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Neil Russell
2014-Aug-14, 10:34 PM
The latest estimate for the age of the BB universe is 13.8 billion years, which suggests a sphere for the universe of 13.8 billion radius light years.
However, our latest observations of furtherest observed galaxies is approaching that 13 billion light year figure, which suggests a sphere radius 13 billion light years, which surely suggests we are close to the centre of the BB universe? (Fitting our observed sphere within the suggested size of universe sphere)

How do we explain this fluke!!

Jeff Root
2014-Aug-14, 11:22 PM
I'm not going to try to explain it, I'm just going to mention
two bullet points:

The size of the Universe is completely unknown. All we have
are estimates of the minimum size it could be. There is no
observation or theory which even suggests a maximum.

Whatever the size of the Universe might be, it probably has
no center and no edge. So nomatter where you are in the
Universe, the sky probably looks pretty much the same.

-- Jeff, in Minneapolis

ben m
2014-Aug-14, 11:41 PM
The age of the universe does NOT suggest that it's a sphere of that radius. That is what you'd conclude if you imagine that the universe started as a small bounded volume, and then the edges of the volume moved apart at the speed of light. This is a common but erroneous mental picture. In standard Big Bang theory, the Universe started as a uniform bath of matter with no known boundaries but with everything very close together. Then it expanded, experiencing a spacetime behavior that makes everything fall away from everything else. There is no edge and no center. Any observer, anywhere in the Universe, could look and see 13 Gy old galaxies 13 Gly away.

John Mendenhall
2014-Aug-15, 02:11 AM
The age of the universe does NOT suggest that it's a sphere of that radius. That is what you'd conclude if you imagine that the universe started as a small bounded volume, and then the edges of the volume moved apart at the speed of light. This is a common but erroneous mental picture. In standard Big Bang theory, the Universe started as a uniform bath of matter with no known boundaries but with everything very close together. Then it expanded, experiencing a spacetime behavior that makes everything fall away from everything else. There is no edge and no center. Any observer, anywhere in the Universe, could look and see 13 Gy old galaxies 13 Gly away.

So well said! Anytime you read that the Universe started as an x sized point, don't bother with the rest of it. The author doesn't understand BB.

Neil Russell
2014-Aug-15, 03:18 AM
http://ssscott.tripod.com/BigBang.html, well this still suggests an expansion from a point? I agree with Jeff that the age of the universe is an unknown, that being the case would it not suggest that the universe is much older and bigger than current estimates?

wd40
2014-Aug-15, 03:40 AM
However, our latest observations of furtherest observed galaxies is approaching that 13 billion light year figure, which suggests a sphere radius 13 billion light years, which surely suggests we are close to the centre of the BB universe?

"All this evidence that the universe looks the same whichever direction we look in might seem to suggest there is something special about our place in the universe. In particular, it might seem that if we observe all other galaxies to be moving away from us, then we must be at the centre of the universe.

There is, however, an alternate explanation: the universe might look the same in every direction as seen from any other galaxy, too. This, as we have seen, was Friedmann’s second assumption. We have no scientific evidence for, or against, this assumption. We believe it only on grounds of modesty: it would be most remarkable if the universe looked the same in every direction around us, but not around other points in the universe." (Stephen Hawking)

Shaula
2014-Aug-15, 04:32 AM
http://ssscott.tripod.com/BigBang.html, well this still suggests an expansion from a point? I agree with Jeff that the age of the universe is an unknown, that being the case would it not suggest that the universe is much older and bigger than current estimates?
It is a common pop-sci misrepresentation of the theory to say that the entire universe expanded from a point. The current model simply does not go back that far, it starts (as others have said) with the observable universe (not the entire universe) as a small, hot, dense state that then expands. As has been explained in several other similar threads you have started on this topic.

Strange
2014-Aug-15, 07:07 AM
I agree with Jeff that the age of the universe is an unknown

Jeff did not say that. He said the size is unknown. There are multiple lines of evidence supporting the fact that the universe is expanding and that it was once hotter and denser. These all give a consistent view of the timeline.

Edit. That timeline goes back to about 13.8 billion years. That is the earliest time that we can say anything about the conditions with our current theories. We don't know how the universe got to that state (or how long that might have taken). So "the age of the universe" is a bit of a misnomer.

Jeff Root
2014-Aug-15, 07:32 AM
I agree with Jeff that the age of the universe is an unknown,
NO, YOU DON'T.

I SAID THAT THE SIZE OF THE UNIVERSE IS UNKNOWN.

I DID NOT SAY THAT THE AGE IS UNKNOWN.

Although it is true that I expect that the Universe may be
older than the current best estimate of 13.8 billion years,
because we don't know how long it took for the Universe to
"come into existence" in the first place-- General relativity
just assumes it was instantaneous-- But the observed
redshifts of galaxies and CMBR pretty clearly show that the
CMBR was emitted not much more than 13.8 billion years
ago, and that age seems to be consistent with most other
observations.



that being the case would it not suggest that the universe
is much older and bigger than current estimates?
It could be older. It can't be bigger than current estimates
because there really are no such estimates. The age of
the Universe is more-or-less known. The size is not.

-- Jeff, in Minneapolis

Strange
2014-Aug-15, 07:35 AM
General relativity
just assumes it was instantaneous

General relativity says nothing about that.

Jeff Root
2014-Aug-15, 07:58 AM
The calculations done with general relativity assume that the
mass-energy of the Universe is constant even though space is
expanding. The calculations predict a singularity 13.8 billion
years ago: a point in time at which the expansion began.

General relativity does not deal with matter. It does not have
the concept of "particles". It cannot and does not say anything
about the creation of particles or any kind of matter, so it just
assumes that it all existed all the way back to the beginning
of time, which results in a prediction of infinite density at t=0.

Other theories talk about the creation of particles and matter,
and they can modify the prediction made with GR. But GR is
the theory that describes the expansion of space, and gives us
the 13.8 billion year figure, and it assumes an instantaneous
beginning.

-- Jeff, in Minneapolis

.

Strange
2014-Aug-15, 08:00 AM
it
assumes an instantaneous beginning.

Citation needed.

ETA: this is genuine curiosity. I have never seen any such statement in any of the (few) papers I have read about big bang cosmology.

Neil Russell
2014-Aug-15, 08:17 AM
My point is that if the size(as suggested) of the universe is not known,surely it can be a lot bigger than the current 13.8 billion light years distance estimate. We have one known (the diameter of observed space) versus an estimate for the size, I am asking how is this discrepancy to be explained?

Strange
2014-Aug-15, 08:37 AM
My point is that if the size(as suggested) of the universe is not known,surely it can be a lot bigger than the current 13.8 billion light years distance estimate. We have one known (the diameter of observed space) versus an estimate for the size, I am asking how is this discrepancy to be explained?

There is the observable universe, which is what we can see. Beyond this, the universe is assumed to extend for some unknown extent. I'm not sure what the discrepancy is?

Jeff Root
2014-Aug-15, 08:51 AM
Neil,

Almost every good book on cosmology will explain how
cosmic expansion works. That will answer your question.
We can probably answer it here, but it is pretty involved
and could take a lot of time and effort.

You don't need to be able to work through mathematical
formulas to understand it, but the geometry is neither
simple nor obvious. There are scads of books on the subject.
Cougar has posted a list of books that include several on
cosmology. Maybe you can find that list, or maybe Cougar
will see this and post it again for you. I'm sure others will
post their own personal favorites. Mine are somewhat old,
and I don't know much about more recent titles. Basically
what you want is an explanation of general relativity's
description of the evolution of the Universe, the FLRW
(Friedmann-Lemaître–Robertson–Walker) metric.

-- Jeff, in Minneapolis

NEOWatcher
2014-Aug-15, 11:57 AM
My point is that if the size(as suggested) of the universe is not known,surely it can be a lot bigger than the current 13.8 billion light years distance estimate. We have one known (the diameter of observed space) versus an estimate for the size, I am asking how is this discrepancy to be explained?
One of the keys is in the article you posted.

During this creation and annihilation of particles the universe was undergoing a rate of expansion many times the speed of light. Known as the inflationary epoch...
I'm not so well versed on it myself, but maybe I can spark something with a simple view of it.

The quoted line means there are vast areas of the universe that we will never see because the light returning from them is not as fast as they have travelled.

There is also the concept of expanding space. Where things cannot move faster than light within their own local area of the universe, but as you expand that concept, things outside the local area are moving faster than light.

No matter where you are, there is the 13.8 billion LY boundary where no light is coming from, so all those locations look the same.

Cougar
2014-Aug-15, 12:59 PM
The latest estimate for the age of the BB universe is 13.8 billion years, which suggests a sphere for the universe of 13.8 billion radius light years.

That naive suggestion turns out to be incorrect. The age of the universe (since the beginning of the expansion) is very tightly constrained by half a dozen different methods observing different phenomena in the universe.


The best estimate of the age of the universe (http://en.wikipedia.org/wiki/Age_of_the_universe) as of 2013 is 13.798 ± 0.037 billion (http://en.wikipedia.org/wiki/1,000,000,000_%28number%29) years[2] (http://en.wikipedia.org/wiki/Observable_universe#cite_note-planck_cosmological_parameters-2) but due to the expansion of space (http://en.wikipedia.org/wiki/Metric_expansion_of_space) humans are observing objects that were originally much closer but are now considerably farther away (as defined in terms of cosmological proper distance (http://en.wikipedia.org/wiki/Comoving_distance#Uses_of_the_proper_distance), which is equal to the comoving distance (http://en.wikipedia.org/wiki/Comoving_distance) at the present time) than a static 13.8 billion light-years (http://en.wikipedia.org/wiki/Light-year) distance.[3] (http://en.wikipedia.org/wiki/Observable_universe#cite_note-expandingconfusion-3) It is estimated that the diameter (http://en.wikipedia.org/wiki/Diameter) of the observable universe is about 28 billion parsecs (93 billion light-years (http://en.wikipedia.org/wiki/Light-year)),[4] (http://en.wikipedia.org/wiki/Observable_universe#cite_note-4) putting the edge of the observable universe at about 46–47 billion light-years away. - wiki (http://en.wikipedia.org/wiki/Observable_universe)



Alan Guth's early theoretical calculations of cosmic inflation yielded the size of the entire universe to be something like 1024 times the size of the observable universe.

mkline55
2014-Aug-15, 01:45 PM
Citation needed.
You might try here (http://www.ugcs.caltech.edu/~yukimoon/BigBang/BigBang.htm)

Tracing back this expanding universe, we see that the separations between galaxies become smaller while the density becomes higher. This continues until all matter is compacted into a completely shrunk volume of the universe with an incredible density—the moment of the big bang.
or here (http://science.nationalgeographic.com/science/space/universe/origins-universe-article/)

A Belgian priest named Georges Lemaître first suggested the big bang theory in the 1920s when he theorized that the universe began from a single primordial atom.
or here (http://education-portal.com/academy/lesson/origins-of-the-universe-the-big-bang-and-expanding-contracting-universes.html#lesson)

The universe used to be nothing and have nothing. It started as a little speck of a hot, super-massive, and super-dense ball. Everything that is currently in the universe came from that speck. Every single proton, neutron, atom, and so forth came from that ball. About 13.7 billion years ago, BANG!
or here from Steven Hawking (http://www.hawking.org.uk/the-origin-of-the-universe.html)

If Einstein's General Theory of Relativity is correct, there will be a singularity, a point of infinite density and spacetime curvature, where time has a beginning. Observational evidence to confirm the idea that the universe had a very dense beginning came in October 1965, a few months after my first singularity result, with the discovery of a faint background of microwaves throughout space.
or here from CERN (http://home.web.cern.ch/about/physics/early-universe)

LeMaître proposed that the universe expanded explosively from an extremely dense and hot state, and continues to expand today. Subsequent calculations have dated this big bang to approximately 13.7 billion years ago.]
or here from Stanford (http://news.stanford.edu/news/2014/march/physics-cosmic-inflation-031714.html)

In the first fleeting fraction of a second, the universe expanded exponentially, stretching far beyond the view of today's best telescopes. All this, of course, has just been theory.

Researchers from the BICEP2 collaboration today announced the first direct evidence supporting this theory, known as "cosmic inflation."

Strange
2014-Aug-15, 02:16 PM
I know this is the standard line in most popularizations. I was hoping to see something from, say, a paper on cosmology.

ETA: And, actually, only one of those really echoes Jeff's comment. Most of them, like the CERN one, are more accurate.

mkline55
2014-Aug-15, 02:57 PM
I know this is the standard line in most popularizations. I was hoping to see something from, say, a paper on cosmology.
Sorry. I thought you just wanted citations. Could you be clearer about what qualities a "paper on cosmology" might need for a citation you might find acceptable? This sort of clarification might be useful for many readers of "popular" science.

ETA: I gather magazines like "Scientific American" do not qualify.

Strange
2014-Aug-15, 03:48 PM
Sorry. I thought you just wanted citations. Could you be clearer about what qualities a "paper on cosmology" might need for a citation you might find acceptable?

Thanks for your links.

I guess a paper that has been (or could be) published in scientific journal. Or any paper or article that discusses in detail how GR and other theories are used to describe the evolution of the universe. I haven't seen any such serious paper talk about "instantaneous creation". They all seem to start with the universe in a hot, dense state (as do most of the pages you provided links to). There may be various speculations from people such as Hawking and others. But these are not (yet) part any scientific theory (as far as I know). And I'm not sure that even any of those speculations describe "instantaneous creation".

But I could be wrong, which is why I asked.

Shaula
2014-Aug-15, 04:05 PM
Sorry. I thought you just wanted citations. Could you be clearer about what qualities a "paper on cosmology" might need for a citation you might find acceptable? This sort of clarification might be useful for many readers of "popular" science.

ETA: I gather magazines like "Scientific American" do not qualify.
A paper should present a valid and verified model along with the observations that support it and should have been published and peer reviewed in a journal widely accepted as adhering to high standards of review and scrutiny. Said model should unify quantum and GR effects at the required energy scales and densities and describe the proposed instantaneous creation event and the subsequent evolution of the universe.

And no, Scientific American, New Scientist - these are magazines, not peer reviewed journals.

mkline55
2014-Aug-15, 04:14 PM
A paper should present a valid and verified model along with the observations that support it and should have been published and peer reviewed in a journal widely accepted as adhering to high standards of review and scrutiny. Said model should unify quantum and GR effects at the required energy scales and densities and describe the proposed instantaneous creation event and the subsequent evolution of the universe.

And no, Scientific American, New Scientist - these are magazines, not peer reviewed journals.
Great! I appreciate the responses from you and Strange. I'm sure you both understand the subject better than I do. I'll look a little deeper. But just for comparison, can I get a citation of one paper meeting your requirements including the model, quantum and GR effects, etc. which excludes an origin? Hopefully, a paper that I can view without subscribing to something. That will at least set the bar as to what I am looking for. I don't mind searching, but searching in all the wrong places is not time well spent.

Jeff Root
2014-Aug-15, 06:15 PM
I haven't seen any such serious paper talk about
"instantaneous creation". They all seem to start with the
universe in a hot, dense state (as do most of the pages
you provided links to).
Exactly. The FLRW description of the evolution of the
Universe assumes that it began instantaneously in a hot,
dense state, rather than being generated by any kind of
process which takes time. It does that necessarily because
the FLRW metric is calculated from general relativity, which
doesn't include any physics which can describe creation
of matter.

-- Jeff, in Minneapolis

Strange
2014-Aug-15, 06:20 PM
Exactly. The FLRW description of the evolution of the
Universe assumes that it began instantaneously in a hot,
dense state, rather than being generated by any kind of
process which takes time.

Maybe we are just talkiing at cross-purposes then. I agree that all(?) descriptions begin with a hot dense state. I have not seen anything saying the "universe began" (as in created?). Instantaneously or otherwise.

Shaula
2014-Aug-15, 06:28 PM
Great! I appreciate the responses from you and Strange. I'm sure you both understand the subject better than I do. I'll look a little deeper. But just for comparison, can I get a citation of one paper meeting your requirements including the model, quantum and GR effects, etc. which excludes an origin? Hopefully, a paper that I can view without subscribing to something. That will at least set the bar as to what I am looking for. I don't mind searching, but searching in all the wrong places is not time well spent.
The point is that there is no paper out there that covers all the effects listed. Because current theories cannot unify QM and GR, which is why there is no creation event in current cosmological models. We cannot describe the physics under those conditions. The LCDM model has been around for so long that tracing one good citation as the genesis of it is tricky - what you have is a number of early papers and then thousands of papers refining and improving it. Whereas GR/QM unification has not yet been done, at least beyond some highly speculative first attempts at it. So if it had happened recently then it should be far easier to find a genesis paper for it.

Here are examples of fairly good citations covering aspects of the theories:
http://arxiv.org/abs/1303.5076 - Planck results constraining LCDM parameters
http://arxiv.org/abs/astro-ph/9909478v2 - Dark matter profiles

You are looking for, as I said, a good journal publishing them, a reasonable citation count and usually affiliation with a strong research team.

mkline55
2014-Aug-15, 06:31 PM
Maybe we are just talkiing at cross-purposes then. I agree that all(?) descriptions begin with a hot dense state. I have not seen anything saying the "universe began" (as in created?). Instantaneously or otherwise.
That's confusing - to me at least. To say that the universe began without a beginning. Some of the articles I am finding refer to the state of the universe at microseconds after the beginning, yet readers deny there was a beginning point in time. I am totally confused. I found tracks of exactly the paper I wanted, describing the entire theory, but guess what? Paywall. Still looking.

Strange
2014-Aug-15, 06:36 PM
That's confusing - to me at least. To say that the universe began without a beginning.

I would not say the universe began because there is no evidence for such a statement. (I wouldn't deny it either, for the same reason.)

ETA. So descriptions often reference a "time 0" as a starting point. This is obtained by just extrapolating back naively. It is a handy, but possibly meaningless, reference point.

For example: http://www.astro.ucla.edu/~wright/BBhistory.html

This description starts at 10-43 seconds. You could reasonably ask, 10-43 seconds after what? Ultimately, we don't know. The universe might have existed in the hot dense state for a billion years before that. It might have been created from nothing. It might have been created by the clash of branes or from a black hole or a quantum fluctuation or the collsape of an earlier universe or ...

mkline55
2014-Aug-15, 07:12 PM
I should remember to leave reason at the door before I come in here. Any other familiar use of "at n seconds" means there was a "at zero seconds". I finish a race at 31.2 seconds. That means the race started 31.2 seconds before that. But when it comes to BB theory and the universe, .00000000001 - .00000000001 does not equal zero. It's "undefined".

Strange
2014-Aug-15, 07:14 PM
It just means we don't know if it is valid to extrapolate back like that. So it is useful as a reference point, but it may not have any physical meaning.

Jeff Root
2014-Aug-15, 07:33 PM
We don't know if it is valid to extrapolate any farther back
than the start of nucleosynthesis. That's the earliest event
that is constrained by observations. Everything before that
is speculation, with many wildly divergent possibilities,
because we don't have observations to constrain them.

-- Jeff, in Minneapolis

primummobile
2014-Aug-15, 07:42 PM
I should remember to leave reason at the door before I come in here. Any other familiar use of "at n seconds" means there was a "at zero seconds". I finish a race at 31.2 seconds. That means the race started 31.2 seconds before that. But when it comes to BB theory and the universe, .00000000001 - .00000000001 does not equal zero. It's "undefined".

I interpret it as 10^-43 seconds after the universe started to expand, (not after it was created) and that before that expansion we don't know what happened. It could have been there as a hot dense state for a long time or it may not have.

korjik
2014-Aug-15, 07:43 PM
We don't know if it is valid to extrapolate any farther back
than the start of nucleosynthesis. That's the earliest event
that is constrained by observations. Everything before that
is speculation, with many wildly divergent possibilities,
because we don't have observations to constrain them.

-- Jeff, in Minneapolis

It would be back to the separation of the strong force from electroweak that we could go back to. Electroweak constraints set up the future composition of the universe.

Shaula
2014-Aug-15, 07:45 PM
It just means we don't know if it is valid to extrapolate back like that. So it is useful as a reference point, but it may not have any physical meaning.
Much like absolute zero. Can't be reached, still a valid reference point.

korjik
2014-Aug-15, 07:53 PM
I should remember to leave reason at the door before I come in here. Any other familiar use of "at n seconds" means there was a "at zero seconds". I finish a race at 31.2 seconds. That means the race started 31.2 seconds before that. But when it comes to BB theory and the universe, .00000000001 - .00000000001 does not equal zero. It's "undefined".

All that means is that you do not know what a theory is. The current state of our knowledge of physics (the theory) is insufficient to describe what happens during the first instants of the universe. It isnt that 1-1 does not equal zero, it is that 1 second minus 1 second dosent mean much if you cannot define the second. Seeing that is is quite well known that the second isnt a constant, and is very much not a constant at the energy levels involved at the beginning of the universe, tracking that first instant is not a defineable thing with current theory.

The fact that you find that unreasonable is utterly irrelevant

ben m
2014-Aug-15, 07:53 PM
That's confusing - to me at least. To say that the universe began without a beginning. Some of the articles I am finding refer to the state of the universe at microseconds after the beginning

There's a certain early state that we understand pretty well. We understand its density, its temperature, its particle-physics content, and its spacetime. If you take the General Relativity description of that spacetime and extrapolate forwards it gives you ... well, it gives you an apparently-correct description of the Universe as it passed through nucleosynthesis, recombination, galaxy formation, reionization, etc., and arrived where we are today. If you take that same early spacetime and extrapolate backwards---very naively---it looks nice and smooth and it gives you what looks like a start-time. "here is a true singularity at t=0 and here's the state you understand at t=10^-37s, and here's the BBN and CMB and etc. etc. etc." But that early extrapolation cannot be correct, because we know GR doesn't work at those densities and temperatures. So the early times you see---"10^-37s" or whatever---are not invented out of whole cloth; nor are they a really correct description of the Universe prior to the "certain early state that we understand pretty well".

Jeff Root
2014-Aug-15, 08:49 PM
But that early extrapolation cannot be correct, because we
know GR doesn't work at those densities and temperatures.
My understanding is, as you suggested earlier in your post,
that the densities and temperatures are extrapolated by GR.
They are predicted by GR. It is QM that we know doesn't
work at those densities and temperatures. GR doesn't care.

-- Jeff, in Minneapolis

.

Neil Russell
2014-Aug-15, 10:29 PM
http://en.wikipedia.org/wiki/Age_of_the_universe, this refers to the age of the universe. "They" have worked out this by calculations, my question still stands how can it be right? None of the replies so far have helped me greatly. There appears to be much disagreement within the theory, healthy but not helpful! So my understanding will remain that the universe is much much older than currently accepted as per the link.

ben m
2014-Aug-15, 10:42 PM
http://en.wikipedia.org/wiki/Age_of_the_universe, this refers to the age of the universe. "They" have worked out this by calculations, my question still stands how can it be right? None of the replies so far have helped me greatly. There appears to be much disagreement within the theory, healthy but not helpful! So my understanding will remain that the universe is much much older than currently accepted as per the link.

"How can it be right"? Think of it this way: what is posted is the time elapsed between the oldest known initial state and today. That time is 13.798±0.037 billion years. The initial state in question is a time when the Universe was a hot particle-physics soup; the matter that later became the Milky Way was compressed into a sphere a few nanometers across. Nanometers! There is no substantial disagreement about what happened between this initial state and today. That's our 13.798 Gy. You have not explained why you object to it, or what part of it you misunderstand.

Had that initial-state been there for 10^-36 seconds (as a GR extrapolation suggests), or 10^-100 seconds, or for 100 seconds? (An error of 100 seconds doesn't make much difference in the measurement of 13,798,000,000 years, does it?) Had the initial state been there for an infinite length of time-does-not-exist-yet non-time? (There is no such claim "as per the link" and no good theory to inform "much disagreement" as you suggest.)

Please explain what you think is going on; if you've made a specific mistake someone can correct it.

Strange
2014-Aug-15, 11:11 PM
http://en.wikipedia.org/wiki/Age_of_the_universe, this refers to the age of the universe. "They" have worked out this by calculations, my question still stands how can it be right?

Perhaps if you could explain more precisely what it is you don't understand, then maybe we could help fill the gaps. Just expressing general disbelief doesn't help anyone to help you get a better understanding.

Jeff Root
2014-Aug-16, 07:38 AM
I understand what the apparent contradiction is that Neil sees.

Right at the beginning of the thread, I thought of asking Neil
to explain exactly what he thought the contradiction is, but I
immediately realized that it would be a waste of time. He
would not be able to explain it, and we would not be able to
resolve it for him. The only solution to this conundrum is for
him to read a good book on the subject of the Big Bang which
explains the FLRW metric in terms he can understand. There
should be lots of such books available. If he doesn't want to
take the time to read a book, that's his problem. There is no
royal road to geometry.

-- Jeff, in Minneapolis

Cougar
2014-Aug-16, 11:43 AM
The only solution to this conundrum is for
him to read a good book on the subject of the Big Bang....

I'm not sure I agree with that. Nevertheless, there certainly are good books explaining the evolution of the universe and the evolution of our thinking about it....


Big Bang, the origin of the universe [2004] -- by Simon Singh

Origins, Fourteen billion years of cosmic evolution [2004] -- Neil DeGrasse Tyson and Donald Goldsmith

The State of the Universe, A Primer in Modern Cosmology [2006] -- Pedro Ferreira

How Old is the Universe [2011] -- David A. Weintraub

The Universe at Midnight, Observations Illuminating the Cosmos [2001] -- Ken Croswell

The Runaway Universe, the Race to Find the Future of the Cosmos [2000] -- Donald Goldsmith

Neil Russell
2014-Aug-16, 10:20 PM
Ben m and Strange I am not taking issue with the BB theory as such rather a conundrum I see between the observed universe we can see at 13+billion light years, an actual, and the estimate published of the age of the BB universe, namely also around 13-14 billion light years. I pointed out if these figures were both correct it would place us at the centre of the universe.
Now I cannot believe we really are at the centre of the universe, so I simply asked how have "they" arrived at the published age of the universe, why/how, given our observed universe is a given, then the estimated age of the BB universe could be wrong. Is my observation wrong? then how,please?

ben m
2014-Aug-16, 11:07 PM
Ben m and Strange I am not taking issue with the BB theory as such rather a conundrum I see between the observed universe we can see at 13+billion light years, an actual, and the estimate published of the age of the BB universe, namely also around 13-14 billion light years. I pointed out if these figures were both correct it would place us at the centre of the universe.

We have been here for 13 Gy. Therefore, we've had time to collect photons from 13 giga-light-years in every direction. That's what makes the two numbers equal, by definition. Think about it. We don't know the "size of the universe", we know the "size of the portion of the universe that we can actually see". We can actually see as far as light has traveled in any direction in the time we've been here and the time stuff has been emitting light, so we see a 13 giga-light-year depth in any direction, i.e. a sphere with us at the center.

Think about it.

Swift
2014-Aug-17, 03:35 AM
Ben m and Strange I am not taking issue with the BB theory as such rather a conundrum I see between the observed universe we can see at 13+billion light years, an actual, and the estimate published of the age of the BB universe, namely also around 13-14 billion light years. I pointed out if these figures were both correct it would place us at the centre of the universe.

Neil Russell,

When you posted this in the first post of this thread, it was just barely in the form of a question (and just barely not advocating a non-mainstream idea). This has been answered for 40 posts. If you haven't found the answer yet, repeating your problem with this won't get it solved on CQ.

I'm closing this thread. If someone has a good reason to reopen it... you know the drill.