- #1
pellman
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Occasionally I come across statements to the effect that quantum field theory has replaced particles as the basic consituent of matter with continuous fields. Is this right?
From what I understand, a quantum field is an operator field. Which is to say--I would think--that by itself it is meaningless without something to operate on. And what do these operators operate on? Quantum states--essentially the same kind of quantum states that we encounter in quantum mechanics, right? So aren't we still talking particles?
Sometimes I read someone saying that particles are really just excitations of a field. Of an "operator field"?
Isn't it the case that the field really consists of raising and lowering operators that govern pair production/annihilation? So that, with the field "turned on", a quantum state consisting of an electron and a proton, for example, is no longer orthogonal to a state consisting of zero electron/positrons + 2 photons. That is, there is a non-zero probability of observing 2 photons instead of the electron+positron that you started with. But we're still just talking regular-old particle quantum states, right? or wrong?
Hoping someone will clarify this for me.
Todd
From what I understand, a quantum field is an operator field. Which is to say--I would think--that by itself it is meaningless without something to operate on. And what do these operators operate on? Quantum states--essentially the same kind of quantum states that we encounter in quantum mechanics, right? So aren't we still talking particles?
Sometimes I read someone saying that particles are really just excitations of a field. Of an "operator field"?
Isn't it the case that the field really consists of raising and lowering operators that govern pair production/annihilation? So that, with the field "turned on", a quantum state consisting of an electron and a proton, for example, is no longer orthogonal to a state consisting of zero electron/positrons + 2 photons. That is, there is a non-zero probability of observing 2 photons instead of the electron+positron that you started with. But we're still just talking regular-old particle quantum states, right? or wrong?
Hoping someone will clarify this for me.
Todd