Quantum multiplication as a challenge. Why it can work and why it is difficult.

Quantum computing teaches and forces us to think differently because it is impossible to understand it in terms of classical physics. Superposition, entanglement, oracles, diffusers, invisible answers and impenetrable state vectors all combine to present us with an entirely new conceptual world that unmakes sense of the older one.

How do we extract a usable answer from a Grover oracle that marks solutions but doesn’t and can’t tell us what they are? The answer lies in the diffuser, which amplifies marked states and suppresses others.

What is the Grover oracle? Why is it called an oracle? How it works. And how it doesn’t.

We are made by the universe and can only experience what our evolved states allow. The persistents that are the building-blocks of our existence also define what we can know, how we must learn it, and the limits of what we can know. All our experiments embody interaction Hamiltonians so by measuring one thing we can learn of the things they are entangled with. And nothing else. That defines the limits of our world.

When a photo interacts with an object and then entangles with the pointer states that are the persistent characteristics of that object, how does it then convey that information either to ourselves as observers or more importantly to the environment itself? How do we leverage this mechanism to learn about objects in the world? This is an inconclusive exploration; a much better answer will be given in episode 26.

When we observe the world by interacting with photons and other particles that act as witnesses, do we interpret the world only in the way in which our brains invent things like colour, secondary qualities as John Locke described them, or do we see the world as it in some sense ‘really is’?

This is the first of three episodes that explores the question of how information about the objects in the world is transferred into us as human observers, and more particularly and importantly how it is transferred into the environment as it monitors the persistence of the objective classical world that emerges from the quantum world.

Once we see that entropy is a measure of deficit, we can immediately extend the notion to concepts themselves and see that when we have things still to learn things still to understand our conceptual entropy is high but when we learn them our conceptual entropy falls. Of course overall entropy must increase but at a conceptual level we can still learn things and we do. 

Entropy can decrease locally but not globally; the total entropy of a closed system cannot decrease but the entropy of a part of it can. Otherwise there would be no order, no life.