[ExI] Limiting factor to the Intelligence Singularity?

[Jason Resch]

On Tue, Jan 2, 2024, 6:04 AM BillK via extropy-chat <
extropy-chat at lists.extropy.org> wrote:

> On Tue, 2 Jan 2024 at 05:13, Jason Resch via extropy-chat
> <extropy-chat at lists.extropy.org> wrote:
> >
> > All quantum computers are reversible computers, it is required so they
> don't leak energy into the environment which would cause decoherence and
> spoil the result.
> >
> > Jason
> > _______________________________________________
>
>
> The chatbots seem to be saying 'Yes, But...' and sort of disagreeing
> with this statement.
>
> Quote:
> This is due to the fundamental principles of quantum mechanics, which
> dictate that the time evolution of a quantum system is governed by
> unitary transformations, also known as quantum gates.
>
> Unitary transformations are inherently reversible, meaning that they
> can be inverted. This property is crucial for the functioning of a
> quantum computer because it ensures that every operation can be
> undone, allowing the system to return to its initial state after the
> computation is complete. This characteristic is what makes quantum
> computing potentially more powerful than classical computing, as it
> enables a much wider range of algorithms to be implemented.
>
> However, it's important to note that while the quantum gates
> themselves are reversible, the process of measuring a quantum state,
> which is an essential part of the computation process, is not. Once a
> measurement is made, the quantum state collapses into one of the
> possible outcomes, and this process cannot be reversed.
> -----------------
>
> And -
> Quantum computers are not reversible computers in the traditional
> sense. Reversible computing refers to a computing paradigm where every
> computation step is reversible, meaning that it is possible to
> uniquely determine the previous state of the system from its current
> state. This property allows for the elimination of information loss
> and enables the computation to be performed in a manner where there is
> no increase in entropy.
>
> Quantum computers, on the other hand, are based on the principles of
> quantum mechanics and operate using quantum bits, or qubits, which can
> exist in superpositions of states and can be entangled with each
> other. The computation in a quantum computer is typically performed
> using a sequence of quantum gates, which are unitary transformations
> that act on the qubits. These gates can be reversible, meaning that
> they have an inverse operation that can be used to undo the
> computation. However, not all quantum gates are reversible.
>
> While reversible gates are important in certain aspects of quantum
> computing, such as error correction and the implementation of certain
> algorithms, the overall operation of a quantum computer involves the
> measurement of qubits, which is an irreversible process. Measurement
> collapses the quantum state of a qubit to a classical state, and this
> irreversible step is necessary to obtain the final result of a
> computation.
>
> So, while some aspects of quantum computing involve reversible
> operations, the overall computation performed by a quantum computer is
> not reversible in the same sense as classical reversible computing.
>

I think interpretational issues are throwing it off. Wave function collapse
is considered irreversible in some interpretations (Copenhagen), but not in
others (many worlds), and this happens, (or appears to happen), when we
interact with the quantum computer to observe the final result.

Also, the issue of reading the result (which requires copying information)
is irreversible (leaks entropy into the environment) whether you are
dealing with qubits in a quantum computer or classical bits in a classical
irreversible computer.

No computer can overcome this. If you read and copy information from a
reversible computer, then it is you, not the computer, who have performed
the thermodynamically irreversible operation.

A civilization that uploads themselves to live for a million years in a
virtual heaven could do so, and run for eons on a reversible computer which
no one needs read. They have all their experiences within that computer,
with no minimum amount of energy required to sustain it.

"A simulated world hosting a simulated person can be a closed
self-contained entity. It might exist as a program on a computer processing
data quietly in some dark corner, giving no external hint of the joys and
pains, successes and frustrations of the person inside."
-- Hans Moravec in "Simulation, Consciousness, Existence" (1998)

Jason
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