Physicists, like economists, have trouble coming up with clearcut answers
to fundamental questions in their field. For instance, physicists do not have a
proper theory of time:
“Einstein once
described his friend Michele Besso as “the best sounding board in Europe” for
scientific ideas. They attended university together in Zurich; later they were
colleagues at the patent office in Bern. When Besso died in the spring of 1955,
Einstein — knowing that his own time was also running out — wrote a now-famous
letter to Besso’s family. “Now he has departed this strange world a little
ahead of me,” Einstein wrote of his friend’s passing. “That signifies nothing.
For us believing physicists, the distinction between past, present and future
is only a stubbornly persistent illusion.”
Einstein’s statement
was not merely an attempt at consolation. Many physicists argue that Einstein’s
position is implied by the two pillars of modern physics: Einstein’s
masterpiece, the general theory of relativity, and the Standard Model of
particle physics. The laws that underlie these theories are time-symmetric —
that is, the physics they describe is the same, regardless of whether the
variable called “time” increases or decreases. Moreover, they say nothing at
all about the point we call “now” — a special moment (or so it appears) for us,
but seemingly undefined when we talk about the universe at large. The resulting
timeless cosmos is sometimes called a “block universe” — a static block of
space-time in which any flow of time, or passage through it, must presumably be
a mental construct or other illusion.”
Related:
Time’s (Almost) Reversible Arrow by
Frank Wilczek (Nobel Prize-winning physicist at the Massachusetts Institute of
Technology)
Ruminations on the meaning of time:
http://www.nybooks.com/articles/archives/2013/jun/06/time-regained/