Return to Answer

If you look at dBB theory, there is a quantum potential energy (which is determined buy the wavefunction an there is a classical potential. Both together guide the particle through configuration space. So what regular quantum mechanics thinks of as kinetic energy (i.e. not potential) is to dBB theory sometimes quantum potential energy and sometimes is the actual motion through configuration space. Do not confuse the motion of the particle(s) through configuration space (and the associated energy) with the regular kinetic energy operator from quantum mechanics. The regular kinetic energy operator from regular quantum mechanics contains two terms.

If you look at dBB theory (de Broglie-Bohm theory), there is a quantum potential energy (which is determined buy the wavefunction an there is a classical potential. Both together guide the particle through configuration space. So what regular quantum mechanics thinks of as kinetic energy (i.e. not potential) is to dBB theory sometimes quantum potential energy and sometimes is the actual motion through configuration space. Do not confuse the motion of the particle(s) through configuration space (and the associated energy) with the regular kinetic energy operator from quantum mechanics. The regular kinetic energy operator from regular quantum mechanics contains two terms.

Please accept that in regular quantum mechanics there is classical potential energy and "all other energy" and that a Copenhagenist will say that that energy is all kinetic, and hence that there must be momentum in a situation where dBB theory has no motion whatsoever. The two theories radically disagree on when there is momentum in the system. So you can't just describe a double slit experiment as an experiment to "transfer momentum" when talking about two theories that radically disagree about who has momentum and when.

People agree that that's why and when it is meanful to say an experimental result has occured. They simply disagree about the words they use and the stories they tell. Which is why it is not helpful to use words from Copenhagen that don't have exact cognates in dBB, it confuses the issue aboutwhat you are talking about.

And a double slit is clear. You have something somewhere that moves differently based on whether the screen/hitter interact in one place versus another place. Could be air molecule near the screen, could be your eyeball, could be the ink on your lab notebook or the parts of your hard drive or the parts of the screen itself, it could be lots of things. The wavepacket for those different options start to separate and eventually will never again overlap in configuration space, the part of the wavefunction that has the world particle is what happened, the other packets are the empty packets, and you can ignore them now because they no longer do anything measureable or detectable. Wether the dBB theory says that motion can from a transfer of kinetic energy from the traveler to the screen or from a transfer of quantum potential energy from the traveller to the screen doesn't matter and ... is not obvious. It could depend on whether the particle was in the leading edge of the wavepacket or a straggler near the tail. The theory will tell you, but you can't just assume it because you want to assume it.

Please accept that in regular quantum mechanics there is classical potential energy and "all other energy" and that a Copenhagenist will say that that energy is all kinetic, and hence that there must be momentum in a situation where dBB theory might have no motion whatsoever. The two theories radically disagree on when there is momentum in the system. So you can't just describe a double slit experiment as an experiment to "transfer momentum" when talking about two theories that radically disagree about who has momentum and when.

People agree that that's why and when it is meanful to say an experimental result has occured. They simply disagree about the words they use and the stories they tell. Which is why it is not helpful to use words from Copenhagen that don't have exact cognates in dBB, it confuses the issue about what you are talking about.

And a double slit is clear. You have something somewhere that moves differently based on whether the screen-and-traveller interact in one place on the screen versus another place on the screen. It could be air molecules near the screen, it could be your eyeball, it could be the ink on your lab notebook or the parts of your hard drive or the parts of the screen itself, it could be lots of things. The wavepacket for those different options start to separate and eventually will never again overlap in configuration space, the part of the wavefunction that has the world particle is what happened, the other packets are the empty packets, and you can ignore them now because they no longer do anything measureable or detectable. Whether the dBB theory says that motion came from a transfer of kinetic energy from the traveller to the screen or from a transfer of quantum potential energy from the traveller to the screen doesn't matter and ... it is just not at all obvious. It could depend on whether the particle was in the leading edge of the wavepacket or was a straggler near the tail of the wavepacket. The theory will tell you, but you can't just assume a result because you want to assume it.

edit

Please accept that in regular quantum mechanics there is classical potential energy and "all other energy" and that a Copenhagenist will say that that energy is all kinetic, and hence that there must be momentum in a situation where dBB theory has no motion whatsoever. The two theories radically disagree on when there is momentum in the system. So you can't just describe a double slit experiment as an experiment to "transfer momentum" when talking about two theories that radically disagree about who has momentum and when.

So how is a particle detected in a double slit?

You have something somewhere that moves differently based on whether the screen/hitter interact in one place versus another place. The wavepacket for those different options start to separate and eventually will never again overlap in configuration space, the one that has the world particle is what happened, the other packets are the empty packets. It's is always, I repeat always about the separation of wavepackets in the dBB it is never, absolutely never about anything else in the dBB theory.

To be fair, it's actually the same in Copenhagen too. To get real predictions and avoid the quantum zeno effect making things never move you have to be objective about when, where, and how measurements happen, and once you get honest and detailed about that, then everyone agrees again. Whether dBB, Transactional, Ithaca, MWI, MIW, or Copenhagen they all literally turn to the exact same picture and setup about identifying that the Schrödinger equation always holds and that a time comes where it is practical to ignore the effects of the other parts because the different parts never overlap so don't affect the ratios of outcomes anymore.

People agree that that's why and when it is meanful to say an experimental result has occured. They simply disagree about the words they use and the stories they tell. Which is why it is not helpful to use words from Copenhagen that don't have exact cognates in dBB, it confuses the issue aboutwhat you are talking about.

And a double slit is clear. You have something somewhere that moves differently based on whether the screen/hitter interact in one place versus another place. Could be air molecule near the screen, could be your eyeball, could be the ink on your lab notebook or the parts of your hard drive or the parts of the screen itself, it could be lots of things. The wavepacket for those different options start to separate and eventually will never again overlap in configuration space, the part of the wavefunction that has the world particle is what happened, the other packets are the empty packets, and you can ignore them now because they no longer do anything measureable or detectable. Wether the dBB theory says that motion can from a transfer of kinetic energy from the traveler to the screen or from a transfer of quantum potential energy from the traveller to the screen doesn't matter and ... is not obvious. It could depend on whether the particle was in the leading edge of the wavepacket or a straggler near the tail. The theory will tell you, but you can't just assume it because you want to assume it.

People assuming that at hidden variable theory works the way they want to assume it does rather than learning the theory is why people think so poorly of them. And it happens to Relativity too, and its just not fair to bring your assumptions and preconceptions to a theory and then blame the theory.