it gets you thinking..... is there a end to the universe? does it loop like a doughnut shap theory?, whats outside the universe if anything..... is it possible the universe cannot end?
are their differnt dimentions? parrale worlds....
Oh! will man ever discover the facts of the universe!


what do you think?!

PS: please, Do Not Bring Religion Into This!

We could reach other Universe,that is at other Dimension with the help of Artificial Blackholes Vehicles etc.I dont know whats the end of the Universe.I heard that Universe is Flat.And Flat is just a part of a Circle...so possibilities are Infinite...



bye!

I think that you've gotta breach our dimension somehow, because if you just fly around in a rocket ship you'll go around in circles no matter how far you fly.

if youd go in circles, then the universe would be a bubble, so its plausable that theres something outside this "bubble"?? but what if anything?

Yes, but it's safe to say that anything beyond four dimensions is somewhat beyond our comprehension. We're in the shape of a bubble, but only the outside skin of the bubble itself.

From apolo
Reply to" A CANADIAN" My short answer is no.
Personaly I tend to agree with Fred Hoyle, G. Burbidgr, V.Narlikar,
Halten Arp and others, that the universe is infinite in both time and
dimention. In other words it was never created and it will never die.
It is infinitely large. All the things we observe including the 2.73
degree background radiation can be explaned if we start with the asumtion of an infinite universe instead of a Big Bang.
As a bonus we avoid those nasty question; What came before the B.B.
and What caused it.:)

I kinda always thought the universe was like one of the old ATARI games where if you went all the way to the right end of the screen you would just pop right back up on the left. :D

Thats the only thing I can think of happening. Personaly i dont think the universe has an end. It doesnt have a begining so how can it have an end?

If you think about it, this galaxy could just be an atom on some guys head!

But thats out of the box thinkin.....:p

Originally posted by sly1
If you think about it, this galaxy could just be an atom on some guys head!

But thats out of the box thinkin.....:p



stop stealing my ideas! :D

When I think about this kind of stuff, I start screaming. Its too amazing.

If there was no source of light, would the universe exist?

Whatif we are just making up the universe as we go along. ;)
Or what if the universe is making us up as it goes along.?

Let's say the "end of the universe" is 15 billion light years from here. (For the sake of argument. If any of you has the correct figure, feel free to plug it in.) Let's also say we have spacecraft that can travel close enough to the speed of light that the difference is not large enough to affect the answer to this question.

Therefore, it will take a human spacecraft 15 billion years to reach the end of the universe -- whoops, the place where the universe ends today, which will be 15 billion years in the past for the crew of the ship.

How much would the universe have grown during that time? The matter could not be expanding as fast as our ship can travel so we might eventually run off the edge of the mappable universe into the empty space beyond, but that space will still be full of light rays and other EM radiation traveling at the speed of light from the bodies inside the populated universe.

No matter how far we go, the light from the universe is still ahead of us.

First the universe can not be infinite...
infinite # of stars=infinite amount of light=always daytime
You have the same problem if you say "we can not reach the end because we'd go in a loop". If you go in a loop then light would too, which would cause the same problem.

some theories predict the the universe is finely tuned so that it will expand forever...( therefore infinite space)...

if it is closed then it will be finite ( and slowly contract to a big crunch)

if it is open then it will still expand forever....

infinite # of stars=infinite amount of light=always daytime
Its reffereing to a universe which is full... where you can go how every far you want, and there are always stars infront and behind you.

Its a simplification of Carl Sagan's idea... but basically:
Stars give off light
Light travels forever until absorbed
Every direction you look there will be a star... because the number of stars are infinite
Every direction will have the light of a star

This does not say that space is finite, but that FILLED space is finite

"Stars give off light
Light travels forever until absorbed
Every direction you look there will be a star... because the number of stars are infinite
Every direction will have the light of a star

This does not say that space is finite, but that FILLED space is finite"


-hmmm. i like that.
my bet is that the universe is some kids science experiment. we're all in a sphere on some kids lab table. wouldn't that be great:D

It's great until that kid sneezes:)

But my question is... then where did the kid's universe come from;)

But my question is... then where did the kid's universe come from

you just blew my mind!!!
:D

Here (http://www-cfa.harvard.edu/seuforum/explore/bigbang/L3/infinite.htm) is a link to some info saying the universe might be similar to a hypersphere. This object has no boundries, sounds promising.

Thanks for the link Tallguy.

I've also seen theories that the universe expands as mass does, so the instant you go to the end of the universe, the boundary goes out further. In essence this is the same as having an infinite universe with finite mass... because there is no way to tell the difference.

It seems to me, as you get further toward the "edge" of the universe, there would be less and less light. Like stars, and other celestial bodies would not have had a chance to be formed. Sounds kinda creepy to me.

Originally posted by Fraggle Rocker
Let's say the "end of the universe" is 15 billion light years from here. (For the sake of argument. If any of you has the correct figure, feel free to plug it in.) Let's also say we have spacecraft that can travel close enough to the speed of light that the difference is not large enough to affect the answer to this question.....

Even if the universe were to stop expanding and become static somehow, there would still be no edge or center. Just as there is no edge to the surface of the earth, there is no end of the universe.

Just as there is no edge to the surface of the earth, there is no end of the universe. So eventually while travelling in one direction you end up at the same place? See the infinite light paradox above.

If the universe is finite, then yes you would. This does not create a paradox, since the speed of light is finite and so is the age of the universe.

Reply to pesol

An infinite number of stars does not mean light all over the sky because obviously most of them are too far away from us to see them.
I thought that old conundrum had been solved years ago by someone much more famous than me.
Here is an experiment you can do. Take a look at a picture of the sky taken by one of the giant telescopes (in a book or the internet) and you will see a multitude of bright stars and galaxies,some of them even fairly close together.
Now let us assume that picture was takin of that portion of the sky that lies betveen the 2 stars marking the shoulders of orion.
Then you go outside and look at orion, you will see no stars between the 2 shoulder stars. Where has all the stars gone? They are obviously too far away and too faint to be seen with the naked eye.

Regards M.J.

most of them are too far away from us to see them. but a small fraction of that light gets to us from each star... just not enough to see... if you have an infinite number of stars every direction will have an infinite number of stars. Add up all the light from all the stars and you'd have visible light.

I know this is not the case.... which is why I think that there is a finite amount of filled space.

the speed of light is finite

Just curious, I've heard the speed of light in Miles per Hour Is approx. 640,000,000 MPH; Is that right?

Fraggle Rocker,

Yes, the analogy of the 2D surface of the earth has it's shortcomings. The universe would be the 3D equivalent of a curved surface, which we cannot imagine since we only see things in 3 dimensions. Such a closed universe is a prediction of general relativity for finite universes. For some reason, a normal sphere (or non hyperbolic) shape is not even an option.

The speed is 186,000 miles per second, so yeah you're close.

Originally posted by Persol
First the universe can not be infinite...
infinite # of stars=infinite amount of light=always daytime
You have the same problem if you say "we can not reach the end because we'd go in a loop". If you go in a loop then light would too, which would cause the same problem.




#1 star are spread out so there "space" inbetween them (thus the darkness)
#2 its possible that the universe is so big that even somes stars light havnt even reached earths view yet, or mabey a big planet is blocking them


BTW ever hear of blinking stars, when a planet covers the star with its orbit and viewing them from earth it looks like they are winking at you :D



but still if we are in a loop in the universe, like there being no edge of the earth, then that means there has to be something outside of it....

mabey we live in a multiverse!

It's a lot cooler in metric: 3*10^8 m/sec

Originally posted by A Canadian

but still if we are in a loop in the universe, like there being no edge of the earth, then that means there has to be something outside of it....


Logically, there doesn't need to be an outside. Unless someone has a found reason, but isn't sharing it with us.

Originally posted by A Canadian: If we are in a loop in the universe, like there being no edge of the earth, then that means there has to be something outside of it....No. That's the whole thing about using fractals and saying that the universe has 4.2 dimensions. The .2 accounts for the curvature and nothing more. It does NOT imply that there is another whole dimension in which the universe extends to infinity. (The ".2" is certified arm-waving, I have no idea how they "count" partial dimensions. A fractal specialist I am not.)Maybe we live in a multiverse! Hey, wasn't that a great book by James P. Hogan? Or am I thinking of "Entoverse"? One of his finest, and they're all good.

Originally posted by Fraggle Rocker
No. That's the whole thing about using fractals and saying that the universe has 4.2 dimensions. The .2 accounts for the curvature and nothing more. It does NOT imply that there is another whole dimension in which the universe extends to infinity.


No - the surface of a sphere, for example, is exactly 2-D, it's not a fractal. The non-integer part of a fractal's dimension arises because of its 'jaggedness', not its curvature. The surface of the Earth, with its irregularities, could be assigned a fractal dimension but it would be very close to 2.


(The ".2" is certified arm-waving, I have no idea how they "count" partial dimensions.

By measuring the slope of a Richardson plot - basically a graph of, for example, the length of a coastline versus the length of the 'measuring stick' being used.

A fractal specialist I am not.)

I am.

Cheers,

Ron.

#2 its possible that the universe is so big that even somes stars light havnt even reached earths view yet, or mabey a big planet is blocking them The big planet blocking them doesn't work... because even if you block a portion of infinity you are still left with infinity. The speed of light problem is an interesting one which I hadn't thought of. It argues with the big-ban theory though. There's probably other ways around the infinite light problem. BTW ever hear of blinking stars, when a planet covers the star with its orbit and viewing them from earth it looks like they are winking at you I call them satalites:) j/k

I don't know why Olber's paradox is still being discussed. The fact the universe is of finite age, and expanding means we will only ever be able to see a finite amount of starlight. The paradox is thus resolved with the big bang, even in an infinite universe.

Originally posted by Beercules
I don't know why Olber's paradox is still being discussed. The fact the universe is of finite age, and expanding means we will only ever be able to see a finite amount of starlight. The paradox is thus resolved with the big bang, even in an infinite universe. Someone stated that the universe was infinite... which seemed to be discounted by this paradox and the big bang.

>>So eventually while travelling in one direction
>>you end up at the same place?
If the universe is finite, then yes you would. This does not create a paradox, since the speed of light is finite and so is the age of the universe.
My question is, how? If you go in a strait line it seems wrong that you'd end up in the same position. At some point I thought you'd have to hit the end of the universe. Unless the universe is a hypersphere... It seems just as logical that there is an end boundary...

The big bang does not require the universe to be finite, as that is just a popular misconception. See http://www.astro.ucla.edu/~wright/infpoint.html

And under general relatvity, finite universes are hyperspheres, or hyperbolic. But since the light from stars has only been travelling for a finite period of time, you get a dark sky at night.

Originally posted by Beercules
The big bang does not require the universe to be finite, as that is just a popular misconception. See http://www.astro.ucla.edu/~wright/infpoint.html

And under general relatvity, finite universes are hyperspheres, or hyperbolic. But since the light from stars has only been travelling for a finite period of time, you get a dark sky at night. Thank you.... a quote from that site:The Universe was not concentrated into a point at the time of the Big Bang. But the observable Universe was concentrated into a point. Every time I heard the big bang explained, it was the the universe expanded from a point... I guess it is dumbed down for public consumption.
Does this suggest that the universe was not 'viewable' because atmos had not been formed, or atleast not in substaintial quantities to be seen? Then when they did form... about the same time everywhere... the radiation took time to reach us, so the distance we can see =c*time sine radiation?

If this is an over simplification and the error is too tedious to explain just state so so I know to read up:)

you are at the temporal edge of one universe now. And now...

Originally posted by Persol
If this is an over simplification and the error is too tedious to explain just state so so I know to read up:)
By definition we cannot say what is outside our observable universe. It may be either finite or infinite. Either way, the only thing that matters is the observable universe. Any discussion of what's outside it just abject speculation, because it can have no physical consequence.

- Warren

you are at the temporal edge of one universe now. And now...

Smile and shoot yourself in the head because you have seen that there is no God. I cannot express my pure joy at the thought of the edge.

My friend said that when he dies, he wants to be ejected into space because eventually some alien race will find him and regenerate him. Its completely possible, I think, because there would not be any bacteria to decompose him. Although, space dust may cause erosion. Although, think about the possibility of being regenerated in 6 billion years (possibly somewhere beyond our galaxy)!!!!

Originally posted by Persol

Does this suggest that the universe was not 'viewable' because atmos had not been formed, or atleast not in substaintial quantities to be seen? Then when they did form... about the same time everywhere... the radiation took time to reach us, so the distance we can see =c*time sine radiation?


While visible light was not around until 300,000 years after the BB, the same would apply if it had been since the very beginning. Just imagine an infinite universe. Since light travels at a finite speed, and the universe is expanding, there are regions in the universe from we will never be able to see light from. So while we can see only a small part of the whole universe, it is possible that universe as a whole is, and always has been infinite.

Originally posted by Slacker47
My friend said that when he dies, he wants to be ejected into space because eventually some alien race will find him and regenerate him. Its completely possible, I think, because there would not be any bacteria to decompose him. Although, space dust may cause erosion. Although, think about the possibility of being regenerated in 6 billion years (possibly somewhere beyond our galaxy)!!!!


know what! thats a really good idea :D
cept you might loss your genitals to a comet or something!

While visible light was not around until 300,000 years after the BB, the same would apply if it had been since the very beginning. Just imagine an infinite universe. Since light travels at a finite speed, and the universe is expanding, there are regions in the universe from we will never be able to see light from. So while we can see only a small part of the whole universe, it is possible that universe as a whole is, and always has been infinite. Thanks... I'm going through some of the books and links suggested so I can learn a little more about this. There are still problems I see with this, but I'm assuming that they'll be addressed somewhere.

The big bang was invented originally to redress two key problems in cosmology.

1) The horizon problem-- the Universe looks the same in all directions, there is `uniformity` of the background radiation. There has not been enough time since the Big Bang for light/information to travel across the Universe and back. So how do the opposite horizons `know` about each other?

2) The flatness problem-- this is the puzzle that the space-time of the Universe is (probably) flat, the Universe i imagine sits on the dividing line between eternal expansion and eventual re-collapse.

The flatness problem can be looked at using mass. The density parameter is a measure of the amount of gravitational attracting matter in the Universe, (omega ). It is defined in such a way that if space-time is exactly flat then Omega would equal 1. One of the big difficulties in cosmology was the fact that the actual density of the Universe today is very close to this critical. This is extraordinary because as the Universe expands the density parameter should move away from the critical value.

If the Universe starts out with the parameter less than one, omega gets smaller as the Universe gets older, but if it starts out bigger than one , omega gets bigger as the Universe gets older. The weird fact that omega is between 0.1 and 1 today means that in the first second of the Big Bang it was precisely 1 to within 1 part in 10^60! My gut feeling is that it is EXACTLY 1.
BTW another important feature of this is that there is a large amount of dark matter or energy in the Universe. Another is that the Universe was made flat by inflation.
(like the floor in your room is flat, but the earth is round...)

Inflation, in a short period of exponential expansion, caused the very early Universe, to blow-up to the size of what is now. The observable Universe was once a tiny region about the size of a grapefruit. This process would flatten out space-time to make the Universe smooth, and would also resolve the horizon problem.

BTW Another reason why theorists came up with the idea of inflation was to get rid of magnetic monopoles -- particles carrying isolated north or south magnetic fields, predicted by the old Grand Unified Theory (GUTs) but we haven`t seen any!(?) Standard models of inflation solve the "monopole problem" by arguing that the Universe grew from a quantum fluctuation so small that our universe probably just has one monopole.
But forget about that...

The Universe we live in is like a hole in a foamy sea of superdense, exponentially expanding inflationary `cosmic` material, within which there are other holes. All kinds of bubble universes will exist, and it is possible to work out the statistical nature of their properties. But we can never physically contact these other universes.

Because very dense regions blow up exponentially quickly (doubling in size every fraction of a second), it turns out that the volume of all regions of the super-Universe with twice any chosen density is 10^10 million times greater than the volume of the super- Universe with the chosen density.
For any random density, most of the matter at that density is near the middle of an expanding bubble, with a concentration of more dense material round the edge of the bubble.

BTW this exponential expansion can be faster than the speed of c, as it is the `fabric` of space/time that is expanding.

Basically, it may mean that not only could we be living near the middle of a bubble universe, but that the density of the region of space we can see may be less than the critical density, compensated for by extra density beyond our visible horizon.

Observations by the Hubble Space Telescope have suggested that cosmological models, which require exactly the critical density of matter, may be in too low. (Perhaps solved by a double/ two inflationary periods?) .

Of course i assume that the parameter, which measures the rate at which the Universe is expanding, the Hubble Constant, really is a constant, the same everywhere in the observable Universe.
Perhaps the measured value of the "constant" may be different for galaxies at different distances from us. We may seem to live in a low-density universe in which both the measured density and the value of the Hubble Constant will depend on where these properties are measured!

Yes, It is true that about 300,000 years after the Big Bang, the temperature of the Universe had dropped sufficiently for electrons and protons to combine into hydrogen atoms,
p + e --> H.
From this time on-wards, radiation (photons) was effectively unable to interact with the background gas; it has propagated freely ever since, while constantly losing energy because its wavelength is stretched by the expansion of the Universe.
So we CAN look back theoretically back to that piont...

You can switch on your TV and the static you detect is the radiation of the Universe at a very early stage on what is known as the `surface of last scattering'.
Photons are the cosmic microwave background . Unfortunately the beginning of the universe will not be televised.

The visible horizon is really a horizon of information. it is an illusion to those in the center of the sphere.

So if you go past this visible horizon eventually you will see the `edge` of this bubble universe .the transition face to the next bubble/ universe .

And if you go past this expanded foamy universes ultimately you will see nothing, the VOID.

Originally posted by blobrana

And if you go past this expanded foamy universes ultimately you will see nothing, the VOID.

You can't get past this foamy inflationary universe, because if you went far enough you'd end up where you started. Besides, if there is a void, it must have 4 spatial dimensions.

It was a flight of imagination.
By definition this universe is separate from any other universe.
The boundary condition may even lie just outside the visual horizon , but we could never have any knowledge of it as all information is lost beyond OUR visual horizon.

Well if we're talking about inflation, our universe is not seperate from what lies outside our visible region. In fact, what would we would call a universe (perhaps with different laws of physics) is just one region of the universe as whole that....inflated. Kind of makes the term multiverse redundant.

Sry, not putting the idea over clearly,

The universe grew exponentially, lets say 10^50 times. This leave our tiny visual universe in the midst(?) of a vast bubble .
.All the regions that could host our region of local space, excluding any density gradients and boundary phases are essentially the same.

for any observers at the extremities of our visual universe, the properties of space/time would appear the same as our properties of space time.
However,
The radius of each of the observers visual universes would be (say) 15 billion light years...therefore information about regions out side this are `lost` (due to the continual expansion of space/time)

Yes, that's true, but there's still no edge to the whole collection of bubble universes. Hence, no 3D void outside.

Hehe , that was just one senareo...an infinite amount of bubble universes...
But i can also suggest that, perhaps though some sort of Darwinian principle, many/most bubbles universes that were created did not have the correct `properties` and (say) quickly collapsed back again...
perhaps the reason why our universe is so finely tuned is because if it were NOT, then we wouldn`t exist.

Perhaps we ARE the only universe, the Creation of of which may have swamped or excluded the formation of all the other bubble universes...We will never KNOW for sure...

As for `edges` , i can propose that it the boundary condition (4d) of this universe, but who knows if that is the boundary condition of the foamy universe sea senareo...

Beercules, 2-05-03- 8:21 am is right. Olbers Paradox was solved a long
time ago. Unfortunately i forgot the name of the guy who solved it
(he was quite famous for other reasons too) and the solution aplies equally to an expanding finite universe and a steady infinite universe.

M.J.

if you think of the universe as concept, then it would never end, unless of course you can imagine its ending. then it would be finite.

I don't recall the paradox being solved for a static universe, at least not one that had existed forever. There were many attempts at this, such as using interstellar dust to block out the light, but they all failed.

At any point of time , we are (any point in space), at the edge of 4-dimensional Universe.

Well pointed out!

This is the basis of quantum tunneling.