In "A Brief History of Time" - Chapter 9, Stephen Hawking gives an explanation of how the arrow of time works, i.e. why time seems to move forward in one direction while space can go in different directions.
He first explains that there are 3 arrows of time:
- The psychological arrow of time: The fact that humans can only perceive time as moving in one direction and can only remember the past not the future.
- The thermodynamic arrow of time: The second law of thermodynamics, that systems move in the direction of increasing disorder (increasing entropy).
- The cosmological arrow of time: The direction of time moving with the expanding universe.
He then explains why we perceive all three to be the same, by first merging 1 and 2, and then merging 2 and 3.
My question pertains to how he merges 1 and 2, i.e. why the psychological arrow of time and the thermodynamic arrow of time move in the same direction. Here is his reasoning:
- Every time a computer performs a calculation it consumes energy and increases the entropy of the universe (Although he doesn't mention it by name, here he is just spelling out Landauer's principle). Computation can thus only move in the direction of increasing entropy.
- Since the mind works the same way a computer does (per Hawking), human thoughts can only move in the direction of increasing entropy.
So it is not that the psychological arrow and the thermodynamic arrow of time happen to move in the same direction. They are one and the same because humans can only process information (and therefore perceive things) in the direction of increasing entropy.
Here is now my question: Is Hawking here just refining Kant's idea that we perceive space and time the way we do because that's how the mind organizes our sensory input, not because that is how they really are? (i.e is my understanding of Kant correct?)