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If the Universe is flat and the total energy of the universe can be zero (we don't know if it is, but many theorists support the idea, i.e. at BB initial conditions: t = 0, V = 0, E = 0) then is it possible that all matter in the universe could have emerged from nothing? If so, that what is the total energy of the matter compensated by?

Edit: Yes, I've watched the lecture by Lawrence Krauss, and I know about his book. Haven't read it though (I guess it's too difficult for me).

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Related: – Qmechanic Oct 11 '12 at 21:18
If the total energy of the universe is zero, then do we exist? Now we have reached the realm of philosophy. – ja72 Oct 11 '12 at 21:54
@ja72, well, I'm not asking whether we exist or not (no matter what do you mean by "existance") – Artur Udod Oct 12 '12 at 6:57
@ArturUdod, Sorry I was just thinking out loudly there. – ja72 Oct 12 '12 at 14:22
paraphraphrasing something I heard somewhere in a popular account of string theory, "Nothingness is unstable". Unfortunately I wasn't able to find any useful references. – NeuroFuzzy Oct 13 '12 at 12:48
up vote 9 down vote accepted

The answer crucially depends on what is meant by nothing. From the philosopher's nothing, nothing comes.

But the physicist's nothing is something, i.e., there is at least physical law and whatever obeys it.

For example, matter and anti-matter can materialize from the "vacuum" and, in some sense, this is something (matter) from nothing (no matter). But this presupposes the existence of quantum fields and the laws that govern them.

So, your question is actually far more subtle (and ancient) than you might grasp at this moment.

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Well, basicaly I know this all. But I don't ask about the origin of physical laws. For this question we just assume they are present. I wanted to know whether to concept of 'universe-from-nothing' is plausible. In the sense, that nothing = anything, but matter & energy. – Artur Udod Oct 12 '12 at 7:01

You open a box and say "there is nothing inside". In a strict mathematical (math-logic) language what you mean is: $$!\,\exists x\in ObjectsCouldBeInTheBox: InABox(x) $$ What you do next is just a "linguistic trap" -- you take a word "nothing" out your sentence. Which roughly corresponds to a "$!\exists$" part of your statement. And it's not an object. It's not even a predicate.

But "nothing" is a noun, so it feels like you can operate with it as it was an object. Well, that is a wrong feeling.

Just try to formulate the statement "Universe could emerge from nothing" strictly. I can only get something like: $$\exists x\in SetOfNothings: UniverseEmergesFrom(x) $$ And I don't know what $SetOfNothings$ is...

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+1 for trying to make people think more formally and phrase questions and answers more carefully, hence more scientifically. – Urs Schreiber Aug 28 '13 at 9:46

Because there is a law such as gravity, the universe can and will create itself from nothing. Spontaneous creation is the reason there is something rather than nothing, why the universe exists, why we exist,

Hawking writes.

but another question is why our universe has laws of physics?

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Thanks for the answer. Could you also read my updated quetion (2nd edit)? – Artur Udod Oct 12 '12 at 7:19
@ArturUdod it is better to ask a new question by referring to this, instead of editing question. – Battle of Karbala Oct 12 '12 at 8:17

Much of the idea of "a universe emerging from nothing" relies on a naive sense of how time should behave. In a recent work by Yasunori Nomura, he describes how the multiverse can be viewed as intrinsically static. The waveform of the multiverse is completely stationary with no evolution.

He describes that the concept of "time" (and related notions of causality) are tied up with the concept of ordered vs. disordered states (look at the chair example on page 8). The entire multiverse as a whole doesn't need to evolve, only the probabilities within a single universe.

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Thanks for the article =) – Artur Udod Oct 16 '12 at 8:18

You say that

If so, then what is the total energy of the matter compensated by?

then you say that

Yes, I've watched the lecture by Lawrence Krauss

My point is that if you watch even one of his full lectures on this topic like this one, you would have your answer.

then is it possible that all matter in the universe could have emerged from nothing?

The answer to above is YES as already summarised by @juanrga

As Prof.Krauss says not only matter even space-time itself can pop up into existence if we mix gravity with quantum mechanics

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not exactly this one, but the one absoluately similar by content. Not sure (it's been some time ago) but haven't heard anything about negative energy of gravitational field. Propably should watch it again. – Artur Udod Aug 28 '13 at 12:32

No. The Friedmann equation says that the fractional expansion rate grows with energy density. If the energy density were really zero and there were no curvature, then the universe (or the lack thereof) would simply sit still.

Quantum fluctuations (antimatter + matter annihilations) of the vacuum are not zero energy. In fact, they act like a cosmological constant or dark energy. One of the mysteries of modern physics is why the vacuum energy is so much smaller than what we expect. If we set the planck length as the UV cutoff scale, the vacuum energy would be roughly 120 orders of magnitude denser than the observed amount of dark energy. So there must be something (a symmetry, holography, etc) that reduces this to within observation constraints.

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Keep in mind Friedmann equations assumes the universe is completely uniform, etc.. – namehere Aug 28 '13 at 9:35

As of right now, there is no physical theory able to demonstrate the creation of universe out of nothing; even worse, there is no theory able to pass before the big bang (if there is anything or nothing there). The general relativity gives a very mathematical solution to the question, in terms of existence of solutions to the Einstein's equation; but that hardly provides any physical insight. However, there is hope, that String theory can surpass the difficulties raised by the singularities (in the General Relativistic sense of the word) at the big bang and go before that. But even if that happens and String theory provides some descriptions for the universe before the big bang, the issue of going back in time, until some beginning or something, will remain as puzzling unless String theory has more interesting things to say.

As a very amateur and very patient physicist, I believe we have to wait for the new ideas about spacetime (including the "emergent spacetime" notions, that are supported by the String theoretic investigations) to become more mature and hopefully then we will have our knives sharpened enough to analyse the difficult problems concerning the creation/existence of the universe.

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Well, im i little bit sceptic about the String theory as TOE. It's been under particular attention since mid 1990s and yet it hasn't really singnificantly advanced. – Artur Udod Oct 16 '12 at 8:23
There are theories that predict a uneverse before 'this' big bang. The hark from conformal cyclic cosmologies (CCC). – Killercam Oct 16 '12 at 9:03

There is really no answer to the question asked as yet because the laws of Quantum gravity are not known. So We really dont know what happened.

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I am not asking what actually happened and how, this would be another topic for discussion. The question is: is this possible (does this idea contradict any of the existing laws or fact in science?) – Artur Udod Oct 12 '12 at 10:30
I am saying that this question is beyond the scope of what is answerable. What we Know is what happen several movements after the big Bang, Everything before that is in the realm of speculation. Which includes a question like, Can the universe emerge from Nothing? – Prathyush Oct 12 '12 at 13:32
"Which includes a question like, Can the universe emerge from Nothing?" Does it? – Artur Udod Oct 12 '12 at 15:58
It is not true that we have absolutely no idea what quantum gravity could be ... The question can be addressed (but of course not definitively answered) from these different approaches to quantum gravity. I disagree with what you say, it is too pessimistic. – Dilaton Oct 12 '12 at 17:08
Let me know if you find a logically consistent answer. – Prathyush Oct 12 '12 at 17:23

It is possible albeit speculative. This is the free-lunch cosmology model. In such model it is supposed that the positive energy of the matter is compensated by the negative energy of the gravitational 'field' to give total zero energy.

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protected by Qmechanic Mar 21 '13 at 18:48

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