The Universe is a Quantum gravity computer, maybe!?

[Simon Laub]

Physicst Sabine Hossenfelder writes in Time
https://time.com/6208174/maybe-the-universe-thinks/
that ''Maybe the Universe thinks, hear me out''...

- To be more precise, the distribution of matter in the universe looks a
little like the ''connectome''
the network of nerve connections in the human brain. Neurons in the
human brain, too, form clusters, and they connect by axons, that are
long nerve fibers which send electrical impulses from one neuron to
another.

She is inspired by a Vazza and Feletti article
https://www.frontiersin.org/articles/10.3389/fphy.2020.525731/full
which says there is ''a remarkable similarity''.

Now the Universe is different from a brain because the Universe
expands. Another ''difference is that it takes a long time for signals
to cross the universe''. Whereas, ''neurons in the human brain send
about 5-50 signals per second''.

''This means, if the universe is thinking, it isn’t thinking very much''...

Because, as far we know, there >>is<< such a thing as ''locality'' in
the Universe. Objects, always continuously move from one place to nearby
places. As far as we know - And we don't really know that much about
''locality''.

Indeed, ''It could be that space itself has many more connections than
we observe, non-local ones, not unlike portals: You go in one end and
are instantaneously teleported to a different place''.

''These non-local connections would have to be very small tough,
too small for us, or even elementary particles to go through –
otherwise we’d have noticed already. But they would still connect
space with itself.
This way, two places we think are at opposite ends of the universe might
be very close to each other''.

E.g. some physicists have speculated that e.g. ''dark matter'',
is really just normal matter, it is just because
gravitational attraction is multiplied and spread out because places are
non-locally connected to each other.

Sabine Hossenfelder ends by telling us that there are zero evidence for
non-local connections. so far, but to her ''the idea that the universe
is intelligent is compatible with all we know so far''.
There is no evidence against it, which brings her to the point
of her story.
Science has more to say than ''nope, you can’t''.
It also opens our mind to new possibilities, new sources of wonder, and
new ways to make sense of our own existence.

''The universe might think.. Currently, it is not
supported by evidence and it might never be.
But it not contradicted by evidence either''.


Indeed, the idea that the Universe might be doing some kind of
''thinking'' is not new, just remember Fred Hoyle's ''Black Cloud'',
https://en.wikipedia.org/wiki/The_Black_Cloud
Here scientists try to communicate with the cloud,
and succeed. The cloud is revealed to be an alien gaseous superorganism,
many times more intelligent than humans.

And, well, in Science, it is now possible to work with ''qubits''
physically realized as e.g. spin of the electron, where quantum
mechanics allows the qubit to be
in a superposition of two states simultaneously,
https://en.wikipedia.org/wiki/Qubit
which eventually leads to ways to do computations, in quantum computing.
https://en.wikipedia.org/wiki/Quantum_computing

This all leads to physicist Seth Lloyd and his statement that
''the Universe is indistinguishable from a quantum computer.
The universe supports quantum computation and can be efficiently
simulated by a quantum computer''.

Back then, when this came up (in a comment to
Lloyds book, and earlier) I suggested we should take a step deeper, and
consider how to calculate with SpaceTime itself. Afterall, particles are
just a kind of a field, and if they/that can calculate, then why now
SpaceTime?

Enters Quantum Gravity computers.
Currently, not formulated in a way where it is particular clear
what would constitute inputs and outputs (as normally understood in
computation).

Working at scales where there is no (making sense of) causality?
a quantum gravity computer might end up seeing its result before running
its algorithms -
it is essential the same as quantum computer strapped to a time-machine

And, in the words of Lucien Hardy, there is a problem here:
''A lack of conceptual clarity about what would constitute inputs and
outputs that prohibits the development of a theory of quantum gravity
computation''.
https://arxiv.org/abs/quant-ph/0701019

But there is also potential:
''Allowing us to define a new class of computers which may have greater
computational powers because they may be able to harness the indefinite
causal structure as a computational resource
https://arxiv.org/pdf/quant-ph/0701019.pdf

There might be some thinking going on here,,,
whatever that really means...

Simon