
#1
Sep1806, 03:27 PM

Emeritus
PF Gold
P: 8,147

Here is a very interesting discussion of a proposal to allow backward causation in quantum mechanics. The basic idea is that the time asymmetry of QM ("collapse of the wave function") violates our expectations of a fundamental theory; all previous candidates from Newton on have been time symmetric and time asymmetry then arises from statistical probabilities. The ideas are discussed back and forth in a refreshing way, and I strongly recommend it.




#2
Sep1906, 02:43 AM

P: 1,603

Certainly fits very well with my current philosophy (timesymmetric, realistic, deterministic, "freewill skeptical" physicalist that I am) Thanks for this. 



#4
Sep2906, 02:52 AM

P: 2

Causality in QM
Here is a site that gives an explanation of backward causation from an analysis of the consequences of the Minkowski metric.




#5
Jan2507, 01:49 PM

P: 2,043

Also there are several essays related to this on Mathpages




#6
Feb1007, 12:32 AM

P: 244

It seems to me that the very concept that the future can affect the past is incredibley absurd. It is in the same catagory as saying 0=1. The only way that 0=1 is to change one or both of thier definitions. IF you assert that the future has affected the past, you have changed one or both of their definitions.
Why do we not accept the proposition that there is a particle that is superluminal (probably a form of a graviton) that is connecting the photons. If this particle had less mass than the photon, it would be possible for it to be much faster than the photon, but it's combination of less mass and greater speed would together equal that of the the photon. Only particles of less mass than the photon can exceed the speed of the photon. This is speculation but it is at least possible. The future affecting the past is semantically, logically and conceptually impossible. 



#7
Mar1707, 04:52 AM

P: 1,603

MF 



#8
Mar1907, 08:22 PM

P: 244





#9
Mar2007, 02:13 PM

PF Gold
P: 2,215





#10
Mar2007, 02:26 PM

P: 2,043

The distance between the emission and absorbtion of a photon in spacetime is exactly zero, even if that spacetime is curved. How do we know for sure that absorbtion is not causally connected to the emission as is the emission to the absorbtion? 



#11
Mar2107, 02:20 AM

P: 1,603





#12
Apr1207, 02:48 AM

P: 10

Maybe both are just one.



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