Big Bang Theory or can we drop 'theory' now?

[Moonliner]

From the news (http://www.cnn.com/2006/TECH/space/03/16/cosmic.inflation.ap/index.html)today:

By the faint cosmic glow of the oldest known light, physicists say they have found evidence that the universe grew to astounding proportions in less than the blink of an eye.

Two comments on this..

I guess that sort blows the "nothing is faster than light" theory. Unless light was a lot faster back then....

Also, can you name anything in nature that happens once? Planets, stars, hurricanes, rain, etc?? Why would you think there was only one "big bang"? I'd guess our 'big bang' was just one of an uncountable number of similar events and that our current concept of the 'universe' is really just one little drop in an ocean of "big bangs".

[Ghoulish Delight]

Two answer your two questions:

1) Essentially, yes the speed of light was a lot faster back then. At least, so goes a current viable theory, that the density and extreme temperature of the universe meant the speed of light was faster (i.e., the speed of light in a vacuum is constant for any single state of the universe. At this point, the rate of expansion has slowed enough that the continued variation is imperceptible on a human scale)

2) You've hit upon another common viable theory, that the universe does through periodic expansion and contraction. Some observations seem to suggest that perhaps the current rate of expansion is slowing, signaling that the next contraction is coming "soon" (i.e., several billion years).

[scaeagles]

In a battle of the four fundamentals forces - being electromagnetism, strong nuclear force, weak nuclear force, and gravity - gravity will win every time. May take a while, but it will, and eventually the universe will collapse back upon itself.

[JWBear]

In a battle of the four fundamentals forces - being electromagnetism, strong nuclear force, weak nuclear force, and gravity - gravity will win every time. May take a while, but it will, and eventually the universe will collapse back upon itself.
Dinner at Milliways, anyone?

[Moonliner]

Two answer your two questions:

2) You've hit upon another common viable theory, that the universe does through periodic expansion and contraction. Some observations seem to suggest that perhaps the current rate of expansion is slowing, signaling that the next contraction is coming "soon" (i.e., several billion years).

No, what I am saying is that there are "big bangs" going off all the time all over the place. What we currently see and think of as "The universe" is but one grain of sand to the true universe.

Also, just for the record, current observations show that the rate of expansion is not slowing. It is in fact Accelerating. (http://experts.about.com/q/Astronomy-1360/big-bang-excelleration.htm)

[Moonliner]

In a battle of the four fundamentals forces - being electromagnetism, strong nuclear force, weak nuclear force, and gravity - gravity will win every time. May take a while, but it will, and eventually the universe will collapse back upon itself.

Not necessarily. You are assuming a universe that is essentially coasting. That does not seem to be the case. As I posted above the "universe" has been shown to be accelerating.

[innerSpaceman]

And since "science" comes up with something new every decade (collapsing, accellerating, warbling), let's just assume we will really never know what's going on.

There may in fact be zillions of universes existing all at once, on different planes of existence. Or there may be just one, our own. If just one, what is "beyond" that one universe? For that matter, if there are a zillion, what is beyond the zillion of them?

Unanswerable questions, fun to ponder.


Though it doesn't matter a whit in my daily life, I am unaccountably thrilled to be amoung to first generations of humans to know that we live on the outer arm of the quadrillionth galaxy in the known universe (which may or may not be one of many now existing, or periodically existing due to endless expansion and contraction) - - that the earth beneath us is changing and moving all the time, with continents joining together in mega-gloms and separating again with oceans filling in between - - that humans are the latest blip in eons of different life forms on the planet, constantly evolving, elephants ages after mastodons, birds ages after dinosaurs, dinosaurs ages after each other (Disney was wrong: The Tyronnosaur 'fighting' that stegosaurus are separated by a lava stream of several hundred million years) - - and that all the life on this planet that now lives or ever died has been constructed from the atoms of the stars that lived and died long before our sun burned hot in space.


None of this gets me so much as a cup of coffee, but I love knowing it.





:iSm:

[Gemini Cricket]

I have a horny friend who is 6'8". He calls himself the Big Bang.

:D

[Prudence]

Just remember that you're standing on a planet that's evolving
And revolving at nine hundred miles an hour.
It's orbiting at ninety miles a second, so it's reckoned,
The sun that is the source of all our power.
The sun and you and me, and all the stars that we can see
Are moving at a million miles a day
Through an outer spiral arm at forty thousand miles an hour
Of the galaxy we call the Milky Way.

[Moonliner]

Just remember that you're standing on a planet that's evolving
And revolving at nine hundred miles an hour.
It's orbiting at ninety miles a second, so it's reckoned,
The sun that is the source of all our power.
The sun and you and me, and all the stars that we can see
Are moving at a million miles a day
Through an outer spiral arm at forty thousand miles an hour
Of the galaxy we call the Milky Way.

Don't let NA catch you making a python reference or you'll be turned over to Dimsdale straight away and you without a hedgehog I might add.

[Not Afraid]

Who's Dimsdale?

[scaeagles]

Not necessarily. You are assuming a universe that is essentially coasting. That does not seem to be the case. As I posted above the "universe" has been shown to be accelerating.

Nope. I am assuming a universe that is not accelerating as quickly as it once did. From what I've read, over the next several billion years, the acceleration will continue to slow to a point where it is not accelarating any longer, and gravity will take over, leading to the "big crunch".

[Alex]

Big Crunch or Eternal Expansion have been the question for a couple decades now but the recent evidence is pointing towads Eternal Expansion and figuring out where the energy for that is coming from is a new Big Question.

[Moonliner]

Nope. I am assuming a universe that is not accelerating as quickly as it once did. From what I've read, over the next several billion years, the acceleration will continue to slow to a point where it is not accelarating any longer, and gravity will take over, leading to the "big crunch".

Fair enough, but how about this..

You are also assuming that there are no outside influences acting on what us puny humans think is the universe.

[scaeagles]

Interesting.....I thought new theories about the existance of "dark matter" that provides a large portion of the mass to the universe were contributing to thinking in the other direction. As in more mass = higher energy output to continue the expansion = slower accelaration to the point of stopping and reversing.

But to be honest, I do not consider myself an expert or even well read on the subject.

[scaeagles]

Fair enough, but how about this..

You are also assuming that there are no outside influences acting on what us puny humans think is the universe.

Oh, I agree....I'm not thowing in any of my personal religious beliefs into this whatsoever, as that would certainly take it a bit off topic. Trust me - both in the supernatural realm and in the natural realm there is WAY too much that we have no clue about to make any sort of theory that will last longer than the next important discovery will allow it to. In that way, I agree with ISM wholeheartedly.

[innerSpaceman]

I agree with ISM wholeheartedly.
I'm going to be using this, completely out of context, for the forseeable future. :iSm:

[Alex]

Here's an example (http://www.aip.org/pnu/2004/split/675-1.html) of the recent evidence for an ever expanding universe (not only that but a universe in which the rate of expansion is increasing).

One of the key things to keep in mind is when discussing the expansion and contraction of the universe you are not simply talking about the movement of matter moving away from the center of the universe but of spacetime itself actually expanding (that is, if you took two galaxies side by side and gave them the exact same movement they would still move apart from each other because the spacetime between them is expanding).

When talking about a Big Crunch it is not just that all matter recondenses in the middle of a now very huge empty space but that all space crunches down into a very small volume, outside of which neither space nor time as we understand it exist.

As for the "speed of light" thing Moonliner mentioned, GD is right that in the way we think about it now the speed of light was much higher in the early moments after the big bang. However, "speed of light" as an applicable concept didn't become relevant until after the four forces (electromagnetic, gravity, strong nuclear, weak nuclear) "condensed" out of the cooling universe aftre the Big Bang. At sufficiently high temperatures these forces "evaporate."

And on multiple big bangs it is possible that there are others in our universe but nothing in the "visible" universe supports the idea of multiple expansions in our spacetime. However, the "visible universe" will never be equal to "the entire universe" in an ever expanding universe so it is always possible that there is contrarian (blue-shifted galaxies, for example) evidence in parts of the universe we'll never be able to see.

There are cosmologies that conjecture beyond our universe that involve multiple (and perhaps frequent) Big Bangs creating other universes. For example, one theory has pieces of spacetime being lost through wormholes at sizes near the Planck constant, these wormholes evaporate and then the lost bit of spacetime creates its own Big Bang creating a new universe, but one that is completely separated and unmeasurable from our own.

But this is another topic (like GD's mechanical thinking thread a couple weeks ago) where I quickly get into territory I'm sometimes just happy to understand the questions being asked, even if I don't understand the answers being provided.

[Alex]

And if interested, Brian Greene's The Fabric of the Cosmos: Space, Time, and the Texture of Reality is a mostly accessible lay account of the issues involved. I strongly recommend it for anybody interested in the topic.

Greene is best known for his book on superstring theory (that was turned into a popular PBS show) called The Elegant Universe.



And of course this is all irrelevant if there is a God because any attempt at figuring out how the universe works is pointless since the rules can be changed at any time and may have changed at any time in the past.

[scaeagles]

I always liked A Brief History of Time by Hawking.

[Not Afraid]

.......existance of "dark matter"

Dark Matters laughed and danced and lit the candles one by one. bum bum bum.

Or, how about....

Old dark matters, keep on rollin’
Mississippi moon, won’t you keep on shinin’ on me

I'm easily amused.

[scaeagles]

I'm easily amused.

I guess so.

[Kevy Baby]

Gravity sucks

[CoasterMatt]

What if instead of a 'Big Bang', it was more of a 'Big Handjob'?

(credit that one to George Carlin)

[Alex]

That would be a cosmology in which there was a lot of oscillation prior to a final massive explosion producing the universe we now see?

[sleepyjeff]

In a battle of the four fundamentals forces - being electromagnetism, strong nuclear force, weak nuclear force, and gravity - gravity will win every time. May take a while, but it will, and eventually the universe will collapse back upon itself.

Ok if electormagnetism is your Point Guard and strong nuclear force is your power forward and weak your small; does that make gravity your center or your shooting guard?

:confused: /;)

[Alex]

No, gravity would be the head coach. On the court at any given moment it is an extremely weak influence but casually over time and distance it is the strongest force on the team.

[Alex]

Coincidentally, this video interview (http://meaningoflife.tv/video.php?speaker=gingerich&topic=limitsci) was posted at Slate today and is a bit on topic.

[sleepyjeff]

That was pretty interesting....I feel smaller now than ever before:)

[alphabassettgrrl]

I'm actually reading Brian Greene's book at the moment. Trying to understand it. The biggest thing for me was how things are either very large or very small depending on the factor at which you look. I have to read that bit again to hopefully gain some understanding, but basically you can turn it on its head by calucalations.

Personally, I think "time" is an illusion, that it all overlaps somehow. Something's circular, concerning the creation of this all. I don't know how it works, but that's the starting idea in my head.