Why I don’t think that Quantum Computers will work, ever

For instance, we could try to use our cat to crack a password by making sure that the superpositional quantum memory cell encodes all possible passwords simultaneously. Since the cat inherits the superposition until the outside universe gets entangled, all possible cats will now try to use one of the possible passwords, one of them will find the solution, and when we open the box, we will discover if we happen to share a universe with the particular cat that found the solution that we are interested in. This in itself is not very helpful, so we are going to build additional constraints (entanglements) into the interaction between cat and quantum memory cell, to make sure that the cat can in principle only end up in one of the states we are interested in (like one where the key decrypts a bunch of text into something that looks like plain English).

There are many variants of quantum computing devices, but they all exploit the fact that quantum processes involve an uncertainty that is intrinsically costly to compute in classical systems

For instance, if we want to determine how an electron that inhabits an orbital will interact with other electrons, we might have to do simulations for all possible positions of the electrons, even only one will eventually be actualized.

This gives rise to the notion that quantum computation is intrinsically more powerful than classical computation. No, it won’t mysteriously enable consciousness in ways that classical computation cannot, because we are still looking at good old Turing computability. Quantum systems compute the same things as classical systems, only much, much more efficiently.

What if the difficulties of computing the position or spin of a particle in a classical paradigm do not result from the fact that quantum processes require more complexity, but from the fact that this position or spin does actually not exist? In the spacetime paradigm, we assign a position in space to every particle, and discover that our equations do not result in a single solution, but rather in multiple solutions (for spin) or a distribution (for positions). This is only confusing if we believe in the reality of space. But what if we accept that the universe is not a continuous space with stuff in it, but a computation?