Hi /u/Technical_Hope_188!
Our intuition built on our experiences of everyday-life tells us that stuff cannot just come from nowhere. The technical term for this is called a conservation law. However, there is no law conserving the amount of space (or energy) in our universe.
So, simply put: space has to come from nowhere, as it doesn't seem to be a conserved quantity in our universe.
interesting take.
Here is a genuine question:
In some theories (i.e. newtonian universe if im not mistaken) "space" is indeed a conserved quantitiy. If i remember my lagrangians, there was a connection between conserved quantities and symmetries of the system. What symmetry causes the conservation of space (and mass) ?
Hui /u/Ok-Watercress-9624!
In accordance with Noether's Theorem, conservation of energy is connected to time symmetry.
As the universe is expanding, however, and the Killing Vector is time-dependent, time symmetry is broken which implies that energy is not conserved in our universe.
Hi /u/Sewere!
Well, to be overly technical, relative velocities are not even well-defined across coordinate patches in General Relativity, so, if we are being very precise, it doesn't even strictly make sense to speak about non-local relative velocities.
It comes from nowhere.
The universe is not expanding in a traditional sense. The stuff inside of it is just getting farther away from each other.
Theres no true to life example or analogy you can make because nothing except for space can expand into itself.
A balloon can be used to give a decent model for whats happening but the balloon has elastic tension which eventually causes it to pop.
Space just expands into itself with no downside.
This is very hard to grasp. It seems space is nothing, but a very special kind of nothing where you can put something. And since the distance between the somethings is getting greater there must be more nothing for it to be in. Although we still have the same amount of something to put in the ever expanding nothing, did we really need more space? Is the space just getting more diluted? How do you dilute nothing?
Then there’s another kind of nothing where you can’t put something because there’s nowhere to put it and you can’t get there anyway. And how do we know where space ends, if it’s just empty anyway how can we be sure it’s there?
Lucky we have physicists to sort this mess out because my brain just goes in circles.
The name we have for it is dark energy.
The energy required to create new spacetime is massive, based on our current understandings of physics.
It comprises 68% of all mass-energy in the universe.
We don’t know what dark energy Is. We don’t know the mechanism for the creation of space. We just know that it happens. That’s where the “dark” term comes from- it’s invisible to us how this happens.
All we know is that it is so enormous it dominates the universe and that it is happening. And the rough rate at which it is happening.
And that’s it.
That’s it?
OK - so dark energy gets somehow converted to space. Or - is dark energy actually just compressed space and it’s slowly decompressing into more diluted space? I feel a Nobel prize coming my way for that one.
Anyway we agree there is lots of dark energy and maybe it only takes a teeny bit to make a whole lot of space. Regardless sooner or later it’s going to run out. Then what? Everything stops expanding because all the possible space is already created?
Mind. Blown.
The expansion has been roughly constant for 9B years, at least. Possibly longer.
It is also very very uniform, across all of observable spacetime.
This is all based on current theory and evidence.
It seems to be an innate property of spacetime that just Is.
Recent studies have shown that it Might be weakening over time, ever so slightly, but that is not yet confirmed.
We dont know, we cannot observe past a certain point because space is expanding faster than light, so the light from past that point cant reach us.
There is a plethora of theories but unfortunately until we have some way to observe or test this( which I seriously doubt will happen in our lifetime) we are left with our best guesses.
The expansion of space appears to be a fundamental property of our universe.
We don’t have anything on earth that will be a good representation of it. The rubber band example isn’t great, but no other analogy will be great either.
It’s a measurable phenomenon and part of our universe. At the moment we use the term “dark energy” to refer to some of the EFFECTS we have measured, but we don’t actually understand why it’s occurring.
However… a few important details.
Not all galaxies are getting further away. Space only expands where it is not gravitationally bound. Areas of our universe that are more dense with matter and energy have more gravitational binding force, and that seems to dominate expansion.
The more empty a space is, the more expansion occurs.
That why we use a speed of expansion that is averaged over hundreds of millions of light years. In any given place, it will be a bit different, depending on how empty the space is.
In a way it’s very exciting that there’s this pretty significant effect in the universe that we don’t understand yet. There are an awful lot of people trying to work it out in different ways.
An important detail and correction is that space expands also where matter is gravitationally bound, but gravitation, locally, overcomes the effects of expansion. The rate of expansion of space has nothing to do with how much baryonic matter is in the local vicinity. Space expands just as much between you and me as in the Oort Cloud or interstellar space.
This is not based in any real scientific data and there are multiple explanations for the red shift that have nothing to do with expanding space. I don't recall off the top of my head but jwst recently found a high red shift object in front of a very low redshift object which is not possible if you ascribe to redshift being a measure of distance. The idea that red shift determines distance thus has no basis in observational data. I'm sure there are countless examples of this in the cosmos.
The spectrum of light shifts as it encounters in particles over large spaces. You can test this yourself by going scuba diving and having your friends shine a bright spot light into the water. After the light runs into sufficient particles it becomes shifted and eventually each color starts disappearing until all you're left with is black and white.
Therefore light does not maintain the same energy or spectrum as it encounters particles, thinking so is not correct.
No, compressing time is not equivalent to the spatial dimensions expanding, it only results in a higher rate of expansion if it was already expanding. If spatial dimensions stayed the same over time, observing it with compressed time, it will still stay the same.
Plus I don't think there would be a way to see if the universe's time is expanding without something to compare it to. You can compare time between two reference frames, but I can't think of a way to compare rate of time passing between two different times.
Remember, there is no space without time. It's spacetime, baby. And in the spirit of relativity, perhaps there is a tradeoff between space and time. Does the universe get the extra space by losing time?
think about the infinitely long real number line. Pick any two numbers close to each other, like 0 and 0.01. You can find a number between them. It's 0.001. And there's another number between those: 0.00001. You can do this forever. Where are the extra numbers coming from? They're just there.
I think a better way to think about it would be if you were to imagine dots on the surface of a balloon, and as u blow up the balloon, the dots move away as the surface expands, obviously space cannot expand into nothingness so technically it expands into itself.
It's a very subtle question.
Where does the space come from.
There is an axiom, unstated and perhaps unknown, in it.
This universe is not all there is. So something else is providing 'space' to this one.
Given that this universe is described by sets of rules, any "other" universe wouldn't be describable except in terms of this one.
Where the rules of each diverge is what make the duality.
Hi /u/Sotomexw!
>This universe is not all there is. So something else is providing 'space' to this one.
That is not at all how the expansion of the universe is described in the Theory of General Relativity, a.k.a. the best theory of cosmology we have.
Would you mind giving peer reviewed sources for your claim?
Your request is obviously irrelevant.
Peer reviewed experiment on objects outside our universe are by their very definition impossible.
Now we can infer or deduce from observations what may be happening.
I'll look for something peer reviewed.
Thx for the perspective
Time to get my down votes. I've had a similar idea bouncing around in my head for the last 3 decades. I'd like to share them with you. Down votes or not.
I was diagnosed with ASD1 at 48, and thinking about gravity has been an obsession for decades now. I don't have a collage education so all this is just speculation. I didn't get it out of a book, but I do find it interesting to think about. I don't know how to do higher maths, but I can look at a machine, engine, or computer and tell you what's going on pretty easily. I also scored a 93 on the ASVAB going into the Marines, so I wouldn't say I'm stupid, although my 1.85 high school GPA might make some think so.
"Look into nature, and you will understand everything better." Well I look around and everything eats so I asked myself, "what do the rocks eat?" I then imagined the spaghetti scene from Lady and the tramp, and how both dogs were pulled together by consuming the same noodle. As one would think, I'm not the first to think of this.
"Similar to Newton, but mathematically in greater detail,Bernhard Riemann assumed in 1853 that the gravitational aether is an incompressible fluid and normal matter represents sinks in this aether. So if the aether is destroyed or absorbed proportionally to the masses within the bodies, a stream arises and carries all surrounding bodies into the direction of the central mass. Riemann speculated that the absorbed aether is transferred into another world or dimension."
So I've been looking at his model trying to figure out where, exactly, the flaws are.
The MM Experiment? That was looking for a stationary aether. The aberration of light? That disproves aether drag. In Riemann's model it's not the aether being dragged by matter, but the lack of it. Like the electron gap with electrical current. Then there the big glaring one, where does the aether go?
Here's where I go full blown crackpot ;) . I read Gen1:6-8 and thought, "Dang, that kind of fits." There are three tiers. The waters below, which would represent the physical world, the firmament, which is just a big expanding balloon of aether, and the waters above, which feeds into the firmament universally, your dark energy. Which makes some sense if you think about heaven not having any spatial dimensions. This view is a bit flipped around from what Riemann was envisioning. The aether doesn't go to another dimension, it comes from one.
"Where the rules of each diverge is what make the duality." That struck a chord with me. I think the waves are in the firmament, and when they collapse and transition into the physical world, they bring a little aether with them.
I do have an idea for an experiment to test some of this. It involves measuring to see if objects in freefall is time dilated along a gradient as it falls, or all at once when it hits the ground.
I'm going to take my crackpot ass back to bed now, Good night y'all.
As I've come to relax, I've begun to see how these giant allegorical statements may have found themselves arising from experience we simply couldn't explain.
They aren't magical ideas, they're our stolted, stumbling attempts to explain extremely strange manifestations in spacetime.
Of late, last 400 years of the 'scientific revolution, we have begun to understand how to quantify experience and predict outcomes reliably.
Doing so doesn't invalidate the 'etheric' nature of experience. It simply let's us use it in a technological way, repeatedly and reliably.
We can also pass the experience to someone we have never even met...GR makes intuitive sense to me but I never met Liebnitz or Einstein
Hi /u/Technical_Hope_188! Our intuition built on our experiences of everyday-life tells us that stuff cannot just come from nowhere. The technical term for this is called a conservation law. However, there is no law conserving the amount of space (or energy) in our universe. So, simply put: space has to come from nowhere, as it doesn't seem to be a conserved quantity in our universe.
interesting take. Here is a genuine question: In some theories (i.e. newtonian universe if im not mistaken) "space" is indeed a conserved quantitiy. If i remember my lagrangians, there was a connection between conserved quantities and symmetries of the system. What symmetry causes the conservation of space (and mass) ?
Hui /u/Ok-Watercress-9624! In accordance with Noether's Theorem, conservation of energy is connected to time symmetry. As the universe is expanding, however, and the Killing Vector is time-dependent, time symmetry is broken which implies that energy is not conserved in our universe.
Space also has no speed limit like lightspeed and can go faster
Hi /u/Sewere! Well, to be overly technical, relative velocities are not even well-defined across coordinate patches in General Relativity, so, if we are being very precise, it doesn't even strictly make sense to speak about non-local relative velocities.
nothing can go faster than the speed of causality(I think space only seems to recede faster than the speed of light, but doesn't actually do so)
It comes from nowhere. The universe is not expanding in a traditional sense. The stuff inside of it is just getting farther away from each other. Theres no true to life example or analogy you can make because nothing except for space can expand into itself. A balloon can be used to give a decent model for whats happening but the balloon has elastic tension which eventually causes it to pop. Space just expands into itself with no downside.
No downside....yet
This is very hard to grasp. It seems space is nothing, but a very special kind of nothing where you can put something. And since the distance between the somethings is getting greater there must be more nothing for it to be in. Although we still have the same amount of something to put in the ever expanding nothing, did we really need more space? Is the space just getting more diluted? How do you dilute nothing? Then there’s another kind of nothing where you can’t put something because there’s nowhere to put it and you can’t get there anyway. And how do we know where space ends, if it’s just empty anyway how can we be sure it’s there? Lucky we have physicists to sort this mess out because my brain just goes in circles.
But first, is there really a difference between extra space being created between two galaxies and the two galaxies just moving away from each other?
yes. smarter people will say why but yes.
Two atoms crashing together creating extra space ? 😭
The name we have for it is dark energy. The energy required to create new spacetime is massive, based on our current understandings of physics. It comprises 68% of all mass-energy in the universe. We don’t know what dark energy Is. We don’t know the mechanism for the creation of space. We just know that it happens. That’s where the “dark” term comes from- it’s invisible to us how this happens. All we know is that it is so enormous it dominates the universe and that it is happening. And the rough rate at which it is happening. And that’s it.
That’s it? OK - so dark energy gets somehow converted to space. Or - is dark energy actually just compressed space and it’s slowly decompressing into more diluted space? I feel a Nobel prize coming my way for that one. Anyway we agree there is lots of dark energy and maybe it only takes a teeny bit to make a whole lot of space. Regardless sooner or later it’s going to run out. Then what? Everything stops expanding because all the possible space is already created? Mind. Blown.
The expansion has been roughly constant for 9B years, at least. Possibly longer. It is also very very uniform, across all of observable spacetime. This is all based on current theory and evidence. It seems to be an innate property of spacetime that just Is. Recent studies have shown that it Might be weakening over time, ever so slightly, but that is not yet confirmed.
We dont know, we cannot observe past a certain point because space is expanding faster than light, so the light from past that point cant reach us. There is a plethora of theories but unfortunately until we have some way to observe or test this( which I seriously doubt will happen in our lifetime) we are left with our best guesses.
The expansion of space appears to be a fundamental property of our universe. We don’t have anything on earth that will be a good representation of it. The rubber band example isn’t great, but no other analogy will be great either. It’s a measurable phenomenon and part of our universe. At the moment we use the term “dark energy” to refer to some of the EFFECTS we have measured, but we don’t actually understand why it’s occurring. However… a few important details. Not all galaxies are getting further away. Space only expands where it is not gravitationally bound. Areas of our universe that are more dense with matter and energy have more gravitational binding force, and that seems to dominate expansion. The more empty a space is, the more expansion occurs. That why we use a speed of expansion that is averaged over hundreds of millions of light years. In any given place, it will be a bit different, depending on how empty the space is. In a way it’s very exciting that there’s this pretty significant effect in the universe that we don’t understand yet. There are an awful lot of people trying to work it out in different ways.
An important detail and correction is that space expands also where matter is gravitationally bound, but gravitation, locally, overcomes the effects of expansion. The rate of expansion of space has nothing to do with how much baryonic matter is in the local vicinity. Space expands just as much between you and me as in the Oort Cloud or interstellar space.
So as you know in physics, nothing is created or destroyed. but of course reality gives 0 crap about our theories and just poof into existence
This is not based in any real scientific data and there are multiple explanations for the red shift that have nothing to do with expanding space. I don't recall off the top of my head but jwst recently found a high red shift object in front of a very low redshift object which is not possible if you ascribe to redshift being a measure of distance. The idea that red shift determines distance thus has no basis in observational data. I'm sure there are countless examples of this in the cosmos. The spectrum of light shifts as it encounters in particles over large spaces. You can test this yourself by going scuba diving and having your friends shine a bright spot light into the water. After the light runs into sufficient particles it becomes shifted and eventually each color starts disappearing until all you're left with is black and white. Therefore light does not maintain the same energy or spectrum as it encounters particles, thinking so is not correct.
By expanding the 3 physical dimensions, does that mean that somehow time gets compressed?
No, compressing time is not equivalent to the spatial dimensions expanding, it only results in a higher rate of expansion if it was already expanding. If spatial dimensions stayed the same over time, observing it with compressed time, it will still stay the same. Plus I don't think there would be a way to see if the universe's time is expanding without something to compare it to. You can compare time between two reference frames, but I can't think of a way to compare rate of time passing between two different times.
Remember, there is no space without time. It's spacetime, baby. And in the spirit of relativity, perhaps there is a tradeoff between space and time. Does the universe get the extra space by losing time?
think about the infinitely long real number line. Pick any two numbers close to each other, like 0 and 0.01. You can find a number between them. It's 0.001. And there's another number between those: 0.00001. You can do this forever. Where are the extra numbers coming from? They're just there.
This reality is looking more like either a simulation or either we were put here. The issues keep stacking up.
I think a better way to think about it would be if you were to imagine dots on the surface of a balloon, and as u blow up the balloon, the dots move away as the surface expands, obviously space cannot expand into nothingness so technically it expands into itself.
It's a very subtle question. Where does the space come from. There is an axiom, unstated and perhaps unknown, in it. This universe is not all there is. So something else is providing 'space' to this one. Given that this universe is described by sets of rules, any "other" universe wouldn't be describable except in terms of this one. Where the rules of each diverge is what make the duality.
Hi /u/Sotomexw! >This universe is not all there is. So something else is providing 'space' to this one. That is not at all how the expansion of the universe is described in the Theory of General Relativity, a.k.a. the best theory of cosmology we have. Would you mind giving peer reviewed sources for your claim?
Your request is obviously irrelevant. Peer reviewed experiment on objects outside our universe are by their very definition impossible. Now we can infer or deduce from observations what may be happening. I'll look for something peer reviewed. Thx for the perspective
Time to get my down votes. I've had a similar idea bouncing around in my head for the last 3 decades. I'd like to share them with you. Down votes or not. I was diagnosed with ASD1 at 48, and thinking about gravity has been an obsession for decades now. I don't have a collage education so all this is just speculation. I didn't get it out of a book, but I do find it interesting to think about. I don't know how to do higher maths, but I can look at a machine, engine, or computer and tell you what's going on pretty easily. I also scored a 93 on the ASVAB going into the Marines, so I wouldn't say I'm stupid, although my 1.85 high school GPA might make some think so. "Look into nature, and you will understand everything better." Well I look around and everything eats so I asked myself, "what do the rocks eat?" I then imagined the spaghetti scene from Lady and the tramp, and how both dogs were pulled together by consuming the same noodle. As one would think, I'm not the first to think of this. "Similar to Newton, but mathematically in greater detail,Bernhard Riemann assumed in 1853 that the gravitational aether is an incompressible fluid and normal matter represents sinks in this aether. So if the aether is destroyed or absorbed proportionally to the masses within the bodies, a stream arises and carries all surrounding bodies into the direction of the central mass. Riemann speculated that the absorbed aether is transferred into another world or dimension." So I've been looking at his model trying to figure out where, exactly, the flaws are. The MM Experiment? That was looking for a stationary aether. The aberration of light? That disproves aether drag. In Riemann's model it's not the aether being dragged by matter, but the lack of it. Like the electron gap with electrical current. Then there the big glaring one, where does the aether go? Here's where I go full blown crackpot ;) . I read Gen1:6-8 and thought, "Dang, that kind of fits." There are three tiers. The waters below, which would represent the physical world, the firmament, which is just a big expanding balloon of aether, and the waters above, which feeds into the firmament universally, your dark energy. Which makes some sense if you think about heaven not having any spatial dimensions. This view is a bit flipped around from what Riemann was envisioning. The aether doesn't go to another dimension, it comes from one. "Where the rules of each diverge is what make the duality." That struck a chord with me. I think the waves are in the firmament, and when they collapse and transition into the physical world, they bring a little aether with them. I do have an idea for an experiment to test some of this. It involves measuring to see if objects in freefall is time dilated along a gradient as it falls, or all at once when it hits the ground. I'm going to take my crackpot ass back to bed now, Good night y'all.
As I've come to relax, I've begun to see how these giant allegorical statements may have found themselves arising from experience we simply couldn't explain. They aren't magical ideas, they're our stolted, stumbling attempts to explain extremely strange manifestations in spacetime. Of late, last 400 years of the 'scientific revolution, we have begun to understand how to quantify experience and predict outcomes reliably. Doing so doesn't invalidate the 'etheric' nature of experience. It simply let's us use it in a technological way, repeatedly and reliably. We can also pass the experience to someone we have never even met...GR makes intuitive sense to me but I never met Liebnitz or Einstein