Big Bang and Ether (split from direction of the big bang)

[Strange]

What was a kinetic energy of big bang?

 

I don't think it is well-defined. After all, what frame of reference are you calculating it in?

 

For example : when you turn hydrogen into helium then you create additional space, which expands universe.

 

Why do you think that "creates space"?

 

 

Please stop doing that.

[michel123456]

 

Help me out then. If two people are observed to be moving away from you, one moving east and one moving west, what is that doesn't make sense when I say at earlier times, they were closer to you and, by extension, to each other?

 

Please try and address only that, without changing the conditions of the example.

 

Now I am going to change the conditions a little bit.

 

We don't have to imagine where the two people were in the past. We are observing right now the situation in which they were in the past.

 

The one on the west has its nose litterally collated to the back of "another one" in front of him.

The same goes for the guy going east. That's what greater density means.

 

The BBT states that those two "other ones" are closer to each other than the 2 people we are observing. (or am I wrong here?)

 

Following Ned's diagram, at the extreme those two "other ones" are one and same person:

 

it is ourself in the past.

 

Do I understand clearly?

Edited December 2, 2014 by michel123456

[Strange]

 

We are observing right now the situation in which they were in the past.

 

No you are not.

 

 

or am I wrong here?

 

Yes.

 

You are not taking into account the finite travel time of light and the fact that space is expanding (while the light is travelling).

Edited December 2, 2014 by Strange

[michel123456]

 

No you are not.

 

 

Yes.

 

You are not taking into account the finite travel time of light and the fact that space is expanding (while the light is travelling).

Oh. Do you mean that we do not observe the 2 people with their nose collated to the back of the "other one" because the space between the nose & the back has expanded?

[Strange]

Oh. Do you mean that we do not observe the 2 people with their nose collated to the back of the "other one" because the space between the nose & the back has expanded?

 

Something like that. It is slightly more complicated because the space that the light has travelled through has also been expanding. So the one from the more distant object took longer to arrive and so they appear further apart.

 

But, again, you need to look at the maths. For someone who claims they cannot accept something until they understand it, you seem surprisingly reluctant to do that.

[michel123456]

Am I wrong here too?

 

The BBT states that those two "other ones" are closer to each other than the 2 people we are observing. (or am I wrong here?)

 

Following Ned's diagram, at the extreme those two "other ones" are one and same person:

 

it is ourself in the past.

 

Do I understand clearly?

 

 

 

But, again, you need to look at the maths. For someone who claims they cannot accept something until they understand it, you seem surprisingly reluctant to do that.

In this case, the maths (and the diagrams) explain things that I cannot put into my mind.

 

The only one way I could understand the situation would be that the very ancient galaxies were already there, far away from us, a long time ago IOW, not close to each other.

[michel123456]

Isn't it what we are observing from the POV of the Earth ?

The arrows representing the direction & apparent velocity

 

 

 

[Strange]

OK. Your problem seems to be the fact we see things further apart than they were in the past. This seems to be because you are not taking into account that the light they emit is being "dragged back" by expansion.

 

I'm not sure this diagram will help (I'm not quite sure it is 100% correct) but ...

 

 

The galaxies appear farther away then they were when the light was emitted. (Because of expansion.) This also means that they look further apart from each other.

 

And you could populate that with more stars at different ages and convince yourself that the older they are, the further away and further apart they appear.

Edited December 3, 2014 by Strange

[michel123456]

And you could populate that with more stars at different ages and convince yourself that the older they are, the further away and further apart they appear.

Yes, yes, yes.

The older they are, the further away and further apart they appear.

They do not come together to the singularity, they spread away in the past.

[swansont]

Yes, yes, yes.

The older they are, the further away and further apart they appear.

They do not come together to the singularity, they spread away in the past.

 

"Come together to the singularity" is from turning the clock backward, to envision how things were in our past. They could not have been further away from us, since they are moving away.

[MigL]

Michel123456's problem seems to be that he is considering concentric spheres, and that in each further additional sphere,things are moving farther apart. He cannot reconcile expansion with past time/distance. He is inside an expanding observable universe, but expects to be able to look far enough away to be able to see the original compactified,post big bang universe. As if he were outside it !!!

 

Miche123456, consider looking outwards radially along one direction, analyse the observational evidence, and then draw your conclusions.

Remember,you are INSIDE the expanding universe.

[Strange]

Yes, yes, yes.

The older they are, the further away and further apart they appear.

They do not come together to the singularity, they spread away in the past.

 

They only appear to get further apart in the past because they are moving away. Once you take that expansion into account, you find that the more distant (further back in time) they are, the closer together they are. You could demonstrate this by doing diagrams with galaxies at different distances and times. But you have convinced me that you are not interested in learning (because it might mean you have to change your mind) so I am not going to waste my time on it.

[DimaMazin]

 

I don't think it is well-defined. After all, what frame of reference are you calculating it in?

 

 

Why do you think that "creates space"?

 

 

Please stop doing that.

You can't define KE of BB because you don't know mass of unvisible part of our universe. It is infinite. Why visible part of our universe is unchanged(we can see only galaxies, which illuminated our Earth earlier)?

We have no center of BB, therefore maybe usual phenomenons create space which expands the universe.

[Ophiolite]

Now will you please answer the two questions that Strange asked. (Hint: your reply was not an answer to those two questions.)

[michel123456]

 

"Come together to the singularity" is from turning the clock backward, to envision how things were in our past. They could not have been further away from us, since they are moving away.

But we are envisioning how things were in our past. The vision is deformed, yes, but still what we see comes from the past.

Michel123456's problem seems to be that he is considering concentric spheres, and that in each further additional sphere,things are moving farther apart.

Yes. And each additional sphere is more in the past.

He cannot reconcile expansion with past time/distance.

True, I cannot.

He is inside an expanding observable universe, but expects to be able to look far enough away to be able to see the original compactified,post big bang universe. As if he were outside it !!!

 

Miche123456, consider looking outwards radially along one direction, analyse the observational evidence, and then draw your conclusions.

Remember,you are INSIDE the expanding universe.

I am inside an observable universe and yes I expect to be able to capture coming from far away in distance and from far away in time, the original big bang or at least its remnants. And I think we actually do that, It is supposed to be the CMB.

 

They only appear to get further apart in the past because they are moving away. Once you take that expansion into account, you find that the more distant (further back in time) they are, the closer together they are.

That's what troubles me. How is it reconcilable that we observe galaxies C & D totally appart & in the past and from this observation conclude that they were co-located & in the past?

[swansont]

That's what troubles me. How is it reconcilable that we observe galaxies C & D totally appart & in the past and from this observation conclude that they were co-located & in the past?

 

They are moving apart. How do you come to any other conclusion?

 

Your two references to "the past" are not talking about the same time. "Closer together in the past" means that you take whatever observation you have and turn the clock back from that point.

[Strange]

That's what troubles me. How is it reconcilable that we observe galaxies C & D totally appart & in the past and from this observation conclude that they were co-located & in the past?

 

I don't really know how else to help you visualise it. Maybe it can't be understood "purely intuitively" as you wish to.

 

Imagine the universe were not expanding; it is purely static. Then as we look further away, we would see galaxies closer and closer together (because of perspective).

 

Now, if there were just fewer galaxies in the past, it might look as if the distance ones had the same spacing as the newer ones.

 

Having typed that, I don't really know what it tells us ... Except that all observations have to be interpreted in the light of a model based on all the available data. You can't just take it as it appears. In the first case, we could use a normal perspective transformation to interpret the observations. In the second case, we could add a model of the rate at which galaxies are formed.

 

As it is, we use a model of expanding space (based on theoretical predictions and countless lines of evidence) to interpret what we see.

 

If everything, everywhere is, and always has been, moving apart (at a rate proportional to velocity) it is hard to see how they could not have been closer together previously.

 

Here are a couple more good articles that don't address your question directly but might help:

http://www2.astro.psu.edu/users/caryl/a10/lec16_2d.html(mentions that we see tidal distortion of distant galaxies caused by them being closer together - even though they don't look it)

http://www.cfa.harvard.edu/webscope/activities/pdfs/galaxiesT.pdf(includes a nice explanation/diagram for why space expands).

[michel123456]

 

I don't really know how else to help you visualise it. Maybe it can't be understood "purely intuitively" as you wish to.

 

Imagine the universe were not expanding; it is purely static. Then as we look further away, we would see galaxies closer and closer together (because of perspective).

 

Now, if there were just fewer galaxies in the past, it might look as if the distance ones had the same spacing as the newer ones.

 

Having typed that, I don't really know what it tells us ... Except that all observations have to be interpreted in the light of a model based on all the available data. You can't just take it as it appears. In the first case, we could use a normal perspective transformation to interpret the observations. In the second case, we could add a model of the rate at which galaxies are formed.

 

As it is, we use a model of expanding space (based on theoretical predictions and countless lines of evidence) to interpret what we see.

 

If everything, everywhere is, and always has been, moving apart (at a rate proportional to velocity) it is hard to see how they could not have been closer together previously.

 

Here are a couple more good articles that don't address your question directly but might help:

http://www2.astro.psu.edu/users/caryl/a10/lec16_2d.html(mentions that we see tidal distortion of distant galaxies caused by them being closer together - even though they don't look it)

http://www.cfa.harvard.edu/webscope/activities/pdfs/galaxiesT.pdf(includes a nice explanation/diagram for why space expands).

Here below an excerpt of your first link

 

Can we prove that the galaxies were once all together, and that they were somehow ejected into space via a Big Bang? Well, if all the matter in the universe was at one time squeezed together, then galaxies in the past would have been closer together, and there would have been many more interacting galaxies. If we had a time machine, we could see this.

Well, we do have a time machine -- it's called a telescope. Light travels at a finite speed, so, for some galaxies, the light has taken literally billions of years to get here. We are seeing those objects as they were billions of years ago. We are seeing back in time. When we take the deepest pictures of the universe, we see many irregular galaxies that are obviously tidally distorted. Far away galaxies do seem to be closer together.

(from here)

That is fine. It means that galaxies close to D were closer in the past. That's what is happening on the East past of our sky (in my example, see the circular graph in my post above)

What about C galaxy which is on the west side of the sky?

How the hell was it closer to D?

How the galaxy on the west was closer to the galaxy on the east?

 

If we pick even older galaxies than C and D, say galaxies E and F.

like this

E-C-A-Y-B-D-F

Where Y represent You on the earth.

You are observing that galaxies E and F are even more separated from each other than C and D. And yet they are closer to the Big Bang instant.

At each step, observing older and older galaxies they are further away from each other.

That is what I cannot understand.

----------------------------------------------------------

This below stolen from your second link on page 7, with some additions from me related to our conversation.

 

The explanation looks clear, in the past the universe was smaller and denser, however

 

What really troubles me is that we don't have to imagine what the past could have been, the past is happening there in front of our eyes, like this below:

 

 

And that does not ressemble to a "space no bigger than a grapefruit". It ressemble to something huge.

Edited December 6, 2014 by michel123456

[Strange]

And that does not ressemble to a "space no bigger than a grapefruit". It ressemble to something huge.

 

But you are seeing galaxies billions of years after that. Do you really expect galaxies to fit into a grapefruit. Even the CMB comes from 380,000 years after the "grapefruit" phase.

 

So maybe it is just that your expectations are unrealistic.

[michel123456]

 

But you are seeing galaxies billions of years after that. Do you really expect galaxies to fit into a grapefruit. Even the CMB comes from 380,000 years after the "grapefruit" phase.

 

So maybe it is just that your expectations are unrealistic.

There are observable galaxies some hundred millions years after the "grapefruit phase" (I like that expression).

 

The universe we are observing gets wider and bigger as much we look into the past. The universe becomes smaller once it becomes unobservable. Is that it?

Edited December 6, 2014 by michel123456

[swansont]

 

What really troubles me is that we don't have to imagine what the past could have been, the past is happening there in front of our eyes, like this below:

 

That's part of the problem. What is happening in our past is not right in front of our eyes. What's right in front of our eyes is what we're observing right now. It's not what we would have observed at some time in the past.

 

You can't impose your personal view of time on a model that doesn't use that view and expect the model to make sense.

[michel123456]

 

That's part of the problem. What is happening in our past is not right in front of our eyes. What's right in front of our eyes is what we're observing right now. It's not what we would have observed at some time in the past.

 

You can't impose your personal view of time on a model that doesn't use that view and expect the model to make sense.

Aren't we observing the past? O.K. not our past, but anyway: things happening in the past?

[swansont]

Aren't we observing the past? O.K. not our past, but anyway: things happening in the past?

 

Yes, not OUR past, and for these observations, that's what matters.

[DimaMazin]

Now will you please answer the two questions that Strange asked. (Hint: your reply was not an answer to those two questions.)

If KE of big bang created mass of universe ( mass of universe is the same in any frame) then Strange's question about reference frame is senseless.

[Strange]

If KE of big bang created mass of universe

 

There is no evidence that the big bang created the mass of the universe.

 

then Strange's question about reference frame is senseless.

 

Energy is observer dependent. So it depends what reference frame you measure it from.

 

Also, there is no universal definition of energy in GR, so I doubt the "kinetic energy of the universe" is even defined.

 

Finally, we have no idea how large the universe is (it could just be very large or it could be infinite) so, again, there is no way to calculate the kinetic energy.