Timeline for Time reversal symmetry in the Schrodinger equation and evolution of wave packet
Current License: CC BY-SA 3.0
6 events
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| Sep 15, 2016 at 17:06 | comment | added | knzhou | @Oti That's not how quantum measurement works. Measurement is interaction with a macroscopic system. Interaction with a single other particle is perfectly time-reversible by the exact same procedure I said -- just complex conjugate the joint wavefunction of the two particles. | |
| Sep 15, 2016 at 6:27 | comment | added | Oti | Thus, time reversal is broken by the act of measurement, and we cannot run Schrodinger's equation backward to recover the Gaussian wave packet. The interaction with the photon changes the wave function of the particle in such a way that all previous information is lost. The wave function stops evolving in time (we can consider the new wave function to be a very highly localized state, like a spike). Is this still consistent with time reversal symmetry? | |
| Sep 15, 2016 at 6:20 | comment | added | Oti | Thank you for the response. I would like to extend the question on time evolution and time reversal symmetry slightly by introducing measurement of particles position at some future or past time t (or -t). For example, let's take a Gaussian wave packet at t=0, propagate it forward in time, so that the width of the packet increases. If a measurement of particle's position is made at some future time, t, the wave function changes irreversibly. The act of measurement can be made using another particle (such as a photon) that itself follows laws of QM and time reversal symmetry. | |
| Sep 15, 2016 at 2:54 | comment | added | udrv | Related details in 2nd answer to physics.stackexchange.com/q/54534 | |
| Sep 15, 2016 at 2:46 | history | edited | knzhou | CC BY-SA 3.0 |
added 229 characters in body
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| Sep 15, 2016 at 2:40 | history | answered | knzhou | CC BY-SA 3.0 |