What Is the Universe Expanding Into?

[p764rds]

Lost the plot..

If it were possible to 'be' a photon then for us time would stand still. For example, think of a photon that records a person falling from a building at the instant of starting the fall. This photon (or 'me' in this thought experiment) would travel through the Universe for many millions of years. When the photon (me) steps out into reality (a plastic photo film of an amateur astronemer guy in the alpha centaura galaxy) millions of years later, no time would have passed for me (the photon). I would still be starting my fall off the building. When I was stopped in my tracks by this plastic photo film I would then whizz round and round an atom because I am trapped in a chemical substance loop (probably silver nitrate). But still no time is passing for me, and I would whizz round my gauge symmetry U(1) in the film until its (the photo's) destruction. Then I would continue on my way. I assume, I must connect, in such a way to the infinite future and likewise to the origin of me at the BB. Light seems to have no length or time of itself and exists 'beneath' our space-time Universe, I am losing the plot now...why are we here at all? Someone take me down pls.

 

[SdogV]

The end.

Just a skim through all the schemes to answer the question of "How big is big?" Obviously the answer is BIG.
Seriously, to start from zero (a beginning) and get to 1 (the present) makes what we know as "unity", in this case called the "universe". But Bucky Fuller has said that "unity" is plural, and at a minimum, 2. There's the problem, 2 is beyond us.

 

[a_g]

If there was a second universe what is in between us and them? Heaven? Hell? Ect?

your on the wrong message board

 

[zankaon]

Complement of the universe

In a mathematical sense, using a domain of discourse, one could consider the universe, and it's complement i.e. that which is not part of universe. Visualizing in terms of Venn diagram might be helpful.

 

[Amp1]

Chronos said …

…The volume occupied by galaxies and such are otherwise meaningless. There is no space outside of space. Space can only be described in terms of the distance between physical objects.

I like Garth’s post and JesseM’s was most enlightening. I haven’t read all the posts yet and those that I mentioned are among the first replies to Ulnarian’s post.

Even the brief brush with the ‘R’ word by SOH CRATES -I’m reading the last few- brings together something I’ve pondered.

I get the sense that setAI is on to what I’m thinking in a way. The universe isn’t expending into anything in the physical sense – I think that like the symbolic use used in this thread of imagining the universe as a sphere expanding in a plane, one can think of the universe as being analogous to intangible quality of electricity used measure to impedence, reactance being complex along with the resistance being real combine into impedence. So that the concept, existence could be a combination of spirit which isn’t physical or tangible and reality which analogous to resistance is physically real and tangible (measurable-detectable).

Existence would then be dimensionless or the totality of indefinitely/infinite dimensions.

If the universe is ‘… expanding into its future’ as Garth proposed, running time in reverse would give null time just before the BB. Concepually and sequentially, existence was before eternity - (all time). So, Garth the universe expands into Existence as well. ;)

 

[H.M. Murdock]

I don't know much about cosmology, but string theory has proposed the hypotezis that there are huge branes outside the space of the universe. and they were the ones that made posible the explotion of the big bang. I personately don't take seriously the brane hypotezes, but apparently millions of dollars are being spend right now in order to detect huge gravitational waves that could prove their existens.

 

[nanoWatt]

If the Universe is expanding, then why don't our atoms in our bodies expand apart?

Also, before the Big Bang, if there was such a thing, wouldn't there have been an infinite amount of time? Or am I thinking too linearly?

 

[Garth]

I don't know much about cosmology, but string theory has proposed the hypotezis that there are huge branes outside the space of the universe. and they were the ones that made posible the explotion of the big bang. I personately don't take seriously the brane hypotezes, but apparently millions of dollars are being spend right now in order to detect huge gravitational waves that could prove their existens.

Welcome to these Forums HMM!

Brane (as in membrane)Theory is one possibility that seems to come up with the correct numbers. As you say large detectable gravitational waves are predicted by the theory.
If they are detected then we will know more!

Garth

 

[Garth]

If the Universe is expanding, then why don't our atoms in our bodies expand apart?

Also, before the Big Bang, if there was such a thing, wouldn't there have been an infinite amount of time? Or am I thinking too linearly?

nanoWatt you might find a basic introduction to cosmology useful, such as the website by Ned Wright.

In the standard model the universe on the largest scales is described by the Friedmann-Lemaître-Robertson-Walker metric, often abbreviated to the R-W or FRW metric, and space either expands or contracts on the largest scales.

Hubble red shift shows that we are in an expanding phase of the universe.

On local scales objects such as galaxies, solar systems, and atoms are gravitationally bound and do not expand.

Actually it depends on what you use to measure length, if you use a steel rule, then by definition the atoms it is made of, and by extension all other atoms, do not expand. A steel rule is 'rigid' (of fixed length to a co-moving observer) and the universe on the largest scales expands around it.The standard model may be projected back in time to about 13.7 billion years ago to the Big Bang. Whether or not the BB itself was a genuine beginning of time in our universe, or just a 'pinch-point' from a universe beyond is a subject of active debate, not least on these Forums!

Garth

 

[marcus]

Also, before the Big Bang, if there was such a thing, wouldn't there have been an infinite amount of time? Or am I thinking too linearly?

Not too linearly for me anyway! I don't know if I'd call it linear, but it's how I think too. I agree with everything Garth just said and also I don't know of any scientific reason to suppose that time-evolution doesn't extend back indefinitely

Time is a dimension, not a substance----so it is a little odd to think of it as an "amount".
But I think what you are saying is basically right. People used to think that the fact that the classical vintage 1915 version of General Relativity broke down at a certain point PROVED that time stopped there. But that's not a proof, it just shows that classic GR breaks down, not that Nature does. So a lot of researchers have made it their business to model the Big Bang, get rid of the classic "singularity", and investigate what could have been happening prior. they just had a conference at Cambridge where this was discussed a lot. And in January 2007 there was a 3-week international workshop on it in Santa Barbara.

the extent of time----or the extent of the PROCESS governed by physical law, which we associate with the passage of time----is something we don't know.

To sum it up, you could say that the backwards extent of time could be unlimited or cut off-----the classical model breaks down but some other model do not----so we can't say. For now we have to entertain both possibiliities, including that the process of time-evolution may extend back indefinitely.

 

[marcus]

According to the Big Bang Theory, at the time of the Big Bang, all forces, matter, dimensions, etc.. were created...

Is this your own theory or do you have a LINK to a source that you can share with us?
It doesn't sound like a contemporary professional mainstream consensus view, so it makes me curious as to where you are getting it.

It seems premature to me to be talking about THE Big Bang Theory as if we already knew the right model to replace the classic singularity. As you probably realize, classic General Relativity breaks down right at the Big Bang, so it does not give us a theory.
the only theories that describe the Big Bang itself are quantum cosmology models which extend back in time BEFORE.

I think your use of the word "created" seems a bit pretentious, since it is not generally the case in today's models that all forces, matter, and space begin at that point.
As far as I know, it has not yet been established in modern quantum cosmology that these things (forces, matter, space) have any beginning at all! Indeed they may have always existed. This simply isn't known.

Even if they do have beginnings, I know of no scientific reason to believe that their beginnings would coincide with what is called the big bang.

 

[dvy001]

Just wanted to point out that the ever quoted balloon analogy has flaws. Here is a previous comment from someone:

"Livio is up to the task. He dredges up the old expanding balloon as his prop. "An ant traveling on the surface of a balloon will never reach an edge," Livio explains. "In the worst case it will return to its starting point."

The fallacy is that the ant has reached the edge of the balloon and is in fact standing on it. The surface is the edge.

 

[Garth]

Just wanted to point out that the ever quoted balloon analogy has flaws. Here is a previous comment from someone:

"Livio is up to the task. He dredges up the old expanding balloon as his prop. "An ant traveling on the surface of a balloon will never reach an edge," Livio explains. "In the worst case it will return to its starting point."

The fallacy is that the ant has reached the edge of the balloon and is in fact standing on it. The surface is the edge.

To make the analogy work you have to specify that it is a two dimensional ant living in the two dimensional surface of the sphere, represented by the (thin) membrane of the balloon.

The whole point is that it is possible, if it is helpful, to visualize a representation of four dimensional space-time by suppressing one space dimension.

Garth

 

[nanoWatt]

And all this time I thought the Universe was 13 dimensions.

 

[Garth]

And four dimensional space-time is four dimensional!

Garth

 

[petm1]

On local scales objects such as galaxies, solar systems, and atoms are gravitationally bound and do not expand.

This is the type of statement that I have to disagree with, the intrinsic motion of the celium atom that we use as the ruler in our atomic clocks, too me, appears to be in phase with time, Times only motion is dilation, therefore I've always thought that everything dilates.

Actually it depends on what you use to measure length, if you use a steel rule, then by definition the atoms it is made of, and by extension all other atoms, do not expand.

By definition I change the size of steel by adding energy, one of the reasons we set standards at elevation and temperature. Atoms with their intrisnic motion changes locally to phase with each other, does not mean that they are always the same globally.

A steel rule is 'rigid' (of fixed length to a co-moving observer) and the universe on the largest scales expands around it.[/

I see the rigid ruler expanding with the mostly empty universe expanding just a little bit faster around it.

The standard model may be projected back in time to about 13.7 billion years ago to the Big Bang. Whether or not the BB itself was a genuine beginning of time in our universe, or just a 'pinch-point' from a universe beyond is a subject of active debate, not least on these Forums!

Truth if I ever saw it.

 

[Garth]

This is the type of statement that I have to disagree with, the intrinsic motion of the celium atom that we use as the ruler in our atomic clocks, too me, appears to be in phase with time, Times only motion is dilation, therefore I've always thought that everything dilates.

The question is: "dilates relative to what?"

That is, the question is: "What is the standard unit of length that you measure this dilation with and how do you mentally transport that standard unit around the universe to make astrophysical and cosmological measurements?"

By definition I change the size of steel by adding energy, one of the reasons we set standards at elevation and temperature. Atoms with their intrisnic motion changes locally to phase with each other, does not mean that they are always the same globally.

You have to define the standard unit of length, mass and time.

You need a conservation prinicple, something that does not change by definition and show that this principle leads to results that are consistent with experiment and observation.

In GR the 'rest' mass of an atom is constant, this is a consequence of GR's conservation principle the conservation of stress-energy-momentum:

$$T^{\mu}_{\nu;\mu} = 0$$

I see the rigid ruler expanding with the mostly empty universe expanding just a little bit faster around it.

Again relative to what standard?

Note that we have been talking about GR, the standard theory that fits the data and leads to the mainstream $\Lambda$CDM cosmological model; there are alternative published theories out there.

In conformal gravity theories the standard atomic units may well change from place to place and over time, but these theories need to have alternative and clearly defined standard units of mass, length and time to replace the atomic ones.

One such published theory that you may be interested in, although in its present form it has just been falsified by the Gravity Probe B experiment, is http://en.wikipedia.org/wiki/Self_creation_cosmology .

Garth

 

[petm1]

"dilates relative to what?"

Intrinsic motion is relative to everything, as to this question I'm thinking more of relative to when and the where is itself.

"What is the standard unit of length that you measure this dilation with and how do you mentally transport that standard unit around the universe to make astrophysical and cosmological measurements?"

Don't we already do this using the meter and or the second? We measure this dilation as the difference between clocks, maybe this same dilation explains why things that we view via photons at the farthest reaches of our visible universe appear to be getting bigger.

You have to define the standard unit of length, mass and time.

I use webster's

You need a conservation prinicple, something that does not change by definition and show that this principle leads to results that are consistent with experiment and observation.

I'm not talking about changing the one we have. Relative we don't change, our dilation rate is always the same locally.

In GR the 'rest' mass of an atom is constant, this is a consequence of GR's conservation principle the conservation of stress-energy-momentum:

I am not saying that rest mass changes relative to anything, I see two types of motion that of time like or if you will intrinsic motion of matter and the other as space like or the motion of matter through space.

 

[petm1]

I've tried to think of matter as static for the last couple of days, and I can't get it. Thinking of a steel ruler in my mind, it is constantly dilating when you put heat to it you are changing the rate of its time dilation, we see it as the steel expanding, after you remove the heat it goes back to the local dilation rate. I'm watching the snow melt and I can feel the difference in the time dilation rates between in my house and the outside air. I see time dilation everywhere. How about this for a thought experiment: if you could step back far enough to see the entire light cone of our visible universe, and then reach out and place it under a microscope, what would you see?

Getting to the original subject, I think using the meter and the second, I would except that our visible universe is expanding into time and when we get there we will measure it as space.