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First Experimental Evidence That Time Is an Emergent Quantum Phenomenon

KentuckyFC writes "One of the great challenges in physics is to unite the theories of quantum mechanics and general relativity. But all attempts to do this all run into the famous 'problem of time' — the resulting equations describe a static universe in which nothing ever happens. In 1983, theoreticians showed how this could be solved if time is an emergent phenomenon based on entanglement, the phenomenon in which two quantum particles share the same existence. An external, god-like observer always sees no difference between these particles compared to an external objective clock. But an observer who measures one of the pair — and so becomes entangled with it--can immediately see how it evolves differently from its partner. So from the outside the universe appears static and unchanging, while objects that are entangled within it experience the maelstrom of change. Now quantum physicists have performed the first experimental test of this idea by measuring the evolution of a pair of entangled photons in two different ways. An external god-like observer sees no difference while an observer who measures one particle and becomes entangled with it does see the change. In other words, the experiment shows how time is an emergent phenomenon based on entanglement, in which case the contradiction between quantum mechanics and general relativity seems to melt away."

3 of 530 comments (clear)

  1. Re:Hmm by hodet · · Score: 5, Informative

    It's because the subject takes time to digest and respond to intelligently. As opposed to the usual "NSA is Monitoring My Brain" headline. It's nice to see this type of article, it's what brought me to slashdot so many years ago. I still come everyday hoping to see more stuff like this.

  2. Re:I think... by LateArthurDent · · Score: 5, Informative

    After reading a lot on this is that sometimes an issue becomes a problem without reason.

    Now, time is ONLY a man made measure - a measure between events. Nature/the universe doesn't know what time is nor cares about it. It is only us humans that need to try to explain time dilation and various other 'time issues' to make the maths work. Remove time, and I bet it will balance these equations.

    Time cannot run backwards,as there is no such thing as time except in the human brain and the human concept of measuring changes.

    Nature doesn't care about time? Tell that to the laws of thermodynamics. Entropy only goes one way.

    If you watch a video of a ball rolling on a desk, you can't tell just by the video whether time has been reversed. The physics governing that motion don't care about time. If you watch a video of an egg being shattered, you'll know when the video is reversed. You know all the contents of the egg can't spontaneously get back together as time moves forward. That would be going to a much more well-ordered state.

    Also, the GPS device you use to triangulate your position and navigate to your destination? Well, consider that relativity tells us that the satellites zooming up above us have slower ticking clocks. They're actually moving through time slower than you are, and our current GPS accuracy wouldn't be achievable if we didn't take that into account.

  3. Re:Time is dependent on observation? by MozeeToby · · Score: 5, Informative

    Just keep in mind that an 'observer' does not mean a conscious entity. An observer, in the quantum mechanical sense, is more accurately an "interactor", as in anything that interacts with it. Which, when put into those terms, their thought process in this paper is much clearer: without interaction there is no way to determine if time has passed, if there's no way to tell if time is passing... it may as well not be.