Is this universe infinite?

nutball said:
This result really should be treated with scepticism. It relies heavily on standard candles, which is always an assumption at best. It's not clear to me that our understanding of the mechanisms underlying Type 1a supernovae is yet sufficiently robust that we need to overturn our entire understanding of physics on the basis on the apparent evidence.

Put simply... our models of Type 1A supernovae are incomplete at best. So when observational evidence comes along which suggests that either a) our models are incorrect at high redshift, or b) that we need to invent some fancy new type of energy which gives mathematicians a hard-on, which should we choose? Dodgy incomplete model, or overturn a century of physics?

But, no, negative energy is much more "stimulating". It seems that Occam has moved into disposables these days.

:LOL: Yeah, let's create the 5th interaction because after postulating field number 5 we can in fact quantize it. Even I, as a theoretical physicist, find it funny when the qfts (quantum field terrorists; incld. string theory) jump to even more exotic models without conclusive evidence. The central problem with those theories is that they've yet to produce a measurable effect.
 
OpenGL guy said:
Except the universe is expanding. In fact, the expansion seems to be accelerating.

My gut feeling used to be that the universe went through perpetual big bangs and collapses, but recent evidence seems to rule out that idea.

Well if the universe is spatially finite, which it might be(Maybe, who knows), expanding or not,
you could travel in a straight line and wind up back where you started eventually, kinda like travelling the outside of a sphere.
 
Cartoon Corpse said:
the universe is infinite (as i 'see' it). the stuff contained in the blast area of the big bang is not the universe, but a part of it. what contains it...even if nothing is part of the universe and MUST be infinite.

This reminds me of when I asked my physics prof who was a theoretical physicist, what was outside the cone of time he drew when describing, well time i think. He just kinda looked at me like a person might a dog. I guess to talk about anything outside of the universe is well missing the point or something, because there isn't any such area. No time, no nothing.
 
mondoterrifico said:
This reminds me of when I asked my physics prof who was a theoretical physicist, what was outside the cone of time he drew when describing, well time i think. He just kinda looked at me like a person might a dog. I guess to talk about anything outside of the universe is well missing the point or something, because there isn't any such area. No time, no nothing.

I have my suspicions that it's actually full of meringue. Physicists want it all for themselves.
 
If I could start college all over again I would have taken astrophysics as my major, but in the Spring I took a class with Greg Laughlin who heads up the Planetary Search here at UCSC and the class was about the "Future of the Universe."

It started out slow as he laid it out in his book "Five Ages of the Universe" but as it began to pick up he gave us a few ideas on where the universe is headed and his take on it.

Pretty much I'm convinced that our universe will expand forever and at some point, the Dengereate Ear, followed by the Black Hole Era, and finally the Dark Era, it will get cold and desolate that even if we managed to survive that long as a species until then, it would pretty much suck since all the galaxies would have faded away because there's no more hydrogen and everything so far away that not even the most powerful telescopes can see them.

He also brought up somehting about how the force of gravity which holds galaxies together keeps a check on the expanding space. He mentioned that the more empty space there is that is devoid of mass, the the more it fuels the expansion of of the universe, thus explaining why the expansion of the universe is accelerating.

So pretty much we're living in the most prime life of the universe, there's still plenty of hydrogen, galaxies are far enough away we can see them, and some atronomical circumstances helped our species adavnced. For example, the moon is now at the right distance that allows us to have solar eclipses that let us observe the sun's corona, if the moon was closer or farther then astronomers couldn't have observed the sun's coronoa and discovered helium.

I can't wait for the many new discoveries coming out of those observatories and even the particle accelerators at FermiLabs and CERN in Switzerland. I met a grad student who's studying quantum mechanics and astrophysics and he's on a team that's working on a design for a different kind of particle accelerator to be funded by Congress someday.

The substructure of the universe regresses infinitely towards smaller and smaller components. Behind atoms we find electrons, and behind electrons quarks. Each layer unraveled reveals new secrets, but also new mysteries.
-Academician Prokhor Zakharov
"For I Have Tasted The Fruit"
 
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I vote for Sims game gone on too long. Any minute some kid will turn his computer off and the lights will go out for us all.
 
OpenGL guy said:
One problem with your idea about things on the far sides of the universe attracting each other is that it's impossible ;) Imagine our universe was the surface of a balloon. Draw two points on the balloon and inflate it. The points only get further apart, never closer. Also notice that the center of the "universe" is not on the balloon, but inside it. Our universe may be similar, but a 3 (or n) dimensional sphere as opposed to the balloon's 2 dimensions (we neglect the thickness of the balloon). Hopefully our universe never "pops" like a balloon does if you over-inflate it! :D

Then you're assuming that outer radius of matter originating from big bang is the "end" of the universe. That's not how I see it. In fact, that's hardly any different from the view that the universe is infinite. IMO, space and where matter exist are two completely unrelated things.
The ballon is a good illustration of a 2D surface in 3D space, where my view of the universe is a 3D ballon in 4D space. The ballon is fully inflated and always was. It neither expands or contracts. Now place big bang on the surface (not in the center in 4D space). Matter flows in all directions from the explosion. After going across 1/4 of the ballon, objects will get closer to each other again, but on the other side of the ballon.
 
Humus said:
The ballon is a good illustration of a 2D surface in 3D space, where my view of the universe is a 3D ballon in 4D space. The ballon is fully inflated and always was. It neither expands or contracts. Now place big bang on the surface (not in the center in 4D space). Matter flows in all directions from the explosion. After going across 1/4 of the ballon, objects will get closer to each other again, but on the other side of the ballon.
That's a flawed notion because your model is not how the BB theory explains the redshift seen in galaxies - that's caused by space itself expanding, ie. the rubber fabric of the balloon is stretching. The measured redshifts of distant quasars is not be caused by relative motion (which is what you are implying with your steady state balloon idea) or more importantly, it can't be, as one can get "recession velocities" exceeding c.
 
Alright, so let's say the ballon expands. Matter can still travel around over to the other side and get closer to each other again.
 
To do so, the motion of the matter would have to exceed the expansion rate of the balloon; AFAIK there's no evidence of this in the observable universe.
 
Deepak said:
What is beyond this universe? Another universe? There has to be something. Will we ever find out?

I guess we won't know that until we find the edge of it. Only by finding the edge can we ever know if it is infinite or not......
 
Since everything else inside the universe is finite, I'm going to assume the universe itself follows the same ideas and is finite too. My theory is that outside the universe there is absolutely nothing, a wall through which nothing can move. Stars bounce off the edge. They leave stains which are the distance 'quasars' we can see, this bouncing produces quite a bit of radiation and stuff.

Also, the moon is made of cheese.
 
Am i the only one that feels that maybe there are some things that we will just never understand?

I mean, thinking in perspective, we have come a long way, we're meaningless tiny little specks in the Universe and still we've opened our eyes and "looked" at things that are immensely far from us, immensely bigger and more powerful than us, and made theories, explained what is going on out there.

But maybe out reach will be limited by technology, by our own life expectancy (as a species). Maybe we as humans will end our existance without knowing most of what goes on around us. Even today, the best we can do for many phenomena is make up theories that "best describe" how they work.

I think Religion, Phylosophy and Science will one day go back to being very close, like they were not too long ago.
 
london-boy said:
Am i the only one that feels that maybe there are some things that we will just never understand?
"Some people think that if the universe is ever completely understood, it will change into something ever more inexplicable. Others think this has already happened." - Douglas Adams

(Sorry for the lousy paraphrasing from memory.)
 
EasyRaider said:
By definition, there cannot exist anything outside the universe. I suppose there could be multiple universes though, in which case the whole cosmos might better be termed the multiverse.

which would make it infinite since nothing containing something, in this case would be something.
 
Humus said:
Alright, so let's say the ballon expands. Matter can still travel around over to the other side and get closer to each other again.


where is the balloon? contained in what space? contained by what limit?
 
london-boy said:
Am i the only one that feels that maybe there are some things that we will just never understand?

I mean, thinking in perspective, we have come a long way, we're meaningless tiny little specks in the Universe and still we've opened our eyes and "looked" at things that are immensely far from us, immensely bigger and more powerful than us, and made theories, explained what is going on out there.

But maybe out reach will be limited by technology, by our own life expectancy (as a species). Maybe we as humans will end our existance without knowing most of what goes on around us. Even today, the best we can do for many phenomena is make up theories that "best describe" how they work.

I think Religion, Phylosophy and Science will one day go back to being very close, like they were not too long ago.


if you add up everything everybody nows or will know, it doesn't come to 1 millionth or 1 percent of what there is to know. there is an infinite number of mathematical equations for instance.
 
Cartoon Corpse said:
where is the balloon? contained in what space? contained by what limit?
The balloon in my analogy is space. There is no inside or outside. The whole universe is the surface of the balloon. Read "Flatland" for an interesting take on space and perception.

Obviously, our universe is much higher dimensional than the two dimensional surface of a balloon and our universe may not even be an n-dimensional sphere (could be a torus, who knows?). I merely proposed this as a model that can easily be visualized.
 
Neeyik said:
To do so, the motion of the matter would have to exceed the expansion rate of the balloon; AFAIK there's no evidence of this in the observable universe.

Is there evidence of the opposite?
 
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