
#1
Jun611, 04:08 PM

PF Gold
P: 779

Can you consider the particles in Bohmian Mechanics mixtures?




#2
Jun611, 05:57 PM

P: 42

DeBB theory describes the likely state of matter as it actually is, whatever processes it may be part of. If you start talking e.g. about density matrices or mixtures this refers to our partial knowledge of a system which is in itself welldefined. You need to distinguish between the case where the components waves do not physically coexist (a 'proper mixture') and the case where they do physically coexist but do not overlap (an 'improper mixture'). 



#3
Jun611, 09:43 PM

P: 269

Can actual particle position (the one that comes out of the guiding equation) be observed/measured or even influence anything at all? If yes, how? If not, what's is good for?




#4
Jun711, 02:48 AM

Sci Advisor
P: 4,495

Bohmian Mechanics  One Quick Question 



#5
Jun711, 04:46 AM

P: 269

If we knew the entire initial state we could predict the evolution at any arbitrary moment of time and the uncertainty principle would not have applied. But since we do not know the initial state, the numbers are out of our reach. And we cannot increase our knowledge through experiments because every time we do a measurement we gain some knowledge but at the same time we introduce more unknowns through the degrees of freedom of measuring apparatus. In fact we cannot learn enough of it to increase out predictive power beyond the capabilities provided by wavefunction alone (w/o guiding equation). Does this all make sense? Is this a fair summary? To be honest, I sort of see how it all works but I still don't see a point. All these definite trajectories sound like an attempt to describe magnetic field of a permanent magnet by postulating the existence of invisible metal shavings that line up along the field lines DK 



#6
Jun711, 05:12 AM

Sci Advisor
P: 4,495

So let us concentrate on it. The following may also change your mind: http://www.physicsforums.com/blog.php?b=3077 



#7
Jun711, 08:05 AM

P: 269

I guess my complain is that we have a guiding equation that is supposed to produce nice clean definite trajectories at all times but it is impossible to use for the stated purpose because we never have sufficient input data. And even when we do have definite trajectories, the only way we can use them is to plug them back into the same equation where they immediately get tangled with unknown/random environment to become probability distributions. The equation certainly makes sense, it helps visualise the flow of probability, I guess it can be handy in montecarlo simulations etc. But there is nothing in it that requires coordinates to have definite values at all times. They might as well be distributions. DK 



#8
Jun711, 08:23 AM

Sci Advisor
P: 4,495




Register to reply 
Related Discussions  
bohmian mechanics  Quantum Physics  4  
Bohmian Mechanics  Quantum Physics  13  
Is Bohmian mechanics true?..  General Physics  2 