hello. I am a student of philosophy who has recently become enlightened to the marvels of the known universe through the brilliant words of Dr. Hawking. However, I have serious questions regarding the big bang. All the evidence points to the existence of a singularity that was infinitely hot and infinitely dense which I do not deny. I firmly believe in the creation of the present universe beginning with a explosion beginning some 15 billion years ago. Yet how can this be? How can something as powerful as the big bang come from nothing? There must have been a point in the histroy of the universe where nothing was present because something could not always have existed because then we run into the problem of the infinite regress. My question becomes are there any theories that attept to explain the universe before the big bang, or is this fundamental period relatively unexplored?

One theory is that there are an infinite series of big bangs and then that unicerse collapses in on itself into a big crunch, this then causes the next big bang.

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Welcome to Universe Today, kjpoz!

This is a very interesting question!

However, if I may, your summary needs some qualification.

1) Our two best theories - quantum theory (QFT) and General Relativity (GR) - are mutually incompatible in the Planck regime, which would be approx the first 10^-43 second. This means that, based on the science we have today, we cannot say anything about this era.

2) Finding a theory that is compatible with both QFT and GR, and addresses regimes such as the Planck era is what a great many of the smartest minds are working on today. The current best ideas are String Theory/M-Theory and Loop Quantum Gravity (LQG). More prosaically, a consistent quantum theory of gravity would be very helpful, even if it didn't fully unify QFT and GR.

3) One can, of course, speculate what happened 'before' the Planck era. One can, for example, assume one of the myriad of M-Theories, and see where that takes you. Many folk have done just this (Tegmark, for example, wrote an interesting Scientific American article a few years ago). You need to keep reminding yourself however that, no matter how brilliant the scientist who wrote it, it is speculation.

4) The reason we can't do any better, today, is that the nature of the universe where QFT and GR are mutually incompatible is so far from what we can observe or do experiments with ... There is some hope that the next generation of particle accelerators (e.g. the LHC) will give us a glimpse into a faint echo of effects that would dominate in the Planck regime; likewise, better 'telescopes' (gravity wave, neutrino, cosmic ray, TeV gammas, ...) might do the same.

In response to Matthew, I have already pondered this question and come up the conclusion that there are two possibilities in our search for the answer to the origin of the big bang. The first possibility is that the universe re-collapsed and therefore triggered the present big bank era in which case the present universe, which would be one in a series of universes. In this scenario the universe expands and collapses and the whole process begins anew with a new universe born out of the destruction of the former. If this is the case, we are still no closer to answering the question then if the explosion 15 billion years ago was the first instance of the event in question. I am looking for the explanation of the first instance whether it is one in a series or this is the first instance.
Furthermore, I do not believe in the concept of the infinite. I believe that answering in this fashion is rather similar to evoking the divine when explaining the creation of the universe. Simply there is no such thing and everything mush have a beginning, a creation if you will (pardon the religious connotations) and an end. Nothing can exist for ever, or be created without a beginning. There must be a cause and I am trying to find the answers to the first cause of the universe.

In response to Nereid, you lost me. Are you saying that we got nothing yet?

Basically Nereid has said we cannot yet know the first cause of the Universe. Perhaps later when some other issues are resolved, but until then we don't know.

I am surprised that as a philosopher that you take the position that everything MUST have a beginning, an end, and a cause. Observations suggest that there was a beginning 13.7 billion years ago, and before that this universe did not exist. There is no observation that states that EVERYTHING must have an end. There may well be neutrinos and photons forever. As to a cause for everything... I am not sure where your line is between cause and chance.

The bottom line is that you are asking about something that it is possible that some day in the future people will be able to know, but today we cannot. In the mean time, we continue to try very hard to understand what we do see, and use those observations to test ideas about the underlying principles of our universe.

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Forming opinions as we speak

So here's my question to you, kjpoz: in light of the amazing success of quantum theory (most accurate predictions - by far - of any scientific theory) and its utterly counter-intuitive content (I presume you've read about the Bell inequality, tunnelling, Schrödinger's cat, etc), why do you think that 'pondering' alone will likely produce results that have any relationship with the way the universe is (other than purely coincidental)?Logically, the concept of the infinitesimal is identical to that of the infinite.

Hmm, do you have a PC? Access to the internet? I guess so (otherwise I couldn't read your post). OK, so did you know that, in order to make PCs and the internet, engineers need to make extensive use of 'the concept of the infinite'?

Maybe you meant something different from what you wrote?Gets too close to the UT ban on religion, IMHO, so I won't comment.Why? I mean, do you know this from good observations and experiments? Or is it merely your intuition?Let me try again ...

At the risk of grossly over-simplifying, if you haven't got a good scientific theory*, what leads you to think that any commentary has any significance/validity/etc (beyond pure speculation)?

*i.e. one which can be shown to be internally consistent, consistent with good observational and experimental results, etc. The best we have are QFT and GR. If they are mutually incompatible (when it comes to describing the universe in the Planck era), and if there's nothing better (in terms of scientific theories), then what - sensibly - can you say about 'time before 10^-43 seconds'?

Nereid, I don’t think that I fully understand your question. I am not pondering alone since I posed the question aloud on a forum concerned about the universe. I pondered aloud so that I could get feedback and help to provide ideas to the crucial question I posed at the beginning. Secondly, I believe my pondering alone is what all people do when they are confronted with a seemingly impossible question. They think about it and then they begin to write what they think and share it with other people who share a similar interest. Furthermore, I am not concerned with the way the universe is, my question pertains to the way it came to be, what were the conditions prior to the big bang? What caused it and how did it form?

Also, when you began your discussion of the infinite and infinitesimal I believe that you are somewhat confused. While they are sequential in the New Shorter Oxford English Dictionary dictionary, they relate to two totally different concepts. By definition, infinite means having no limit or end; boundless and endless while infinitesimal means to relate to a fraction which approaches zero, or an extremely small or insignificant quantity.... while they share the same root, they are clearly different in that infinite is limitless and infinitesimal is limited. From what I understand, infinitesimal is used to explain something very small, approaching or nearly approaching zero, but still a concrete, real number. While, I may not be an engineer, (since I have a personality, but seriously…….) I don’t not believe that they work with the concept of infinity since the infinite is a abstract concept and engineers work in the concrete world of concrete rules and hard numbers. Try going up to an engineer say build me a circuit that is infinitely small and infinitely powerful, it simply does not make any sense.

As you may be very well aware, our world and universe is built on numbers (which is why capitalism works so well, but that’s another debate entirely). As we all know mathematics is the language of the universe and its secrets are written in it for all to see. My question then becomes how can one, especially a physicist rationally argue for the infinite when it is a concept fraught with religious connotations used to explain god? So no I do not mean something different from what I wrote. Infinity is a concept born out of ancestors as a way to explain things that they could not explain; to describe god and all his/her/its powers. Nothing is really infinite and everything is reducible to a number no matter how large that number may be. In turn, I will ask you this, show me and example of infinite somewhere in the universe, point it out to me and explain how this thing could have no limits, no boundary, have no beginning and no end and exist forever and I will forever change my views on the subject.


And yes, I know that everything must have a beginning and an end, and nothing can exist for ever and Yes I know this from good observations and experiments. First off, look at you own existence; you most probably had a beginning and will have an end (as depressing as that sometimes sounds) right? Secondly, the planet had a beginning, the solar system had one, the galaxy, and the universe had one (the big bang). And just as each had a beginning, each will have an end, the sun will burn out, destroy earth and all the planets in our solar system, turn into a black hole, radiate information and then completely disappear as will the rest of the stars, or everything will be destroyed in the big crunch. Therefore, everything has a beginning and an end and unless you can prove to me otherwise; I think that you should do some research and prove to me the contrary. As I have said before, show me the money!!!!

Finally, thank you Antoniseb, that’s what I was looking for. Could you please elaborate on the roadblocks and in your opinion, are we close? I am a mere dust speck trying to understand something beyond my limited comprehension.

And what I said was, in essence:
"what were the conditions prior to the big bang?": this cannot be addressed with today's science (indeed, it may not even be a question with any meaning whatsoever)
"What caused it and how did it form?": the answers to these (assuming 'it' = big bang) will be among the many addressed by a theory (or theories) that 'unify' QFT and GR; at the moment there are no such theories with firm foundations in good observations and experiments.

Note that the 'singularity' cannot be 'right'; running the GR and QFT equations to see what happens in the first Planck second yields nonsense results ... a sure sign that one or both theories are 'wrong'.As a philosophy student, I assume you're familiar with Zeno's paradox (Archimedes and the tortoise)? 'Infinite' and 'infinitesimal' are ying and yang; wherever you have one, you automatically have the other.

More generally, rigourous treatment of 'limits' shows this indivisibility clearly. You may already know this: calculus includes the concept of limits, and all engineering uses calculus. IOW (in other words), you can't 'do' the engineering which produces our PCs without using the concept of the infinite.It seems to me that you are using 'infinite' in a way quite different from its normal use in math and science, 'the infinite' as a synonym for 'gods'. In this sense, it seems we were 'talking past each other'.First, since we're talking science, neither of us can 'prove' anything ('proof' is only possible in maths, and has a rather narrow meaning; in the last 100 years or so, we have come to realise that the best we can do, in science, is good theories - they are internally consistent, consistent with other good theories where their domains of applicability overlap, and consistent with all good experimental and observational results, within their domain of applicability).

Second, I can only discuss your philosophical ideas of 'beginnings' and 'ends' in terms of QFT and GR. For the universe, any discussion of 'during or before the first Planck second' must be speculation - we have no good theory for this regime! For the rest, well, in the Standard Model of particle physics (which is based on QFT), the 'fundamental' particles' of the first family are forever; these include the electron, the (electron) neutrino, the photon, and the up and down quarks (unless they collide with their antiparticle!). IOW, in this theory, there is no necessity that 'everything must have a beginning and an end'If I may be so rude as to answer a question you addressed to antoniseb ... today, I think everyone would agree that we cannot detect the 'footprints' of the Planck era (t ~< 10^-43 s), so we have no way of directly testing the only regime we know 'for sure' where QFT and GR are hopelessly mutually incompatible. Yet we need a theory which 'reduces' to each, in the limit of their respective domains of applicability. So our best bets are to explore energy regimes several OOM (orders of magnitude) above those which our most powerful particle accelerators reach. There is some hope that one or more of the extra dimensions hypothesised in various ToEs will become 'visible' in these regimes. Another approach - testing LQG - is to look for the footprints of spin foam in images of extremely distant supernovae. A third is to test GR more stringently, e.g. looking for gravitational waves.

Thanks Nereid, your filling in for me here is certainly not rude, and very welcome. I hope the answer was clear enough kjpoz. I doubt I could say it better. The roadblocks are that we know physics at energy levels and spatial scales very different from what the early universe must have been like, and that our models for how physics work in our familiar space cannot explain accurately the earliest moments of the universe.

Several theories are on the table trying to explain things at the tiniest level, but these are immature theories that can't yet make good numerical predictions, and so there are few tests that can support one versus another.

Personally I doubt that the next generation or two of particle accelerators will be able to say anything definitive on this subject, but they will help on more immediate physics concerns. Concerning when we might know... I don't think it will be in this century.

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Forming opinions as we speak

The big-bang, and the false concepts that go along with it are a figment of human imagination, that can't conceive of anything without a beginning & end.

Prime

One track for this question is whether there are hidden dimensions "curled up"
where we can't interact with them directly but there are theoretical arguments
that gravity is a force that interacts on some level with these dimensions and
one sign of this interaction would be revealed by a close study of the inverse
square law of gravitation but with checking when objects get closer and closer
together. If there are proven deviations from the inverse square law it
strengthens the idea there are hidden dimensions. News at 11.

What a great queistion and I have enjoyed reading the replies... it seems there is a lot we don't know about the first "infinitesimal" few moments of creation. Time , if I am not mistaken was created at the same "moment" ,was it not? So to ponder "time" as we know before it's creation is a paradox to mindboggling for us who are so dependent on it , we are drivin by it like salmon upstream.
b4 the creation moment . a billionth of a second could have stretched for eons until such "time" as the conditions in whatever was, decided to be the new universe... I don't mean that there was an actual decision. but more that conditions were conducive to an event that lead to the Big Bang. be it a big crunch preceding, or something yet thought of, it can and may always be only speculation.
Kipoz , as for an example of the truly infinite, well, start counting and if you run out of numbers let us know...
great debate , thanks for the insight to the possible and maybe the impossible.

Our Time/Space continuum came into existence at the "Big Bang". There was no such thing as time without the "Big Bang", thus there was no before or after. It may be hard to get one's head around the idea of timelessness, but it is a construct of our universe therefore time does not exist necessarily in other universes.

Hello, Wow! some great minds you all have, so I hope you can bare with a less educated thought process per say.

First time in any forum as well, but be that as it may, I often have found my self musing over these ideas and the meanings of our words.

Word ideas that label our thoughts, formed from the information contained in whatever physical entity of interest in nature we probe for real knowledge and translate it into Word/Mathematic communication of its factual cranial reflection .

I know that We are also apart of this whole and all of our objectivity is within the subjective observers observational science views and that produce the interpretation of the observed real World/Cosmos.

Removed lengthy mild religious discussion
jw137, welcome to the UT forum. Sorry to have to cut your first post, but we have rules about religion and politics. Please feel free to join in on any topic.

Thanks, talk to you later.

How did the universe begin is a great question--ubfortunately, it's one science can't answer and never will be able to (objects within a system cannot encompass the entire system except from outside it.) However, wee can toy with philosophical concepts regarding the question (like my own.) I doubt you will belive my concept though--it is the only possible answer though.

We think of a universe of a thing having certain laws and obeying our natural (biased) logic of the need for cause and effec, and a "beginning." You must reject these logics for the pre-big bang (or creation event) universe! The pre-universe contained no laws or restraints at all. There, anything coud happen at any point for no reason at all! Things could appear from nothing and disappear in the same way. Thus the universe came to be, along with time and space, and all the laws we know of today.It will continue to exist for some undefined and undeterminable period of time. That's it! We are biased by the laws we see today and human observation in THIS universe. It's hard to reject that but we must to explain the "beginning" and to avoid the perils of infinite regress present in any other conceivable model.

This is the concept I came up with over 50 years ago when I was a mere 17 y.o. In all this time I've never come up with a better one. Call it magic if you will, but it is what it is--it is the only solution. ...tonyC

Photons are infinite & eternal - from their own vantage point. As massless entities travelling at the speed of light, photons do not experience duration or distance.

There's also the possibility that this universe is a complete accident - a sheer random "vacuum fluctuation" out of nothing. We are here pondering these deep fundamental issues through sheer luck (anthropomorphic principle).

Or perhaps there's external agencies pulling the strings.

We'll never know! And I don't think it's healthy to dwell on it too much!

I expect that was said about a theory that predicted a flat Earth too. There is surely no such thing as a good theory. Observations tend to serve the theory. (We cannot see the edge, so it must be flat.....). And, for the purposes of debate, how do we experiment with a galaxy? The simple fact is we cannot.

It seems to me that the only absolute certainty in the field of Big Bang must be death and taxes.

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Keep seeking whatever it is that sparks the mind. There is more of it there than most people can ever know exists and the effort pays dividends infinitely higher than anything Wall Street deals in.

For what it's worth, Emmy Noether, one of the greatest female mathematicians ever (biography here: Noether Bio) showed that conservation laws (like conservation of energy, conservation of momentum, etc.) derive from symmetries in physics.

Specifically, conservation of energy (energy is never created or destroyed, it only changes form) derives from time symmetry: conduct an experiment today, tomorrow, next year, next century, you will always get the same result (the exact same experiment, of course - ignore technological advances). It is this symmetry in time that leads to conservation of energy. Interestingly, if time began at the Big Bang, it was certainly not symmetric at that point, and energy did not have to be conserved.

I point this out because some people claim that the Big Bang cannot have happened because it would violate conservation of energy. In fact, Noether's Theorem shows that conservation of energy does not apply at the moment of the Big Bang, and also provides a clear answer to the question, "What was before the Big Bang?" The answer is, there was nothing before the Big Bang, no time, no space, nothing.

By the way, current observations show that the expansion of the universe will not slow down - there will not be a Big Crunch. So the infinite progression of universes (Big Bang, Big Crunch, Big Bang, Big Crunch, ...) is not supported by current observations.