Black holes

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spacechick09

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black holes in pictures i see they have light going into them but then agian the light is comming out of them to so if everythging is destoryed in a black hole how does this happen?
 
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MeteorWayne

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Hi spacechick09, and welcome to Space.com.
This is not the right place to ask this question, it would be better in Space Science and Astronomy. In fact there are a number of threads there discussing this.

I'll give you a quick answer, but please take some time to look around and see the types of subjects that are discussed in the differnt forums.

The quick answer is that the light (and radio waves, and gamma rays, etc) come from just outside the event horizon of the black hole. At this location the material being pulled in by the enormous gravity of the black hole is being compressed and heated to enormous (astronomical :) ) temperatures, so that disk and jets are what is radiating the energy. Once it enters the black hole itself, it in gone from our view.
 
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derekmcd

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spacechick09":2wxf19hc said:
black holes in pictures i see they have light going into them but then agian the light is comming out of them to so if everythging is destoryed in a black hole how does this happen?

There are three features to a black hole. The singularity, event horizon, and accretion disk. The accretion disk is only associated with a black hole if substantial matter is "falling" in. For example, if a star gets too close, it will fall within the Roche limit and begin to shed its mass. This mass will begin falling towards the black hole forming an accretion disk. While doing so, the infalling matter will become ionized and superheated. Along with this, the accretion disk will form a magnetic field.

As this magnetic field gets twisted by the spin of the black hole, the infalling matter, being superheated and compressed, produces electromagnetic radiation in the form of x-rays. This electromagnetic radiation follows the magnetic field, which is ultimately collimated through the polar axes of the black hole, and gives us the pictures you are describing.
 
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xXTheOneRavenXx

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Hey fellas, how's everyone this evening? As many of you know sometimes I have been known to come up with very different theories (such as my Big Bang theory) utilizing much of the known theories as a bases. I know this might sound strange, god knows it does to me... but I think I know why black holes can be found anywhere including not near any galactic center and just floating around in the universe, microscopically, etc... We all know the theory of space itself expanding. This theory allows for the expansion of the universe to be greater then the speed of light without the objects themselves moving greater then the speed of light. This is the only work around to Einsteins theory of Relativity. So it space is expanding, then this means it should be expanding in all directions right? Well this also poses the question that it expansion occurs then perhaps gaps in space can also occur too, allowing a microscopic black hole to be present. These gaps may be generated by a great deal of energy. We all know gamma ray bursts generate intense energy and spread quite far across the universe. One theory I have is that gamma ray burst may cause these micro-black holes. On a larger scale in this theory a collapsing star's gravity itself doesn't generate the black hole, but rather the energy from the exploding star causes the space within it's center to rapidly accelerate it's expansion causing the void (black hole) to occur. In this case space tries to return to where it once occupied, but twists like water going down a drain. This twisting and collapse rate accelerate the gravitational force in the epicenter causing the initial black hole. From here the black hole acts like a run away train. It continues this twisting and collapsing affect. I cannot explain it much more then there. I will leave that to the experts. What do you think?
 
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origin

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xXTheOneRavenXx":10fuuylm said:
Hey fellas, how's everyone this evening? As many of you know sometimes I have been known to come up with very different theories (such as my Big Bang theory) utilizing much of the known theories as a bases. I know this might sound strange, god knows it does to me... but I think I know why black holes can be found anywhere including not near any galactic center and just floating around in the universe, microscopically, etc... We all know the theory of space itself expanding. This theory allows for the expansion of the universe to be greater then the speed of light without the objects themselves moving greater then the speed of light. This is the only work around to Einsteins theory of Relativity. So it space is expanding, then this means it should be expanding in all directions right? Well this also poses the question that it expansion occurs then perhaps gaps in space can also occur too, allowing a microscopic black hole to be present. These gaps may be generated by a great deal of energy. We all know gamma ray bursts generate intense energy and spread quite far across the universe. One theory I have is that gamma ray burst may cause these micro-black holes. On a larger scale in this theory a collapsing star's gravity itself doesn't generate the black hole, but rather the energy from the exploding star causes the space within it's center to rapidly accelerate it's expansion causing the void (black hole) to occur. In this case space tries to return to where it once occupied, but twists like water going down a drain. This twisting and collapse rate accelerate the gravitational force in the epicenter causing the initial black hole. From here the black hole acts like a run away train. It continues this twisting and collapsing affect. I cannot explain it much more then there. I will leave that to the experts. What do you think?

No.
 
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xXTheOneRavenXx

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Explain? I read many theories. Why isn't this one possible?
 
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Saiph

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Well, that all sounds great Raven...but that's just all it is. Space is elastic...from everything I've gathered, it doesn't rip, it doesn't get punctured...it stretches (and may be full of tunnels, sorta porous...go figure). As for a stars core gravity not causing BH's, but the intense energy...energy causes gravity too, it's the same thing really, the intense concentration of mass and energy cause the BH.


to the OP: Another thing to remember about all the pictures of BH's you see..they are all (to my knowledge) artistic renderings, so keep that in mind.
 
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origin

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xXTheOneRavenXx":1dlpmo1s said:
Explain? I read many theories. Why isn't this one possible?

Your conjecture is based on there being 'gaps' in space (if I understand you correctly) which there is no evidence of and no theoretical basis for. Therefore my opinion as to whether this conjecture is viable of not, is simply - no.

Good science fiction or fantasy is based on the following: Assume this one fantastic thing is true. From that point on you then follow the normal laws of nature. Such as a assume that there are vampires.... or assume there is faster than light space ships... or assume that we are invaded by aliens on the 4th or July...

What you are saying is the same - assume that there are gaps in space....

Maybe there are gaps in space, what ever that means, but in the absence of any evidence or a viable theory of how that is possible - there is no reason to abandon a working theory of black holes to go there.
 
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xXTheOneRavenXx

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lol, the whole vampires, alien invasion thing was cute. Nah, it's not really gaps in space. But what I was really refering to is talked about in this article: http://en.wikipedia.org/wiki/Micro_black_hole
A theory I had was to describe that the actual explosion of a star could for all intensive purposes "tear" space which the tear itself is the black hole, rather then the stars gravity itself causing the star to turn into a black hole. It is a theoretical possibility as we currently do not know what happens at the final moment between the stars explosion & a black holes formation. No one has actually "witnessed this transformation. I just wanted to know how possible it was from the professionals.

origin":26x3l0tv said:
xXTheOneRavenXx":26x3l0tv said:
Explain? I read many theories. Why isn't this one possible?

Your conjecture is based on there being 'gaps' in space (if I understand you correctly) which there is no evidence of and no theoretical basis for. Therefore my opinion as to whether this conjecture is viable of not, is simply - no.

Good science fiction or fantasy is based on the following: Assume this one fantastic thing is true. From that point on you then follow the normal laws of nature. Such as a assume that there are vampires.... or assume there is faster than light space ships... or assume that we are invaded by aliens on the 4th or July...

What you are saying is the same - assume that there are gaps in space....

Maybe there are gaps in space, what ever that means, but in the absence of any evidence or a viable theory of how that is possible - there is no reason to abandon a working theory of black holes to go there.
 
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derekmcd

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xXTheOneRavenXx":33252taz said:
A theory I had was to describe that the actual explosion of a star could for all intensive purposes "tear" space which the tear itself is the black hole, rather then the stars gravity itself causing the star to turn into a black hole. It is a theoretical possibility as we currently do not know what happens at the final moment between the stars explosion & a black holes formation. No one has actually "witnessed this transformation. I just wanted to know how possible it was from the professionals.


What you are saying is the same - assume that there are gaps in space....

Maybe there are gaps in space, what ever that means, but in the absence of any evidence or a viable theory of how that is possible - there is no reason to abandon a working theory of black holes to go there.

For there to be gaps in space, you have to define what 'space' actually is. I think you will find it rather difficult to describe space as something you can physically objectify. Space is not tangible. It is simply a distance metric.
 
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xXTheOneRavenXx

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Well in actuality "Space" has to be something if it is to be expanding. You can't have nothing expand at speeds greater then the speed of light, causing separations between masses at these relevant speeds. So far it is theoretically impossible for anything with a mass to travel greater then the speed of light, yet galaxies recede from each other beyond this limit. That is my proof "Space" is in fact something. We may not know exactly what it is, or be able to define it, but it is definitely something. Now that I have defined it as something, and we all know space is warped around masses (don't need to get into proving numerous theories that already exist), is it not possible that mass explosions within space cause tears (i.e black holes). Here is the best analogy I can come up with: A leaf can float on water, it can follow the current of water... but you cause that leaf to explode in some way and the water is pushed away for an instant before filling back in. Since space does not have the density, mass, nor friction of water... I think perhaps it "may" be possible that during a massive explosion that space could get distorted, torn, twisted, whatever you want to call it when it tries to reform at the epicenter of the explosion. Since space cannot "fix" this problem it faces, the Black hole is formed. Even if space is elastic, we haven't even begun to understand the power of these massive explosions from various bodies within space.
 
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derekmcd

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xXTheOneRavenXx":2i3y37y3 said:
Well in actuality "Space" has to be something if it is to be expanding. You can't have nothing expand at speeds greater then the speed of light, causing separations between masses at these relevant speeds. So far it is theoretically impossible for anything with a mass to travel greater then the speed of light, yet galaxies recede from each other beyond this limit. That is my proof "Space" is in fact something. We may not know exactly what it is, or be able to define it, but it is definitely something. Now that I have defined it as something, and we all know space is warped around masses (don't need to get into proving numerous theories that already exist), is it not possible that mass explosions within space cause tears (i.e black holes). Here is the best analogy I can come up with: A leaf can float on water, it can follow the current of water... but you cause that leaf to explode in some way and the water is pushed away for an instant before filling back in. Since space does not have the density, mass, nor friction of water... I think perhaps it "may" be possible that during a massive explosion that space could get distorted, torn, twisted, whatever you want to call it when it tries to reform at the epicenter of the explosion. Since space cannot "fix" this problem it faces, the Black hole is formed. Even if space is elastic, we haven't even begun to understand the power of these massive explosions from various bodies within space.

I'm not sure where to start with this. I'll just pick on the very first sentence I highlighted. A common misconception is to objectify space as a physical object. General Relativity (GR) doesn't define space other than to consider it a metric. Hence the statement "metric expansion of space". It is NOT space that is expanding in GR... only the metric that defines space.

Picture coordinates in x,y,z in your head... not on paper, the surface of a balloon, a rubber sheet. The x,y,z don't exist on the surface of anything. They exist in Euclidean space... nothing physical. Now, expand those coordinates. The x,y,z defined on your grid stay the same... only the distances grow.

In my opinion, it is futile to describe something physical expanding in the framework of GR. A pointless endeavor and unnecessary.
 
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xXTheOneRavenXx

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Rubbish. How can you have space being the cause of two objects moving apart at greater then the speed of light if space is not physical. Space itself has expansion as a whole. It explains the expansion. Space cannot be nothing and the cause of the expansion at the same time. It's not possible relistically or theoretically.
 
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SpeedFreek

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The question as to whether it is a good idea to say that "space is expanding" is currently a hot topic in cosmology. Nobody denies that the notion lends itself well to helping people understand the concepts, but there is the question as to whether it also introduces misconceptions - i.e. attributing "space" with intrinsic qualities it may not actually possess.

The links below are all the recent papers relating to this issue, in chronological order. You may have seen some of them already. (My notes in italics)

Inflation and the Cosmic Microwave Background See how space seems to expand in these 2 papers
Expanding Confusion: common misconceptions of cosmological horizons and the superluminal expansion of the Universe
Misconceptions about the Big-Bang and here is the easy version of the above paper
Is space really expanding? A counterexample Are you sure that "space" expands?
A direct consequence of the expansion of space? Expanding "space" is not a physical reality, it is a matter of philosophy
Eppur si espande Well it's definitely not due to the kinematic motion of galaxies
Expanding Space: the Root of all Evil? Maybe not, but General Relativity doesn't need "space itself" to expand.
Coordinate Confusion in Conformal Cosmology Oh yes it does!
Cosmological Radar Ranging in an Expanding Universe Oh no it doesn't!
A short answer to critics of our article "Eppur si espande" Yes it does! We were right and here's why!
Eppur si muove No it doesn't, you are using the wrong metric.. I will soon show you why.

This is where we are at, right now.

For anyone who is wondering, all of these papers accept the expansion of the universe, they are just arguing about whether it is the "space" that is expanding.
 
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xXTheOneRavenXx

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Are you trying to say these guys can't agree on whether it is "space" that is expanding or not? Let's put it this way, nothing with mass can exceed the speed of light, we all know that. Yet, things within space can descend away from each other faster then the speed of light, while doing so no molecule, atom, particle, etc... that we have found so far within space moves at this speed. Not unless it were the expanding motion of space between these substances that was causing them to descend from each other at this rate. We see it everywhere throughout the universe. Mass cannot exert past the speed of light, yet space can because it contains no mass in it's physical properties. The one work around to General Relativity.
 
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manifolder

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To say space is physical is the same as saying time is physical. One can't exist without the other. Both are simply(or not so simply) metrics for measurement. Space as you describe it is an illusion akin to time. This is turning into a philosophical debate. Space is where physicality occurs. Space cannot be wieghed, however, the things within it can.
 
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MeteorWayne

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ellinne":10hz4km6 said:
black holes are really dangerous if that blackhole cannot stop maybe our world turn to an ash i mean gone black hole are cause by using time machines or any machines that can go back to the past using everything using time travelers can be a good way to stop black holes as to the scientist black getting bigger to the surface of the earth it looks like a pasta that the rays of a sun under the two parallel lines causing the black holes getting bigger as it shown by the scientiston national geographic channel black holes can cause death of people who wants to save earth as before

Black holes are only dangerous if you are VERY close to them...please keep these foolish comments to the "black holes are dangerous" thread that I moved to "The Unexplained" forum. Welcome to space.com. We discuss real science here, not irrational hype, except sometimes in "The Unexplained".
 
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xXTheOneRavenXx

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manifolder":zha3rrsv said:
To say space is physical is the same as saying time is physical. One can't exist without the other. Both are simply(or not so simply) metrics for measurement. Space as you describe it is an illusion akin to time. This is turning into a philosophical debate. Space is where physicality occurs. Space cannot be wieghed, however, the things within it can.

I can't say that I agree manifolder in reference to saying space is physical, time must be as well. Time is calculation while space being a physical carrier if you will of mass without having mass itself. Yes, I do agree on the other hand that this is turning into a philosophical debate. but that can be a good thing, especially on this topic. That is how many things are resolved, expanded upon, and sometimes things are discovered that others did not see. Would others like to also participate in this debate?
 
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manifolder

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xXTheOneRavenXx":3m0zgaw8 said:
manifolder":3m0zgaw8 said:
I can't say that I agree manifolder in reference to saying space is physical, time must be as well. Time is calculation while space being a physical carrier if you will of mass without having mass itself. Yes, I do agree on the other hand that this is turning into a philosophical debate. but that can be a good thing, especially on this topic. That is how many things are resolved, expanded upon, and sometimes things are discovered that others did not see. Would others like to also participate in this debate?

Time isnt calculation, time just is, every event that has ever happened, or will ever happen, has already happened. Time is to non-linear to be calculation. Time as a point in space relative to another point in space, can be used as measurement in calculation, but again, this is not a physical thing. Time and Space are physical inasmuch as numbers are physical. We had a similar debate on another old forum of mine.
 
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SpeedFreek

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xXTheOneRavenXx":3abmzviy said:
Are you trying to say these guys can't agree on whether it is "space" that is expanding or not? Let's put it this way, nothing with mass can exceed the speed of light, we all know that. Yet, things within space can descend away from each other faster then the speed of light, while doing so no molecule, atom, particle, etc... that we have found so far within space moves at this speed. Not unless it were the expanding motion of space between these substances that was causing them to descend from each other at this rate. We see it everywhere throughout the universe. Mass cannot exert past the speed of light, yet space can because it contains no mass in it's physical properties. The one work around to General Relativity.

How about this approach?

Everything is at rest in relation to the Hubble Flow. Ignore the Hubble Flow itself for now and concentrate instead on the things we can measure - the objects that reside in space. We can see that objects have apparently receded from us during the history of the universe, but if objects are all at rest and it is the Hubble Flow that has caused them to become more distant, then have they actually receded? What does it mean to recede? The usual definition is to move away, but these objects aren't moving, the metric is changing around them. So, distant objects are not receding faster than light - they just end up so far away that if they had moved there they would have had to break the speed of light to do so. This is why the proper term to use is apparent recession.

So, what is the Hubble Flow? Why is the metric that defines cosmological distance changing, over time?

If you want to prove that space is expanding, you will have provide a mechanism as to why expanding space would "push" objects apart, rather than simply expand around them. What properties does space have then, that it can push galaxies apart? Why can't those properties be more appropriately attributed to something that resides within space, rather than the space itself?

It is not as simple as you might think. :)
 
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xXTheOneRavenXx

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No, I agree. It is a very difficult subject. Doesn't the Hubble Constant proven space itself expands? It certainly proves the recession rate. 70 km/s per megaparsec is still quite fast if you ask me. Looking at the properties of space itself, can I ask your opinion of whether virtual particles are considered a property of space or not?
 
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SpeedFreek

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xXTheOneRavenXx":2l90a8rz said:
No, I agree. It is a very difficult subject. Doesn't the Hubble Constant proven space itself expands? It certainly proves the recession rate. 70 km/s per megaparsec is still quite fast if you ask me. Looking at the properties of space itself, can I ask your opinion of whether virtual particles are considered a property of space or not?

Are bubbles a property of water? ;)

The Hubble Constant shows that distances apparently increase, over time. This gives us an apparent recession velocity for distant galaxies. Note that we also have that same apparent recession velocity in relation to those galaxies - from their point of view it is the Milky-Way that is apparently receding. (The more I use the word "apparent", the more we can see why popular astronomy articles tend to leave it out!)

Of course, our Milky-Way is not moving faster than light, and nor are those distant galaxies. Nothing ever overtakes a photon in space, so nothing ever moves faster than light. But none of this answers your question.

I am unsure as to whether virtual particles are considered to be a property of space, as these virtual particles seem to appear and disappear in space. They are often described as a property of space, it is true. But they appear in all sorts of places in different forms - from the vacuum of space to the inside of atoms.

The fundamental question is "what is that which causes the galaxies to apparently recede from us?" and "expanding space", is not the fundamental answer.

To me, space is just the background, the stage on which this universal play is set. Space is an abstract concept to describe the dimensions. Space is not something physical, it is quite the opposite. Space is absolutely nothing. The universe expands, the size of the gaps between things at the largest scales increases, but it is not simply space that is causing it.

If we were to come to some understanding of the nature of the expansion, the initial impetus behind the increase in the scale of the background metric, would it make a difference? If, say, we find evidence that inflation is correct and there was a higgs like replusive gravity field that drove the universe apart and then settled towards a possibly non-zero value, and that the remnant of that higgs field exists today as dark energy, which is starting to drive things apart again now its influence isn't dominated by gravity as everything is now far enough apart, does "space" still expand?

If that dark energy that we think pervades the universe is not only responsible for the acceleration of the expansion, but is also linked to the original cause, why can't space simply be the background within which all this happens? What use is there in assigning coordinates to events in space and saying that because those coordinates separate that the space is moving them apart when it the action of a field that pervades that space.

Or how about this?

If space is expanding, is it "stretching" or is more of it appearing out of nowhere? Is there a difference?

If dark energy works like a cosmological constant (which seems to be the case) then it doesn't weaken as space expands - the energy density is not reducing with the expansion. So in that case, if dark energy were a property of space then new space must be appearing out of nowhere, otherwise the dark energy density would reduce as space "expands". So space is not expanding, the space is not growing and stretching the dark energy within it - space is, err... constantly respawning!

:D
 
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xXTheOneRavenXx

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lol, I like that explanation. It is true that dark energy may be the driving force of the expansion, and who knows may be a property of space... then I agree we have no idea if space is expanding or stretching. If space-time is one as in GR, then if space is expanding then would not time?
 
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ellinne

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wow your really great welcome to space.com know i make a topic too like that but no one was reading it
 
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dragon04

Guest
xXTheOneRavenXx":1dtx0lue said:
lol, I like that explanation. It is true that dark energy may be the driving force of the expansion, and who knows may be a property of space... then I agree we have no idea if space is expanding or stretching. If space-time is one as in GR, then if space is expanding then would not time?

Space could also be expanding because it's being pulled apart as opposed to being pushed apart.
 
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