Concept of time

[Craterloads]

I'm not sure if you're genuinely interested or just trolling now, as you seem to refuse most of the points being made at you? I've already told you that to explain the actual details would be way, way beyond what we can do in a forum post. You're talking degree/PhD level at the minimum to truly understand most of the things you're asking about, so to have it explained to you via an internet forum based on computer hardware, you're going to have to make do with severely dumbed-down analogies.

But here's a paper on quantum vacuum fluctuations, read it if you want. If not then I'm sure there's enough on wiki you can read, or anywhere else around the web.
http://www.sciencedirect.com/science/article/pii/S1296214701012707

I was refering to the

no one really knows

and im not requesting it to explained here by you guys. Im not refusing anything, i just doesnt make sense and so much of it is unproven and the most important parts, no one has a reasonable idea.

Ive read the wiki, it was only short. But as Cas pointed out above its not "creating something out of nothing" a vacume is not nothing, far from it.

 

[Castiel]

Quite true, but more of a subtle technical distinction than a devastating flaw, it's a similar principle.

Although there's always the more fanciful end of string theory, or M-theory, which says that higher-dimensional constructs known as 'branes' exist and that a collision between branes, or some kind of fluctuation on then, could have caused the universe as we know it to start. If you're willing to believe in branes, then you could at least shift the question to 'But where did the branes come from?' and give yourself a universe-from-something.

:edit:

That was all aimed at Castiel, but there's another post inbetween ours now.

I wasn't trying to create a flaw, just trying to clarify a few points along the way. And indeed, M-Theory is something that fascinates me no end, particularly given the 'connected multiverse' kind of concept that makes me wonder just how interconnected everything in existence actually is, forget about religions, gods and other 'explanations' for a moment and consider the idea that maybe the entire point of all existence (as in everything infinitely so) is that we are simply alive in various forms within what coukd be described as a living infinite organism without boundaries or any limitations of concept that we simply cannot define in our current form. Exestentialist claptrap perhaps, but I often wonder about this kind of stuff.

 

[DAnDan]

I was refering to the



and im not requesting it to explained here by you guys. Im not refusing anything, i just doesnt make sense and so much of it is unproven and the most important parts, no one has a reasonable idea.

Ive read the wiki, it was only short. But as Cas pointed out above its not "creating something out of nothing" a vacume is not nothing, far from it.

No, from a physicist's point of view it's not creating something out of nothing, there's a lot more to it than that. But from a view of anyone without a working knowledge of quantum mechanics, it is making something out of nothing. It's a way of explaining it, rather than a model.

 

[sjt269]

Have you got any links regarding "quantum vacuum fluctuations" because from what i can see, its not actually creating something from nothing?

I'm looking, haven't found anything accessible so far. It's the creation of particles from the vacuum energy. Particles and antiparticles just leap out of nowhere, for a very short time, and then vanish again.

As Castiel said, the source of the fluctuations is ultimately the energy held in the vacuum (i.e. the fabric of spacetime, such as it is) rather than absolutely nothing, but it highlights the principle that you seem to object to that particles can, and do, just appear. If you can accept that part, then reducing the size of the universe down to a point isn't so crazy, since particles are just energy and energy can be crushed as much as you like. In fact, I think the vacuum energy itself would go away when you crushed the universe down (though it's density would remain constant).

Other energies don't go away as the universe gets smaller; we can show that at the beginning, the universe was extremely hot, and various other forces conspired with the heat to cause the universe to expand from it's pointlike zero-size. We can't explain why the universe was so hot or dense, but we can trace it back to tiny fractions of a second after the big bang when the universe was too miniscule to imagine and show that it did indeed expand from such a small size. Look up the Cosmic Microwave Background, or CMB, for an indication of how well those predictions match up with the experiments that can be done to test them (insofar as they can be tested).

 

[Morbius]

So you have to "buy" the "fact" the balloon contracted into nothingness.

The balloon is not going to contract into nothingness. The expansion of the universe is accelerating which makes a big crunch scenario highly unlikely.

Have you got any links regarding "quantum vacuum fluctuations" because from what i can see, its not actually creating something from nothing?

Over short timescales conservation of energy can be violated because of Heisenberg's uncertainty principle. In vacuums, virtual particle-antiparticle pairs are spontaneously coming in and out of existence all the time. Supposing you had a state of "nothing" then quantum level behaviour means it won't stay that way as at any future time you'll have a snapshot that contains lots of virtual particles.

Ultimately, conservation of energy has occurred. If you sum the total energy of the universe, you get exactly zero. This is because the shape of the universe is flat. This has been experimentally verified. This means that a universe could have arisen from nothing. In my opinion, it seems likely that the universe arose from a single virtual particle creation in an absolute vacuum.

 

[sjt269]

I wasn't trying to create a flaw, just trying to clarify a few points along the way.

Quite so. Though you've landed us in a bit of bother now by poking holes in that analogy, but I suppose I should thank you for making me think it through a little better before I try explaining it.


(If you haven't read The Elegant Universe by Brian Greene, then do, it's a fantastic book about string theory. Well enough known that you've probably heard of it, but worth me mentioning anyway!)

and im not requesting it to explained here by you guys. Im not refusing anything, i just doesnt make sense and so much of it is unproven and the most important parts, no one has a reasonable idea.

It does make sense if you're familiar with the detailed physics. I think the analogies are fairly clear, and I can see why you don't want to believe them, but as I mentioned, what we can test from these theories has been brilliantly confirmed every time. Ultimately, we can't (yet) test everything about them, but we can go back a pretty fair way with confirmed success, and back to times just fractionally after the big bang with a good deal of confidence that the physics is actually sound.

 

[Craterloads]

No, from a physicist's point of view it's not creating something out of nothing, there's a lot more to it than that. But from a view of anyone without a working knowledge of quantum mechanics, it is making something out of nothing. It's a way of explaining it, rather than a model.

Ive been going on about even if something is 99.9999* nothing, even the 0.00000*1 of it, is something, so when using that example it was misleading. Ive been saying its impossible for there to be nothing yet you gave an example that even physicists acknowledge is not creating something out of nothing.

 

[Kanifee]

If matter always exists and can never be truly wiped from the universe without leaving some by products amounting to its mass and that rule holds true throughout the universe doesn't that rule of thumb then say there had to be something before there was everything? does this mean that energy is something that is always present even after we see it as being expelled we just aren't able to measure its presence after the fact?

hope that makes sense!

 

[sjt269]

The balloon is not going to contract into nothingness. The expansion of the universe is accelerating which makes a big crunch scenario highly unlikely.

Oh dear, stop before this gets any more twisted!

We're using the big crunch as an example for the logic of the big bang, since it's essentially the same arguement in reverse. Yes, it looks like the expansion is accelerating and the final fate of the universe is unknown, but the big crunch is a physically sound solution and illustrates our concepts better. Concepts that are, I should add, still valid no matter what the shape of the universe, though its final fate may indeed differ.

 

[DAnDan]

Ive been going on about even if something is 99.9999* nothing, even the 0.00000*1 of it, is something, so when using that example it was misleading. Ive been saying its impossible for there to be nothing yet you gave an example that even physacists aknowledge is not creating something out of nothing.

But that 0.000001% but that you're referring to is still in a massively different league to the background fluctuations we're referring to here. That 0.00001% "stuff" in an atom is ALL of the protons, neutrons, and electrons in that atom. They're solid, physical lumps of matter. The quantum background fluctuations aren't matter at all, they're energy. So you're creating some matter, from no matter.

This is what I mean, no matter how it's explained, it will always have to leave out key details, which you then pick holes in.

 

[sjt269]

Ive been going on about even if something is 99.9999* nothing, even the 0.00000*1 of it, is something, so when using that example it was misleading. Ive been saying its impossible for there to be nothing yet you gave an example that even physacists aknowledge is not creating something out of nothing.

No, you've misunderstood. That 0.000....1% of matter is created out of pure energy borrowed from the fabric of the universe. The energy is there, true, but the matter itself isn't there, the particles themselves don't exist for more than a few seconds. That's the point - matter can be created from energy, particles don't have to exist and can be created and destroyed.

 

[Kanifee]

surely if matter can be converted to energy the opposite applies?

 

[panyan]

What is time, when did it begin, is there such a thing as time, what was there before time?

From my understanding:

Time began at the exact moment that the "Big Bang" happened. There was nothing before then as the "Big Bang" WAS the creation of the universe and nothing can exist outside of the universe (not even concepts like time).

Before time began there was no universe and therefore, there was nothing. There was no time, there was no universe.

Time is what i would call a concept. It is something can can be measured everywhere in the universe but is not constant as it relies on mavity. When i say that it isnt constant that means 1 second will last a different amount of time wherever you are in the universe because mavity varies.

On Earth we use time to do loads of things from data security to satellite tv so how can we rely on it if it is different everywhere? Well essentially the amount time varies across the globe due to mavity is minuscule - possibly less than we can measure - I dont know.

This is my understanding from watching numerous documentaries on TV and Physics lessons at college

 

[DAnDan]

surely if matter can be converted to energy the opposite applies?

Yeah, that's the point that SJT has been making .

 

[sjt269]

The quantum background fluctuations aren't matter at all, they're energy. So you're creating some matter, from no matter.

Again, this explanation is bang on. This is the principle we're trying to get across here - matter can in fact be created and destroyed. The rocks and debris you were worried about earlier are irrelevant, because the matter that makes up the rocks and debris can be turned into pure energy, and can be squashed into as small a space as we want.

:edit:

And panyan has finally dragged us all back to the original question with an equally lucid post saving us all from more talk of fluctuations in the M-branes.

 

[DAnDan]

From my understanding:

Time began at the exact moment that the "Big Bang" happened. There was nothing before then as the "Big Bang" WAS the creation of the universe and nothing can exist outside of the universe (not even concepts like time).

Before time began there was no universe and therefore, there was nothing. There was no time, there was no universe.

Time is what i would call a concept. It is something can can be measured everywhere in the universe but is not constant as it relies on mavity. When i say that it isnt constant that means 1 second will last a different amount of time wherever you are in the universe because mavity varies.

On Earth we use time to do loads of things from data security to satellite tv so how can we rely on it if it is different everywhere? Well essentially the amount time varies across the globe due to mavity is minuscule - possibly less than we can measure - I dont know.

This is my understanding from watching numerous documentaries on TV and Physics lessons at college

With regards to time variations across the Earth, we can measure them and do. It's a key part of GPS satellites. If we couldn't measure, and correct for the differences in time dilations between the Earth and the satellite, then we couldn't have functioning GPS.

 

[Craterloads]

But that 0.000001% but that you're referring to is still in a massively different league to the background fluctuations we're referring to here. That 0.00001% "stuff" in an atom is ALL of the protons, neutrons, and electrons in that atom. They're solid, physical lumps of matter. The quantum background fluctuations aren't matter at all, they're energy. So you're creating some matter, from no matter.

This is what I mean, no matter how it's explained, it will always have to leave out key details, which you then pick holes in.

Im not trying to pick holes, well maybe i am. Only to rationalise it, where probably lies my mistake in your view.

Lets just say for example its just energy (not sure if thats even actually proven), energy is still something and not absolute nothing according to the big crunch.

 

[arc@css]

It exists, so to speak, in the earth realm - but not where you'll be after passing over. For the loved ones that you will see again, time doesn't exist.

 

[DAnDan]

Im not trying to pick holes, well maybe i am. Only to rationalise it, where probably lies my mistake in your view.

Lets just say for example its just energy (not sure if thats even actually proven), energy is still something and not absolute nothing according to the big crunch.

The energy part is certainly proven, and experiments based around it have already been referred to in this thread, I can't provide specifics on the experiments though as they're way outside my field!

We're still only discussing a small part of the big crunch idea here though, simply how you get from solid matter to "crunchable" energy (and back), where you can compress it to ridiculously small volumes because it no longer has any physical dimensions. What happens after that is where the debatable theories come into play, some are based around the formation of a singularity, and some are closer to the nothingness of the pre-big bang (but again, these are way out of my field).

 

[Castiel]

It always confounds me that there is a finite amount of matter in an infinite Universe if the FLRW model is correct.....and the point my brother made once about the whole universe expanding but essentially nothing is actually moving, only the spaces 'inbetween' stuff is getting wider...or something like that..I will try to hunt the analogy out.

I love this kind of stuff, it frustrates me that I do not have the Maths to truely grasp it outside of the abstract.

However this has moved away from 'Time' a little bit..