On Sat, Aug 10, 2019 at 6:16 PM smitra <[email protected]> wrote: > On 10-08-2019 09:49, Bruce Kellett wrote: > > > > But when you cannot reach, or ignore, some of this larger number of > > degrees of freedom, you end up with a mixed state. That is how > > decoherence reduces the pure state to a mixture on measurement -- > > there are always degrees of freedom that are not recoverable -- those > > infamous IR photons, for example. The brain does not take all this > > entanglement with the environment into account, so it is a classical > > object. > > > > And that step of tracing out the environmental degrees of freedom is > where we make a mathematical approximation in order to be able to do > practical calculations. But as you have said in this thread, the > mathematics we use to describe a system is not necessarily a good > physical representation of the system. It's not up to the brain to > decide to not take entanglement into account.
No, the brain has no choice. It simply cannot take these environmental dof into account. So on its own reckoning, it is a classical object. We may describe the brain > as a classical object, but that doesn't make it so. > Tell me one practical way in which this makes a difference. Bruce -- You received this message because you are subscribed to the Google Groups "Everything List" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To view this discussion on the web visit https://groups.google.com/d/msgid/everything-list/CAFxXSLR8cRGh6RfETE4QCrwUha-pxKZAVYqk9xA8GBKpH-Omrw%40mail.gmail.com.
