Quote:
Originally Posted by xelasnave
Would it not be possible to make models that could indeed tell us those things...if we could measure and input all the data maybe it could be done..we certainly know, unless we are wrong, how these things work.
Alex
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Hi Alex,
Say you could keep track of the motions of every particle.
As Julian just alluded to, Heisenberg then gets in the way.
But even if you were to put that aside for one moment and let's say one
could know the position and velocity of every particle in the Universe.
The other day I posted a link to a story in Nature about quantum thermodynamics.
See :-
https://www.nature.com/news/the-new-...-rules-1.22937
That article made mention of the solution to the Maxwell's Daemon paradox.
Quote:
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Originally Posted by Zeeya Merali, Nature
But the solution to a famous thought experiment, laid out 150 years ago by Scottish physicist James Clerk Maxwell, provided a clue about where to turn, posing an intriguing link between information and energy. Maxwell imagined an entity that could sort slow- and fast-moving molecules, creating a temperature difference between two chambers simply by opening and closing a door between them.
Such a 'demon', as it was later called, thus generates a hot and a cold chamber that can be harnessed to produce useful energy. The problem is that by sorting particles in this way, the demon reduces the system's entropy — a measure of the disorder of the particles' arrangements — without having done any work on the particles themselves. This seemingly violates the second law of thermodynamics.
But physicists eventually realized that the demon would pay a thermodynamic price to process the information about the molecules' speeds. It would need to store, erase and rewrite that information in its brain. That process consumes energy and creates an overall increase in entropy3. Information was once thought to be immaterial, “but Maxwell's demon shows that it can have objective physical consequences”, says quantum physicist Arnau Riera, at the Institute of Photonic Sciences in Barcelona, Spain.
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In a similar vain, to keep track of the positions and velocities of all particles
in the Universe you would need to build a memory store, its size
necessitating it probably be of a similar number of particles to what you
were tracking leading, to a paradox. Such a computer would even need
to track itself.
You might need another alternate Universe in which to store and run the computer.
But even if you were satisfied just to know all the governing laws of the
Universe without keeping track of particles in models, Gödel, Turing
and friends might get in the way first.