The Dark Universe

[Slammr (imported)]

It's 'dark' in that current theories show that whatever it is, it doesn't really interact with the stuff we're made of, other than gravitationally.

It's a sad state in some ways. First we weren't the centre of the universe, our sun was. Then our sun was just one in an astronomical number in our galaxy, and in an unfashionable end of an arm, too. From there, our place was reduced still further, as just one minor galaxy in our Local Group, which is a small part of the Virgo Supercluster.

If all that isn't enough to make a person feel inconsequential, now it turns out that everything we see around us isn't even made of the same stuff as the vast majority of matter and energy in the universe.

Not only that, our Universe is likely only one of a Multiverse. One thing to think about, though, there may be other copies of ourselves in those other Universes, each of them thinking he's the real us, and effectively, he is just as real as we are real - or it may all be an illusion.

[moi621 (imported)]

So Dark Matter would have to be matter matter and not anti matter.

It could be unique in sub atomic structure from what we know as common, known matter.

Like the neutrino, it does not react with matter other then gravitationally.

Weakly interactive massive particles? Like bigger then a neutron?

After this maybe you can explain Quantum Mechanics.

I'm going to go play with a string now.

Moi

Who needs sentences when a clause communicates?

[Slammr (imported)]

So Dark Matter would have to be matter matter and not anti matter.

It could be unique in sub atomic structure from what we know as common, known matter.

Like the neutrino, it does not react with matter other then gravitationally.

Weakly interactive massive particles? Like bigger then a neutron?

After this maybe you can explain Quantum Mechanics.

I'm going to go play with a string now.

Moi

Who needs sentences when a clause communicates?

It wouldn't be a subatomic particle such as a Quark. We can detect those and there's no science to explain why they would exist on their own.

Neutrinos move too fast, close to light speed, and tend to stream out of any over dense region and wouldn't account for the pattern of galaxies observed in the Universe. Neutrinos are known as hot dark matter as opposed to cold dark matter, and it looks like the bulk of dark matter is cold, not whirling through space at near light speeds.

Quantum Mechanics would require its own thread - or two - or three.

[moi621 (imported)]

Two or three threads for Quantum Mechanics.

I get it, that's part of the uncertainty.

Cold Dark Matter. I propose three photons bound by a Higgs boson or some new configuration of sub atomic matter because it appeals to me.

How about a plasma of neutrons or some uncharged stuff that doesn't have to move at all. Only gravity. Hhhmmm.

Moi

[StefanIsMe (imported)]

First off, interpreting Moi's posts is half the fun of them

Also, Slammr mentioned something up there about the universe eventually dying a cold, dark death...

From what I've read lately, there are, I think, three possibilities; that the 'curve' of the universe is either positve (closed), resulting in an eventual slow-down of expantion and a rebound, down to a "big crunch"; next, that the curve is non-existant, i.e., "flat", which results in eventual stasis (a cessation of expantion); and finally, an negative curve, resulting in an "open" universe, which gives the end result mentioned by Slammr, i.e., continuing expantion, until the universe cools to the point it cannot support life.

Now I think the thinking right now is leading scientists to (on average) believe the actual condition of our universe is 'flat', meaning we never will get to a cold (everything being near 0 kelvin), ultra-expanded universe... instead, we will reach stability, where everything is in equilibrium and change ceases to occur; in this particular state, time ends.

All very, very esoteric and conjectural type thinking... not my best type of thought. I barely understand any of this stuff. I'm far too uneducated!

[BossTamsin (imported)]

Not only that, our Universe is likely only one of a Multiverse. One thing to think about, though, there may be other copies of ourselves in those other Universes, each of them thinking he's the real us, and effectively, he is just as real as we are real - or it may all be an illusion.

Actually, I find the many-worlds hypothesis (whatever variation is currently in flavour) to be more positive then negative. Although I suppose to some it might be seen as negative. For instance if you view it as it not mattering what you do or choose, since every possible decision happens somewhere, then I could see that being quite demoralizing. (Someone did a short story about worldwide suicide rates going through the roof after it was proven there were multiple universes, and somehow I think I'm gonna spend the next few days trying to track down who wrote it and what the story was titled.)

[Slammr (imported)]

First off, interpreting Moi's posts is half the fun of them

Also, Slammr mentioned something up there about the universe eventually dying a cold, dark death...

From what I've read lately, there are, I think, three possibilities; that the 'curve' of the universe is either positve (closed), resulting in an eventual slow-down of expantion and a rebound, down to a "big crunch"; next, that the curve is non-existant, i.e., "flat", which results in eventual stasis (a cessation of expantion); and finally, an negative curve, resulting in an "open" universe, which gives the end result mentioned by Slammr, i.e., continuing expantion, until the universe cools to the point it cannot support life.

Now I think the thinking right now is leading scientists to (on average) believe the actual condition of our universe is 'flat', meaning we never will get to a cold (everything being near 0 kelvin), ultra-expanded universe... instead, we will reach stability, where everything is in equilibrium and change ceases to occur; in this particular state, time ends.

All very, very esoteric and conjectural type thinking... not my best type of thought. I barely understand any of this stuff. I'm far too uneducated!

Actually, in the Universe as it's seen today, the expansion of the Universe is speeding up, and flat means that it keeps expanding forever. A few billion years from now, we'll only see a few of the galaxies we see now. The others will have moved beyond the light horizon, and will as far as we're concerned no longer part of our universe. Equilibrium is when the Universe cools down to 0 deg Kelvin. Matter will eventually break down and black holes will evaporate. The universe will be dark and cold. We have a few trillion years before all the stars quit shining. The Universe can't just stop. It either expands forever or it contracts with gravity, and now, it looks like it will expand forever.

[Slammr (imported)]

Actually, I find the many-worlds hypothesis (whatever variation is currently in flavour) to be more positive then negative. Although I suppose to some it might be seen as negative. For instance if you view it as it not mattering what you do or choose, since every possible decision happens somewhere, then I could see that being quite demoralizing. (Someone did a short story about worldwide suicide rates going through the roof after it was proven there were multiple universes, and somehow I think I'm gonna spend the next few days trying to track down who wrote it and what the story was titled.)

The story was mentioned in a book I recently read about the Universe. I'll have to see if I can find it.

The Multiverse makes sense to me; universes popping in and out of existence throughout eternity makes more sense that one Universe somehow, by itself, popping into existence out of nothing. The Universe was once so small that Quantum mechanics would apply to it, and Quantum mechanics almost demands that infinite Universes exist. Stephan Hawking and others now believe in the Multiverse. Inflation, string theory, and m theory all suggest the Multiverse.

[BossTamsin (imported)]

The story was mentioned in a book I recently read about the Universe. I'll have to see if I can find it.

The Multiverse makes sense to me; universes popping in and out of existence throughout eternity makes more sense that one Universe somehow, by itself, popping into existence out of nothing. The Universe was once so small that Quantum mechanics would apply to it, and Quantum mechanics almost demands that infinite Universes exist. Stephan Hawking and others now believe in the Multiverse. Inflation, string theory, and m theory all suggest the Multiverse.

I'd be most appreciative if you could provide any information about the story. I've looked through the most obvious choices, and have come up blank so far.

As for the Multiverse, ever since I heard about the theory I've liked it. Something about a near-infinity of alternate universes just feels right to me on so many levels. The fact that most modern theories seem to back the idea (especially the variations on string theory and the still-developing m-theory) pleases me to no end. Whether or not any proof they exist ever arrives, and even if future theories turn away from the idea, I think I shall continue to believe in the Multiverse. The idea amuses me just that much. In fact, finding out the Multiverse didn't exist would be an incredibly depressing discovery for me. The universe would be much less grand, were our reality to be the only one out there...

[Arab Nights (imported)]

I originally could accept the concept of the Big Bang. But then I ran into a real conceptual problem. I still visuallized it as the universe explosively forming from a point of infinite density. That means that it is from a point source and moving outward in all directions from the point. When I asked astronomy types where that point was, I got mumbo jumbo answers like 'it was everywhere.' That makes no sense to me in terms of the Big Bang and an expanding universe.

I was watching some program on the universe. It was one of those programs narrated by Morgan Freeman, I think. Anyway, I that particular program had a segment on string theory which leads to more than 3 dimensions. The physicist explaining the story could actually communicate like a regular human being.

A very simple model that he used for simple people to understand was of two towels hanging parallel in space. Our universe is one towel. Another parallel universe was the other towel. Within each towel are three dimensions, but the whole system also has three dimensions for the each towel, time, etc.

Now, our universe is one towel. Within it matter is flying apart and at some point in the distant future our universe will be very cold and very dead with matter and energy widely dispersed thru it. Now, the idea is that the parallel 'towel' or universe is also doing the same thing.

When both three-dimension universes reach that point, the math allows them to begin moving together again. When they collide, it is a 'Big Bang' moment and we start from zero again. The thing is that it is a collision along the entire area of the two 'towels' or universes, hence not from a single point and it then follows that the starting point was everywhere and not just a single point.

Finally, an explanation that a simple mind like mine can understand!