Cosmic Expansion

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DrRocket":1351mre8 said:
....under Einstein-Cartan has no singularity, just as very compact initial universe ( a centimeter or so in diameter). The universe would be quite hot in that situation.
How is the size of the universe measured when it's only a centimeter in diameter? It seems that you can't be "outside" the universe with a ruler because there is no outside the universe. Does size have any real meaning under these conditions?
 
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DrRocket

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kg":3kloh8sp said:
DrRocket":3kloh8sp said:
....under Einstein-Cartan has no singularity, just as very compact initial universe ( a centimeter or so in diameter). The universe would be quite hot in that situation.
How is the size of the universe measured when it's only a centimeter in diameter? It seems that you can't be "outside" the universe with a ruler because there is no outside the universe. Does size have any real meaning under these conditions?
You can look at it in terms of the metric that is associated with space-time. In this case there are some assumptions that lead to large-scale models, for which the Lorentz metric of space-time provides a Riemannian metric on "space-like slices".

Conceptually it is no more or less a problem than measureing the length of your living room with a tape measure. You are inside the universe, but you can still take measurements.

If, on the other hand, you asking how one would conduct some sort of experiment to measure the diameter of the universe at 10^-33 seconds after the Big Bang or something like that, then there is indeed a problem.
 
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how my non educated mind deals with the questions: "what happened before the big bang"? and "where did the big bang singularity come from"? The standard and probably true answers are, there was no "before" as there was no time. There was no "where" for it to come from as there was no "space".

my answers to myself:

space/time is an expanding field of strings and it appeared in perhaps a void which may have many contents including singularities which can expand becoming a field of strings described as space/time. The field of strings is space, the expansion of the space is time.

the expansion of space/time happened in an "area" which is not expanding and which is not a field of strings. This allows there to be an "outside" to the Universe but it cannot be described as "space" and it does not expand so it does not experience time.

So, while there was no "Space" for the initial singularity to appear in, there was a place or an area, give it whatever name you see fit, but it was not an expanding sea of strings. This also gives the initial singularity a period but not a "time" to come to be. So there was a before the big bang but not a "time before" there was a "place" but not a "space".

I can make sense of things this way.
 
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DrRocket

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Boilermaker":246sciyy said:
how my non educated mind deals with the questions: "what happened before the big bang"? and "where did the big bang singularity come from"? The standard and probably true answers are, there was no "before" as there was no time. There was no "where" for it to come from as there was no "space".

my answers to myself:

space/time is an expanding field of strings and it appeared in perhaps a void which may have many contents including singularities which can expand becoming a field of strings described as space/time. The field of strings is space, the expansion of the space is time.

the expansion of space/time happened in an "area" which is not expanding and which is not a field of strings. This allows there to be an "outside" to the Universe but it cannot be described as "space" and it does not expand so it does not experience time.

So, while there was no "Space" for the initial singularity to appear in, there was a place or an area, give it whatever name you see fit, but it was not an expanding sea of strings. This also gives the initial singularity a period but not a "time" to come to be. So there was a before the big bang but not a "time before" there was a "place" but not a "space".

I can make sense of things this way.
If you can make sense of things in that manner, I suggest that you do some reading so that you can uncerstand how physics and cosmology are really formulated. You will find that what you are suggesting is formulated in a manner that is not conprehensible, and that when you see how cosmology is actually formulated, then yyou will no longer be able to "make sense of things this way."
 
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Boilermaker

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"If you can make sense of things in that manner, I suggest that you do some reading so that you can uncerstand how physics and cosmology are really formulated. You will find that what you are suggesting is formulated in a manner that is not conprehensible, and that when you see how cosmology is actually formulated, then yyou will no longer be able to "make sense of things this way."

with all due respect, it would not matter what I read or how long I read it, there is no explanation at all to make sense of the fact that the Universe came to be from an "initial quantum singularity" or a "quantum fluctuation in the vacuum" or from "m branes colliding"

the fact of the matter is that we do want to know how the initial quantum singularity came to be and what made it expand and where it was when it came to be, as well as did it form fully whole or was there components, some composition? If there was a vacuum which had a quantum fluctuation how am I to make sense of that? what caused the fluctuation? what caused the singularity? what caused the expansion?

science simply states that physics breaks down at the singularity. that there was no where for the singularity to exist and there was no time for it to come to be.......the thing just was and it was apparently unstable as it was because it was not at rest, so this is all very empty for me.

you know, I paint a little and through my art I discovered something I did not know before. I discovered that not everyone's brain can connect the dots to the same extent. I did a poster for a band and it was of a gangster or one of eliot ness's untouchables type of a man, he had a fedora hat on and a trench coat and he had a cigarette hanging out of his mouth with smoke rising from it.........I did not put any more detail, any more lines than I thought were necessary but when I presented it, some people thought it was "brilliant" while others turned it upside down and all around and could not even see the picture at all which amazed me, for to me it was obvious.........it became quickly obvious I could not use it for advertising as what use is a picture you can't see?

but that intrigued me, I showed it to many people and some could see it as easily as I did while others took a little time to connect it and then the majority of people just could not see it even after having it all pointed out to them....I am still puzzled by that................but if that is the case, then there could be many people who cannot join the dots of science........I might be one of them, I don't know. But I do know, there are people who just cannot see something right there in front of them, visible information, patterns elude them, but not everyone, but for those it does, they cannot even be shown, they just cannot see.

I think in pictures, I visualize what I am hearing and thinking and it either makes a balanced picture or it doesn't...for me.

what I am trying to say in my uneducated posts I can picture and I like it, it all makes sense to me. but when I read a cop out, that all the laws break down and so we cannot know.............that is unbearable to hear or read, that is not an acceptable answer to any question, there has to be a correct answer and so far, it has never been given, right?

so, what help will I get by reading something that concludes finally that we just can never know?
 
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DrRocket

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Boilermaker":1gvzrqsl said:
I think in pictures, I visualize what I am hearing and thinking and it either makes a balanced picture or it doesn't...for me.

what I am trying to say in my uneducated posts I can picture and I like it, it all makes sense to me. but when I read a cop out, that all the laws break down and so we cannot know.............that is unbearable to hear or read, that is not an acceptable answer to any question, there has to be a correct answer and so far, it has never been given, right?

so, what help will I get by reading something that concludes finally that we just can never know?
Lots of people think in pictures. Many scientists and mathematicians do. I do.

What you will get by reading real science is an understanding of the basis of our scientific knowledge. You will understand what it tells us and what it does not tell us. You will understand how science progresses -- in steps and in successive approximations.

It is NOT TRUE that you can conclude that "we just can never know". It is important to realize this.

It is true that the current models of cosmology, models based on general relativity, result in the prediction of a singularity at the "Big Bang". But that indicates only that we don't yet understand what is going on. It does NOT say that we will never know. It merely points out the need for more research and for the formulation of a more complete theory than what we have now. There are other models that do not predict a singularity, but do predict an extremely compact universe at the "Big Bang". Maybe that model is correct. Or maybe we will eventually find a theory that encompasses both quantum field theories and general relativity and maybe that theory will provide a better explanation.

But unless you understand what is known, you cannot hope to understand the limits of that knowledge or what a better theory might be able to tell us. The fact that current theories are not complete does not mean that they are not extremely good at showing how nature behaves within known domains of validity. To dismiss those theories because they are not complete and instead substitute fantasy is simply silly. In order to improve on existing theories yo first need to understand them. You cannot even criticize them intelligently if you don't understand what they mean, when they are valid, and when they have reached the limits of their validity.
 
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Boilermaker

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you make a lot of assumptions about what other people read...........a little while back I posted a few names of some of the books I've read, books such as "A Brief History of Time" "The God Particle" "The Arrow of Time" "Black holes and baby Universes" "The Physics of the Impossible," "Hyperspace", "The Illustrated Brief History of Time, Updated and Expanded Edition ", "Black Holes and Baby Universes and Other Essays", "Carl Sagan Cosmos", "The Universe in a Nutshell",

those are a few off the top of my head which I read but which you somehow consider less than Correct and not true Science Books.

well your majestic brain must already be in demand by the Smithsonian, did they get first dibs on it or are you holding out for other offers?

perhaps your enormous Cranium could offer up some other Books worthy of contemplation for those with an appetite for Real Science, unlike that drivel I just named...........I really never knew, I thought those books were real science Books by real scientists, how could I have known without the good Dr. pointing this out continually as if it were some sort of tic?

so, I eagerly await some direction from you, please point me to more worthy authors.
 
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DrRocket

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Boilermaker":e6uyv2xs said:
perhaps your enormous Cranium could offer up some other Books worthy of contemplation for those with an appetite for Real Science, unlike that drivel I just named...........I really never knew, I thought those books were real science Books by real scientists, how could I have known without the good Dr. pointing this out continually as if it were some sort of tic?

so, I eagerly await some direction from you, please point me to more worthy authors.
Sure. Go look at the sticky in SS&A that lists books and videos. Then look at some of the more serious texts as well as the popularizations.
 
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