Cosmology Principle vs the actual center of the Universe

Sure - a 1-sphere is a circle, a 1-dimensional line that loops back on itself. There is no unique point on the circle that can be considered "the" centre, but all points can equally be considered "a" centre. The 1-sphere is not to be confused with the 2-ball, which is a disc: a 2-dimensional area bounded by a 1-sphere (circle). The disc does possess a centre.The 2-sphere is the 2-dimensional area that closes in on itself exemplified by the surface of the earth. Once again, there is no unique point on the 2-sphere that can be considered "the" centre, but all points can equally be considered "a" centre. The 2-sphere is not to be confused with the 3-ball, which is a solid 3-dimensional volume bounded by a 2-sphere. The earth is a reasonable 3-ball. The 3-ball does possess a centre.The naive impression that n-spheres have centres occurs because n-spheres are most often visualised embedded in an n+1 dimensional space (circle drawn on piece of paper.) A point completely divorced from the n-sphere is viewed as the centre as it conincides with the centre of the corresponding n+1-ball.Cool facts: the boundary of an n-ball is an n-1-sphere. An n-sphere has no boundary.

Nobody has yet used the balloon analogy - excellent (bleedin terrible analogy and a lot to answer for).I normally start with the piece of elastic analogy when trying to explain expansion and the lack of centre. Pull elastic and your fingers move apart. They are not moving relative to the elastic so each can claim, justifiably, to be stationary. From that POV the other finger is rushing away at increasing speed (and in fact the speed is proportional to the distance - the further away, the faster it recedes).
There is a basic analogy for expansion.When it comes to inflation - many physicists don't really much like it, it has the feeling of a convenient patch, but it does work and you don't ditch a theory because of it's origin - you test it and try your very best to refute it - that's science.On GR - we know that GR is wrong, but it is so right for most things that, rather like Newtonian mechanics, it is a very useful and used model. If we can ever get QED/QCD and Relativity together for long enough in the same room without one of them sulking and dividing itself by zero until it feels better, then we will know a bit more. If we ever find the damn elusive Higgs then a bit more still, and if we start seeing micro black holes at the LHC then (and only then) I'll dust-off some string theory texts and start swatting.

I was looking at the short article on Wun-Yi Shu's proposed "No Big Bang model" that was posted at Psysorg and wondered if it makes any sense yet, or if it accounts for some things we do see, like the background radiation?As a totally ignorant onlooker I wondered what you, cavediver and Son Goku might be able to tell us.

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Anyone so limited that they can only spell a word one way is severely handicapped!

Well, it isn't pseudo-science and it isn't junk-science but it does need a health warning.
It is speculative to a huge degree and is nothing I would call a coherent theory - more of a half-developed speculation.
Scientists play these sort of games all the time - fiddle around with some quantities and see what develops. In this case Shu is fiddling with what we believe to be constant - the speed of light.
Many other assumptions are made which are almost equally questionable.
It is the sort of article of interest to the theorist and interesting in that it apparently spots new patterns of behaviour which may have some basis, but I wouldn't attach any more importance to it than any of the huge number of alternative models being played with in universities around the world.

I think that Bikerman is being exceptionally generous. It's pure bollocks. Yes, we do experiment with all sorts of crazy ideas, in my case typically whilst otherwise engaged in the bathroom, but there is plenty of evidence from the paper that this guy is seriously confused on a number of issues.Now, this could be an interesting article on what some random and completely un-physically motivated "nonsense" can produce, but to publish this garbage on arxiv as serious research puts this into crank territory, if only as it is an unashamed (and somewhat successful) attempt at making a name for oneself in pop-sci and the blog-sphere.

Now don't hold back here...tell us what you REALLY think, and don't cloak it in these neutral non judgemental terms. :-)I was being a bit 'criticism lite' with it and I really don't like it, but I don't want to give the impression that weird sounding speculation is always pseudo-scientific bollox. As Penrose once said (paraphrasing Bohr)
'You may think that what I propose here is crazy, and I agree - it is completely crazy, so here is the only question remaining - is it crazy enough to be true?'"In the case of this paper, to borrow another voice from the yoof I teach ...
nah mate it just aint right in the soul, it isn't speekin to me man, no respect for this is my word, I ain't likin this dissin of my man Einstein-a-gogo, you hear wat I'm saytin'? Rrrrresppectttt!Edited by Bikerman, : No reason given.Edited by Bikerman, : No reason given.

Strangely, after several years attempting to coach ICANT and Buzsaw in the rudiments of cosmology, I found that my once bountiful patience had been eroded down to a blackened core of harsh intolerance towards bullshit. Carry on in your current form with them, and you are only seeing in me what lies in your own future...

Trust me - I've been there and out of the other side :-)
15 years debating these bunnies does strange things to you periodically. I once caught myself staring at a particularly stupid piece of creationist tripe on the screen and wondering if the whole world was some distopean nightmare, and there was a man jerking the strings just outside the room, testing how far subject bikerman would be pushed by experimental bunny number x01. A sort of Turing test for aliens.That way lies madness indeed :-)I find nowadays that it is best to take regular breaks and1) recharge your own sanity
2) Observe that most people are not as stupid as the vocal minority that you have to engage with on the net
3) Look at the stars and go wow (or whatever phrase you find suitable to express the wonder and marvel of the universe). When the inevitable thought creeps in about how creationists are missing all this wonder for the sake of trying to stick to a text which was never intended literally - don't. Dismiss it from your mind along with the pity it invokes.Courage mon ami!
Illegitimi non carborundum

So how about yet another strange sounding speculation, this one redefining the properties of Inertial Mass.

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Anyone so limited that they can only spell a word one way is severely handicapped!

The same points apply. MOND has been around for a while but to my knowledge has not been supported by experiment/observation and you have to be clear that what is advocated is essentially tearing-up relativity AND the standard model. Whilst I am not saying that either is sacrosanct - in fact I would be the first to say that GR looks wrong, certainly at the smallest scale, I am saying that before we burn current theory we need more than this. The meat of it seems to be an attempt to explain anomolous acceleration in the Pioneer craft. I am pretty sure we haven't exhausted all the less dramatic possibilities yet, and to suggest it as support for a different physics seems to me a tad premature.
So, no, I'm neither convinced nor overly impressed.

A couple of questions from ignoramus central.Why am I wrong in thinking that if there was a BB then the actual location where it occurred must be the centre of the universe?How do we know that the farthest away galaxies (that we can see) are on the other side of the centre? In other words, could the bubble that is the surface of the last scattering not be moving away from the actual location of the BB in one direction? Like a ball thrown by a pitcher. Or is the SOLS a ball that has the location of the BB as its centre? Is the SOLS not a sphere relative to the viewer?

Because the 'location' where it occurred is 'everywhere'.

Exactly - and the same is true with the surface of last scattering.

So this diagram is incorrect?

No - it is a reasonable representation. Arbitrarily pick any spatial coordinate on the right hand side of the diagram as of 'special interest'. Now move to the left, (keeping the same spatial coordinates but going backwards in time). Eventually you'll arrive at the big bang. Now pick another spot and do the same.Now look at the big bang. Point to a single spatial coordinate that exists that is not at the big bang at the time of the big bang.You can't.Why? Because the big bang happened every'where'. Confused? That's a good sign. Here's another diagram If it still doesn't make sense - keep reading about it. It's difficult to think in four dimensions so 'pretend' the universe has only two spatial dimensions and one temporal one - you'll pick up the 'gist' of it in I'm sure.