Laplace's Demon -- Is Future Pre-Determined?

Early in the 19th century, the French mathematician and astronomer Pierre-Simon Laplace claimed that if some entity could  know the precise location and momentum of every atom in the universe then it could use Newton's laws to reveal the entire course of cosmic events, past and future. This hypothetical all-knowing entity later came to be referred to as "Laplace's Demon" .

Implicit in Laplace's claim is the presumption that future is "pre-determined". Many people question this presumption -- mainly in view of "uncertainties" in the world of the atom, and particularly in Quantum Mechanics.  However, it would seem that this is not a valid refutation of "determinism".

The "uncertainty principle" of modern physics concerns the "tolerance band" that limits "measurement" and "observation" -- and not about the impossibility of future actually being pre-determined -- even if we cannot ever get to measure the "precise location and momentum of every atom in the universe". The future may well be deterministic, even as Laplace's Demon remains an impossibility.  

Let us consider the implications of a world where the future is pre-determined. In such a world, time will have no absolute meaning. Time will at best need to be regarded as a fourth spatial dimension along with length, breadth, and height.  Without referring to standard bearings, we would tend to confuse "North" with "South" on the surface of the earth. In outer space, where there is no gravitational pull towards the earth, we would have no means to differentiate the "top" from the "bottom". A "pre-determined" world would suggest that there are possible circumstances where we may similarly confuse between the future, past, and the present! 

There are some serious objections to this, as thermodynamics postulates the existence of an "arrow" of time in the absolute sense. Anywhere in the universe, the "future" is always distinguishable from the "past" -- in the sense that the net "disorderliness" (or entropy) of the world increases with time. This is the reason why it is trivial for us to move from North to South or vice versa; but not so in case of moving from the present (or the future) to the past. We cannot retrace over time; as we can over space. 

Another objection to a "pre-determined" world can be based on the principle of parsimony. If the universe is "pre-determined", then what role do the laws of Physics play? The apple falls down from the tree because this was "pre-determined" to fall at that moment in time! So where does the universal law of gravity come into the picture? What is clear is that it is NOT the imperative of "pre-determinism" that causes apples to fall; nor the moon to revolve around the earth. Just the reverse -- perhaps pre-determinism could be an occasional consequence of certain basic laws that characterize the mode of existence of matter. 

The very fact that we can predict the future to a reasonable level of accuracy shows that at least some things are pre-determinable. This is quite different from saying that the future is pre-determined. Our ability to predict the future is based on what we know about the trends from the past -- and not a "vision" of a pre-determined future.

Which is why the accuracy of our predictions is directly proportional to the amount of information that we possess about the past and the present. 

But even so, the future could really be pre-determined -- even if only as a consequence of the laws of Physics. Again, this postulate too cannot stand scrutiny. There may well be "switches" in the universe that may flick this way or that, fully conforming to the deterministic laws of Physics.

Even in a purely materialistic context, the circumstance of switching in a particular direction may well be a pseudo-random decision making algorithm that is based on available information. What is important is that there is no need for the random number sequence (used by the switching algorithm) to be "truly" random. When "switching" occurs based on a pseudo-random sequence, the future suddenly become unpredictable -- purely based on knowledge of laws of Physics.  

Of course, one may still say that if Laplace's demon can "somehow" obtain a copy of pseudo-random sequences that are used for such switching, the future would be predictable. Indeed so.  But that takes us to another issue -- suppose we have two computer programs playing chess with each other, and if we observe that Computer A usually beats Computer B. What would be our conclusion?

That Computer A was "pre-determined" (by kismet) to win more games? We can say that, but this will NOT be revealing of anything useful. It is far more meaningful to say that the chess playing algorithm within Computer A is smarter than this within Computer B.  

Let me conclude:-  

a) It is more useful to say that gravity causes apples to fall down, than to say that Apples fall down because of "destiny"  

b) It is more useful to say that Computer A wins more often in chess games against Computer B, because the former has a better software program, than to say it is "kismet" that causes A to out perform B.

In the case of human fortunes too, the above applies in a general sense. However in this case, there is one more factor at play -- that of social conditions under which a person is born. This latter has the power to influence the future of the individual, far more than personal skills (whether acquired through genes or otherwise) and hard work.