Quantum Mechanics and the Nature of Belief

I often tell people I don't believe in quantum mechanics – here is what I reckon.

First up. Here is my brief summary of what QM is. Quantum mechanics is the branch of physics that deal with really small shit. Shit that is so small it literally is invisible. (Mostly cos it is smaller than the wavelength of visibly light.) In our everyday world there are two types of shit: continuous shit (like milk and love) and discrete shit (like cows and apoplexies). The essential thing in quantum mechanics is that the small invisible shit is always discrete, i.e. it comes in individual quanta.

We should clarify exactly what it is and what is it not that I don't agree with. As a system of equations for predicting the outcomes of experiments nobody (even me) can argue with QM. You set up some lasers and stuff and QM tells you what is going to happen, and then it does. Sometimes those predictions are statistical in nature, so you do your experiment a hundred times and it behaves like you expect. Whatever. In this sense QM is very well tested. What I don't like is the "accepted" interpretation, viz. the Copenhagen interpretation.

The Copenhagen interpretation sounds barking when you hear it, and there has been plenty said against it. Especially when it first appeared. But it seems to have stuck for lack of something better to replace it. In short, it says that when physical systems (e.g. a particle) are not being observed they spooge around into an amorphous blob. Then when somebody looks at them they instantaneously snap back and become fixed in one specific state. Just so long as you keep looking. (Quantum Zeno effect.) The simplest example of this is to consider just one particle, "at rest". Quantum mechanics tells us that whenever you look at it, it could be anywhere, but it is very likely to be near where you last saw it. The exact description of this involves a Gaussian probability distribution.

68% of the time the particle will be extremely close to where you left it
95% of the time it will be very close to where you left it
99% of the time if will be quite close to where you left it

So, you get your particle and then go make a cup of tea. While you are doing that it is apparently not a particle (not point-like anyway) but happy spreading itself all over your lab. Then you get back and look at it and it becomes a point-like entity, somewhere near where you last saw it. The key point here, is that it didn't just wander from where you saw it to last to where it is now, but when you weren't looking it was everywhere and nowhere all at once. Then you look and the particle actually changes its physical state. You used the power of your mind to alter the physical world.

I don't like that it is "accepted" by scientists when there are plenty of people that don't accept it. If somebody writes and argues against the Copenhagen interpretation then people accept your views and may try to counter your arguments. If you don't say anything (perhaps because you don't work in that field at all) then there seems to be tacit agreement. Grr...

Perhaps the first and most famous of all arguments against the Copenhagen interpretation is Shrödinger's cat. I am sure you are all familiar with the idea. You have a box with a cat in it (and some other details) and before you open the box (or shake it of find out what is inside by some other means) the cat is neither alive nor dead. But rather is in a "superposition of states". Both alive and dead at the same time. Then you open the box and find out which it is. Schrodinger came up with this gedankenexperiment to argue that whatever craziness we are prepared to accept at the microscopic scale must also occur at the macroscopic level. He was banking on people accepting that atoms and light could do crazy things like be in two places at once, but people wouldn't accept that a cat could be both alive and dead would they? Well they (apparently) did, and not only that, but his idea is now one of the main ways to tell your friends how crazy-cool-exciting QM is. Instead of going "whoa, that is awesome" my reaction is more like, "the physics (or the interpretation) going on is clearly bollocks."

Another famous opponent of the Copenhagen interpretation was Albert Einstein (who now has reduced himself to appearing in commercials selling bread.) He devised another gedankenexperiment to show that if you accept the Copenhagen interpretation then you must also accept that either particles can behave in a "non-local" way, or information can travel "faster than light" (perhaps even instantaneously – but we don't need to get into relativity). It seems that "scientists" really don't want to think about shit going faster than light, so grudgingly accept "spooky action at a distance". The particular thought-experiment I am referring to here is known as the EPR paradox. (Cos it was published by Einstein, Podolsky and Rosen

Science doesn't seem keen on the EPR paradox and really wishes it wasn't there – perhaps because the authors were Jewish. If these ideas had been put forward by another group, perhaps from Sweden then the Copenhagen interpretation would have been thrown out years ago. It has certainly outstayed it's usefulness – if only there was a good alternative. The EPR has been experimentally verified, the guy credited with that is Alain Aspect.

Alain Aspect has an awesome moustache...
...he is also French.
Alain Aspect discovered the Aspect Ratio – the single most important leap forward in the development of the widescreen TV.

So we have this situation where physicists continue to spout the virtues of these ideas even though the ideas are themselves ridiculous and lead to even more crazy properties which we are also supposed to believe. I just wish that they would accept that it is their choice to believe these things and nothing more. That choice is just as valid as creationists who stedfastly insists that the world is 5000 years old and that dinosaur bones were put in the ground by God to test our faith. Each situation is internally consistent, and I hope you can see now that I see them as being quite isomorphic. But the populace in general regard them very differently. We see these amazingly intelligent scientists that can do really hard maths and treat their beliefs differently to those of the Bible-bashing soccer-moms of the southern states.

We need to accept that at some level all science (and maths) is a matter of faith. Indeed one can't use reasoning to prove that your reasoning is sound. (You can't prove that you are sane, you just have to believe it.) We have clearly reached the point in some sciences where they are merging with philosophy, this is because we have reached the limits of what can be shown experimentally. (On another tack you can't deny the possibility that there is some completely different "reality" going on, where consciousness and the "physical" world are much more connected than we currently like to think. Maybe we first decide what we want to find in our experiments, and then our minds cause that to happen. You would have a tough time devising an experiment to prove that was not the case.)

One clear example of this is the quest for some Grand Unified Theory. We may never know if string-theory is right, or if it is right, then which one. Cos they mostly make the same predictions, and where they do differ the experiment necessary to determine which is right is all but impossible to perform. People in this area have realised we aren't going to be able to empirically choose the "right" theory, and start looking for the "most beautiful" mathematical description.

Another possibility is that there is no theory to describe the subatomic world. We are used to things in our world behaving in predictable and normal ways. And we have used maths to describe their properties and predict what will happen in the future. We discovered Newton's laws of motion and Maxwell's equations and all that and created a whole industry out of explaining the nature of things. So we naturally assume (believe) that this will continue to every possible domain we can investigate. But perhaps the world of very small things doesn't obey mathematical laws, why can't it just do whatever the hell it wants to, and the laws we know and love and use to make TVs and burgers are just some sort of law of large numbers.

Final thoughts:

Here is a quote about QM from N. David Mermin – physicist at Cornell University

Physicists fall into three categories: a small minority is troubled by the philosophical implications; a second group has elaborate reasons why they are not troubled, but their explanations tent "to miss the point entirely"; and a third group has no elaborate explanations but also refuses to say why they aren't troubled. "Their position is unassailable," says Mermin.

and

If I run over a cat and don't get out to look at it, is it dead?