Sunday 7 September 2008

Conversation With Richard - Big Bang Or Big Whimper?

Hi Richard

I hope you got my email with a piece from Reuters on Dark Matter. I cannot reproduce it here because of copyright restrictions. Nor can I provide a reference to it because pieces by Reuters' journalists only survive a few days and are then removed as yesterday's news. I do find journalists are exceptionally good at reporting on this particular subject and I recommend Reuters as a source of news for anyone. I have it fed to my email box several times a day, all for free.

Dark Matter and things to do with the Big Bang are very much in the news this week, in any case, with the switching on of the Large Hadron Collider at CERN on Wednesday. and to celebrate Radio 4 is having a Big Bang Day. This, at least, means that a lot more people are better informed about the state of our scientific knowledge at the present time. I am, therefore, going to take the opportunity to review what I think the state of play is at the present time.

Science, in its various forms, begins from the proposition that the cosmos is made out of substance which, nowadays, is commonly referred to as matter. By very careful observation and experimentation it has been established that matter behaves in quite specific ways, never randomly or unpredictably. The job of all scientists is to detail exactly how this process operates. In order to do this the scientific community put forward various theories to explain a particular part of the story of matter and then set about testing their theory to see how robust it really is. If they find there are problems with a particular theory they will refine it or replace it with a better one. Their belief is that, even though scientific knowledge is changing, it is always moving forward as each new theory is improved upon. The totality of knowledge about matter is growing.

There are, of course, many gaps in the scientist's knowledge. The discovery of Dark Matter is a very good example. Not many years ago the scientific community came to the conclusion that there was another form of matter, as yet unrecognised. This version of matter was invisible and could only be discerned by its gravitational effect, hence the name Dark Matter. It is believed to account for something around 80% of the matter in the universe. Incredibly, we know very little about either it, or it's associated Dark Energy. I have dug out a Reuters piece from 07 Sep 2006, just 2 years ago, reporting on the CERN LHC. The quotes are from Brian Cox of Manchester University:

"We don't know what 95 percent of the universe is made of - which is a bit embarrassing for a subject that claims to be fundamental... There is Dark Matter. It is all over the place but we have no idea what it is."

"There is also something called Dark Energy, and that is an even bigger question. It makes up about 70 percent of the energy in the universe but again we have absolutely no idea what it is."

Now, if that were the end of the story, we could leave the scientists to get on with their quest and wish them good luck. However, in spite of their self-declared ignorance, they claim that what they are doing is the answer to all knowledge, that there is nothing else in the universe except matter or matter like derivatives and that their quest is, in fact, a theory of everything.

Most people understand conventional physics, put crudely how things we can see work. They can extrapolate from that some idea of how the totality of the universe might work in a similar way. However, alongside all of that there has been developing what is called particle physics, which is the science of the small, very, very small. Although sub atomic physics has been around for about a century it is still a huge puzzle to scientists. Initially, it was believed that there were only a few bits inside the atom. Indeed, the very word atom means an indivisible unit. I think the present count is something like 8 but don't quote me - they may have found some more by the time you read this! The frustrating thing is that as well as finding particle physics just gets more and more complicated, there is a serious problem about linking it in with conventional physics. Unfortunately, the maths just does not add up. Here we go again, I hear you say. So, we have hypothetical Dark Matter and hypothetical particle matter and the only way to make sense of the 2 is to posit another missing bit, known as the Higgs boson particle. The problem is about making sense of mass and the Higgs boson would endow the necessary mass. The trouble is, so far, no one has been able to isolate it. Enter LHC. The prize which the scientific community is hoping to win, as I say, is a theory of everything. They wish to join together the science of the large with the science of the small. LHC will examine the basic structure of the universe and, hopefully, explain how the Big Bang happened and what happened then and then, and then.

I wonder what fate lies in store for my now quite famous quip about astro physics:

"In the beginning was nothing - and then it exploded!"

There are 2 ways of looking at this. The scientific way is to say that matter is all we have and it has to explain everything. If we get bits of it wrong, so what. The quest goes on. All that proves is that we are struggling. The project is still worth while. Crucially, everything is made out of particles.

The other way is to say, yes, understanding matter is worth while but where is the evidence that there is nothing more to it than that? We think in material terms most of the time. Matter=facts. Matter=existence. Matter=real. I am not sure that we can even think of existence without thinking matter. And this is becoming so invasive now that even the likes of feelings are considered to be materially produced. And what of God? I wonder how many people today believe that man created God in his own image and not the other way round. But even so the idea is very material like. God does seem very much like a Dark Person.

We have some knowledge of substance and how it works, but this is very limited. We are getting close to being able to make scientific comments on the moment the Big Bang occurred. Where does this take us? In my view, not very far at all. Science, at the moment, has its hands full trying to understand the process tracing back to the Big Bang. But there must have been something there waiting to go Bang. Where did it come from? And if that traces back to another Bang, or a thousand Bangs... What if the universe is one of many contained within many... where does that leave us?

The answer, I would suggest, is the same as it has always been. Science is not erroding philosophy because science cannot answer philosophical questions. It can only answer scientific questions. The details will change but that fact will not. How do I know this? Because science, patently, is dealing with process - how things work - not where they came from. Follow every scientific process to its logical conclusion and you will find yourself in an infinite regress. Science is not an explanation - it is a method. To be honest, it amazes me that so many people have trouble with this concept. Perhaps my mind is more logical than most. The difference between how matter works and where it came from seem so obviously different to me. Let's try approaching it scientifically. Imagine we have a little package, pre-universe, which is about to explode, and bear in mind, this actually happened, how did it come to be there, just waiting to explode? Let's suppose you say to me "It grew, by a scientific process". We then go through the same process again and we get back to the package that grew into the one that eventually exploded. How did that come to be there?

That is an infinite regress and it is why science cannot explain everything.

I will leave for another time what can explain everything and, indeed, the other points made in your reply. I think we have plenty to consider already!

Peter Rayner

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