Im glad you finally understand the BB model a little bit better. The rest of your post I don't care to comment on...
What you have to appreciate is that ICANT likes to discuss hard-core cosmology in the way that an enthusistic maths schoolkid likes to discuss algebraic topology before understanding the rudiments of calculus. It sounds impressive to the peers but to the mathematician, it is worse than horrible. One must first learn to walk, swim and cycle before competing in an Iron Man. This has been explained to ICANT ad nauseam, but it does no good
So, essentially our universe has always been expanding even prior to T=0
No, certainly not in standard Big Bang. T=0 is the singularity and there is no T<0. T=0 is simply a point in space-time in the region of which quantum gravitational effects will dominate and so we do not know how to make calculations.
Well, current theorom suggests that there our view of a "universe" is skewed. Dr. Michio Kaku explains it quite well
Be very careful here. There are a multitude of possibilities, depending on your assumptions and models. Michio has always been a little too keen on stressing one particular route, as have others, leaving the impression that that is the only possible route. I could spend weeks discussing all potential possibilities, and we still are very far from having a clue as to which, if any, is correct.
Since you love this analogy so much explain how it can represent expansion of the universe.
Simple - paint globe lines on the ball and pick the north pole of the globe as the Big Bang. The lines of longitude, running from the north pole to the south pole, are lines of time. The circles of latitude are lines of space. As you move forward in time from the Big Bang, following one of the line of longitude, the circles of latitude grow from zero size at the big bang, to a maximum at the equator. This is the expansion of the Universe.
If you do not like the Big Crunch as a feature of this analogy, and would prefer a perpetually expanding model, simply cut open the ball at the south pole, and stretch the southern hemisphere surface outwards into a bell shape, keeping the northern hemisphere largely the same.
Now lets take your beach ball and fill it with marbles.
Unfortunately, no. The Universe at varying times is represented by the succession of circles of latitude, and space-time as a whole is represented by the *surface* of the beach ball. The interior of the ball plays no part in this analogy, nor does anything exterior to the ball.
Now if the quote from Cambridge is incorrect please correct it.
Unfortunately, I am no longer a member of the department, so correcting it will be a challenge. But I would certainly force a re-write of that first paragraph were I still there...
Are you saying that the universe at T=10-43 does not expand in all directions by the space between the particles expanding?
No, why would I say that?
Does the CMBR tell us that everything is receeding away from us in all directions?
No, not really, or at least certainly not in isolation. Expansion is observed in the red-shift of galaxies and quasars. Simple observation of the CMBR does not tell us this; not even with spectral analysis. However, once we appreciate the expansion, we would expect to see a CMBR... and we do.
Because everything that exists at T=10-43 has to get to the surface of your beach ball.
There is only the surface of the ball. T=0 is a point on the surface of the ball. T=10-43 is a very small circle on the surface of the ball, surrounding T=0. We are looking at space-time, not just space. The ball is not the Universe at some time, T. It is the Universe at all times.
In this model, the Universe is finite. Space, the latitude circles, only goes so far before it wraps back on itself.
If you want to believe the Universe is created, that's fine by me. But if that is case, realise that just as the ball is created as a whole in an injection mould, so every point in space and time, past present and future, can equally be regarded as the point and moment of creation.
In the more common beach ball analogy space has the two dimensions you describe for the surface of the ball
To be fair to lyx2no, he is correctly refering to the "balloon" analogy which we understand to represent space as 2d. My earth/globe/ball analogy/model is not so common as to have a "name" but I ensure I don't use a balloon to minimise the confusion
so every point in space and time, past present and future, can equally be regarded as the point and moment of creation.
What I mean by creation here is "divine" creation - I'm not talking about the origin of the time dimension (T=0), which most would point to as a moment of creation. If I construct a ruler, I don't bring it into existence at the 0cm mark, I just make the whole ruler. If i asked, which point on the ruler is the point of creation, you would reply "huh?". Same here. T=0 is as much a point of creation of the Universe, as the 0cm mark on a ruler is its point of creation. Make sense?
If one thinks of length as the distance between objects and time as the distance between events they will both map in the same way in the models.
Nice Great post, lyx2no...
The distance between two objects is not made of a material as one understands materials
Hmmm...is it not?
"Materials" are simply collections of values in the quantum fields (quarks, electrons, photons, gluons, etc.) "Distance" is simply a collection of values in the metric field. The quantum fields and the metric field, in most schemes, are facets of a unfied field. So time, distance, and stuff is all the same! Cool, huh?
From all the information I can find time did not always exist. Therefore time began to exist.
If time is a property of the universe, time did not exist until after the universe began to exist.
Can you honestly read this and not see the gaping hole in your understanding? How can you say "time did not exist until after the universe began to exist." What does the word "after" mean in this context?
You tell me how both can begin to exist without Metaphysics being brought into play.
I don't know how many times I have to say this, but even if the Universe is only finitely extendable into the past, it still never "began" to exist. You are fixated on arguing against this strawman notion of having nothing then having something. But this is impossible, for to be able to speak of this ordering (nothing then something) you require something, namely a framework for this ordering. This contradicts your assumption and thus makes your arguments meaningless. There has never been nothing, there has always been something, even if that something is only finitely extendable into the past.
I appreciate that many cannot get their heads around this far-from-obvious fact, and admit that they are out of their depth.
Your problem is that because you do not understand, you assume it is incorrect, and proceed to ignore this as you have been doing for the past two+ years.
The universe can't exist without time.
Well, I wouldn't agrre with that, but I guess I can agree to the sentiment for the purposes of this thread.
I have continually ask in this thread for the scientific evidence of facts that prove how the universe began to exist.
Well, given that the Universe never began to exist, you'll be waiting a while. T=0 is a point where the Universe changed form, grew out of some background, was born out of some collision within higher dimensional space, or is just possibly a finite limit to existence in that direction.
Would our undertanding of time not change if string theory is theorized?
More or less. Much depends on what you mean by string theory, as there are various ways of viewing its implications, and it has changed noticably in the past fifteen years as M-theory has come to dominate. The biggest changes will come as we begin to understand what lies behind M-theory.