Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Doesn't relativity define time as an illusion?

  1. Nov 27, 2009 #1
    Like everything is in 4 dimensions. The 3 spacial ones and time. The past, future and present are already determined and just waiting to happen. There is no flow of time. What are your opinions on time, and what about a block time universe? How can time not be a flow, don't you need time in between each snapshot?
  2. jcsd
  3. Nov 27, 2009 #2


    User Avatar
    Science Advisor

    An observer is a worldline in spacetime. Along his worldline, proper time, which is read by atomic clocks, passes. The difference from Newtonian time is that it is not universal, each observer has his own time.
  4. Nov 28, 2009 #3
    To answer your question no. The four dimensional solid you talk about is a mathematical construct. Here in the physical world there only exists an infinitesimal thin sheet with three large dimensions (spacial) and one infinitesimal (time).
  5. Jan 1, 2010 #4
    an interesting and deep question. Relativity does indeed force us to view the universe as a four-dimensional space-time manifold.

    Thus, time apparently doesn't flow, it simply "is."

    Whether you should now choose to describe time or the flow of time as an "illusion" is up for debate. Certainly psychologically the flow of time is certainly very tricky; we can be fooled. But should we describe the disconnect between the physical descriptions of time and our internal experiences as an Illusion? maybe.

    It is thought that the possible physical bases of a "direction in time" may some day explain why we experience a forward flow. Current work relates to Entropy, information theory, as well as cosmological explanations.
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook