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Writer's picturePeter Haycock

Is physics right?


Someone sent me a quote recently by JBS Haldane in his 1928 book Possible Worlds: "Now, my own suspicion is that the universe is not only queerer than we suppose, but queerer than we can suppose." That seems to be absolutely true. Physics, the most fundamental of the sciences in terms of the basic nature of the Universe, ultimately tells us something that is completely bizarre. So is physics actually right?


As a physicist myself, I am unlikely ever to say that it is completely wrong. However, we need to consider what physics actually is in order to understand the answer, or even perhaps the question. Many people put their faith in the fact that science is generally right. It does indeed tell us a lot that is true. However, we have to recognize that science aims just to give us the best 'model' that we can find of the Universe and how it works, largely so that we can predict what will happen if we do something. If we have a model which says that stones rise up if dropped, then it must be wrong. Our model of the Universe is constantly being tested by experiments and then modified to fit better to what is actually observed - stones fall. These models are essentially mathematical, so that we can be precise about, for example, how much a car will accelerate if I push the accelerator pedal down a certain amount, or if a rocket with people on board will reach the moon when pointed in a certain direction at a certain time. We can, of course, then talk about these models in words - that is when we can realize that some of what they say is really strange.


In order to understand the nature of this amazing Universe, our minds come up with concepts which are truly bizarre. Perhaps God sees it more simply because he has a bigger mind.

We do know that there are some key aspects of physics which are actually wrong at the moment and if you look on the right pages, you will find quite a bit about this in the media. For example, the rate at which the Universe seems to be expanding is quite contradictory, and it appears to be increasing, so physicists talk about 'dark energy' which causes this. There is also not enough matter in most galaxies for them to be rotating in the way that they are, so physicists talk about 'dark matter' as well. We don't really have any idea what dark matter or dark energy are, although they make up about 95% of the Universe if current concepts are correct. For a brief description of them, you could do worse than consult NASA.


Our current model for gravity is Einstein's general relativity. So is Einstein right about the Universe, but we just don't know enough about what it is composed of, or is the Universe actually what we see? If the latter, was Einstein wrong and we need to change our physics? As you will have seen if you looked at the NASA article, physicists are divided about this. Einstein effectively gave us the concept of curved space-time to describe what we observe as the force of gravity. Is that very counter-intuitive idea actually how things are, or is it really just a model that gives us the right mathematical predictions? In fact, there are often different ways of describing and explaining the same phenomena, which are equivalent to each other. There are alternative theories to Einstein's which explain some of the issues that his general relatively doesn't, without the same reliance on dark matter and dark energy. These theories are sometimes also quite good at explaining what general relatively does, but tend not to hold up as well overall. Nothing at the moment is as good as Einstein's geometric concept of gravity in curved space-time. Yet, it is just a model and requires vast amounts of dark energy and matter, for which there is no direct evidence.


I would like to give one other example of a model. The more we look at electrons, the more tenuous their existence becomes. The standard model of particle physics is based on quantum fields. We are familiar with magnetic fields: if you are in one and you have a piece of iron on you, you will feel it being pulled in one direction or another. Similarly, an electrostatic field will pull you your hair towards a balloon that has been rubbed; indeed, when a large electrostatic field breaks down it can cause lightning. There is also a quantum electron field everywhere all the time and when it becomes excited, we recognize that as an electron. So the tiny particle that we know as the electron is described as a quantum excitation in the electron field. When we try to look at the electron as a particle, we find that it isn't really a 'thing' but we can just say that it has certain properties. 'The electron is a quantum fluctuation in a field that has properties that make it seem to be a particle' is about as close as we can get to a description in words of the most useful mathematical model. When I get to that point I always ask myself, "Is this actually what reality is, or just the best way that we can get useful mathematical predictions about electron behaviour?"


If this is reality, then how God manages to turn electrons and atomic nuclei (which have the same kind of nature) into all that we see around us is quite miraculous. Physics gives us a means of making a lot of correct predictions about what will happen if we do something (which is very useful when playing snooker) but how much it tells us about what things actually are is another question. I wonder how God thinks about it all.

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