Discussion Board

Topic: Causality Experiment

From: John Koziol
Location: Tallahassee, FL
Date: 12/06/2006

Hi Greg,

Apparently, there is a means to test time causality as mentioned here: http://www.msnbc.msn.com/id/15817394/

I have to admit, to a degree, this freaks me out as it is a fundamental test of the elasticity of spacetime in my opinion. On one hand, I'd love for the experiment to succeed because that'd open the door for the "many worlds" hypothesis. On the other, if the universe is rigid this might be the "God takes his dice and goes home" trigger.

What say you? Does this rank along with changing the false vacuum state or am I being paranoid?


Re: Causality Experiment

From: Greg Bear
Date: 12/06/2006

Thanks, John! John Cramer (mentioned prominently in this piece) is one of our brightest Seattle folks, and I highly recommend his novel TWISTOR and columns in ANALOG, also available on his web site,

http://faculty.washington.edu/jcramer/

Testing quantum entanglement is cool, but I'm not sure that it will confirm or deny time travel to the past. "Spooky action at a distance" has its own intriguing possibilities, however! No one has yet figured out how to transport large quantities of information using entangled photons, however, so FTL seems held at bay for the moment.

Re: Causality Experiment

From: John Koziol
Location: Tallahassee, FL
Date: 12/06/2006

I wasn't thinking about time travel, just causality. For example, if Cramer stops the beam before it is sent but was already detected 50 microseconds ago. If it's not sent, how could it have been detected.

Also, if I recall my creaky quantum physics, it's theoretically impossible to convey information via quantum entanglement.

Now my head hurts

Re: Causality Experiment

From: Greg Bear
Date: 12/06/2006

If information other than the state change can be conveyed between entangled particles, this does indeed become an open question, or at least a new kind of question. I never was very convinced by classic, formal causality to begin with... Too rigid for a happening place like our universe-- like a very tight tuxedo!

Re: Causality Experiment

From: patrick
Location:
Date: 12/07/2006

Hmhmhmhm. For a somewhat parallel direction, you might be interested in Fred Alan Wolf.

Respond to this discussion

May we post your correspondence on this site?
Yes
No
IMPORTANT: For form verification, type the following number in the box below: 75




See Also...

Archives: [Oct-Dec 2004] [Jan-June 2005] [July-Dec 2005] [Jan-June 2006] [July 2006] [Aug-Dec 2006] [2007] [2008] [2009] [2010] [2011] [2012] [2013] [2014] [Current] [Search Blog Archives]