On 1/12/2014 8:20 AM, John Clark wrote:
On Fri, Jan 10, 2014 at 4:47 PM, LizR <lizj...@gmail.com 
<mailto:lizj...@gmail.com>> wrote:

    > "Retro-causality" (time symmetry is a better term) only exists at the 
quantum level.


Why? Where is the dividing line? And with a Schrodinger's Cat type device a quantum event can easily be magnified to a macro-event as large as desired, you could connect it up to an H-bomb.

That's a good question. But I think it has a good answer. "The quantum level" really means "isolated from the general entropy increase of the universe". The Bucky Ball Young's slit experiment exemplifies this. If the bucky balls are hot enough to radiate photons that will provide "which way" information, the interference pattern doesn't appear. In the t-symmetry model this means the paths don't interact with the rest of universe. If you tried to send a message back in time via the zig-zag path it would require an interaction between the wave-function and your macroscopic message forming and environmentally decohered instruments.

Brent

--
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 everything-list+unsubscr...@googlegroups.com.
To post to this group, send email to everything-list@googlegroups.com.
Visit this group at http://groups.google.com/group/everything-list.
For more options, visit https://groups.google.com/groups/opt_out.

Reply via email to