What is NOT Random?

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Recommends Jerryno · 2016-01 · Physics Stack Exchange · on “Does quantum mechanics play a role in the brain?”

@Graham true, but that is because the brain is not deterministic so you cannot build a prove around it. Humans can decide some halting problems that Turing machines can't. If a brain was a classical computer you could foretold everything about it given the initial conditions. Which is clearly not how it works. You should watch this to the end: [this video] everything is explained very nicely there.

Cites Vikrant Chaudhary · 2014-07 · Physics Stack Exchange · on “Is the future already determined?”

I've always wondered (and was re-inspired to explore further from these two [this video] videos [LINK] ) that if at a single point of time we know about the complete state (position, momentum, spins, everything.) of every particle in an isolated system (e.g., the whole Universe), can we perfectly determine its future? And by same analogy, also the past? I understand that according to the uncertainty principle [LINK] , it is impossible to determine all state properties of a particle accurately at the same time. So my question is, is it like future of an isolated system is already determined but is just not perfectly predictable by an observer because of limitations in observability? UPDATE: To be

Cites mattecapu · 2014-07 · Physics Stack Exchange · on “Is this theory about Universe and information true?”

I recently saw this [this video] video about information and randomness. At some point, it states that a completely predictable universe would infringe the second law of thermodynamics, because it would imply that the overall information of the Universe would be conserved throughout time, thus leading to a costant entropy Universe. Also, it states that the additional information that is increasing entropy is coming from QM randomness. I recognize it's a really fascinating theory, but is it true? Is the equivalence between information and entropy sensible?

Cites Skyler · 2014-11 · Physics Stack Exchange · on “What is the entropy of a pure state?”

The issue is that when a wavefunction collapses it has an inherent randomness to it. Since entropy is fundamentally related to information, I'll start with information to explain why this is significant. Information, Randomness, and Entropy If you think of the information of a state as what is needed to completely define a system something interesting happens. This is best illustrated by taking a picture and trying to compress it. Let's take this image: You can think about the information necessary for us to completely define a system as being the total amount of details we need to describe the system. For this image, you CAN represent it as a collection of 2000 x 2000 pixels which each requ

Cites Jerryno · 2016-01 · Physics Stack Exchange · on “Does quantum mechanics play a role in the brain?”

signals in brain are deterministic and can be truly "foretold". But the way neuron paths are formed is totally random because it happens on a quantum level. **Thats where Quantum mechanics plays a role**. See: [this video]

Cites freejuices · 2018-02 · Physics Stack Exchange · on “Is the random nature of quantum mechanics what creates new entropy?”

So I was watching this video [this video] and found what I think is a really compelling idea, and I would like to know how accurate, if at all, it is. The point Derek makes, if I understood it correctly, is this: In the context of classical mechanics, if one could know the position, momentum, charge, and a few more things, of every particle in the Universe, one could predict with certainty the future. Then one would be Laplace's Demon. This means nothing really is random, we model as random things that are too complex to describe in any other way, such as human behavior arising from zillions of particles interacting in very complex structures. This would mean that information in the universe is c