, among other things, that God holds the stars so that they don't get close to each other. The second approach, on the other hand, brought us Hubble's law and the concepts of cosmic cosmological inflation and dark energy)

To Doron

By the way, not every space can be contained in a larger space than the type you know. For example, our space-time (the so-called SO(3,1) type space) cannot be contained in any space larger than the type we know (the n-dimensional Euclidean space – R^n ). This is a mathematical fact. And this thing is the real physical space in which we live and it is the one that expands (not only space expands. Time too).

Doron.
The problem starts long before your question and it is not about words at all.

In your question you assume that you understand what the universe is, what space and time are in essence, and then you ask your question about its expansion.

The truth is that we do not understand at all what the universe is, what the essence of the fabric of space is.

So after you understand what space is, try to make it difficult with questions. Until then, just as you do not understand the essence of space but you live with it in peace, so you will also behave regarding the fact of its expansion.

From the outset, it is clear that the concept of a finite but limitless universe cannot be illustrated. In illustrations there are always limits.

Posek
I understand.
We all, including you, make claims (in real words!) about “expansion” and ”inflation” and the differences between them, etc.’… but now the great truth has been revealed: all this is just because we actually understand nothing about anything and our words have no meaning at all.

Are you convinced?

Forget words. Get busy understanding. The very concept of space is incomprehensible. I wrote this in the first response.
“What exactly is actually happening? It is not clear. It is not clear what space itself is made of.”

Emmanuel
As I said, I think the pragmatist position you advocate (“the main thing is fertility”, “what works as a criterion for truth” etc.) is inconsistent and in practice you are introducing theoretical and even metaphysical assumptions through the back door. You are forced to do so. In fact, pragmatism itself, as a philosophical position (and not, God forbid, a “scientific”) is based on a premise that is not at all pragmatic. Even if it also has pragmatic considerations.

Secondly, in my opinion, you have not succeeded in showing that fertility is necessarily a recipe for the abhorrence of science (although in practice this has certainly happened and is happening).

Thirdly, you have opened a new and interesting topic here regarding the implications of
mathematics on the picture of reality. I don't know if you tried to bring evidence from mathematics that there is an “other”space that we cannot dwell in infinite space. In any case, I wonder (I don't fully understand this) how mathematical truths can be translated into philosophical and metaphysical language. Since mathematics is largely dependent on convention (and I say this as a Platonist), it is probably not always the case that sentences have a parallel in the real world. It seems to me that the test is first and foremost philosophical (i.e. logical): if there is a logical flaw in the translation, the claim that it is possible to deduce from mathematics about reality is probably incorrect.

There is no pragmatic position here. Or if you like, it is philosophical pragmatism. But all this is nonsense. There is no need to prove anything here and there is no back door here. That is how they think. Anyone who does not understand this on their own does not know what it is to think. If a person steps in a place and does not advance anywhere, they should understand that they are on the wrong path. That they are not thinking correctly. There is no theoretical assumption here. This is an assumption that is part of our thinking. I did not try to show anything at all and do not need to prove it. Anyone who does not understand it on their own is because they have not sufficiently experimented with independent thought. This is metaphysics that is part of the paradigm of the philosophers of nature (part of the intellectual infrastructure of scientific thinking). It is metaphysics to the same extent that physics itself (the assumption that there is order in the universe) is itself metaphysics. Understanding this is part of philosophical maturation (i.e., it is not something that can be proven. When you grow up, you will understand).

Well, I see we've moved on to the announcements stage. I'm also happy to discover that you, unlike me, have moved on to the "independent thinking" stage. I wish the light of the sun would shine on me too.

With the help of the ’ quickly nowadays. But really it's a matter of growing up. It's not that there's anything wrong with you (except that you're stubborn and think you discovered America. The intuition that when space curves (or expands) then a larger space is needed (into which it will curve) was in front of the eyes of all geometers, starting with Riemann. But it turned out that mathematically from the moment they started talking in terms of metrics and intrinsic curvature, there was no need for such a space. And that was long before the theory of relativity). Keep thinking for yourself and ponder my words. .It's not wrong not to be an adult. And besides – maybe socially what I'm saying is unacceptable – it's also okay that there won't be equality between the two of us. It's not a sin for either side.

The issue of fertility is indeed not trivial either. In history, there have been many times when people have faced holes and tried all kinds of methods and there have been many philosophical disputes and it took time for them to make progress (the God of the Gaps was one of those too. I already mentioned Newton). And that only happened from the moment they tried to be productive - to ask about the implications of the different opinions. There is the famous story about the controversy over the EPR paradox in quantum mechanics (in relation to the interpretation of quantum mechanics) which they said was similar to the Christian debates about how many angels can sit on the head of a pin. And the debate was stuck until a physicist named John Bell came along and showed a physical anomaly (Bell's inequality) which was indeed tested in an experiment a few years later.

Sha Bracha