
Quantum Machine Appears to Defy Universe’s Push for Disorder - biofox
https://www.quantamagazine.org/quantum-scarring-appears-to-defy-universes-push-for-disorder-20190320/
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pmontra
And almost offtopic, in a scifi story, an advanced civilization found a way to
extract energy from these systems billion of years ago (or use them just to
store stuff, lot of it). Taking positive energy out of the system creates
negative energy which is inflating the universe faster and faster. Most of
them don't care because it will take billion of years for matter to be stirred
into pieces. Some of them think it's not a good idea and should be controlled
somehow but cheap energy is too tempting.

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jandrese
That's a pretty blunt metaphor for fossil fuels.

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tabtab
Did they have Global Schrodingering deniers?

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tabtab
The more they study quantum phenomenon, the crazier the things they find. I
suspect quantum computers will take longer than expected to make practical,
but researchers will find interesting phenomenon along the journey that may
eventually lead to other practical tools.

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udev
Purely intuitively, the 'scarrig' seems to limit the state space for this
51-qubit quantum system.

So it is not clear why the authors believe this development will lead to
better quantum computers.

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selimthegrim
The state space is constrained because the Rydberg blockade forces it to grow
in a certain manner like the Fibonacci sequence. Lukin and Ho come up with a
toy model that shows some features but it’s not clear it captures all the
physics. The authors make this statement because people want passive (not
optimal control) ways of preserving quantum information that aren’t (quantum)
integrable. (I can go into detail on the definitions here if you want.)

NB: my department chair was Rick Heller’s grad student and we’ve been
discussing these preprints here just like everyone else

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mmastrac
Maybe an example or related to time crystals?

[https://en.wikipedia.org/wiki/Time_crystal](https://en.wikipedia.org/wiki/Time_crystal)

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selimthegrim
Time crystals generally require active driving of some sort. They have a
periodic behavior the opposite of parametric oscillation. A key feature of
most time crystals is their long ‘prethermalizing’ behavior which is to say
that it behaves like it isn’t thermalized for some very long but finite time.
Whether these scars decay similarly especially within this constrained SU(2)
space Lukin has cooked up is still out.

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selimthegrim
Here’s a nice paper on prethermaliztion -
[https://arxiv.org/abs/1812.04776](https://arxiv.org/abs/1812.04776)

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squozzer
Is the Second Law dead?

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philipov
There's a saying in physics that if your theory predicts the demise of General
Relativity or Quantum Mechanics, you might have just earned a Nobel Prize, but
if your theory violates the Second Law of Thermodynamics, there's no hope: you
better go check your work again.

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throwaway66666
I love how they are giving cows grazing grass as an analogy leading to the
possible explanation of the quantum effects. Of course, as cows are lazy to
climb hills, atoms are also lazy to climb the invisible hills so they roll
back to the valley). It's proof that a farmer heard the "whoever solves this
gets a nobel prize", and wanted to give it a go.

I 'll give it a go too. IT'S A RACING CONDITION!!!! See. In the latest patch,
we switched universe rendering from QT to Electron, because we read a very
compelling argument on twitter. As you know, certain CSS properties cause
reflows, repaint, relayouts. Here, outside of time, WASM still didn't get the
needed adoption, so in order to optimize universe rendering, we split it into
different threads. However, these threads do not have shared memory, so what
happens is you change state in thread A. In order to have you see a loading
gif, we make the change locally to your system but it is not propagated
everywhere yet, then the render loop runs again, and it overwrites the local
change you made. You need to hit the particles with an attribute that will
trigger a recalculate style call, not just a repaint, because repaint is
overwriten and does not actually modify the element's width and height.

I will stop being throwaway when you need an address for the mr Nobel please!
:)

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polytronic
I'd like to stand at the last paragraph of the article above stating “There is
some beautiful structure that somehow coexists with a totally random
environment,” Papić said. “What kind of physics allows this to happen? This is
a kind of deep and profound question that runs through many areas of physics,
and I think this is another incarnation.”

This comes as a blow in the face for those who believe that the universe is
the result of randomness or that intelligent design is a fairy tale.

My response to Mr Papic is that this is the kind of physics our Creator has
built! The kind of physics causing another familiar entity, the DNA, to refuse
to submit to entropy as well. It is another proof of the existence of God and
He's greatest creation, the Soul!

