My Ramblings On Dark Energy And Space-Time

[Sylandro]

A couple of days ago, i was thinking about dark energy and space-time.

Here's what i computed:

Dark energy has various "currents" around our universe, but the currents are too faint to be detected, currently. The currents also guide various particles throughout our universe, but, the currents, like space-time, gets distorted around a gravitational pull. So, the particles will be absorbed around a planet, asteroid, star, etc.

And on space-time, i do think it's a gelatinous existence.

I do not have any sophisticated equations to prove the dark energy currents, but remember; these are ideas that i came up during school.

[Sylandro]

DP -

Hey, why isn't anyone putting their two cents in? This is intriguing.

[TheGatesofLogic]

no one replies because your ramblings are simply pulled out of your rear

[Ralathon]

Pretty much what GatesofLogic said.

Science doesn't work like this. You can't make stuff up and hope it sticks. Before any hypothesis has any relevance you need support, either logical or observational.

We've never observed dark energy directly, we can only infer its existence thanks to the expansion of the universe. We have no reason to assume it has currents or swirls or any kind of nonlinear nature. Infact, we have no reason to assume anything about it other than it being the driving force for the expansion of the universe.

[jwenting]

and even that is only a hypothesis for lack of a better one...

[K^2]

and even that is only a hypothesis for lack of a better one...

It qualifies as more of a prediction, since it's based on established theory. But that's almost a semantics point in this case.

[G'th]

Anything is possible with that thing inbetween things.

But for seriously though, I have this question:

nfact, we have no reason to assume anything about it other than it being the driving force for the expansion of the universe.

Wouldn't the driving force behind expansion just be residual kinetic energy from the Big Bang? IF so I can't imagine that there'd be anything special about a shockwave that's still dragging matter along with it.

Edited January 19, 2014 by G'th

[K^2]

Wouldn't the driving force behind expansion just be residual kinetic energy from the Big Bang? IF so I can't imagine that there'd be anything special about a shockwave that's still dragging matter along with it.

Expansion of the universe is accelerating. General Relativity requires average stress-energy density to have considerable pressure for this to happen. The mysterious source of that pressure is what scientists call dark energy. Though, what that actually is, or if that's even what's really happening, nobody knows. But it's the best explanation for accelerated expansion that we have for now.

[G'th]

Hmm, well here's an idea straight out of the stadium based nothing but a thought that popped into my head. What if there's some kind of universal gravity?

And what I mean by that is, what if in the universe there is some minuscule amount of "gravity" affecting the content of the universe, which would be localized (ie, strongest) wherever the universe originates (For the big bang to have happened then there had to have been one location where everything expanded out from, as otherwise the idea of the entirety of the universe being a singularity before the big bang doesn't make sense, because then the singularity would occupy the same amount of space as the universe that is about to expand from that singularity) and as such, as the content of the universe expands away from this central location, it accelerates as the "gravity" becomes weaker? Just as with a normal planet, the farther away from its gravity well, the more able is an object able to accelerate away from it compared to being much deeper into it.

[rkman]

For the big bang to have happened then there had to have been one location where everything expanded out from

Not according to cosmology.

otherwise the idea of the entirety of the universe being a singularity before the big bang doesn't make sense

The singularity is not actually part of the standard cosmological model.

[K^2]

And what I mean by that is' date=' what if in the universe there is some minuscule amount of "gravity" affecting the content of the universe, which would be localized (ie, strongest) wherever the universe originates (For the big bang to have happened then there had to have been one location where everything expanded out from, as otherwise the idea of the entirety of the universe being a singularity before the big bang doesn't make sense, because then the singularity would occupy the same amount of space as the universe that is about to expand from that singularity) and as such, as the content of the universe expands away from this central location, it accelerates as the "gravity" becomes weaker? Just as with a normal planet, the farther away from its gravity well, the more able is an object able to accelerate away from it compared to being much deeper into it.[/quote']

You are picturing expansion as stuff flying out into space. But what it actually is, is space itself expanding. Which means that every point in space used to be the center of the Big Bang.

[G'th]

scratch this, see below

[G'th]

You are picturing expansion as stuff flying out into space. But what it actually is, is space itself expanding. Which means that every point in space used to be the center of the Big Bang.

Hmm, interesting. So this would mean then that, as space expands then matter/energy also expand out thus forming what see in the universe no?

Presuming that then this leads me back to what I originally suggested. If the initial state of the universe was a singularity before the big bang, then could the acceleration of space simply be a matter of space just getting away from that gravity well, as the initial expansion rate would grow as the forces acting against it become weaker?

[Stargate525]

I'll admit that a LOT of this is way over my head... But isn't the main evidence of a space-time expansion the fact that everything seems to be red-shifted more as it gets further away? IE, the further it is from us, the faster it's going away from us? But wouldn't that also be what you would observe if you were looking at a shock-wave from its point of origin?

From the little skimming I've done, it looks like almost all of this is taken from some very, very derived mathematics based on relativistic equations, then blown up to galactic scale. Since we now know that very, very small stuff seems to do some very freaky things that disobey regular scale physics, I see no reason to think that very, very large systems don't behave in the same way. I don't really see enough experimental or observational evidence to corroborate any of these models.

[K^2]

Presuming that then this leads me back to what I originally suggested. If the initial state of the universe was a singularity before the big bang' date=' then could the acceleration of space simply be a matter of space just getting away from that gravity well, as the initial expansion rate would grow as the forces acting against it become weaker?[/quote']

Weakening forces would explain why expansion isn't slowing down as much. That's what people expected. But measurements say that it actually speeds up. There has to be a force pushing things apart. Like gravity, but repulsive. The only thing that fits with that observation and General Relativity is dark energy.

Trouble is, there needs to be lots of dark energy, and for some reason, it's not anywhere we've looked. Of course, if for some reason, dark energy doesn't "like" being near matter, that might explain everything.

Since we now know that very, very small stuff seems to do some very freaky things that disobey regular scale physics, I see no reason to think that very, very large systems don't behave in the same way. I don't really see enough experimental or observational evidence to corroborate any of these models.

Our understanding of physics at different scales is way more detailed than that. That's not to say that there can't be something very weird going on at larger scales, but it's very, very unlikely. An unobserved form of energy would make more sense.

That said, people did say the same thing about aether.

[Stargate525]

...An unobserved form of energy would make more sense.

That said, people did say the same thing about aether.

And one can hardly say that quantum entanglement, light acting as a particle and a wave depending on whether it's being watched, and Shrodinger's Cat make sense!

[K^2]

And one can hardly say that quantum entanglement, light acting as a particle and a wave depending on whether it's being watched, and Shrodinger's Cat make sense!

These things do make perfect sense.

[G'th]

Trouble is, there needs to be lots of dark energy, and for some reason, it's not anywhere we've looked. Of course, if for some reason, dark energy doesn't "like" being near matter, that might explain everything.

Anti-energy? We already have the concept of anti-matter after all, so I would imagine it wouldn't be that much of a leap to suggest the same concept for energy. Matter and antimatter annihilate each other, may be the opposing forms of energy repel one another (perhaps one more so than the other, see below) like opposing poles of a magnet.

It actually makes some sense thinking of it as a magnetic-like effect. We already have the normal energy from the big bang going in all directions, so as it encounters anti-energy it accelerates as anti-energy repels it. This of course begs the question of why they don't eventually cancel each other out as the repelling forces between both types of energy equal out at some point in the universe. I would imagine this would be because normal energy may not be able to affect anti-energy in the same way the latter affects the former.

These things do make perfect sense.

I always do wonder why the phenomenon's of the universe particularly care that something or someone is observing them.

[crazyewok]

I do wonder if Dark matter and Dark energy are in fact anti matter. Though the problem with that is why doesnt the edge of our normaly matter universe regually interact with it as we would detect huge explosions of energy at the edge of Galaxys ect. Unless the huge denistys of Anti matter are giveing off Anti Gravity and as such are keeping the universes normaly matter away through repulsion.

[TheDarkStar]

I do wonder if Dark matter and Dark energy are in fact anti matter. Though the problem with that is why doesnt the edge of our normaly matter universe regually interact with it as we would detect huge explosions of energy at the edge of Galaxys ect. Unless the huge denistys of Anti matter are giveing off Anti Gravity and as such are keeping the universes normaly matter away through repulsion.

Antimatter responds the same way to light that matter does. Also, there is even less antimatter than matter. Finally, while antimatter has the opposite electric charge (and each electrically charged particle is attracted to its antiparticle because of this), they still have normal gravity.

I always do wonder why the phenomenon's of the universe particularly care that something or someone is observing them.

They don't actually; what actually happens AFAIK is that various states are indeterminate (certain states are still likelier than others' date=' though) until interacted with. It doesn't matter if [i']you are watching it; it doesn't even matter if anyone is watching it - the actual events happen because of the interactions of particles. This still leads to some counter-intuitive effects, but we can predict most of what goes on.

I'll admit that a LOT of this is way over my head... But isn't the main evidence of a space-time expansion the fact that everything seems to be red-shifted more as it gets further away? IE, the further it is from us, the faster it's going away from us? But wouldn't that also be what you would observe if you were looking at a shock-wave from its point of origin?

You're making the assumption that the universe is a sphere, but it's not. Imagine being on the surface of a balloon being inflated - to you, it looks like everything is traveling away faster and faster from you (the further, the more it accelerates). At the initial time when it started expanding, all points were at the same spot. In some ways, this is like the universe, except that there is one more dimension (I'm pretty sure it's just four) involved.

The analogy isn't perfect, since we don't actually know if the universe has a curve. However, it is still true either way that there is no specific "beginning point", as all places were at the same place at the beginning. An analogy for a flat universe could be a rubber band being stretched - all points get further away from each other, and further apart points get further away faster.

Hmm' date=' interesting. So this would mean then that, as space expands then matter/energy also expand out thus forming what see in the universe no?

Presuming that then this leads me back to what I originally suggested. If the initial state of the universe was a singularity before the big bang, then could the acceleration of space simply be a matter of space just getting away from that gravity well, as the initial expansion rate would grow as the forces acting against it become weaker?[/quote']

See what I wrote above. Also, while space expands, matter does not. All the matter/energy at the beginning of the universe is all the matter/energy now.

K^2 can explain this better than I can, and he probably has some corrections for me.

Edited January 20, 2014 by TheDarkStar

[crazyewok]

Antimatter responds the same way to light that matter does. Also, there is even less antimatter than matter. Finally, while antimatter has the opposite electric charge (and each electrically charged particle is attracted to its antiparticle because of this), they still have normal gravity.

.

Yeah the light issue is problem there.

Though last time I heard they didnt know if anti matter emmited normaly gravity or not did that change?

[Ralathon]

Yeah the light issue is problem there.

Though last time I heard they didnt know if anti matter emmited normaly gravity or not did that change?

They don't know for sure yet (They're having some trouble getting enough neutral anti hydrogen at low temperatures for meaningful data). However, there are some very convincing arguments that antimatter behaves the same in regards to gravitational fields. For example, photons are their own anti particles, so when light gets bend by gravitation you'd expect half to bend 1 way and the rest to bend in the other direction. However, when we look at gravitational lensing all the photons bend the same direction. This in combination with similar indications gives a strong reason to believe that antimatter follows the same old boring gravity that we do.

[InfinityArch]

Regarding the curvature of the universe, weren't there some recent results that implied the curvature constant was very, very close to being exactly 0, which would correspond to no curvature.

[Ralathon]

Regarding the curvature of the universe, weren't there some recent results that implied the curvature constant was very, very close to being exactly 0, which would correspond to no curvature.

They've been getting data that implies a flat universe for ages now. WMAP is the most precise to date, with a flat result and only 0.4% error margin. So, best we can tell the universe is flat. This doesn't mean it actually is flat. The observable universe is smaller than the entire universe. It could very well be curved in all sorts of fancy shapes that just happen to leave this particular area flat. But we can't get any information on that until we either figure out faster than light travel or wait a few billion years.

[TheDarkStar]

They've been getting data that implies a flat universe for ages now. WMAP is the most precise to date, with a flat result and only 0.4% error margin. So, best we can tell the universe is flat. This doesn't mean it actually is flat. The observable universe is smaller than the entire universe. It could very well be curved in all sorts of fancy shapes that just happen to leave this particular area flat. But we can't get any information on that until we either figure out faster than light travel or wait a few billion years.

Yeah, true. It's just easier to make the analogy with a curved universe first for explanation.