1. Limited time only! Sign up for a free 30min personal tutor trial with Chegg Tutors
    Dismiss Notice
Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

I Do we live in a block universe?

  1. Jul 27, 2016 #1
    Experimental violations of Bell's inequality (Alain Aspect, et al) proved beyond a shadow of doubt that local hidden variables do not exist. However, in a 1985 BBC interview, John S. Bell said there was one loophole in those experiments that would allow for determinism: non-local hidden variables. Einstein believed that quantum measurements are not indeterminate, but for that to be true in light of Bell's inequality violations, Bell said that every event in the universe would then have to be predetermined -- superdeterminism.

    In other words, Bell's theorem gives us only two possibilities: One, where quantum measurements are inherently indeterminate, and another where we live in a block universe where everything is laid out in a predetermined, unalterable timeline.

    In a block universe, time would be bi-directional. Past events could be observed as "unhappening" (in principle) simply by going backward along the time axis. Our memories would be erased while going backward through time as well, so there would be no way to tell which direction we were traveling (our "sense" of "time" would just be an illusion). All irreversible processes would be ruled out, meaning that the total amount of information in the universe would have to remain constant. (This is because all information concerning the present state of the universe was already contained in the past. This would be exactly the kind of clockwork universe Laplace envisioned.) But if every process is completely reversible, the total entropy would also remain constant over time, and entropy could only increase in one portion of the universe by importing it from somewhere else.

    John Bell himself said that superdeterminism is implausible. I agree. What do others think?
     
  2. jcsd
  3. Jul 27, 2016 #2

    Nugatory

    User Avatar

    Staff: Mentor

Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook