Physics

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Originally posted by raider1v1
until it starts to contract and then it gets fun

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Hey raider, did you read about the new theory that was proposed about, oh, a month or so ago? Some scientists have presented a model where the universe oscillates... it expands in a "big bang", and then goes on expanding some more and then it begins to contract and will finally collapse into a dense mass (probably something like a HUGE black hole) and then it will have a big bang again and collapse again. They think it might be an infinite cycle of expansion and collapses.

So if and when it starts to contract, we'll all just cease to exist. Not a very nice thought going into a Memorial day weekend, is it? :p

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Originally posted by bluesfusion


Hey raider, did you read about the new theory that was proposed about, oh, a month or so ago? Some scientists have presented a model where the universe oscillates... it expands in a "big bang", and then goes on expanding some more and then it begins to contract and will finally collapse into a dense mass (probably something like a HUGE black hole) and then it will have a big bang again and collapse again. They think it might be an infinite cycle of expansion and collapses.

So if and when it starts to contract, we'll all just cease to exist. Not a very nice thought going into a Memorial day weekend, is it? :p

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I'm not sure if that's a "new" theory.. I remember hearing something like that in 6th-grade Science class. ;)

Not like it matters to us, though. If the human race isn't extinct by then, our technology will be so incredibly advanced that nothing the universe does will affect us.

You wanna explain to me how our technological advances will prevent us from being destroyed by the unimaginable forces of the entire universe contracting into something smaller than the tip of my finger?

btw, any of you hear about the M-theory? It says that the universe as we know it is a gigantic membrane floating in a fifth dimension, and there there may be at least 10 dimensions, not just the 4 that we know of. It explains how the Big Bang happened(our membrane collided with another membrane, which caused a huge explosion)...something that other theories dont do.

He's right the sun will burn out before the universe collapses. But if we are alive to see that we will surely have survived numerous alien invasions and other catostrophic events, bascially making Earth invincable because there will technology you can't even imagine.

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Originally posted by bluesfusion


Einstein did not. And he regretted it later. :)

When he formulated his theory of relativity, (and this is information from other peoples analysis. I don't know much about this personally.) Where was I? Ah, when Einstein formulated his theory of relativity, one of the implications was that the universe was constantly either expanding or contracting and he thought it to be such a ridiculous proposition that he introduced a factor which fudged the equations so that they said the universe was constant and stationary.

Years later it was proved that the universe is constantly expanding and Einstein said he regretted putting in that fudge factor in there. The currently accpeted theory is that the universe is constantly expanding, so presumably there is no end to the universe because as soon as you got to what you think is the end, it'd have expanded and you wouldn't be at the end... ever. :p

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Einstein’s cosmological constant has made something of a comeback in the last few years. In 1999 a survey of distant supernovas came up with the somewhat interesting result that not only is the expansion of the universe not slowing down as previously thought. In fact the expansion is actually accelerating.

To account for this you need to add something that is mathematically the same as the cosmological constant. The physical explanation is something they are calling “Dark Energy”. From my understanding, dark energy comes from the tendency of empty space to repel mater and energy. This means that “empty” areas will inevitably grow like bubbles. In the “populated” regions of space it is opposed by gravity, but as distances increase dark energy begins to dominate.

The end result is a universe that is expanding in the same way rising bread expands. The bubbles inside grow forcing everything else apart. If this theory is correct, not only will the universe never collapse on itself, it will continue to expand more and more quickly.

Yes, but what is the universe expanding into. ;)

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Originally posted by slavik
by "end" I mean when you get to the edge of the universe.

What do you think would happen to a thing that tried to go "out" of the universe?

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The universe is surronded by a large bubble...It won't let you in or out. Just IMO.

From what I understand:

There is a cosmolgical constant which is given the symble omega. If omega is less than 1, the universe will contract. If omega is greater than 1 the universe will expand forever. From our observations, omega appears to be very close to 1.

If you were able to somehow go fast enough to leave our universe, you would have no laws of physics, since the laws of physics were created when our universe exploded fromt the big bang

Of cousre, there is a new theory which is mathematically based on M-theory. It says that parrallel branes are bouncing off each other and cause our universe to exist. This theory would get rid of the troubling "singularity" because in this theory, there would never be a beginning and time would be infinite. The universe would be created from it's own ashes.

you put a quarter in the juke box & you get to hear jim morrison singing 'break on thru to the other side'

http://www.cosmiverse.com/space01170204.html

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Originally posted by DuronFanatic


The universe is surronded by a large bubble...It won't let you in or out. Just IMO.

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What's on the other side of the bubble? Just...nothing?

According to Stephen Hawking, the universe has no boundary but is finite. Thats a difficult concept to think of in 3 dimentions, but in two its like the surface of the earth (or a balloon). Walk in any direction on earth and you will eventually end up right back where you started. An expandind universe can be seen like an expanding balloon (which is what we see).

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Originally posted by CadetLee


What's on the other side of the bubble? Just...nothing?

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Dont think of it as just a bubble. Think of our universe as a warped piece of space-time. If you travel in a straight direction long enough, strange things will happen (ie. either you'll arrive where you started, you'll cease to exist, time will not pass for you, or time will pass infinitely fast for you, etc...) Since space-time becomes too warped before you reach the edge of the universe, there isn't a physical and definate edge you could approach. However, the universe does have a boundary which would explain why its expanding.

However, I never took any advanced physics courses. This theory just makes the most sense to me.

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Originally posted by hu flung dung


Dont think of it as just a bubble. Think of our universe as a warped piece of space-time. If you travel in a straight direction long enough, strange things will happen (ie. either you'll arrive where you started, you'll cease to exist, time will not pass for you, or time will pass infinitely fast for you, etc...) Since space-time becomes too warped before you reach the edge of the universe, there isn't a physical and definate edge you could approach. However, the universe does have a boundary which would explain why its expanding.

However, I never took any advanced physics courses. This theory just makes the most sense to me.

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:confused:

This is getting a bit too complex for me...

Has anybody actually managed to do some experiments with space-time stuff, or is this all hypothetical mathematical calculations?
This is strange..but if everything starts distorting, what if logic/math itself distorts, so 2 + 2 != 4?

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Originally posted by hu flung dung


Dont think of it as just a bubble. Think of our universe as a warped piece of space-time. If you travel in a straight direction long enough, strange things will happen (ie. either you'll arrive where you started, you'll cease to exist, time will not pass for you, or time will pass infinitely fast for you, etc...) Since space-time becomes too warped before you reach the edge of the universe, there isn't a physical and definate edge you could approach. However, the universe does have a boundary which would explain why its expanding.

However, I never took any advanced physics courses. This theory just makes the most sense to me.

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Hmmmn this space-time bending made me cough up this 5 minute theory (real-time theorie took 27 seconds or there-abouts):

What if there was this giant, infinite if you will, "piece" of warped space time, and what we experience the universe to be, is the unwarped part, and the expansion of the universe is actually the "unwarping of the warped", but as stated, neither we, nor anything that has been "unwarped" (or warped if you're on the other side, but I'll not get into that) can get to/from that other side (imcompatible states of warpedness, let's call it that), so we cannot perceive what is beyond the universe, allthough is much there to be found, being not in the state we're in.

(I hope I made myself clear :D)

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Originally posted by CadetLee
This is strange..but if everything starts distorting, what if logic/math itself distorts, so 2 + 2 != 4?

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lol. Reminds me of one of my homegrown theories back in my undergrad days. I was convinced that our numbering system is not natural. I think I was contemplating the nature of fundamental constants like Plank's constant - which appears everywhere and in the most unexpected places. My theory was that the "natural" numbering system of the universe would be such that all the fundamental constants would be integers and what we call '1' now would probably be some strange large number. Considering that most of the fundamental constants are rounded to 9 significant units, in my imagined natural numbering system, 2+2 would most certainly be a little off from 4. :rolleyes:

(Well, I was a little whacky then. So shoot me.) :p