Large Hadron Collider

[Vidar]

Black holes produced by the LHC will simply evaporate because they don't generate enough gravity to hold themselves together, let alone suck up planet earth.

Gravity is a function of mass. More mass, more gravity.
The LHC collides subatomic particles together with such force that a microscopic black hole might exist for a fraction of a microsecond. This black hole has a mass of a few subatomic particles, and that doesn't create enough gravity to pull anything in, let alone sustain a quantum singularity.

[Alondro]

Yep.  They'd just be itty bitty black holes if they manage to form at all.  This type of micro black hole might form naturally all across the universe whereever high-energy particles are ramming together at near the speed of light. 

But as Vidar said, they can't last for more than a few microseconds because the don't even have a fraction of a the mass needed to generate the gravity to sustain a singularity.

Which again makes me wonder what triggered the Big Bang, since it would have had to be itself a super-singularity.  Hmmm.

[Keleth]

However, if they're wrong. We're gonna have to move off of Draenor asap

[Teroniss]

Yep.  They'd just be itty bitty black holes if they manage to form at all.  This type of micro black hole might form naturally all across the universe whereever high-energy particles are ramming together at near the speed of light. 

But as Vidar said, they can't last for more than a few microseconds because the don't even have a fraction of a the mass needed to generate the gravity to sustain a singularity.

Which again makes me wonder what triggered the Big Bang, since it would have had to be itself a super-singularity.  Hmmm.

I had a theory on that. That the universe itself is a perpertual motion generator. When it first bursts out, it does so with somemuch force that it creates a super Blackhole. As the universe spread slows down, it'll eventually be sucked back into the singularity until it reaches critical mass and explodes out again, repeating for eternity.

[Mao]

I had a theory on that. That the universe itself is a perpertual motion generator. When it first bursts out, it does so with somemuch force that it creates a super Blackhole. As the universe spread slows down, it'll eventually be sucked back into the singularity until it reaches critical mass and explodes out again, repeating for eternity.

It sounds like it could be a real trippy Amusement Park ride.

[Vidar]

Nobody knows exactly what kicked off the universe. That's one of the reasons why the LHC was built.
What is knows is what happened from a few thousands of a second after the universe began. That alone is a testament to the power of science.
The name "Big Bang" is not exactly accurate. Just after whatever it was that set the universe in motion, there was a very rapid expansion of spacetime. It wasn't an explosion in the normal sense of the word.

[Kenji]

I hope it makes a bunch of little tiny planets and stars that one day wish to figure out how they came to be and create a LHC to recreate the effect. Which in turn creates tiny planets and stars that one day wish to figure out how they came to be and create a LHC to recreate the effect. Which in turn...

[Vidar]

Yep.  They'd just be itty bitty black holes if they manage to form at all.  This type of micro black hole might form naturally all across the universe whereever high-energy particles are ramming together at near the speed of light. 

But as Vidar said, they can't last for more than a few microseconds because the don't even have a fraction of a the mass needed to generate the gravity to sustain a singularity.

Which again makes me wonder what triggered the Big Bang, since it would have had to be itself a super-singularity.  Hmmm.

I had a theory on that. That the universe itself is a perpertual motion generator. When it first bursts out, it does so with somemuch force that it creates a super Blackhole. As the universe spread slows down, it'll eventually be sucked back into the singularity until it reaches critical mass and explodes out again, repeating for eternity.

Someone else had that theory already. It's the big bang-big chunch model. scientists have already observed that this is not the case in our universe. the expansion of our universe is accelerating. The gravity that all the matter in the universe creates is not enough to lead to a big crunch. Our universe will expand until complete entropy sets in.

[Teroniss]

Yep.  They'd just be itty bitty black holes if they manage to form at all.  This type of micro black hole might form naturally all across the universe whereever high-energy particles are ramming together at near the speed of light. 

But as Vidar said, they can't last for more than a few microseconds because the don't even have a fraction of a the mass needed to generate the gravity to sustain a singularity.

Which again makes me wonder what triggered the Big Bang, since it would have had to be itself a super-singularity.  Hmmm.

I had a theory on that. That the universe itself is a perpertual motion generator. When it first bursts out, it does so with somemuch force that it creates a super Blackhole. As the universe spread slows down, it'll eventually be sucked back into the singularity until it reaches critical mass and explodes out again, repeating for eternity.

Someone else had that theory already. It's the big bang-big chunch model. scientists have already observed that this is not the case in our universe. the expansion of our universe is accelerating. The gravity that all the matter in the universe creates is not enough to lead to a big crunch. Our universe will expand until complete entropy sets in.

True. However, because the overall nature of dark matter, which drives the acceleration of the universe, is unknown, so to is whether or not that theory is correct as well. Also the Big Crunch only theorize the end of the universe in which there is no continuation. My belief is that the universe is an infinite motion/energy model, not necessarily continuing to expand for all eternity, but expanding and contracting an infinite(by our standards) number of times. Since the overall nature of a blackhole and the event horizon is impossible to observe and therefore gather data on, my theory will forever remain theory.

[Vidar]

Yep.  They'd just be itty bitty black holes if they manage to form at all.  This type of micro black hole might form naturally all across the universe whereever high-energy particles are ramming together at near the speed of light. 

But as Vidar said, they can't last for more than a few microseconds because the don't even have a fraction of a the mass needed to generate the gravity to sustain a singularity.

Which again makes me wonder what triggered the Big Bang, since it would have had to be itself a super-singularity.  Hmmm.

I had a theory on that. That the universe itself is a perpertual motion generator. When it first bursts out, it does so with somemuch force that it creates a super Blackhole. As the universe spread slows down, it'll eventually be sucked back into the singularity until it reaches critical mass and explodes out again, repeating for eternity.

Someone else had that theory already. It's the big bang-big chunch model. scientists have already observed that this is not the case in our universe. the expansion of our universe is accelerating. The gravity that all the matter in the universe creates is not enough to lead to a big crunch. Our universe will expand until complete entropy sets in.

True. However, because the overall nature of dark matter, which drives the acceleration of the universe, is unknown, so to is whether or not that theory is correct as well. Also the Big Crunch only theorize the end of the universe in which there is no continuation. My belief is that the universe is an infinite motion/energy model, not necessarily continuing to expand for all eternity, but expanding and contracting an infinite(by our standards) number of times. Since the overall nature of a blackhole and the event horizon is impossible to observe and therefore gather data on, my theory will forever remain theory.

A few remarks here.
First of all, it's dark energy that powers the accelerating expansion of the universe, and nor dark matter. Dark matter and dark energy are completely seperate concepts.

Newer theories on the nature of black holes suggest that there is no true event horizon. We may yet probe the secret sof quantum singularities at some point in the future.

the bang-crunch-bang-crunch cycle theory is a variation of the bang-crunch, and it's still not supported by the evidence.

[Alondro]

I wonder if the universe does cycle, just differently than expected.  If the acceleration is correct, than the universe will eventually expand past the 'ripping' point of space time and somewhere a teeny little ultra-void will appear.

I wonder if that's what triggers a Big Bang, the super-dimensional structure of a multiverse filling an absolute void with an absolute density, which then instantly expands due to its own properties.

Now that's something impossible to prove, as we'd have to see beyond the edge of our universe to examine what is beyond, and we can't do that.  Even if it hadn't already gone past light's ability to travel back to us, all we'd see is utter darkness at apparently absolute zero whether it was all a void or if it was an old burnt out previous universe that had undergone a big rip.  And with nothing but utter darkness at absolute zero, we can't know anything about what it is or where it came from, as information is conveyed by energy, which is all gone in a frigid dead universe (and never existed in a total void).

[Jack McSlay]

I've heard a bunch of stuff about the universe not contracting (and gets even worst when people take is as a proof of god's existence, saying if it doesn't loop, means someone had to create the big bang) and that does seem bull to me. assuming it won't contract because it's still expanding seems really rash.
I find rather plausible to consider all matter in the universe has a gravity field of unlimited range, yet it's far too weak at long distances to be even measurable, and then, after an unimaginably large amount of time the universe's expansion will halt and begin contracting instead

[superluser]

I find rather plausible to consider all matter in the universe has a gravity field of unlimited range, yet it's far too weak at long distances to be even measurable, and then, after an unimaginably large amount of time the universe's expansion will halt and begin contracting instead

The problem is that gravity is already extraordinarily weak, and we can measure its effects over 10**23 miles.  The chances of that happening are extremely remote, and any such effect would be overpowered by the observable effects of gravity and the electroweak force.

[Azlan]

Nobody knows exactly what kicked off the universe.

That was me, sorry, had a bit of... a sneeze there, Nutmeg had made peppercorn strudel.

[Yugo]

Time for an astronomy lesson!

Dark matter: Dark matter is a concept relating to galaxies, not universal expansion, specifically the way matter orbits within the galaxy. Matter should orbit the center of the galaxy similar to the way planets orbit the sun in our solar system. The foci of the orbits are based around where the average concentration of mass is, and in our solar system, that's just barely at the edge of the sun's surface. This is because while the mass of the planets does factor in, the Sun's mass is so much greater as to render it, for the most part, unimportant. According to Kepler's second law, "A line joining the sun and the planet sweep out equal areas during equal intervals of time." This is derived directly from the law of conservation of angular momentum. This basically means that objects orbiting at a greater distance will orbit more slowly and therefore cover the same area.

In a galaxy, we should see a similar concept play out. Visibly, the majority of mass is deposited in the bulge, or the center of the galaxy. However, orbital velocity, for the most part, remains constant throughout most of the galaxy. This suggests that there is mass we cannot observe via the electromagnetic spectrum (dark matter). And that's what dark matter is, and how it came about.

I'll leave dark energy to somebody else. I'm going to go eat a sandwich.

[techmaster-glitch]

Dark matter...dark energy...is there also dark space and dark time? No, seriously.

[Corgatha Taldorthar]

Now, I could be wrong about everything I'm about to say. I'm not even an astronomy or physics major, let alone someone who teaches or whatnot. But I remember learning that the latest Hubble photographs were showing that not only is the universe expanding, but it's expanding at an ever accelerating rate.


Now, if the model that some sort of one time force, AKA a Bing Bang, applied the propulsive force to the universe, then gravity would either make it all contract back to a point or possibly cause the expansion to come at an ever slowing rate until entropy set in. (Complicated mathematic stuff as to which of the above scenario was more likely). Either way, the only way that the universe can expand faster today than it was yesterday is if something is putting energy into the mix. Now, I, for one have no idea what that energy could be, but it does seem like "something" is pumping more energy into the system, or at least converting it from something. A lot of dark matter theories are that somehow this mass is being converted to energy or something.

Bleh. I should keep science to the real experts.

[Yugo]

Hubble's Law: The redshift in light coming from distant galaxies is proportional to their distance. Translation: All galaxies are moving away from each other.

According to recent observations, all galaxies are moving away from each other at an accelerating rate. Observations also point out that the geometry of our universe is relatively flat, which would mean the rate of expansion of the universe should be gradually decelerating, contrary to what we see., according to Hubble's law and the gradual decrease in Hubble's constant. So the only real explanation we have for the time being is that there is some invisible energy that we can't detect that's affecting the expanion of the universe. Hence, dark energy.

Aren't scientists wonderfully creative with names? I'm gonna go eat another sandwich.
Sorry if my explanations are bad, my astronomy is not particularly up to par.

[Vidar]

Not all galaxies are moving away form each other. For instance, the Andromeda galaxy is on a collision cours with our own, and there are many other instances of galaxies crashing into each other. Do a google search on "interacting galaxies" for pretty pictures of this.
The vast majority of galaxies are moving away from each other with great speed.

There's also a rather bizarre hypothesis about the perceived acceleration of the expansion of the universe. It might actually be that time is running out in the most literal sense of the word.
The idea goes something like this: Time is actually finite. It statred with the big bang, and it will at some point end. The universe is not actually expanding faster, it just looks like that because time is slowing down at the edges of the universe, because there is somehow less of it.
Not that this is just a hypothesis, and in no way has it been tested yet. Don't take this for fact, or scientific theory just yet.

[superluser]

The idea goes something like this: Time is actually finite. It statred with the big bang, and it will at some point end. The universe is not actually expanding faster, it just looks like that because time is slowing down at the edges of the universe, because there is somehow less of it.

If that were the case, we should be seeing the opposite phenomenon.  Remember, when we look into space, we see the past, not the future.  Although even that is not technically true, as Relativity precludes the concept of simultaneity. (though, somehow, quantum mechanics requires simultaneity.  We're looking into it.)

[Yugo]

I'm well aware that gravitational pull over (relatively) short distances exhibits a stronger force than outward expansion. And those are exceptions to the rule, like with every rule.

No need to nitpick, I was just trying to help those who don't know what dark energy is.

[Rakala]

All these theories test my mind to the breaking point. I still can't figure out if there's an infinite amount of non-dark matter in the universe or a finite. Because space is (supposedly) infinite, therefore there has the potential to be an infinite amount of matter. However if there is an infinite amount wouldn't it take up all of space? But that would be impossible because space is infinite and therefore has an infinite amount of room but... Gah! My head hurts. Sorry to drift off topic for a moment but I felt my thought needed to be shared.

[Tapewolf]

All these theories test my mind to the breaking point. I still can't figure out if there's an infinite amount of non-dark matter in the universe or a finite. Because space is (supposedly) infinite, therefore there has the potential to be an infinite amount of matter. However if there is an infinite amount wouldn't it take up all of space?

AFAIK the current theory is that the universe is finite but unbounded - i.e. if you travelled in a perfectly straight line for long enough, you would 'wrap around' and come back to where you were before.

Truth be told, I'm not honestly convinced by the Big Bang theory.  Like epicycles, it feels like there are too many hacks needed to bodge it into working, and I would not be surprised if we discover something that we've missed which gives us a far simpler model.

[Alondro]

All these theories test my mind to the breaking point. I still can't figure out if there's an infinite amount of non-dark matter in the universe or a finite. Because space is (supposedly) infinite, therefore there has the potential to be an infinite amount of matter. However if there is an infinite amount wouldn't it take up all of space?

AFAIK the current theory is that the universe is finite but unbounded - i.e. if you travelled in a perfectly straight line for long enough, you would 'wrap around' and come back to where you were before.

Truth be told, I'm not honestly convinced by the Big Bang theory.  Like epicycles, it feels like there are too many hacks needed to bodge it into working, and I would not be surprised if we discover something that we've missed which gives us a far simpler model.

God.

[Jairus]

Truth be told, I'm not honestly convinced by the Big Bang theory.  Like epicycles, it feels like there are too many hacks needed to bodge it into working, and I would not be surprised if we discover something that we've missed which gives us a far simpler model.

I wouldn't be surprised either. It probably won't be in our lifetimes, but we're learning more about the 'verse every day.

Though part of the reason I like your idea is because it bugs me when science-fiction latches onto the newest buzz-words and uses them to explain everything, only to see science move on and leave them in the dust. Of course, in this case it wouldn't really be SF's fault...

[Rakala]

AFAIK the current theory is that the universe is finite but unbounded - i.e. if you travelled in a perfectly straight line for long enough, you would 'wrap around' and come back to where you were before.

So.... the univserse is a sphere? How do you get nothingness into a shape?

[Tapewolf]

So.... the univserse is a sphere? How do you get nothingness into a shape?

I think it's a bit more convoluted than that, but that's the general idea.  IIRC being on the surface of a sphere was what we were taught as an analogy to the true 'shape'.

[llearch n'n'daCorna]

Picture the universe like the surface of a beach ball, and the big bang is someone blowing it up.

It's close enough, and the places where the analogy misses are places where you'd have difficulty anyway, because it all gets a bit murky and hand-wavey.

Only it's a very very very big beach ball.

[Jack McSlay]

then again, there's also the possibility, of multiple explosions, not a single big bang, which would explain the fact there are galaxies apparently moving in arbitrary directions

[superluser]

So.... the univserse is a sphere? How do you get nothingness into a shape?

Another popular shape is the torus.  It's like a ring, but it has a cross-section of two circles, instead of something flatter:



I'm not sure what the pink frosting represents...