Does the EPR “paradox” tell us anything about Physics?
Well the trite answer is yes of course it does – but can we be a bit more specific?
Physics is an “after the fact” science relying on experiments and the observations on the results of those experiments. What do I mean by “after the fact”? I mean you set up an experiment to measure some property or event and the experiment, if successful, will give you a numerical value for that property or event, so far you have learnt absolutely nothing new – but please keep with it 🙂 By setting up various different experiments and conditions we can measure the mass, “apparent” size and the charge on an electron. But we cannot say WHAT an electron actually is. Why not? Well one reason is we don’t know how to set up the experiment to do that. The experiments we set up measure the PROPERTIES of an electron – that is all. We can smash things together in high energy particle accelerators and see how various particles are created (or annihilated) and what the energies involved are – but these experiments say nothing about what the particles themselves are. How can they? They are only measuring the EFFECTS that the particles themselves create.
Mathematical Physics is great at providing predictions. It still requires the experiment to be performed to give the mathematical predictions any substance – any “reality”.
This situation is rather like the 4-year old kid who keeps asking why? to an initial answer to a question. Eventually we come to a stopping point.
The EPR “paradox” was thought up as a hard test for the theory of Quantum Mechanics. Quantum Mechanics gave its answer, a nasty answer that goes (like most things in Quantum Mechanics) against common sense. Aspect and some other brilliant experimentalists created beautiful experiments to measure the results of an EPR-type problem, and yes, Quantum Mechanics gives us the same answer as the experiments and common sense doesn’t. But can you take things further than this? Can you, with the information provided, say anything about the MECHANISMS involved? I don’t see how this is possible. You created the experiment given the parameters you wished to measure to confirm (or otherwise) the EPR “paradox”. You did not set up the experiment to look at the MECHANISMS involved (and basically you wouldn’t know how to do this anyway) so why would you expect an EPR-type MEASUREMENT to give you an insight into the underlying mechanisms? This is very much the situation of the 4-year old kid asking “Why?” one time too many.
But if this is the case, doesn’t every experiment and every part of Physics run into this very same problem? Even the simplest Physics that we think we know EVERYTHING about? I think it has to – doesn’t it?
Let’s take a very quick look at Newtonian Mechanics – not much there we don’t know everything about is there? Masses flying about, velocities, energy (potential and kinetic), acceleration, inertia – oops what’s that one? Inertia? What’s that then? Well it’s the resistance to an applied force exhibited by any body possessing mass. Yes but what IS it? Well it’s possibly caused by the interaction of the body with all the other mass in the Universe – but actually we really don’t know. And what is mass anyway? I don’t think the Higgs Boson goes very far in telling us what “mass” actually is. So even in a science that we think we know quite well and that was dealt with a couple of hundred years ago sufficiently well for us to send space probes on Grand Tours – we don’t have to go very far back with the Why? question to hit our stopping point.
A lot of these Physics problems come down to “fields” as their ultimate answer, where “fields” is a great euphemism for “I don’t know”. When Maxwell came out with his 4 equations for electromagnetism he hit similar issues with the scientists of his day. What were these “fields” where are the “springs” and the ether that carry these waves? What are the mechanisms? I guess I am also asking what the “springs” are in all our theories – and my contention is that we simply don’t know.
If we’re stuck in asking the basics of such “very simple” questions – then where do we stand in asking the biggies? What happened before the Big Bang for instance?
The Scientific Method is a very powerful tool for explaining what we can observe, it should be, after all the experimental method has proven to be a great way to provide the hard numbers to our observations. But for the underlying mechanisms? What do we do for those?
I have a very strong feeling (shouldn’t really allow “feelings” to come into it – that’s getting into Metaphysics 🙂 ) that we are seeing EXACTLY the same problem rearing its head that we have already seen in mathematics. Godel’s Theorem didn’t help us much there – but at least mathematics has a name for the issue – Physics doesn’t. How about Greg’s Enigma??
