John Humphrys - A Theory of Everything : Do You Believe It?

April 09, 2021, 1:21 PM UTC

It seems scientists have discovered a new force of nature. They’re extremely excited about it. The problem is that most of us probably won’t have the first idea why. It doesn’t help much to be told that it’s to do with things called muons. Muons are very small particles – far smaller than atoms which we once thought was as small as it gets. They’ve managed to make them travel at stupendously high speed and they expected that would make them wobble. But it didn’t.

That’s why they think there is a new force at play which might explain the mysterious stuff known as “dark energy”. They’ve never been able to prove it exists, but they’re pretty sure it does and (this is the crucial bit) it’s probably what is causing the universe to expand.

It doesn’t matter whether you or I understand all this stuff. After all, most of us aren’t theoretical physicists. But many who are say it takes science a step closer to developing what they call the “theory of everything”.

Yet even if we do discover exactly how the universe works there remains a question that can never be answered. It can be expressed in just one word: Why?

Popular science, and especially popular physics, is a difficult game. It involves trying to translate into ordinary language you and I might understand something that is originally conceived not just in a different language but in an entirely different sort of language, usually mathematics. It’s a noble endeavour because the rest of us want to know what the scientists are discovering. Yet the traps are obvious, both for the would-be simplifying writer and the unwary reader. Some popularising physicists keep enthusiastically telling us that they’re on the verge of formulating a Theory of Everything that will settle our understanding of the Universe forever. Some go further and promise that such a theory will show us the face and mind of God. Should we have faith that they will?

It was Einstein, a hundred years ago, who first spoke of the possibility that a theory in physics might show us ‘the face of God’. What he was talking about was the reconciliation of two apparently incompatible theories about how the Universe functions. It was something that would preoccupy many theoretical physicist of the latter part of the twentieth-century, including Stephen Hawking. He told us that a Theory of Everything was just round the corner. He died trying to deliver it but his successors are still claiming that they’re almost there.

The latest is Michio Kaku, a physicist at City University, New York, who lost a famous bet he made back in 2002. He wagered £1,000 that by 2020 a Nobel Prize would have been awarded to the physicist who had finally produced a single equation that would explain everything. He still thinks we’re on the brink of it and has just published a book about it called ‘The God Equation’.

What should we ordinary mortals make of this century of claims that physicists are on the verge of explaining everything in a single equation? The first and most obvious point is that a hundred years is a long time for something to be only just beyond our grasp. At the very least we are entitled to be a little sceptical. It’s also possible that the very idea of a Theory of Everything is a bit of a hype, perhaps the product of the unwary zeal of popularising scientists. What these physicists have really been trying to do is something evidently difficult enough but far more modest than the hype would suggest. They’ve been trying to reconcile the two apparently incompatible theories about the nature

of the universe that emerged at the beginning of the last century: Einstein’s Theory of Relativity (which essentially looks at the universe at the level of atoms and larger) and the Theory of Quantum Mechanics (which looks at it at a sub-atomic level). Clearly, it would be a massive achievement to reconcile these two – the delay in doing so is evidence enough of that. But to say that to do so would explain ‘Everything’ is a bit of a stretch.

Even more of a stretch is the claim that by reconciling these two theories physicists would have settled everything for good and could then pack up and go home. In fact, however the popularisers might put it, few reputable physicists would make such a claim because they know that that’s not how science works. What they are in the business of is creating models of how they think the Universe (or, indeed, anything) works. Such models never become sufficient for all time. They get modified as evidence throws up anomalies that don’t fit. Very often the anomalies are so great that the original theoretical model gets junked entirely, or at least superseded by new theories which identify the old theory as just a special case that holds only in certain circumstances. That’s what both Einstein’s theory and quantum theory did to the old Newtonian model of a mechanical universe. Models depend on how scientists look at the universe: the nature of their attention changes what they see and models and theories then change accordingly.

This familiar process is what’s been happening with the so-called Theory of Everything. The current front-runner for such a theory, postulated by Michio Kaku many years ago, is what’s known as String Theory. In the popularised way he expresses it in English, he says that sub-atomic particles may be considered as consisting of hundreds and hundreds of tiny musical notes playing on a string; physics expresses the harmony of those strings; and the Universe is a symphony of strings: ‘cosmic music resonating through the universe’. (I’d give you the mathematical version but I’m a bit short of time.) Professor Kaku concedes that the theory has split the world of theoretical physicsts right down the middle and many don’t agree with it at all. What’s more, recent experiments using the large hadron collider at CERN in Switzerland have thrown up ‘anomalies’ requiring string theory advocates to go back to the drawing board.

In short, the Theory of Everything isn’t quite what the billing suggests; it won’t answer the question for good; and far from being imminently achieved looks likely to take yet more time. Or, in other words, it’s what any sober scientist would tell you is the nature of any scientific theory: always provisional, never complete and most certainly not about ‘everything’. And nothing wrong with any of that: it’s how human knowledge progresses.

But what about the ‘mind of God’ bit? We enter dodgy territory when we talk about science and theology in the same breath. It’s not that we can’t – far from it – but we have to be careful. The prevailing view of our times is that the two are not just in conflict with each other but that it’s combat to the death. Or at least that’s how some scientists see it. They regard religion as making bogus and false scientific claims. And to read some long-dead prelates you can see they have a point. James Ussher, Archbishop of Armagh, published a book in 1650 in which he calculated that the date of the creation of the universe was 23 October 4004 BC. Charles Lyell, the great nineteenth-century Scottish geologist who was such an influence on Charles Darwin, pointed out that the fossil record suggested this might be out by a few billion years.

Religion never recovered in the eyes of some scientists. Militantly atheist scientists tend to see religion simply as bad science and to regard God as a theoretical scientific postulate for which proper science has never found evidence and so can be junked as a theory that doesn’t pass muster. Science alone can explain everything and using terms like ‘God’ is just a sort of indulgence: if it helps sells popular books about science, then what’s the harm so long as no one runs away with the idea that God actually exists in the way that Mars or black holes do.

But there are plenty of scientists – indeed some of the very greatest – who would say that even to think of God in this way, as a discarded theory physics has demonstrated to be false, would be banal in the extreme, the result of zealots drinking their science without water. And many of them would most certainly not regard themselves as atheist. For them, just as it is mistaken to think that religion (pace Archbishop Ussher) makes scientific claims, so also scientists shouldn’t make seemingly religious claims, such as that a Theory of Everything amounts to showing the face of God. For them, religion and science are clearly separate things that shouldn’t be confused with each other. But they are not opposed.

Their point is this. Science is a never-ending quest by human beings to make disciplined sense of our Universe given the limits of physical and mental capacity inherent in our being a particular sort of animal with a particular set of equipment. But given those limitations there are some questions that are and always will be beyond our capacity to answer in a scientific way. The most obvious of these questions is: ‘why does the Universe exist at all?’ Science can address the ‘how’ questions (and even aim to reconcile apparently incompatible answers to such ‘how’ questions), but such ‘why’ questions are beyond its scope.

Atheistic scientists tend to say that any questions that science cannot in principle answer are then, by definition, meaningless questions and so shouldn’t be asked in the first place. The point is, though, that human beings do ask such questions, always have and always will, and scientists who are not militantly atheistic respect the fact. For them questions are not invalidated because they cannot be given a scientific answer; rather, the fact that science can’t answer them shows that we have to treat such questions in a different way from the way scientists treat questions (by assuming there is an answer). What theology explores is what we mean by asking questions that won’t go away but that science can’t answer.

The philosopher, Ludwig Wittgenstein, put it like this. ‘Even if all possible scientific questions be answered, the problems of life have still not been touched at all.’ And like this: ‘To believe in a God means to see that the facts of the world are not the end of the matter.’ And the theologian, Herbert McCabe, said: ‘When we speak of God we do not clear up a puzzle; we draw attention to a mystery.’ This would rather suggest that authentic ‘God-speak’ can’t be translated into an equation.

Such is our attachment to scientific explanation (understandably so, given the power it has afforded us to control the world we live in), our culture has tended to require all questions to be answered in the form of statements whose truth we assert. But from much earlier periods in human history, people have not thought that this is the way to deal with ultimately unanswerable questions such as why the Universe exists and why we are here. Instead, they told stories about the Universe in order to try to make sense of it – they are called myths, a word our more narrowly scientific culture dismisses as meaning ‘false truth’. They created rituals in response to their sense of awe at the ultimate mystery of existence. And, recognising their own finitude and insignificance, they worshipped what they knew not just to be mysterious but unknowable and greater than themselves. Some of our greatest scientists over the centuries (including Einstein) have done all these things and not thought it incompatible with their life as scientists.

In summary, science attempts to find explanations for as much of our experience as is explicable in its terms. Theology (unless practised by dogmatists) respects that and acknowledges that this is science’s legitimate and exclusive domain; but it also, knowing that much of our experience is inexplicable in scientific terms, seeks to focus our attention on the incorrigible fact of the eternal existence of the inexplicable.

Perhaps we need to bear this in mind next time a scientist breathlessly tells us a Theory of Everything will be along Tuesday week and that then, at last, we’ll be able to see the face of God.

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