[Avodah] Time and Emunah

[Micha Berger]

On Sun, August 5, 2007 7:55 pm, Moshe Y. Gluck wrote:
:>From http://discovermagazine.com/2007/jun/in-no-time:
: "Efforts to understand time below the Planck scale have led to an
: exceedingly strange juncture in physics. The problem, in brief, is
: that time may not exist at the most fundamental level of physical
: reality....
: "The trouble with time started a century ago, when Einstein's special
: and general theories of relativity demolished the idea of time as a
: universal constant. One consequence is that the past, present, and
: future are not absolutes."

To my mind, time is a fundamental feature for machashavah. Without
time, there is no discussion of causality, and thus the meaning of
bechirah chafshi becomes suspect. How can we speak of the consequences
of our actions?


Taking a step back to explain the science as I understand it (given
that I haven't taken courses in this stuff in 2 decades, and have kept
up on a Scientific American level)....

In Quantum Mechanics we find that everything in the universe comes in
quanta, in tiny indivisible packets. Eg: Light comes in photons, and
there is no such thing as a half a photon of light. According to
relativity, matter-energy is a product of the geometry of space.
Curved space is what we call mass, and energy is just mass. Therefore,
if we're to combine the two, we would be forced to conclude that even
space and time come in quanta. There is a smallest length and a
smallest duration of time. The universe really comes in pixels.

Right now there are competing ideas of how to combine them. At face
value, they contradict. Both theories work extremely well in their own
domains -- relativity and QM have each stood up to more experimental
evidence without fail than any other theory in history. Relativity
explains the very big and very fast, QM has explained the very small.
But where they intersect, very small units of gravity, space and time,
we get different answers. And yet, we can use quantum effects in our
transistors, throw a bunch of them in a chip, and use them to compute
the relativistic effects of satellites in orbit and it all works to
produce a GPS receiver. The expectation is, therefore, that both are
fundamentally right, there is only a minor lack of understanding on
our part that creates an illusory contradiction in a corner case that
neither was designed for.

(Going off on a tangent: This is useful metaphor for questions of
science and Torah. Science explains how the world works, Torah, to
provide meaning, purpose and values. The expectation when dealing with
historical claims that they seem to contradict on is that that both
are fundamentally right, there is only a minor lack of understanding
on our part that creates an illusory contradiction in a corner case
that neither was designed for. If scientists can live with a
contradiction and engineers can use the data to design devices, why
can't we simply shelve our question without having a crisis of faith?)

But one result that seems to be necessary for any combination of the
two theories is the Wheeler - deWitt equation. It turns out that once
you get to time on the scale where QM says statistics dominate, which
would be the quanta of time and space in any combined theory, there is
no difference between the directions of space, and the direction we
call time. The equation describes the evolution of the state of the
universe as a 4D object, with no difference between time and space.

This is then the first question of time: Why is it, then, that time
actually is different once you get to larger scales? Some actually try
to show that it all just arbitrary that we plug t into all of our
formula as a parameter. That time isn't different in reality, we just
view the world that way. This really just shifts the question, since
we would still need to explain why the we view the direction we call
time differently than the other 3 directions if all are really
identical.

The second is that even with t as a parameter, IOW, we accept the
appearance -- processes really do unfold over time, why does time have
a particular arrow? The formula work whether we plug in t or negative
t. There is no reason why time has a universal past and future. How
does past differ from future? And to add a psychological component:
why do we perceive that as a flow?

Now, stepping back to the topic at hand...

It seems that time in our mesorah, though, is fundamentally
non-relativistic. Since Einstein, space-time is recognized to be one
thing. And in fact, the difference between space and time depends on
which direction in this four-dimensional space one faces in a manner
that "direction" changes depending upon one's speed.

However, we have a universal minhag to say qaddish for 11 months based
on the notion that the niftar, if he is not a rasha, spends a maximum
of that time in gehenom. Note that the niftar is outside of space, but
is assumed to still experience time, and not only that, but time
roughly the same as someone moving at usual speeds in relation to the
surface of planet earth.

However, the existence of time need not be as an external reality. The
notion that time is a product of human perception of that reality
would be sufficient to support bechirah. And WRT what I called the
second question of time, that of its flow from past to future, REED
says just that -- that it's a product of our perceptions as shaped by
the eitz hada'as. See MmE vol II pp 150-154, the discussion at v14n11-
n67, or just cheat and get my summary of the ma'amar as per the end of
the discussion, at <http://tinyurl.com/3bqnjs>.

IOW, it's not important whether our bodies experience time as we
perceive it. What the Torah discusses is the perception, time as part
of a soul's existence.


Besides that, I think causality is as an objective part of nature as
nature itself is. Just that it is hiding in something most physicists
take for granted -- the boundary conditions necessary for solving
their equations. Algebraic formula that can be solved are solved given
only the formula. But differential equations describe derivatives, how
one value changes when you change another. They require boundary
conditions in addition to the formula. You can't map change to reality
without knowing what it is that is changing.

When two systems interact for a short period of time, that interaction
defines the boundary condition for their evolution AFTER the
interaction, but not before.

The formula for waves work whether you go forward or backward in time
-- you can trace waves back to the beginning. However, they are
differential equations, which means that to know what the water looks
like, you need boundary conditions. The waves on a pond are identical
whether or not we later decide to skip a rock across it. The moment of
interaction, the rock hitting the water, is only a boundary condition
for the waves /after/ the collision.

Tir'u baTov!
-mi

-- 
Micha Berger             Spirituality is like a bird: if you tighten
micha at aishdas.org        your grip on it, it chokes; slacken your
grip,
http://www.aishdas.org   and it flies away.
Fax: (270) 514-1507                            - Rav Yisrael Salanter