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Big Bang theory 2

by JulianHeawood
Tags: bang, theory
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JulianHeawood
#1
Mar16-04, 03:42 AM
P: 6
Here follows the first part of the questions. Their appearance here is with thanks to Marcus and Nereids' encouragement:-

Questions arise on what has been written for we ordinary people about how matter began – and on what has received little to no mention at all. To a cosmologist, these questions will show a simplistic line of thought, and certainly the universe is not of simple construction. But theorists could bear in mind that while they ‘dumb down’ books they write for the public (to enable us to understand better), they leave voids that logic says should contain something. These questions are about those voids. They may be naďve, but they have not yet been answered. If cosmological theory were wholly satisfactory within the research community, this outsider would not dare to question it.

The questions relate to the big bang itself – to the event, and how it is described. The phases after the big bang – the quark-gluon plasma era, the lepton era, and so on, are beyond this questioner’s grasp. Whether the elusive Higgs bosun will be dislodged from its hiding place, by how much are anti-matter particles quicker to decay than their matter counterparts, and whether elegant string theory will make further headway and bring with it new dimensions, are questions for the gifted enquirer. It is easier for a simple person to ponder the first phase of all, when there was nothing other than energy.

1) The very early universe was governed by quantum mechanics. Is there no common ground between quantum mechanics and classical Newtonian physics?
Admittedly the latter break down at velocities approaching the speed of light, and big bang events apparently occurred at that speed. But does physical law as applied through quantum mechanics have to be different in every respect to classical law?
One reads that all four fundamental forces of nature are subject to the same mediation by discrete packets of energy-matter, because before a single force of nature broke symmetry, all laws were the same. Laws governing nature’s symmetry before the big bang were laws of potential. One of those laws dictated that it would be the force of gravity that should break symmetry. So gravity cannot be governed by the same packets of energy-matter that direct the functions of the other three forces. If all four forces were subject to the same law, they would either have remained in symmetry, or they would all have broken symmetry at the same moment. So there would either have been no universe at all, or it would have been vastly different to the one with which we are quite familiar.
Gravity has to be subject to distinct physical law, because it was made to break symmetry first. Richard Feynman, a well-loved and renowned Nobel Laureate, exhorted his students not to attempt to rationalise nature’s role in quantum theory. But being advised not to ask ‘How can it be like that?’ need not prevent us from asking questions about how it is. Nothing in quantum theory says that it is always counterintuitive.
Is there no such event in quantum mechanics as a reaction to an action? If there is not, why is it impossible to find a reasoned explanation as to why there is not?
Experts describe the big bang in few words, and they don’t discuss its action. They say simply that it was an explosion, but not an explosion of matter in space, because there was no matter and no space. That part is fair enough, but the events of an explosion are always describable.
Intuition (based on geophysics) says that when gravity broke symmetry, it did so as the action of a physical event (the first), and that the other three forces were launched in equal reaction to it. This was a quantum moment, between nothing and something. The explosion, as a whole, would have involved the emergence of gravity as an implosive force, with the three reactionary forces creating expansion (or the explosion as is commonly described). There are always two ‘sides’ to any action, and I cannot understand (yet) why that isn’t the case at quantum levels as well. The conversion from energy to photons to matter would have taken place at sub-particle level. So does anything that changes from one condition to another: Never more so when changing from or to a state of zero.
When gravity split, it did so with a bang – at the point of its detonation, at the centre of the singularity that rapidly inflated to become the singularity that is the universe of today. But surely the force of gravity imploded, and everything else exploded (or inflated). Everything that is, was packed into that singularity at its beginning. The oddity is not so much the singularity, but the nothing out of which it appeared. Some physicists are professionally squeamish about conditions of nothing.
The first symmetry breaking occurred when gravity separated, yielding gravity and quantum electrodynamics. The next symmetry breaking (electromagnetism) occurred later. By then, inflation was rampant, caused by the pressure and the density of newly-appeared space. But why was there density and pressure? Was it because there was reaction to the force of gravity, which had imploded at the point of origin of space? The force of gravity, having broken symmetry, could hardly have done anything other than to remain centred on the point at which it appeared, because there was nowhere for it to go. The remaining three forces were hardly likely to have remained at that same point, if they were reacting against the force of gravity. Something had to give, and it wasn’t the force of gravitation. It seems logical that the processes of inflation would have begun.
It is harsh to maintain that the big bang could not have featured a reaction to the breaking of symmetry by gravity, simply because it was subject to quantum mechanics. Why cannot quantum mechanics and classical physical law be complementary, with the former providing detailed and the latter general instruction?
When gravity broke symmetry, did it do so with fifty percent of the bang’s energy? If it did, and if it remained at the point of origin, and if the inflationary (reactionary) forces were equal and of the other fifty percent, there seem to be grounds for supposing that there would be equilibrium between anti-matter and matter. If inflation is the product of anti-gravity, gravity should be the force of anti-matter. We know that energy-matter drives the inflationary forces: Why shouldn’t energy-gravity be the counterbalance? That the centre of universal mass would also be the universal centre of gravity is logical, and that it should also be the universe’s point of origin, is even more so. It seems that nature’s role in quantum theory need not always be weird.

2) Why don’t experts writing for the public emphasise more clearly that the universe has a point at which it originated?
To demonstrate how galaxies are pulling further away from each other as the universe continues to expand, a visual aid is sometimes offered in the form of someone blowing up a balloon. Specks on the skin of the balloon enlarge as the balloon is inflated, and grow more distant from each other. They represent (fairly) the galaxies.
As an analogy to demonstrate the increasing separation of the galaxies, it is fine. What the demonstration does not try to emphasise is that the universe is expanding from its point of origin. It would be most helpful if scientific authors would make clear that the cause of inflation of the singularity (or of the universe) is at its centre, and not outside it.
The cause of a bang is at the centre of the area of disturbance it creates. The detonation of a seismic shot in water will cause a bubble to expand, before it collapses back in on itself. A subsurface ground shot will similarly send out a temporary ball of converted energy around its point of detonation. There is no immediate reason to think that a bang that starts a universe should be any different – other than that its action, coming out of nothing and going into nothing, would manifest itself as an implosive rather than an explosive force. This could be where nature’s role in quantum physics plays tricks with human conceptions of logic: But it could also help us to understand from where gravity operates on a universal scale: From its point of origin: Its centre of mass. That we have space in which to live is thanks to the bang’s reactive forces of inflation, it seems.
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FZ+
#2
Mar16-04, 08:01 AM
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1) The very early universe was governed by quantum mechanics. Is there no common ground between quantum mechanics and classical Newtonian physics?
Admittedly the latter break down at velocities approaching the speed of light, and big bang events apparently occurred at that speed. But does physical law as applied through quantum mechanics have to be different in every respect to classical law?
They don't have to be different. They just happen to be different in almost all the cases we have considered. Detailed investigations have shown that classical physics is, at best, a medium scale approximation of the real wierdness that happens at the quantum, or would happen at the relativistic. A analogy is comparing the user interface of windows (classical physics) with the actual source code of the software.

I don't think the BB happened at velocities approaching c. Velocities relative to what?

2) Why don’t experts writing for the public emphasise more clearly that the universe has a point at which it originated?
Because it doesn't! The Big Bang was never meant to be an explosion, or a disturbance, and the experts are always trying to shake off this mistaken impression. As with the balloon, the BB happened at EVERY point in the universe. That is the point.
russ_watters
#3
Mar16-04, 02:45 PM
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P: 22,243
Originally posted by JulianHeawood
2) Why don’t experts writing for the public emphasise more clearly that the universe has a point at which it originated?
To demonstrate how galaxies are pulling further away from each other as the universe continues to expand, a visual aid is sometimes offered in the form of someone blowing up a balloon. Specks on the skin of the balloon enlarge as the balloon is inflated, and grow more distant from each other. They represent (fairly) the galaxies.
As an analogy to demonstrate the increasing separation of the galaxies, it is fine. What the demonstration does not try to emphasise is that the universe is expanding from its point of origin. It would be most helpful if scientific authors would make clear that the cause of inflation of the singularity (or of the universe) is at its centre, and not outside it.
I discussed this in one of your other threads. You're missing a key piece of the analogy: that point of origin is occupied by every one of those polka-dots at the same time and as such does not qualify as a center. It is also not on the surface of the sphere. As you pointed out, it only existed at the instant of the big bang. The center of an explosion (from below and your other post) exists for the entire duration of the explosion and is observable from inside the explosion.
The cause of a bang is at the centre of the area of disturbance it creates. The detonation of a seismic shot in water will cause a bubble to expand, before it collapses back in on itself. A subsurface ground shot will similarly send out a temporary ball of converted energy around its point of detonation. There is no immediate reason to think that a bang that starts a universe should be any different – other than that its action, coming out of nothing and going into nothing, would manifest itself as an implosive rather than an explosive force....

From its point of origin: Its centre of mass.
The BB cannot be modeled as a conventional explosion. Its name is unfortunate as it often leads to the common misconception that it can be. That "no immediate reason" you are looking for is the CMB (and to a lesser extent, HUDF) I discussed in the other thread (and above). It puts the final nail in the coffin for a finite, bounded universe: it simply cannot exist given the evidence we currently have.

confutatis
#4
Mar16-04, 03:23 PM
P: n/a
Big Bang theory 2

Originally posted by russ_watters
[...] It puts the final nail in the coffin for a finite, bounded universe: it simply cannot exist given the evidence we currently have.
I have a question: how do physicists know that the universe is expanding? I mean, if the redshifts we measure are millions, billions of years old, what basis do we have to assert that the universe is expanding right now? What if it stopped, slowed down, or is actually contracting?

Now my understanding of physics is that the question "what is happening right now in star XYZ" has no meaning, since we are separated not only by a huge amount of space but also by a huge amount of time. There is no "now" which is shared by two distant objects. OK, I can buy that. But why is it that the same people who say "there is no such thing as a 'now'", will come and tell us that the universe is expanding?

Just curious
russ_watters
#5
Mar17-04, 01:59 AM
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P: 22,243
Originally posted by confutatis
I have a question: how do physicists know that the universe is expanding? I mean, if the redshifts we measure are millions, billions of years old, what basis do we have to assert that the universe is expanding right now? What if it stopped, slowed down, or is actually contracting?
Good question.

We measure a higher redshift for objects further away, but for closer objects (AFAIK, every object outside our local galactic group), we still see a redshift. Also, there is a well-defined gradiant (the Hubble constant). Though there aren't many objects under 50 million light years that can accurately fit the gradient because of local motion of galaxies, there is no reason to assume a major change in expansion rate (or reversal) in such a short period of time. Indeed, that would violate several laws of physics.

HERE is an interesting link showing distance to and redshift of some of our nearest neighbors.
confutatis
#6
Mar17-04, 08:56 AM
P: n/a
Originally posted by russ_watters
We measure a higher redshift for objects further away, but for closer objects (AFAIK, every object outside our local galactic group), we still see a redshift. Also, there is a well-defined gradiant (the Hubble constant). Though there aren't many objects under 50 million light years that can accurately fit the gradient because of local motion of galaxies, there is no reason to assume a major change in expansion rate (or reversal) in such a short period of time. Indeed, that would violate several laws of physics.
Well, I know about all that stuff, but my point was a bit more on the philosophical side (it's a philosophy forum after all).

The point is that the universe we're looking at doesn't exist the way we see it, therefore the statement "the universe is expanding" is not meaningful. The universe has no "size", therefore it cannot "expand". Whatever is happening, it cannot be expressed in the ordinary language of our day. When physicists try it, they make things simpler than they are and end up confusing people.

Our friend Julian will never understand BB theory until he delves deep into the mathematics of it. Because that's all there is to it, abstract mathematical assertions. To give meaning to those assertions is extremely difficult, and so far all attempts end up as gibberish. The truth is that no one has a clue what is going on, except physicists can calculate it very well. Which is the beauty of physics, you don't have to understand what you're calculating in order to get the right numbers.
russ_watters
#7
Mar17-04, 12:54 PM
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P: 22,243
Originally posted by confutatis
The point is that the universe we're looking at doesn't exist the way we see it, therefore the statement "the universe is expanding" is not meaningful. The universe has no "size", therefore it cannot "expand". Whatever is happening, it cannot be expressed in the ordinary language of our day. When physicists try it, they make things simpler than they are and end up confusing people.
Well, yeah, this is the philosophy forum, so hopefully you won't get upset when I say that the central point of that paragraph is illogical.

Clearly the universe has a "size." What that size is is of course an open question, but I'm looking at a 21" monitor right now, so at the very least the universe must be 21" in diameter.

When physicists say the universe is "expanding," they do mean it in the literal sense of the word.
confutatis
#8
Mar17-04, 03:36 PM
P: n/a
Originally posted by russ_watters
Well, yeah, this is the philosophy forum, so hopefully you won't get upset when I say that the central point of that paragraph is illogical.
Absolutely! Nonsense is what philosophy is all about anyway, why should I get upset?

For instance, here's a good piece of nonsense:

Clearly the universe has a "size." What that size is is of course an open question, but I'm looking at a 21" monitor right now, so at the very least the universe must be 21" in diameter.
You're not stating the size of the universe, you're simply saying it's big enough to contain at least one monitor. That the universe is big we all know; the issue here is "how big". I say that question has no answer. You can't state that the universe is, say, thirteen gazillion monitors big, because you have no way to know if there are more monitors than you can see.

When physicists say the universe is "expanding," they do mean it in the literal sense of the word.
I disagree. For one thing what they say is that space is expanding, not the universe. Your 21" monitor is not expanding; in fact, your 21" monitor can't possibly expand if the phenomenon that causes its expansion also cause your measuring devices to expand by the same factor.

So they can't possibly mean "everything is expanding" because such an assertion is completely meaningless.
billy_boy_999
#9
Mar17-04, 07:12 PM
P: 131
it raises an interesting point about the metaphysics of cosmic expansion, we cannot know what the universe 'is' at the moment.

"there is no reason to assume a major change in expansion rate (or reversal) in such a short period of time. Indeed, that would violate several laws of physics."

...it's true enough but we are already starting to hear about a so-called 'cosmic jerk' about 5 billion years ago when the implosive forces of gravity that seemed to be converging were ripped apart by the expansive force creating a massive change in acceleration. who's to say something even more bizarrely inexplicable hasn't happened within the last million years in the farther flung regions of the cosmos? we can do a better job of inferring such a possibility with a better understanding of BB...

and the concept that the BB was not a physical 'point' is understood if we accept that when we look very far back in time and space we are looking (relatively) closer to the big bang. but this would mean that that point of infinite density crammed into an infinitesimal space exists everywhere we look! which means it is just as valid to say that space is expanding inward as much as outward (and there would be no relative point against which to refute either claim).

one can begin to accept 'infinity' of spacetime if one accepts a)the universe exits; b)the universe is perpetually expanding at some rate; c)there is no discrete static instant in time

a fellow from NZ called Peter Lynds used c as his solution for Zeno's paradoxes - likewise, if the universe is constantly in motion then the "leading edge" could not be measured against a static instant in time and would be always infinite no matter it's relative vicinity to us...

thus, motion = infinity
russ_watters
#10
Mar17-04, 11:56 PM
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P: 22,243
Originally posted by confutatis
You're not stating the size of the universe, you're simply saying it's big enough to contain at least one monitor. That the universe is big we all know; the issue here is "how big". I say that question has no answer. You can't state that the universe is, say, thirteen gazillion monitors big, because you have no way to know if there are more monitors than you can see.
The question "how big?" may well have no answer, but since it must be big enough to contain my monitor, thats a minimum size. Thats by definition of the word "big." ("of considerable size").
I disagree. For one thing what they say is that space is expanding, not the universe. Your 21" monitor is not expanding; in fact, your 21" monitor can't possibly expand if the phenomenon that causes its expansion also cause your measuring devices to expand by the same factor.
My monitor isn't the universe and it isn't space. It is in the universe and in space. "Space" is 3 of the 4 visible dimensions of the universe and they are the ones experiencing the expansion. The universe(space) is expanding.
So they can't possibly mean "everything is expanding" because such an assertion is completely meaningless.
You're absolutely right: that isn't what they are saying.
Erck
#11
Apr3-04, 06:33 PM
P: 176
Quote Quote by JulianHeawood
Why don’t experts writing for the public emphasise more clearly that the universe has a point at which it originated?
Because if they tried to simply state they knew there was a point at which the universe originated... they would not be telling the truth.

They don't know anything about the beginning... nor before the beginning.
Reflector
#12
Jun30-04, 03:50 PM
P: 49
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