Hitoshi Kitada (firstname.lastname@example.org)
Thu, 15 Apr 1999 00:00:24 +0900
Dear Time Folks,
Let me propose a problem about the direction of time, which, at least
seemingly, has a form that has not been considered before. That is partly a
reminiscence of [time 199] and hinted by Ben's remark [time 198].
Direction of time or Does the free will exist?
Let us consider the following observation:
Let an observer O observe a local system L'=(L1,L2,X) or L=(L1,L2). Here L1
and L2 is the direct objects of observation of O and X is some automatic
apparatus that observes the system L=(L1,L2).
In this situation, Wheeler's quantum eraser illustrated in Ben Goertzel's
> In fact, according to (Wheeler, 1980), this even works
> if the choice is <b>delayed</b> -- then one has the phenomenon
> of the "quantum eraser." In other words, suppose one has a
> <b>machine</b> record which slit each particle passed through.
> If after a few hours one destroys the machine's records
> without having looked at them, and only <b>afterwards</b>
> looks at the plate, then result is the same as if the
> information had never existed; the plate shows that the
> particles behaved like waves. But in the same scenario, if
> one looks at the machine's information before one erases it,
> the picture on the plate is quite different: it is consistent
> with whatever the machine said.
may be restated as follows:
If O looks at L', then what O sees in the future about L
is different from what O sees when O looks only at L. (1)
We may regard this as an experimental fact (provided that the situation
describes exactly Wheeler's quantum eraser).
Wheeler's case may be rephrased:
The present affects the future. (1')
Let us consider the observation with time order reversed. The question in this
case is if the following is correct or not:
If O looks at L', then what O sees in the past about L
is different from what O sees when O looks only at L. (2)
This would be paraphrased:
The future affects the present. (2')
Turning to the direction of time, I think it may be understood as the
direction of one's own time when he sees the outside. If we understand the
direction of time in this way, we have two alternatives with (2):
If (2) is true, then the observer's time is reversible,
if (2) is false, then the observer's time is irreversible.
(2) may be tested by experiments, similarly to Wheeler's.
If the direction of time is that of the observer's subjective time as I
proposed, my claim is thus that we can find by experiments if time has the
direction or not.
This might sound a silly assertion, as we feel we experience the direction of
time in daily life. But the statement (2) could be a direct test of asymmetry
of subjective time, and I think the direction of time has not been examined in
Another point about (2) is that, if (2) is true, we have to think it asserting
that all is inevitable fate, or all is determined but we cannot know which
result actually occurs. This point would be illustrated by the following
passage adapted from [time 199]:
We assume (2) is true.
An observer O is informed that an apparatus X records some data about his
objects L1 and L2, but does not see the data on X. He makes observation
of L=(L1,L2). Then he is planned to walk a corridor to the point where the
corridor forks into two directions. Beforehand another person brought the
apparatus X at the end of one of the two corridors. Whether or not
he (observer O) sees X at the end of the corridor depends on his
choice which corridor he takes. If he knows that his observation of L is
the same as the data that he will see the apparatus X, then he knows
that he will choose the correct corridor where the apparatus X is at
the end, whichever way he takes. Or if he knows his observation does
not match those data, he knows in advance he will choose the wrong way.
In short, _if (2) is true_, O must choose one right way always, whichever
direction he takes at the branch, if the data coincide with those that he will
see the apparatus X. He _can_ choose one of the two at his will, but his
choice has been determined in the sense that he has _no ability_ to change his
fate to see the apparatus X.
So if (2) is true, no free will exists,
if (2) is false, the free will may exist.
if the direction of time does not exist, the free will does not exist,
if the direction of time exists, the free will may exist.
This problem may relate with the Classical/QM features of our world: Even if
(2) is true, we have our free will at each stage (QM aspect), but the fate as
a whole is determined (Classical aspect). If (2) is not true, then such
restrictions do not exist and we might have true free will.
P.S. Members who do not have the former mails of time list can get the log
files by sending the message like
get time time.9903
get time time.9904
(one command in each line) with any subject, to the address:
99 of course denotes year and 03, 04, ... month. (I'm not sure if the Y2K
problem has been fixed with majordomo software :) )
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