The Holy Grail of Cosmology?

[peter]

I think Z. it was who mentioned elsewhere the detection of the echo of 'gravitation waves' from the early Universe by a team from Harvard using the Bicep 2 telescope at the south-pole. The account I read said that, if confirmed, the result would be "jaw dropping" representing as it does, the 'Holy Grail' of cosmology.

Can anyone explain why detection of these space-time ripples constitutes such a momentous discovery as to be described in these terms?

[Vraith]

Can anyone explain why detection of these space-time ripples constitutes such a momentous discovery as to be described in these terms?

I've read a lot on this...and there are a number of implications, many of which I have only the tiniest hint of a grasp on.
But the big one that almost all the articles mention is that if the signal exists as decribed/detected:
All models [or at least all the ones I've heard of] that best/most consistently explain the current size/state of the universe include the Inflation we've been talking about in other threads.
And/But...they also say "if Inflation happened, it should have generated gravitational waves. Which no one had discovered/proven yet.
[[[imagine you have a bucket full of water...no, lets stick with a balloon. Say you have a balloon full of water. Suddenly--instantaneously for all practical purposes--the balloon doubles in size. This will cause waves/disturbances in the water. If you can see and measure those waves...even if you are inside that water/balloon...you can see the effects and calculate what happened to the balloon]]]...
SO, the detection of such waves supports inflation models [and eliminates a fair number of other kinds of models...but not all of them I don't think].
ALSO--the characteristics/effects of the waves severely narrows down the number of possible, specific, inflation models...different inflation produces different waves. [[[back to the balloon: the waves will be different depending on--
how "big" the balloon was when inflation hit///
what "temperature" the water was when it hit///
how "fast" the inflation was///
the "size" of the balloon when the inflation stopped [if the balloon was 2 or three, or a million times larger at that point].

And those are just the obvious/big ones]]]

So it provides direct evidence of, and confirms a ton of fundamental things we'd mostly been assuming from indirect evidence, about the nature of the universe...from almost instant 1 up to now. [and gives a bunch of info about where/how to look for the things we don't know yet.]

[Zarathustra]

WF brought it up originally, and posted this quote:

Detection of primordial gravitational waves announced

It's now clear that we've detected the first direct evidence of the inflationary phase of the Big Bang, in which the Universe expanded rapidly in size. [...] Primordial gravitational waves remain one of the outstanding untested hypotheses of inflation, the most popular model that explains the incredible uniformity of the CMB. According to inflationary theory, the Universe expanded very rapidly in the first fraction of a second, filling the cosmos with gravitational ripples. While inflation so far seems to explain a lot about the Universe, we have no direct evidence for it.

The link is on page 1 of the expanding universe thread.

[peter]

Thanks Z. [My apologies (yet again!) Wayfriend ]

Ahh..... now for some reason I had got it chalked up that inflation was a done deal [or at least as much so as anything ever is in this feild]. I had assumed [clearly wrongly] that the 'red-shift' associated with galaxies was only explainable by 'inflation theory' and that from the time of Hubble onwards it had been the accepted model upon which the rest of cosmological theory was based [the 'paradigm' if you like]. This is always the problem with 'popular science'; you get a watered down, simplified version of everything and then fail to grasp the significance of true breakthroughs when they occur.

[Vraith]

that the 'red-shift' associated with galaxies was only explainable by 'inflation theory' and that from the time of Hubble onwards it had been the accepted model

ummm, I think you're still maybe mixing concepts? Expansion has been fairly accepted and around since Hubble. [though it's been altered and refined in that time].
But inflation is something else. The first well-developed form of it was I think in the 70's or 80's.
They may, or may not, be related to each other...but seem to be fundamentally different.
There is at least one proposed way to make them the same [or at least closely related]...but it means making gravity even weirder, and LESS reconcilable than it is NOW. [AFAIK, no one has actually done even rough mathematical description of what it might be like].

Funny thing [at least to me] is that Inflation solves a bunch of problems in our understanding...but it also CAUSES some serious problems. So, kinda like Democracy is the worst, except all the others...
[[It also appears to be a follower of early Wittgenstein...since there SEEM to be a number of things about which it remains silent.]]

[Hashi Lebwohl]

The most pressing question it asks is this: expanding into what?

That question is followed closely by the following:
if it is expanding then is there an actual edge or boundary to the universe?
would it be possible to go past that boundary?

[wayfriend]

would it be possible to go past that boundary?

(This is where I say: Human beings are fundamentally incapable of understanding 'nothing'.)

[Hashi Lebwohl]

I know exactly what you mean. Trying to understand "Nothing" is one of the meditative goals of certain schools of Zen. Far too much of the time the best we can do is imagine "nothing" as "the absence of anything and everything" but even that is insufficient to grasp the concept of "nothing".

[peter]

Atheism often founders on the same inability I think.

V. - That has pulled the rug fully out from under my already 'wobbly' understanding of these concepts. Alright - 'expansion' I understand as the fact that all galaxies are accelerating [?] away from each other and is the explanation that Hubble and others came up with to explain the 'red shift' universally seen when looking at galaxies no matter where they occur in the night sky the world over.

Inflation theory I understood to explain this 'expansion' by suggesting that rather than the galaxies actually flying appart in an already infinite amount of space [ie the same kind of motion that we do in our car down the road, but out in space itself], what we were observing [in red-shift] was the actual expansion of the space between galaxies itself [as per the rubber of a ballon surface as the dots move appart when it is inflated]. In this model rather than have an Universe that is aleady at it's infinite size [with galaxies moving apart within it] we have a Universe that [is alrady at it's infinite size but] is increasing in 'size' as the space within it epands.

How does this sound - am I close to getting the relationship between inflation and expansion right or am I adrift somewhere?

[Vraith]

How does this sound - am I close to getting the relationship between inflation and expansion right or am I adrift somewhere?

Heh...we're way past anything I come close to understanding. [I don't think ANYONE fully understands it...but lots of folk are much closer than me]

Both involve the space itself growing.
But: Inflation started, then stopped.
During that tiny span, the growth was
roughly 1,00000000000000000000000000000000000000000000000000000 times faster than current "normal" expansion. [Inflation was not only faster than light, but unimaginably, ludicrously, faster than light].

Now [I'm just summarizing things, I have no deep understanding] the cause of that, a thing that shows up in the math, is that when the Unified forces in the "original" universe/state "break" into their different forms as they are now, fields are created that "push".
But, once the breaking/separation is accomplished, the fields end, the push stops. [[the Strong Nuke is mentioned most in connection with this...I don't know if that's cuz it matters more than others or some other reason]].

THEN space expands in the "normal" way, sorta "coasting" after that initial push, at something resembling comprehensible speeds.
Hubble-related, it was thought we were just still basically in the blast, but eventually gravity would win.
NOW though, the accelerating [instead of expected diminishing] expansion rate indicates that something is still pushing.
Apparently, it can't be the identical/continuing fields that caused the initial inflation...but it has to be something.

And a lot of people suspect [or maybe hope...hee hee..."for simplicities sake"] the two things are RELATED, even if not identical [[cuz who wants two, or god knows how many completely different forces that cause space itself accelerated expansion?

And while we're there...apparently there is some evidence that whatever the current force is it can get stronger, or weaker, or even change phase/polarity and start pulling.]]


On the "can't understand nothing," my current view is that we can directly and completely understand it. We just can't "be" it fully while meditating or whatever, or describe it...nothing is not describable in relation to something, not even words. I say this because I recently was knocked out for a procedure...the first time I've ever had anesthesia like that. I recall the Nurse saying "any second now." I recall opening my eyes, and the nurse was explaining to my wife what I would need in the next few hours. In between was nothing. I know what "nothing" is like, and I suspect most people do if they think about it.
I suspect folk don't LIKE nothing, don't WANT nothing, don't BELIEVE nothing can be what really is...
....is because they understand it too damn well.

[Zarathustra]

Atheism often founders on the same inability I think.

How so? Something isn't real merely because we can't imagine its nonexistence. (Sounds like the logical fallacies that plague the ontological argument for god's existence.) I think the inability to understand/imagine/conceive of "nothing" (or the idea of something coming from it) is what drives many theists to posit the most extreme existential claim one can possibly make, completely without evidence. In other words, the belief in god is one particular a manifestation of humans' inability to grasp nothingness, namely those humans who are inclined to view their ignorance or lack of comprehension as a legitimate basis for positing existence. It reduces down to a "placeholder" belief as a substitute for understanding.

But this is the basis of all superstition, the inability to imagine a natural explanation. Atheism doesn't founder on any of those lessor superstitions, so why should it founder in this one? In their turn, each one has surrendered to a natural explanation, and our ability to understand what was previously inconceivable expands.

Humans can't really conceive or grasp an 11 dimensional universe, either, but this doesn't imply a corresponding religious belief, nor repudiate nonreligious attempt to describe it (i.e. mathematics).

[peter]

I don't know how old you are Z., but for my generation [and social class] you pretty much either believed in 'God' or didn't believe in [the same] 'God'; the problem was to divest yourself of the concept of 'God' at all. It was so 'root and branch' imbued into you from day one that no matter what form your unbelief took, it was always of the form that your belief would have been had belief been the case for you. {Sorry I can't do a better job explaining this} You could never frame your atheism other than in terms of a negative of the theism it was opposit to. This I think is maybe what Wayfriend was meaning in his comment about never being able to understand nothing. [Like say a person who has gone blind will never be the same 'blind' as the man who was born without eyes.]

(nb. The reason I said about your age Z. is I think that todays [or perhaps] the last generation may indeed be the first generation for [?] millenia[?] to escape this paradox. For the first time some of them will be raised in families that are not only not christian [or whatever] but are also not conciously atheistic either. ie For the first time they actually grow up barely being aware that a thing called religion even exists. It impinges not on them and they give it no thought - now they are the true understanders of atheism. As a matter of interest on the opposit side of the coin, when I was in India first [20 odd years ago] perhaps, I was talking to one indian guy about religion in his country and he said that it just would not be possible, be possible at all, to grow up in that country and not be a follwer and practicioner of a faith on a daily basis. No indian would understand the idea of a life without it.)

[Zarathustra]

I was raised Christian, and my atheism is definitely a reaction against that. But it's no more derivative or dependent upon theism than heliocentricity is a reaction to or dependent upon earth-based models of the solar system. It's a correction. A paradigm shift. An enlightenment.

A Copernican Revolution of the soul. (If there were souls. )