This is my review of Nick Stockton’s “Time Might Only Exist in Your Head. And Everyone Else’s.” From Wired, 26 September, 2016. Published at 0600 hrs. I later modified this piece on 17 October, 2016. It keeps bothering me like a splinter in my mind. In its current revision, it comprises 2,537 words.
“Some physicists blame gravity for time. Others blame observers. Time, the arrow of time, the linearity of time flowing from the infinite past through the present into the indefinite future, cannot exist unless an intelligence, something sentient, exists to observe it, they say.
The moment when particle physics and classical mechanics merge is called “decoherence,” and it also happens to be the moment when time’s direction becomes mathematically important.
Mr. Stockton’s article points out that superposition in quantum mechanics means that an electron can exist in either of two places, a property called probability, but it is impossible to say where an electron is until that electron is actually observed.
Some physicists also say that what matters is not whether time exists, but what direction that time flows. (Claus Kiefer, “Can the Arrow of Time Be Understood From Quantum Cosmology?” in L. Mersini-Houghton and R. Vaas, The Arrow of Time, Springer, Berlin, 2010.) Read the rest of this entry »