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Preface: I know nothing. Is it really a problem that we can’t apply special relativity to subatomic particles? Doesn’t the very nature of our measuring systems

Preface: I know nothing. Is it really a problem that we can’t apply special relativity to subatomic particles? Doesn’t the very nature of our measuring systems being made of atoms and subatomic particles mean they will always destructively interfere with any quantum effect we wish to measure?

Etheryte 3y ago
Even if your measuring system interferes with the measurement, if the interference is small enough or diverse enough based on the conditions, you can still learn useful things.
prof-dr-ir 3y ago
But we do apply special relativity to subatomic particles, using a framework called relativistic quantum field theory. It is important to consider relativistic effects when the subatomic particles move close to the speed of light, which they do in particle accelerators. So the outcome of accelerator experiments is described extremely well by relativistic quantum field theory. The hard part is combining the principles of relativistic quantum field theory with general relativity, or gravity, which describes how matter propagates in a space curved by its very presence. The effects of gravity are indeed completely negligible in particle accelerator experiments, which is why we can describe their outcome in a theory that does not include gravity. But these same effects dominate in other scenarios, for example in early universe cosmology and black hole physics. Understanding the physics of these other scenarios is one motivation, but on top of that physicists just find it really irksome to not have a single theory that (at least in principle) describes all physics at once, because it indicates that they are missing something fundamental. That is why they are working so hard on topics like string theory. All of this is is no way related to the article, by the way. First, everything related to the measurement 'paradox' is a big deal in popular science but firmly in the rear view mirror for almost all practicing physicists. Second, the experiments discussed in the article are described perfectly with ordinary quantum mechanics, which in the above context is just a limiting case of relativistic quantum field theory. (In particular, of course doing a measurement means interfering with the system, but that is all understood perfectly well and does not mean that we cannot observe quantum effects.)

Etheryte 3y ago

Even if your measuring system interferes with the measurement, if the interference is small enough or diverse enough based on the conditions, you can still learn useful things.

prof-dr-ir 3y ago

But we do apply special relativity to subatomic particles, using a framework called relativistic quantum field theory. It is important to consider relativistic effects when the subatomic particles move close to the speed of light, which they do in particle accelerators. So the outcome of accelerator experiments is described extremely well by relativistic quantum field theory. The hard part is combining the principles of relativistic quantum field theory with general relativity, or gravity, which describes how matter propagates in a space curved by its very presence. The effects of gravity are indeed completely negligible in particle accelerator experiments, which is why we can describe their outcome in a theory that does not include gravity. But these same effects dominate in other scenarios, for example in early universe cosmology and black hole physics. Understanding the physics of these other scenarios is one motivation, but on top of that physicists just find it really irksome to not have a single theory that (at least in principle) describes all physics at once, because it indicates that they are missing something fundamental. That is why they are working so hard on topics like string theory. All of this is is no way related to the article, by the way. First, everything related to the measurement 'paradox' is a big deal in popular science but firmly in the rear view mirror for almost all practicing physicists. Second, the experiments discussed in the article are described perfectly with ordinary quantum mechanics, which in the above context is just a limiting case of relativistic quantum field theory. (In particular, of course doing a measurement means interfering with the system, but that is all understood perfectly well and does not mean that we cannot observe quantum effects.)