Monday, August 6, 2018

Why Time?



I've spent a good deal of time thinking about time.  It is a mystery.  We know it passes, the more quickly it seems as we get older.  Since Einstein, we know it is part of spacetime, baked into the fabric of the universe.  But that simply deepens the mysteries.  Why can we travel in all directions in space but only one in time?  And how can it be that there is no absolute time the same everywhere?  The "now" that  I see all around me is punctured during the day by photons from the sun that show me how that looked nine minutes ago and at night by stars showing me how they existed many thousands of years ago?  When we see those stars, we are looking into the past. Our experience of the "now" of those stars is likewise thousand of years in our future.
 
So time varies by distance in space.  The speed of light -- 186,000 miles per second -- connects these.  Contemplation of the speed of light leads to pondering how light can possibly have a speed.  Objects with mass, when not at rest, have speed.  (Actually, nothing is ever at rest except relatively.)  As an object with mass increases speed, time runs slower as it appears to observers not so moving.  Relative motion, in effect, eats relative time; the quicker something moves, the less time remains that seems to pass for the object moving relative to the observer at rest where "normal" time passes.  Mass-less particles, such as photons, do not experience time.  Mass-less particles are everywhere they will ever be at the same moment and are, in this sense, eternal.  Only objects with mass -- including us -- experience light as traveling in time.  A photon that left Proxima Centauri, traveled 4.25 years and just reached our eyes here on earth, took that photon no time at all. 
 
By capturing some of the particles spewing from the Big Bang and giving them mass, the Higgs Boson may in effect have also created time.  But as there is no universal and simultaneous "now," how can we think about time. As noted, under Einsteinian relativity, time is the fourth dimension and relative to location and motion in the other three.  Yet clearly there is also "now."  We live in it.  Is there not a single "now" that exists for all the photons that fill the universe in their one timeless, eternal moment?  Does that create a universal framework of now?  Perhaps each and every particle of matter exists in its own "now" tied to every other such moment within the crystalline universal now established by light?  Light seems to have a speed because it ties together the universe of separate, individual "nows."   Perhaps mass is simply the way everything is kept from happening at once?  Mass separates us from eternity, immersing us in spacetime where our consciousness has space and time to manifest.  Perhaps time exists to provide a way for the universe to experience itself.

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