Big Bang Theory

[plasticdan]

I have been reading up on the big bang theory and can understand how research supports it but can't quite comprehend where all the matter came from. There must have been a point in time where there was nothing at all and if energy cannot be created or destroyed how can this theory be possible ?

[bernardo]

The rule about energy or matter not being created from nothing only started working after the big bang.

[Clanad]

This question arises with regularity... here are some examples:

http://www.theanswerbank.co.uk/Science/Question126115.html

http://www.theanswerbank.co.uk/Science/Question132547.html

(Whatever became of MargeB?)

[jake-the-peg]

The point that most people fail to grasp fully is that the big bang was not the creation of matter into an already existing universe but the "creation" of space and crucially time from an initial singularity.

When we talk about the big bang our language if full of time related concepts like "created" and "before the big bang". These concepts become largely meaningless as you wind back towards time 0.

Most of our "laws" of physics are approximations which work well until put under extreme pressure - Like Netwons laws of motion until you get close to the speed of light when relativistic effects become important. Similarly Laws like conservation of Energy cannot be relied on when we're looking at the big bang.

You might like to look further at the Higgs Boson. This is a particle that has being theorised since the 60's but has only recently been within our technical reach. Cern is currently looking for it. One of the consequences of the Higgs particle would be to explain the mass of all other particles. Finding and understanding this elusive little animal would go a long way to understanding exactly how the Conservation of energy might change in extreme conditions.

[qapmoc]

Your simple question actually goes right to the heart of all science questions about creation, because whatever anybody says about particles, energy, bangs, expansion etc... there is still no answer to the ''why is there something rather than nothing'' question.

[jake-the-peg]

That's not quite true qapmoc.

Consider virtual particles - these can suddenly appear "out of nothing" as long as they disappear within a certain time. The more energy is "created" in this way the briefer the time they can exist for.

Also the more energy the less likely the event is.

But it does happen - a lot! Particles are being created and distroyed all the time on the microscopic scale

In the early 80's Alan Guth pointed out that as far as we can make out the Gravitational energy of the universe is very close to it's mass energy (which is equal and opposite). If it were exactly equal and opposite it could have been created in a similar process - but would be almost infinitely improbable. However in a "proto-universe" without time the concept of probability is moot.

This is of course highly speculative and not really even in the true realm of science as it is unlikely to be provable or disprovable.

Nevertheless matter can be created see Quantum foam in wikipedia

http://en.wikipedia.org/wiki/Quantum_foam

[qapmoc]

Hi Jake, yes to all that, but it is just decribing what has been found to exist it does nothing to explain WHY, but my point was how can anybody say why anything at all exists.

Now before we get into the creator stuff I have to say that I don't believe in God, divine creation, 42 or anything like that but - surely the universe would be easy to imagine as an empty space for ever and ever, past-->future because nothing was/is needed to create nothing, but there is something, why and where did it all come from.
Surely the multiverse should naturally be empty without some kind of creation happening.

[jake-the-peg]

Frankly I don't think the question is meaningful.

Why refers to cause and effect. An effect happens because of a cause that's why.

Therefore to talk about why the big bang happened implies a previous event which brings us back to the "What happened before the big bang?" question.

There is no before - Time was created then - It's almost impossible to get your head around because time is so interwoven in our experience - It's like a triangle trying to understand "up".

We are so hard wired to look for cause and effect and for reasons that things happen we create them even if they aren't there.

[Clanad]

Well, jake, I look forward to the thread wherein you and me can have an agreement... alas, this is not the one. Firstly, the virtual particles are so described only because they exist for short periods of time (billionths of billionths of billionths of a second). They do not appear "out of nothing" nor do are they "destroyed". They are known to be the results of decay of previous particles and their disappearance is known to be further decay into even more fundamental particles. There are particles that annihilate each other. But these are, again, known to be collisions of particles of matter and anti-matter and even in these occurrences the Law of Conservation of Energy is not violated since they exist for such an infinitessimally short period of time. Hence the name, virtual particles.
The search for the Higgs boson is concurrent with the Higgs Field theory. As you've stated, neither have been observed. As you know, there are three generations of matter. The generations increase in mass and higher generation particles tend to decay into lower generation particles. No one knows why, but a lot the efforts of physicists today is directed towards the Grand Unification Theory and most investigators disagree on what that might "look" like or if it's even attainable.
My point is, the appearance and subsequent disappearance of particles is entirely dependant on pre-existing particles and do not come from "nothing" and are not destroyed. (By the way, what is the "microscopic level"?)

[jake-the-peg]

Virtual particles may mediate the forces between existing particles but they also come into existance in vacuum and are known as vacuum fluctuations.

See the Casimir effect.

Virtual particles can in theory become real, this process is involved in Hawking radiation where virtual particle pairs come into existance on either side of a black hole event horizon.

Whilst Hawking radiation is theoretical the Casimir effect is not it was was measured in 1997 at Los Alamos

Things do "come from nothing"

[qapmoc]

Jake you are just saying that everything exists because it does and that the real question of ''why does it exist'' is without meaning because it does exist??

[MrPahoehoe]

Jake, you said:

"Frankly I don't think the question is meaningful.

Why refers to cause and effect. An effect happens because of a cause that's why.

Therefore to talk about why the big bang happened implies a previous event which brings us back to the "What happened before the big bang?" question."

Now get ready to destroy me, cos you guys seem to know what ur talking about and be highly adept at debating, but that seems like semantics to me.

"What happened before the big bang" isn't the point, surely the big bang is the why, not the starting or finishing condition. The interest arises because we know neither the starting condition, nor the cause (the "why"). It does seem though, that if we knew what had caused the big bang then the starting condition would be irrelevant....although, to know what caused it we would probably have to know what the starting condition was :-(

Having said that, I do agree, in that I find it nearly impossible to imagine a timeless condition, I also find it even harder to imagine the universe before the creation of space. Its like imagining and empty space without the empty space >.<

[Clanad]

Something never (with the possible exception of the Big Bang itself) comes from nothing. In the examples cited, there seems to be the implication that the appearance of the particles is equivalent to their creation (and conversely, their disappearance with their distruction). However the Casimir effect along with Hawking's explanation, coupled with the Husinberg Uncertainty Principal all conclude, in my opinion, that the differing states of virtual particles causing near impossibility to predict either their speed or position does suggest that they will appear (to the observer)and disappear randomly. This is not the same as being created or destroyed...
This, from http://zebu.uoregon.edu/~imamura/209/apr14/virtual.html

(I believe it's a University of Oregon web site)

The existence of virtual pairs helps to explain a process known as pair production. The background is always seething with these pairs of particles. However, in order not to violate physical laws, the pairs always return back to the vacuum before they are observed directly.
However, these virtual pairs can become real particles. It is found that when there are very high energy photons, that the energy of the photons can be channeled into the virtual pairs and the virtual particles can become real. This process is known as pair production. The collision and subsequent disappearance of a particle/anti-particle pair is known as annihilation. What this means is that if there is a large supply of high energy photons then particles can be created.

Obviously, the virtual particles come from the pre-existing photons...

[jake-the-peg]

We're dangerously close to agreeing Clanad. But that isn't the only mechanism for virtual particle creation.

I'm really thinking of issues like quantum foam, there's an interesting discussion here:

http://www.physlink.com/Education/AskExperts/ae332.cfm

Mr Pahoehoe - I think you're saying that if you knew what caused the big bang then you still don't know what caused the event that caused the big bang.

This is true and is a fundamental problem of any creation theory whether it's the "who created God" question or "How many turtles support the earth".

But yes imagining the "begining of time" is hard!

[Clanad]

Agreed, jake, probably a quantum event!...