Are some areas of the Universe still "inflating" ?

There are a few books out there on the big bang theory that would do the best job of answering your question

Stephen Hawking wrote: "A Brief History of Time" and "Big Bang Theory and God"

both will answer your question.

THere are other books out there.

The quick answer to your question (as I understand it) is that since the big bang, all 'macro' motion in the universe is subject to the constraint of Einstein's speed of light limit.

Everything is still expanding.

THere is debate as to whether the expansion continues forever or until a certain point is reach and then everything contracts again and starts over as a big bang. But my brain is not big enough to explain all that.

Get the books, they aren't bad reads and are written for the common man.

Mel...

dgiharris said:

There are a few books out there on the big bang theory that would do the best job of answering your question

Stephen Hawking wrote: "A Brief History of Time" and "Big Bang Theory and God"

both will answer your question.

THere are other books out there.

Click to expand...

I'm thinking of something that explains Einstein's theories. The idea that some part of the Universe is going faster than light seems to be a Newtonian interpretation, and that doesn't work for large enough and fast enough things. Newtonian physics stopped working perfectly with the orbit of Mercury, and then it went downhill from there. Fortunately (for the universe, not necessarily our understanding of it), Einstein saved the day.

dgiharris said:

The quick answer to your question (as I understand it) is that since the big bang, all 'macro' motion in the universe is subject to the constraint of Einstein's speed of light limit.

Everything is still expanding.

Click to expand...

That's pretty much how I understand it as well.

dgiharris said:

THere is debate as to whether the expansion continues forever or until a certain point is reach and then everything contracts again and starts over as a big bang. But my brain is not big enough to explain all that.

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Yes, and I believed Einstein asked that question - or was it Hubble? And there's a third state, the "steady state" where everything keeps expanding forever, but at an ever slower rate.

Anyway, in recent years/decades that question has become conflagulated with the latest ideas of Dark Matter (invented or 'discovered' to solve the problem that galaxies don't have enough visible mass for the outer stars to be orbiting the galaxy's center as fast as they do - they don't see extra mass there, so it must be dark) and Dark Energy (because the universe appears to be accelerating at an increasing rate or something weird like that, and the energy has to come from "somewhere" - they don't see that energy so it must be dark).

Thinking more about the words "still inflating" - I vaguely recall the "inflationary period" was some very early part of the big bang where it expanded at a rate an earlier Big Bang model didn't allow for, so they modified the model. I don't think that would apply anymore.

I am not a cosmologist, all applicable disclaimers apply, hope this helps, and have a nice day.

But if you want true understanding, perhaps you should convert to Buddhism or some other spiritual study. I understand that, unlike science, after a few decades of study it all starts to make sense.

Nothing in the material universe can expand faster than the speed of light. It's physically impossible as it would take all the energy in the universe to enable even a tiny mass to do so.

Therefore, the apparent FTL expansion that may be seen is an artifact of the fact that both our location and the remote location are expanding away from one another at some speed.

Take, for example, two cars on the freeway. The cars are such things as galaxies, Earth, etc. Both cars are doing 60mph in opposite directions and neither car is capable of doing more than 99.999999 etc. mph. The highway is the universe. The "rate of expansion" between the two cars is apparently 120mph, but neither car is actually moving at that speed.

See?

The Universe continues to expand, apparently at an accelerating rate, which has led to the idea of "dark energy", which is basically a scientific code for "we really don't know what the hell is going on."

The theory of "inflation" is different, however. doesn't exactly equate to this phenomenon. "Inflation", as the cosmologists look at it, was something that took place in the first few fractions of a second after the Big Bang, when the Universe expanded far faster, for just that instant. Then the expansion slowed, almost instantaneously.

Don't ask me how they know this.

caw

small axe said:

Okay, we always hear how looking up to see the ancient starlight is seeing light as it was x-billions of years ago. But are there areas of the Universe that are still experiencing the original "inflationary" expansion of the post Big Bang?

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Yes, all of them.

If the Universe as we see it is doing the common "expansion" that we observe as we see the Galaxies move apart ... Are there farther regions that are still inflating at the faster-than-light rates? (Probably that we can never see, because they're expanding faster than their light reaches us)?

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One thing that is important to understand, but very difficult to get your head around, is that the expansion of the universe does not mean that anything is "moving". Space itself expands, there is no object that actually move through space. Take the old balloon example. Draw two little dots on a balloon then inflate it. The spots do not physically move, they are still on the same location of the rubber, but they still move apart from each other, because the space between them gets bigger.
Now draw a dozen dots, and you'll also see that all dots move away from all other dots. On whichever dot an observer would stand, he'd see all other dots receding.
And one last thing to see is that the farther away two dots are from each other at start, the faster they move away from each other. Because the space between them all expands at the same rate, but when there is more space between them that means their absolute "speed" is greater. I.e. the expansion is 100% every second, so two spots 1cm apart would move at 1cm/s apart from each other and two spots 2cm apart would move at 2cm/s.
We do not notice this movement at small scales, though it happens. Even the space between the electrons and nucleus of all your atoms expands. However since the distances are so small, the speed is so low that the expansion cannot overcome the forces holding the atoms together.
However, we can observe that the expansion accelerates, so theoretically, if the expansion doesn't slow down, eventually the expansion speed will be fast enough to even pull atoms aparts, leaving you with a universe consisting of a lot of lonely subatomic particles.

How do the two areas of space/time "connect" if one's racing away so much faster than the other? Would Inflation-speed space/time even obet Einstein relativity rules?

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They are not racing. They are not obeying relativity as such, because realitivy only states that material objects cannot move at c, but the expansion of space is not a movement of matter. There is not empty space outside of the universe where it expands into, the space "inside" the universe simply gets bigger and bigger.
"Connect" needs to be defined. What do you mean by connect? Interact? No, they don't. Parts of the universe so far apart that the expansion moves tham apart at c or more are out of each others lightcones. They do not interact.

I guess I'm just brainstorming wondering whether it's logical to imagine two different universes that still co-exist, ours that's slowed down and another existing by alien Inflationary space/time laws of nature -- one that might consider the lightspeed speed limit as meaningless, even when entering our Universe.

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Logical? No. Our universe is still expanding, and lightspeed limit and other such physical laws are properties of a universe, if you enter another universe all its physical laws would apply to you. Heck, if the laws are too different you might not be able to exist at all. If you entered a universe where the strong nuclear force is much weaker than ours, you'd instantly turn into an expanding cloud of particles.
Might make for a nice story though. Many stories are illogical.

Or when the talk about the era of inflationary expansion, did it just end, Universe-wide ... and so no such Universe can exist, even out to where the Big bang is still expanding out to?

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The expansion of our universe didn't end. We actually observe it accelerating. Inflation is different, it was during a short period of time after the big bang.

FOTSGreg said:

Take, for example, two cars on the freeway. The cars are such things as galaxies, Earth, etc. Both cars are doing 60mph in opposite directions and neither car is capable of doing more than 99.999999 etc. mph. The highway is the universe. The "rate of expansion" between the two cars is apparently 120mph, but neither car is actually moving at that speed.

See?

Click to expand...

Nope. The funny thing about relativity is that it doesn't actually work that way. Two spaceships moving at close to c in opposite direction will still not see their dV as bigger than c. Even then calcualtion of two cars' dV adding up to 120mph is wrong, it would actually be a miniscule portion less than 120 mph. At such low speeds, the error is unimportant, but at close to c it gets significant.
This is not the reason for galaxies moving apart at FTL though. Since they don't actually move, realativity doesn't apply.

small axe said:

Are there areas of the Universe that are still experiencing the original "inflationary" expansion of the post Big Bang?

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Yes, understanding the inflationary epoch is still a major factor in interpreting the present universe. It is easiest to see if you look at the US national debt but the phenonenon is also extant in the egos of various political and corporate leaders. It tends to lead to black holes like GM, Chrysler, and AIG.

Nothing to add here except just to agree that the Universe is still expanding, though in local areas like galaxies gravity is strong enough to keep things from flying apart. For example, the effect of the space between the Earth and the Sun expanding is negligible compared to the force of the Sun's gravity on the Earth, so we don't notice it.

And as far as the expansion becoming faster than light, yes. The further something is away from the observer, the faster it will recede (because space is expanding, the more space there is between two objects, the faster the net change will be). Scientists believe that eventually the most distant galaxies will appear redder and redder as they recede faster, and eventually disappear. If one waits long enough, the rest of the universe outside our local cluster of galaxies will vanish.

Lhun, Can't tell whether you're being intentionally argumentative or just not seeing the forest for the trees.

The fact is that objects in space are moving. Space itself is expanding. Therefore, space itself is also in motion.

In the example I gave, the analogy is for 2 objects moving in opposite directions at the same time. Relativity really does not need to enter the equation at this point (that will come later). The objects are moving. The speeds are known or can be measured). They will move apart at X rate although each is only moving at Y rate. Z rate is the absolute maximum the observational sphere allows. Plain, Simple. Period. Easy, 1st year physics.

Relativistic equations, blue-and-redshifting, and other phenomena do not need to be discussed until the individual asking the question understands the basic concepts of what is being asked. At that point, then you have to get into relativistic time dilation, apparent spheres of observation, etc., etc., etc. and the equations can become very complex and confusing.

Keep it simple until it needs to get complicated is usually the best answer when trying to deal with complex dynamic motions.

I apologize if I might have offended anyone, but this sort of response is exactly the reason I don;t come around here often.

Sarpedon said:

Nothing to add here except just to agree that the Universe is still expanding, though in local areas like galaxies gravity is strong enough to keep things from flying apart. For example, the effect of the space between the Earth and the Sun expanding is negligible compared to the force of the Sun's gravity on the Earth, so we don't notice it.
...

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FOTSGreg said:

...
The fact is that objects in space are moving. Space itself is expanding. Therefore, space itself is also in motion.
...

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Can someone come up with a reference that "space itself is expanding" and what that means? Even Wikipedia would be an interesting reference. (I'll check article history to make sure the reference wasn't added after the time of this post.)

If the big bang occured at a point somewhere, there would be evidence of that: we should see objects moving away from that location. We don't observe this. I believe the thought is that the big bang occured everywhere at once.

Objects, as Lhun pointed out, are not moving away from anywhere in particular: space itself is expanding so it only appears things are moving with respect to one another.

And yeah, that whole concept is so far removed from the balloon analogy as to make normally rational people's heads spin. (Which, by the way, is why planets rotate.)

benbradley said:

Can someone come up with a reference that "space itself is expanding" and what that means? Even Wikipedia would be an interesting reference. (I'll check article history to make sure the reference wasn't added after the time of this post.)

Click to expand...

http://en.wikipedia.org/wiki/Universe#Big_Bang_model
Probably some more if you check under the Big Bang article on wiki. Or google a bit, stuff on this is not too hard to find.

FOTSGreg said:

The fact is that objects in space are moving. Space itself is expanding. Therefore, space itself is also in motion.

Click to expand...

That is incorrect. Expansion and movement are different things, and "space itself" could only be in motion if there were some kind of superimposed metaspace, of wich we have no evidence and no reason to believe there is one. Movement, requires the existence of space so that something can move through that existing space from point a to b. If our space itself were to move there would need to be some other kind of space containing our universe inside it through which it could move. Again, no reason to believe that is the case from what we can see.

In the example I gave, the analogy is for 2 objects moving in opposite directions at the same time. Relativity really does not need to enter the equation at this point (that will come later). The objects are moving. The speeds are known or can be measured). They will move apart at X rate although each is only moving at Y rate. Z rate is the absolute maximum the observational sphere allows. Plain, Simple. Period. Easy, 1st year physics.

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No in reality, because relativity dictates that x is not simply 2*y. And what x is, depends on the point of reference from which you observe. An observer on one of the two objects will see x at very different than an observer at rest relative to their starting point. In the universe example, we are on one of the moving objects (i.e. our galaxy) and we will never observe another galaxy as moving FTL because of adding up a dV.

At that point, then you have to get into relativistic time dilation, apparent spheres of observation, etc., etc., etc. and the equations can become very complex and confusing.

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Relativistic effects like time dilation are whole different matter. Nothing to do with the simple lightspeed limit and the relativistc adding of velocities.

small axe said:

I'm confused by the comments I've heard elsewhere, things like "there's no center of the Universe, there's no specific 'spot' where the universe started, that everyplace is expanding away from every other place" etc.

But that certainly isn't the same picture as the oft-cited "dots on a balloon" image.

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What you have to remember here is that the universe in the balloon example is not represented by the balloon, but by the surface of the balloon. It's a 2D universe in the example. Imagine you were a stick figure living on one of the dots of the balloon. There is no point in space where the expansion started. If you deflated the balloon to a single point, everything gets closer, but there is no specific point it gets closer too.
Of course, in reality, you see the balloon shrinking towards the middle of the (rough) sphere it forms. However that is not how it is when you see just the surface. From the point of view of the stickpeople in the 2D universe, everything just gets smaller. The single point where the ballon shrinks towards, the middle, is not in their universe! It is not a point on the surface of the balloon.
Something like this might (might!) be true for our universe, but currently there is no evidence of any outside metaspace, as the thrid dimension is for the 2D universe of the balloon surface.

Common sense demands that the Big Bang had to start at SOME POINT IN SPACE (though we'll never know the "where") even if all Space was contained within that dense point and is now "expanding" away ... right?

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Sorry, no. The first thing when dealing with the more arcane physics as all my physics student buddies (i'm not a physicist, but i have a loaded one, and i'm not afraid to use him!) always tell me is to throw common sense overboard. The universe is counterintuitive. I can easily realte, theoretical philosophy is the same. The problem with common sense is that it evolved for common situtations, and fail in uncommon ones. The big bang being a fairly uncommon occurrence.
Anyway, to the matter at hand: The biggest element of the model you have to get your head around, and maybe the strangest, is that you cannot think of the big bang as things flying apart. It is not as if there was a big empty space and the universe expanded into it. There was a universe, which was very small, and thus very densely packed, and it got bigger. Space itself, the room inside the universe got bigger. Things did not start to fly away into empty space somewhere. You are right of course, if things were flying apart into empty space, there would have to be a central point where it all started.

Otherwise, two points at opposite sides of the Universe would have to be expanding TOWARDS each other, not AWAY from each other. And that doesn't make a balloon.

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I'm really not quite sure how you reach that conclusion. Can you explain more detailed?

I saw a clown twist a balloon into an elephant once ... and that's no Universe that I'll agree to!

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Heh. While there is, afaik, no model for a ballon-elephant shaped universe, there are some models for fairly strange topologies. The universe might be saddle-shaped to pick one of the more normal ones.

I read an article now that said the whole Big Bang idea of an infinitely dense point of Space/Time doesn't hold water anymore, that the Big Bang was just a rebounding from the collapse of another Universe?[/quoe]Can you link the article?
Anyway, you have to remember how physicists arrived at the big bang model. (Which BTW is a nickname which was given to it by an opponent who wanted to mock the idea) We can observe that the universe has no center, and we can observe that everything moves away from each other. We can also, due to finite lightspeed, observe how parts of the universe looked when they were younger. We arrive at the big bang model if we simply extrapolate those observation backwards. I.e. if the universe is expanding now, it has to have been more densely packed earlier. The big bang model is not a theory someone came up with and set out to prove it, it is a conclusion that was arrived at by extrapolating from our observations.
The idea that after the big bang might come a big crunch where everything collapses into a single point and expands again is not new or especially weird. However currently it does not look like that happens in our universe, since the expansion is not slowing down, but acceleration. Since we do not know what drives this acceleration (the placeholder name dark energy is used, but there's nothing knowing about it) we cannot say if the acceleration would some day revert. However by the look of things now, our universe will expand ever faster and not experience a big crunch. This does of course not mean that an earlier universe could not have done that, producing ours, but it is a piece of evidence against that.

I always scoffed at the "Everything-From-Nothing" claims, anyway ... so it doesn't bother me.

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Well, that's a problem you always face. There has to be either something that came from nothing at some point, or something that is eternal (and where came that from?) There really is no way around the question.

What bothers me is, neither will it "bother" (or suggest Humility to) those who insist in the random, meaningless, accidental origins of the material Universe.

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Uh, why should it?

Anyway: If ALL points in Space are expanding, then doesn't something eventually have to collide with the Space beside it? Seriously ...

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There is no space beside it. For to objects to collide, they need to be in the same space, and move into each other (or expand into each other). But what expands is space itself, there is no outside that could bump into something.

And isn't there some sort of rule that would demand that ALL points in space CANNOT expand at the same rate, unless there is a common force acting upon them ALL to keep them at the same rate?

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Not sure what you are referring to. We do see an apparent force accelerating the expansion though, and call it dark energy since pretty much noone has any idea what it is beside the fact that we can se its effects.

How can VOIDS have rules? How can NOTHINGNESS be regulated?

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Noone knows. But then, noone has ever seen nothingnees either. Space, even empty space is not nothingness. Though still, we don't really know how space can have rules either, we just observe that it does.
Though you need to be careful not to confuse physical rules or laws with legal ones. A physical law does not mean there is something or someone that enforces the universe behave correctly, it simply means we can observe a predictable, regular behaviour of our reality.

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blacbird said:

The Universe continues to expand, apparently at an accelerating rate, which has led to the idea of "dark energy", which is basically a scientific code for "we really don't know what the hell is going on."

The theory of "inflation" is different, however. doesn't exactly equate to this phenomenon. "Inflation", as the cosmologists look at it, was something that took place in the first few fractions of a second after the Big Bang, when the Universe expanded far faster, for just that instant. Then the expansion slowed, almost instantaneously.

Don't ask me how they know this.

caw

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I told them. Big mistake.

small axe said:

But the quick answer is: it's from Scientific American, October 2008 "Forget the Big Bang: now it's the Big Bounce -- quantum gravity theory predicts the universe will never die" by Martin Bojowald

Maybe there's a link on their SA website, you might look, but that's what was in the monthly mag.

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Hmm, i'll see what i can find. Anyway, quantum gravity as well as string theory are quite interesting, however still lack physical evidence. Basically, they're theories that make a lot of sense, but haven't been tested yet. The LHC might change that. (or it might disprove them, or be inconclusive)

Well, because Humility is always a good human choice.

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Dunno about that. I don't buy into judeochristian virtues.

Especially while facing one's ignorance about where Everything (dude: Everything) came from, while desperately demanding that while they don't know where it came from, they can assure us with scientific certainty (or the claim thereof) where it didn't come from!

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Heh, that's a misrepresentation. While religions, or at least those who take themselves way too seriously, proclaim to know with certainty where the world came from, science always comes with the disclaimer that knowdledge isn't certain and that what we might know now might be disproven in the future. (Though there are some things we know to be untrue, which will stay that way. Proof is impossible, disproving something not.)
You have to excuse the arrogance of scientists because, quite frankly, science is the one thing that has got us, as humans, consistent results. Science, not mysticism put humans on the moon. Science must be doing something right, since the computers we're typing on are apparently working. The whole human civilization depends on the correctness of the scientific method, and suddenly doubting that when the questions become a little more complex and less easily testable is quite scizophrenic.

Lhun said:

What you have to remember here is that the universe in the balloon example is not represented by the balloon, but by the surface of the balloon. It's a 2D universe in the example. Imagine you were a stick figure living on one of the dots of the balloon. There is no point in space where the expansion started. If you deflated the balloon to a single point, everything gets closer, but there is no specific point it gets closer too.

Click to expand...

A better analogy is the baking of Raisin bread. As the loaf expands, the raisins get further apart.

Here's a question to answer that has some bearing on the problem: Is the expansion of space manifested everywhere?

By everywhere, I mean precisely that. Not just the vacuum of space, but the interstitial spaces between the elements of matter--between molecules, between atoms, between sub-atomic particles. Everywhere.

In the balloon metaphor, the dots, being printed on the surface of the balloon, also expand. In the raisin bread, the raisins move apart (away from one another) as the dough rises, and they do get a bit larger (they plump) as that dough bakes.

But the particles of ink in the dots don't expand, they too move apart as the raisins in the rising bread do.

Seems to me that if the expansion of the universe is ubiquitous, occuring absolutely everywhere at once, it would be extremely difficult to document that. The relationship between all particles everywhere would remain the same, just the scale changes. But we do have documentation of this expansion, eh? So there is some relative movement (as balloon dots and bread raisins) isn't there?

Yes. Space expands everywhere. However, at short distances the effect is overwhelmed by the four fundamental forces. As I mentioned earlier, even weak ol' Gravity is enough to keep our galaxy from flying apart. the expansion of space would do absolutely nothing to the Electromagnetic and Strong forces that keep molecules and atoms together.

All space, everywhere is expanding. the only place where this is noticeable is where there are no stronger effects present. The effect of expansion can be documented, because forces like the Electromagnetic force and Gravity get weaker with distance according to the Inverse Square Law (always the Inverse Square Law) while the Strong force stops working entirely when the distance is too great.

Pthom said:

Here's a question to answer that has some bearing on the problem: Is the expansion of space manifested everywhere?

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Yes.

By everywhere, I mean precisely that. Not just the vacuum of space, but the interstitial spaces between the elements of matter--between molecules, between atoms, between sub-atomic particles. Everywhere.

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Yep.

In the balloon metaphor, the dots, being printed on the surface of the balloon, also expand. In the raisin bread, the raisins move apart (away from one another) as the dough rises, and they do get a bit larger (they plump) as that dough bakes.

But the particles of ink in the dots don't expand, they too move apart as the raisins in the rising bread do.

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Nope.
At small distances, the expansion is so slow that the forces holding the particles together easily compensate. I.e. the moon doesn't fly apart into a piece of rubble because the acceleration from gravity is higher than the speed of the expansion. Since we see the expansion accelerating, that might change in the future.

Seems to me that if the expansion of the universe is ubiquitous, occuring absolutely everywhere at once, it would be extremely difficult to document that. The relationship between all particles everywhere would remain the same, just the scale changes. But we do have documentation of this expansion, eh? So there is some relative movement (as balloon dots and bread raisins) isn't there?

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Well, particles influenced by various forces move of course. (closer to together). What makes the expansion pretty easy to document is the nature of it, i.e. that space expands. Because of that we can see that the further apart to things are, the faster they move apart. If we check two distant galaxies (more like distant superclusters) they move apart very, very fast. If we check two close galaxies they move apart slowly. If we check atoms, we see nothing at all. Theoretically speaking, we could measure the distance between galaxies with a rule we could see the expansion because it is strong enough at big distances to make the galaxies move apart, but the ruler's atoms are so close together that the atoms stay together, keeping it at the same length.
If on the other hand, the universe were not expanding, but matter moving as in an explosion we could for one, observe a center. Draw the vector for every shrapnel in a snapshot of an explosion and they all converge on the center. If we do the same for the universe we see nothing of the sort.
Also, everything close to us (or one piece of the imaginary shrapnel) move in the same direction away from the center. Which is again not what we can see in space.

Sarpedon said:

Yes. Space expands everywhere. However, at short distances the effect is overwhelmed by the four fundamental forces. As I mentioned earlier, even weak ol' Gravity is enough to keep our galaxy from flying apart.

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Space is not expanding (ie the gravitational metric is attractive) between our Galaxy and the Andromeda galaxy. This is because the force that causes the expansion is gravity. There may be some other expansive forces at work, but the standard solutions to how gravity behaves in an ideal "dust" accounts for 2/3 of the observed expansion (the Hubble constant).

Inflation is a completely different phenomena and is a matter of a change in the symmetries available to a field. The Higgs boson is the gauge particle for that field in the standard model these days.

Since we see the expansion accelerating, that might change in the future.

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Do we really see the rate of expansion accelerating? This isn't the same as saying that things that get farther away recede at a greater speed, which is a fact. Could I get a source for this?