Universe Ending (my way of thinking it)

[Universally_thinking]

The universe is functioned by outcomes and paths, everything has a path to choose even our sun.
I was told that if a star exploded it would turn to a black hole or a dwarf. Knowing that a star has a 1 in 2 chance of being a black hole (thats quite dangerous) supposedly saying if all the stars turned into black holes the universe would swallow itself causing the big crunch.



But then, Contantly new stars are being born in nebulas and this couldn`t happen? can it? well it still can we thought what i just said will take an imaginable scale of time but this will take a great immense ridiculously infinate amount of time, what happens is this.

1)
http://i9.tinypic.com/48n7ds6.jpg
2) http://i10.tinypic.com/2gy5amt.jpg

[Nick]

Hmmm... very interesting. Let me see if I understand what you're saying; if every sun turned into a black hole, then everything would eat itself. True, but wouldn't the creation of a sun also lead to a big crunch? Sun's don't give off negative gravity

[Universally_thinking]

i think your rite there... i have to have a think there ( believe it or not i came up with this theory when my aunt was driving me home i`m only 14)

[jinydu]

Knowing that a star has a 1 in 2 chance of being a black hole.

No, the chances are quite a bit smaller than that. The Sun is already more massive than the majority of stars (which are red dwarfs0; and the Sun is not massive enough to form a black hole.

Whether or not a star turns into a black hole is determined by its mass; once a star is sufficiently massive, it will become a black hole. If a star is not massive enough, it will never become a black hole, unless it somehow gains enough matter to become massive enough.

[Nick]

You're missing the point, Jinnydu. The point is that eventually there will be so many black holes that everything will be sucked up.

[batmanmg]

can a black hole gain too much mass?

black holes big crunch... does this theory assume that when a black hole -- the one that will be created when all the black holes combine into one big one -- gains too much mass. it explodes, or does whatever, like the big bang all over again?, or will it remain a black hole forever? also, can the gravitational pull from a black whole trap the wavefunction of a particle?... or any object?

[Nick]

batmanmg made me think...

Black Holes will eventually gain too much mass and explode... so that means that the Universe may not get too many Black Holes at once and implode. Some are being created, some destroyed, so they cancel out. Also, the Universe is constantly growing, therefore the larger it gets the more black holes are required to make it implode.

In addition to this, what do you mean by the "Universe"? If you mean space and time as we know it, then even if we did get enough black holes at one time we would still have a Universe. Black Holes sucks up objects; you know, things that take up space. It doesn't suck in space itself.

( believe it or not i came up with this theory when my aunt was driving me home i`m only 14)

Believe it or not, I just totally debunked your theory while bored watching TV and I'm only 15.

[jinydu]

can a black hole gain too much mass?

black holes big crunch... does this theory assume that when a black hole -- the one that will be created when all the black holes combine into one big one -- gains too much mass. it explodes, or does whatever, like the big bang all over again?, or will it remain a black hole forever? also, can the gravitational pull from a black whole trap the wavefunction of a particle?... or any object?

Have you ever heard of "escape velocity"? An object that is too far from a black hole and moving fast enough relative to the black hole will never fall into the black hole.

[batmanmg]

that assumes that the black hole remains a constant mass... if it gains mass... which it does... and enough mass it will eventualy be powerful enough to suck you in... so that leaves the possibility that you're moving fast enough to escape the pull alltogether... well you're going to have to keep moving in order to keep away from its pull... and chances are,,, in this theoretical end of the universe scenario,,, run into another black hole... you can't avoid all of them forever.

[moonlord]

Last time I checked, black holes didn't explode, they just evaporated in the case they weren't "fed" with enough mass. They shrink in time, as they are incandescent - they radiate electromagnetic waves. So they need to have stuff falling in them to survive.

[batmanmg]

well what if it is fed enough... can it be fed too much? and if it can't then does that mean when the universe is eventualy eaten up by the huge black hole that will likely be created at its center that that will be it... GAME OVER?

[jinydu]

Black holes are extremely compact. Have you heard of the Schwarzschild radius:

http://scienceworld.wolfram.com/physics ... adius.html

The radius of the black hole is equal to its mass multiplied by 2G/c^2, an extremely small quantity. Given the vast distances between stars, the chances of a star getting sucked into a black hole that was initially many light years away is exceedingly small.

By the way, moonlord is talking about Hawking radiation; a theory proposed by Stephen Hawking which claims that black holes radiate away energy through a quantum process. Hawking radiation should be taken with a grain of salt because:

1) It has never been verified experimentally. This is not surprising, given how small the predicted luminosity is.

2) We do not yet have a complete theory of quantum gravity; so we can't be sure how quantum effects work in regions of very large spacetime curvature (i.e. very strong gravity).

[batmanmg]

im assuming that black holes are no exception to the theory/fact (not sure which it is) that the universe is imploding and that everything will eventualy meet at the center... this means that numerous black holes will meet all the other matter in the universe there.. will they suck up everything and then eventualy "burn out" after expelling all this energy? or will something happen after soo much matter is consumed by them/it (assuming they all combine into one big black hole) that will cuase the next big bang?

[jinydu]

No batmanmg, the Universe is currently expanding. In fact, recent evidence suggests that the expansion is in fact accelerating.

[moonlord]

jinydu: Hawking insists his radiation has been observed and measured and it complies with the theory. I agree on the second point.

[PWrong]

well what if it is fed enough... can it be fed too much? and if it can't then does that mean when the universe is eventualy eaten up by the huge black hole that will likely be created at its center that that will be it... GAME OVER?

What center?

[moonlord]

There is no center of the Universe.

[jinydu]

jinydu: Hawking insists his radiation has been observed and measured and it complies with the theory. I agree on the second point.

Hawking radiation has been observed?! Do you have a link?

[moonlord]

Not a link, but somewhere in "Brief History of Time" or "The Universe in a Nutshell" he says it has been observed and the wavelength of the emmision corresponded to a temperature of about 1K or so. Lower than the background microwave radiation. I will look it up.

[batmanmg]

no center? if there is expansion then there has to be a center for the expansion. otherwise its just movement. so theres that. and its accelerating? i thought it was slowing down. ces la vive... ok... i'll ask this then... WTF is the big crunch then? I hear reference after reference to this... and then i hear that the universe is expanding so anything having to do with it colapsing into a single position isn't possible. so if the universe is expanding, and isn't going to implode. what is the big crunch... Is the name ironic or something... cuz i assumed that it meant that everything would slam back into the center.

[houserichichi]

no center? if there is expansion then there has to be a center for the expansion. otherwise its just movement. so theres that.

No there doesn't. Reverse expansion to the beginning - all points in a common place. Now play expansion forward from the beginning...all points that were at the "center" are now dispersed everywhere...every point is the center.

WTF is the big crunch then? I hear reference after reference to this... and then i hear that the universe is expanding so anything having to do with it colapsing into a single position isn't possible. so if the universe is expanding, and isn't going to implode. what is the big crunch... Is the name ironic or something... cuz i assumed that it meant that everything would slam back into the center.

If the mass of everything in the universe is above some critical limit then it will slow down the expansion of the universe and will, in effect, reverse expansion into a compression. If this is the case then the universe will crunch onto itself (the opposite of Big Bang, hence Big Crunch).

[jinydu]

Recent measurements of supernovae indicate that expansion was slower in the past than it is today. Hence, expansion is accelerating, for reasons that are not understood very well.

Here is an explanation about the expansion of the Universe. As you will see, expansion does not require a universal center:

http://map.gsfc.nasa.gov/m_uni/uni_101bbtest1.html

moonlord, I am still interested in hearing about this alleged evidence for Hawking radiation. What I heard was that Hawking radiation was far too small an effect to be detectable in practice.

[Nick]

I understand what you're saying about they're being every point the center, but there is still a center regardless. The universe is finite and spreading equally in every direction, so if we measured the diameter we can definitely find a radius, and therefore find a center.

[houserichichi]

There is no center.

Pretend the universe was a balloon except pretend that the initial balloon was infinitely small. Now, pretend that there was some way to put on thousands of points all over the surface of the infinitely small balloon (or pretend that the balloon was normal size, you drew thousands of points on it with a marker, and then somehow shrunk the balloon to infinitely small for the sake of this experiment). Now, start filling this infinitely small balloon with air. Notice how the points start growing farther and farther apart from eachother? Also notice that there is no center to the points because they all lay on the surface of the balloon (the inside of the balloon isn't part of the dots-on-the-balloon's universe). The analogy transfers to our universe except this time the balloon's surface would be 3D and the inside of the balloon would be 4D.

Notice I used the word analogy. In the case of my balloon example we are watching the expansion of the universe from the "outside" whereas in the real case we are actually "inside" the expansion so we really don't need to have an "inside of the balloon" because the math works fine without it. The fact remains, however, that all points are expanding relative to eachother.

A bit of googling reveals this little gem of a page that duplicates this argument.



If you are standing a billion light years away from me and stare out at space you're going to see every point expanding away from you. I, here on Earth, view the same thing. This is because the universe is homogeneous. If all points are expanding away the same from two points that are separated by billions of light years they can't both be centers of the universe, can they?

[batmanmg]

ummm no it means neither of them are. and quit possibly there is no physcal point in our space that is the center. but a center an expansion still makes.

you talked about the baloon. well that balloon has a center, regardless of what you say. it may not be a point in the physical universe, but its still there. if you make the radius of the baloon = 0 it becomes a point.. that point is in fact the centere.

either way. if you reverse this expansion. That means that everything is getting closer to eachothere. well there has to be a point in time during this unexpansion that all the objects, get close enough to eachother that everything is touching. the points on the balloon aren't points they are stars and rock. and planets. and im assuming that the matter isn't expanding along with the universe? or is it. either way. the distance between all the objects will get close enough that if there are several black holes. everthing well get sucked up into them. and each of them will get close enough to eachother that they will get sucked up into eachother. that leaves one really big black hole.. maybe not at the physical center of the universe. but its the only thing left in it.

[houserichichi]

ummm no it means neither of them are. and quite possibly there is no physcal point in our space that is the center. but a center an expansion still makes.

Yes, it means that neither of them are. And if you apply the same argument to any combination of points in the universe the same argument will always hold. Thus, there is no center of the universe. I don't think I see what you mean by "center of expansion" and "center of the universe"...to me, if the universe is expanding then the center of the universe would be the center of expansion, no? Applying Occam we don't exist in a higher-dimensional hyperspace, so then the center of expansion would then necessarily be a point in the universe itself. Since the universe is homogeneous and isotropic there is no center contained in it and thus no center of expansion.

Is your definition different than mine?

you talked about the baloon. well that balloon has a center, regardless of what you say. it may not be a point in the physical universe, but its still there. if you make the radius of the baloon = 0 it becomes a point.. that point is in fact the centere.

If I make the radius of the balloon = 0 then all points are contained at the one single "center"...if I blow up the balloon (just like the universe is expanding) then all the points grow further apart but which of them was the initial "center" point? Turns out that they all were. It's a mathematical certainty...and since "center" implies "singular" then we're dealing with a paradox and we necessarily have to admit that there never was a center to begin with.

and im assuming that the matter isn't expanding along with the universe? or is it.

Yes it is. Every single thing in the universe is expanding, every single point between atoms is expanding, every single point between quarks is expanding. You are getting expanded as you read this.

either way. the distance between all the objects will get close enough that if there are several black holes. everthing well get sucked up into them. and each of them will get close enough to eachother that they will get sucked up into eachother. that leaves one really big black hole.. maybe not at the physical center of the universe. but its the only thing left in it.

If the universe expands faster than the rate of creation of black holes then the expansion will trump the collapse forced by black holes and the universe will continue to expand until black hole creation hits a critical limit (if such a thing exists). I'm more than happy to be taken incorrectly on this point though because I've no idea what the critical limit would be offhand.

[batmanmg]

i agree that there is no physcal center of the universe IN this univerese. if you scowered every inch of it you'd never find it. but the fact that with the expansion, everything is getting farther away from everything else. well if the opposite occurs, everything is getting closer to everythin else. the distance between objects will eventualy reach zero. right? or will they just condense along with the space in between them and therefore never actualy reach eachother?

and i read on that site the "gem of a page" was found. that galaxies are not expanding. but the distances between galaxies are? So which is it. Is matter expanding along with the space between it. Is the space between matter expanding but not the matter itself? or does it just apply to gallaxies, and galaxies are not expanding, but the space between them is?

if the distances between every object reaches zero. one can only assume that this is essentialy the "center" i'll use it in quote becuase it isn't the actual center. it may not be the point where everything meets but it would be the point where everything is no longer separated from everything else. very similar to an implosion towards a central point. but the way its done is very different and its not, 3 dimensionaly, towards a central point.

[Nick]

The center does not have to be a physical point, it does not have to be marked by something. Take the infinitely small balloon, before expansion. Put a beaed inside the balloon. Fill the balloon with space. The bead, assumming it didn't move, is not the center.

[thigle]

there is an axis running through the cosmos. it can be observed via the distribution of cosmic radiation. it runs through sextans and aquila, and thus the universe IS oriented, contrary to the classical beliefs. if the shape of cosmos is finite manifold, then it has a span and that span has a middle and that middle is the centr of the universe.

check these out for more info:
http://www.aip.org/png/html/birefrin.htm
http://www.rochester.edu/news/show.php?id=1294
http://i24.photobucket.com/albums/c18/t ... seaxis.jpg

[batmanmg]

well center or not... can we agree that when the baloon gets small enough all the galaxies and stars on the surface will collide into a single mass? distance between all the points eventualy = 0.

or are we going to agree that the mass of all the galaxies, or the space they take up, will condense along with the space in between them, and therefore the distance between will never = 0.

or is there a third alternative I don't know about?

in the second case, i would think that since mass is conserved, and distance between the objects is getting really small. that gravity will bring them together? so you will end up with a single mass anyway.

oh yes and still on the topic of center. There is a center of mass, right? or is that circumvented by something else i don't know about?