# Why is there something rather than nothing?

I occasionally get asked why there is a universe at all. Presumably I am asked this because I am meant to be stumped and so be led to a god answer (as if that makes it any better!) However I have a degree in physics and for decades have read articles and books on the origin of everything, so here is what I have distilled so far.

Also, twice I have been asked this by Muslims, so it creates an interesting perspective to post some emails to Muslims for a change (since they are so like Christians, but from a parallel dimension!)

Here is my reply to a long email from Ramin who in 2009 sent me the contents of a whole Muslim website on the origin of the universe and other scientific matters.

Hello Ramin,

I am a physicist and have been reading keenly on this question since I was 18 (I’m 44 now). Note that if your arguments were sound then cosmologists and Nobel prize-winners in Physics would more likely to be theists. In fact the exact opposite is the case and they have a very low proportion of theists – less than 5%

Whilst you’ve obviously read up on the general questions there are a number of mistakes and misassumptions you’ve made and major aspects you’ve missed. The worst is that you’ve missed that the total energy balance of the universe is exactly zero. This is because gravitational energy is a negative energy that exactly balances the positive mass-energy of the universe. This is a result of General relativity and was pointed out to Einstein by George Gamow which literally stopped Einstein in his tracks as he was crossing a road when he realised this implication from his equations! Stephen Hawking also discusses it. So the whole universe does indeed = 0.

Here’s a quote from an email I wrote to someone else:

Physicists such as Edward Tryon, Alan Guth and Victor Stenger describe the universe as indeed being a "free lunch.” My degree is in Physics and as I remember quantum mechanics shows how some properties are impossible to exist together beyond a certain level of precision. One incompatible pair is the limited precision possible for the amount of energy of a system and the amount time it has that energy for. A state of nothingness has zero energy and zero time and so quantum mechanics tells us that nothingness is unstable – i.e. the universe is a quantum event (e.g. paper here). Just as surprising is that the total energy content of the universe is - astonishingly - exactly zero. This odd result is due to the fact that gravitational energy is, (from general relativity), a negative energy which exactly balances out the positive mass-energy content of the universe. This discovery wasn’t even appreciated by Einstein until George Gamow pointed out to him how this was a consequence of Einstein’s own equations – something that literally stopped him in his tracks as they were crossing the street together and nearly got Einstein run over!

The other major part you’ve missed is what Alan Guth contributed. Anyway, I link to all this from my website so you can read it there – I give the links in the cosmology section on my study resources page. in particular see:

· Guth's Grand Guess "Most people really want to know where we came from. We have evidence. We no longer have to rely on stories we were told when we were young"

· Prospects of Inflationary Cosmology by Alan Guth

· A Designer Universe. Nobel prize winning physicist Stephen Wienberg discusses the argument from design based on the apparent "fine tuning" of nature to our benefit, the supposed benevolence of god and the relationship between morality and religion, especially in the slave trade.

Another Muslim wrote to me with similar questions a while ago, this is what he asked:

Hi there,

Here is a question: How can something come from nothing? Now, before you get too excited, let me state 3 points that relate to this question.

1) I know how physicists answer this question. Their answer, however, has limited scope in that the realm of physics is strictly within the bounds of spacetime constructs. I am more interested in how a “universe” can come from nothing (no Guth, please). Perhaps a better way to phrase the question is:

How can existence come from non-existence?

The application of quantum physics to some thing (like a vacuum) negates that “things” non-existence.

2) Is this a meaningful question? What is existence? What does it mean for a thing to exist?

3) I know that the lack of an answer “proves” exactly nothing.

Daniel

Here is the response I sent him:

************* Start of quotes from an old email**********************

Hi Daniel,

A most excellent question. I wish I knew the answer, all I know are some interesting hints I've come across in my attempts to find out. However it is something I often think about and read about when I have the time, and will surely continue doing.

You wrote that you don't want me to discuss the physicists' answers to this, but I wonder what else an answer about the physical universe can involve other than physics? If you ask a physics question but don't want a physics answer then I'm not sure I understand the question. I don't think it is correct to say that cosmological answers are "within space-time constructs" when as far as I understand cosmologists such as Hawking and Hartle discuss the "no boundary proposal" wherein space-time itself does not need a concept outside of physics to explain its existence. As Hawking says "one wouldn't have to appeal to something outside the universe, to determine how the universe began." So I think you are just wrong to dismiss physics as being able to answer this question.

How can something come from nothing? Well first of all we have to be sure that the question is correct. Quantum mechanics tells us that there is no such thing as nothing - the vacuum is full of virtual particles popping into and out of existence. This has measurable effects, such as the Casimir effect, and is implicated in many areas of physics. Anyway I think you said that you were starting a physics course so you'll have plenty of opportunity to discuss that with your lecturers there where they can explain exactly why particles are constantly "coming" from (and going back into) "nothing."

There is another problem with the question. Not only is the notion of "nothing" at variance with physics, but the notion of "coming" is also problematic. To expect there was a zeroth time moment to the universe (a "t=0") is to have a classical (and hence false) view of the universe. As I understand it quantum mechanics and relativity shows that running the universe back to very early times (near the plank time of 10^-43 seconds), time becomes "space like" and less well defined as you go back closer and closer to find "the origin" of the universe. Remember that time does not exist as a separate entity from space, but the two are part of a "space-time" manifold, as Einstein showed. We constantly travel at a constant speed through "space-time." Speed up through space and you slow down in time. You age fastest when at rest. You should learn all this on your physics course. Anyway, according to Hawking et al, under the conditions of the early universe, the "light cone" of the universe does not have a pointed apex, but a rounded one. i.e. time becomes more like space (and quantum mechanically fuzzy with it) as you get to the very early universe. I tried to find a picture of a light cone with a rounded end for you and eventually got one at http://www.bun.kyoto-u.ac.jp/~suchii/hawking.bigbang.jpg (the text of the page it comes from is Japanese though!) BTW, if you don't know what a "light cone" is do a Google search for light cone relativity.

So in physics, as best as we (or at least I) currently understand it, the question of "how did something come from nothing" is rather misleading, as both "nothing" is not a physical reality and neither is a "time zero" for there to be a "before" the other side of.

How can existence come from non-existence? Well I think existence requires the physical universe and hence the question is still the one above (the universe explains its own existence). However philosophers have still managed to intrigue me with their musings on this. I see from your email address that you are at Harvard. Do you know of Robert Nozick who was there until he died in 2002? He has an interesting chapter in his book "Philosophical Explanations" examining your question just as a question in philosophy. It was "Why is there something rather than nothing" which I first read about 18 years ago. Nozick raises many odd questions including the difficult one of what is so primordial about "nothing" that we should see it as "natural." (Indeed how can nothingness have a nature without the existence of nature!) As he says:

“However to ask this question is to presume a great deal, namely, that nothingness is a natural state requiring no explanation, while all deviations from nothingness are in need of an explanation."

Nozick wrote this over 2 years before Hawking and Hartle came up with their "no-boundary proposal." Also what is so expensive about "something" that it needs to be an effect? In 1990 Physicists were writing papers on the universe being a "free-lunch" (http://www.iop.org/EJ/abstract/0143-0807/11/4/008) and this was of course presaged by similar comments by Guth and Turok. In "Why is there something rather than nothing" Nozick goes on to examine whether existence is not a fecund state to be expected (indeed, many universes) with "nothingness" the state that is difficult (if not impossible) to be as a reality (maybe even meaningless?) On the other hand he wonders whether nothingness doesn't still exist anyway (where does it still exist - nowhere?). In general though I find it intriguing that Nozick and modern physics both come to some similar ideas in places. - i.e. that nothingness needs to be questioned, and that all the stuff around us (and even the laws of physics) are fecund, self-contained and costless.

More thoughts...Does existence that we currently experience require something to keep it in existence? It seems existence is very easy to do, indeed it seems impossible to crush something out of existence, merely to transform it. Even black holes eventually return what they swallow as radiation. (Look up recent discussions of the "information paradox"). If existence is now so easy to maintain and difficult to stop (it seems impossible to stop), why should it have been difficult to start or need a start? It is of course possible to stop phenomena, but not possible to stop the existence of mass-energy, just transform it. However, since (as I discussed in an earlier email) all the mass-energy of the universe equals zero (or as close as is allowed by the Heisenberg uncertainty relation between energy and the time an energy state exists for), since the mass-energy of the universe costs nothing (http://www.iop.org/EJ/abstract/0143-0807/11/4/008) and time doesn't go to a classical t=0 moment, then just why should the universe's existence be problematic? It is rather that we are not clever enough to visualise what quantum mechanics means. We can do the maths so that physicists can say things like "one wouldn't have to appeal to something outside the universe, to determine how the universe began", but we can't conceptualise it. As Niels Bohr once remarked, "anyone who is not shocked by quantum mechanics hasn't understood it." But as Richard Feynman said "nobody understands quantum mechanics."

Maybe you are asking "why is there physics at all?" Well, I think superstring theory tells us that there are many different solutions which may correspond to different universes with different physics (see Michio Kaku). Indeed the "multiverse" theory is often described like this, so maybe "anything goes" and physics is zero cost, spawning infinite universes with limitless variants of physics and we can obviously only observe one that is stable and conducive to life.

Ah "why superstring theory" I imagine I hear you ask (that is physics, so the question is still why physics). Well, I still don't understand what exactly a state of "not physics" is.

Thanks for the question. It would be interesting to take this up with your professors at college. When I was studying physics we organised a "physics and philosophy" group which included interested tutors (such as Alastair Rae) and invited speakers - even from overseas. Halcyon days indeed - you should grab the opportunity for something similar, which I imagine should be quite possible at Harvard with its history of Nozick and what looks like a thriving physics department from what I can gather at http://www.registrar.fas.harvard.edu/Courses/Physics.html.

So you should be better placed there to pursue this question than anything I can offer. I'm happy to give you my reading list if you want, but maybe your university can do better for you.

Have you read anything (or spoke to anyone) already which has looked promising on this question?

Best wishes,

Steve

************* End of quote from an old email**********************

As for Islam being a tolerant religion and how all the intolerant Muslims just interpret it wrongly – I get much similar email from Christians asserting that it is their version of Christianity that is right and all the others are wrong, all mutually excluding each other. If you are confident that true Islam is tolerant as you say, then you will have the confidence to prove this to non-Muslims by finding a Mosque where they teach “True Islam” and demonstrate that you are right by taking a recording device and saying to everyone that you no longer believe in Islam, you have become an atheist and that you are gay. Record their reaction and email me the mp3 file.

Regards,

Steve