[QuickTidal]

Slow Ben, on 29 July 2020 - 11:40 PM, said:

Awesome news. Hopefully things will start to ease up for you guys.

Thanks man, yeah, it’s been a ride so far.

[QuickTidal]

I’m relaxing at the cottage, one kid is sleeping, one kid is quietly watching her iPad, my wife is napping, and I’m sat on the deck in the sunshine with a frosty beverage re-reading MIDNIGHT TIDES a mere 2.5hrs from where Steve and ICE took that one photo of the dig they met on.

Life is good.

[Mezla PigDog]

QuickTidal, on 31 July 2020 - 07:17 PM, said:

I’m relaxing at the cottage, one kid is sleeping, one kid is quietly watching her iPad, my wife is napping, and I’m sat on the deck in the sunshine with a frosty beverage re-reading MIDNIGHT TIDES a mere 2.5hrs from where Steve and ICE took that one photo of the dig they met on.

Life is good.

Richly deserved QT. Your wife sounds like she needs to nap for a week. At least.

[Tsundoku]

Caught up with Centz, Shiara and Luci this afternoon. 'Twas good.

[QuickTidal]

Mezla PigDog, on 01 August 2020 - 08:06 AM, said:

QuickTidal, on 31 July 2020 - 07:17 PM, said:

I’m relaxing at the cottage, one kid is sleeping, one kid is quietly watching her iPad, my wife is napping, and I’m sat on the deck in the sunshine with a frosty beverage re-reading MIDNIGHT TIDES a mere 2.5hrs from where Steve and ICE took that one photo of the dig they met on.

Life is good.

Richly deserved QT. Your wife sounds like she needs to nap for a week. At least.

Thanks Mez! Yes, she does indeed. She’s enjoying a restful weekend.

[Mentalist]

QuickTidal, on 31 July 2020 - 07:17 PM, said:

I’m relaxing at the cottage, one kid is sleeping, one kid is quietly watching her iPad, my wife is napping, and I’m sat on the deck in the sunshine with a frosty beverage re-reading MIDNIGHT TIDES a mere 2.5hrs from where Steve and ICE took that one photo of the dig they met on.

Life is good.

Enjoy, QT! Hopefully the downpour that's coming this weekend passes you by.

I'm back from a friend's BBQ, tipsy AF, and looking forward to passing out, and then having 2 more days off starting tomorrow.

[Mentalist]

Found a Kickstarted heavy-duty Android phone with a full physical keyboard.

Now I'll have something to replace my Priv once it dies.

[Tiste Simeon]

9th wedding anniversary today! Going away for a couple of nights and my parents are looking after our son. Got some plans but I'm mainly looking forward to sleeping in without being woken at 6am!

[Tsundoku]

Nah, your maths must be off. You can't have been married for 9 years.

Enjoy your 2nd anniversary.

[Macros]

Nine years?

Piss off, this can not be true

[QuickTidal]

Tiste Simeon, on 13 August 2020 - 07:38 AM, said:

9th wedding anniversary today! Going away for a couple of nights and my parents are looking after our son. Got some plans but I'm mainly looking forward to sleeping in without being woken at 6am!

Happy Anniversary! Hope you guys get some solid relaxing time in!

[Raymond Luxury Yacht]

Tiste Simeon, on 13 August 2020 - 07:38 AM, said:

Got some plans

Nudge nudge, wink wink, say no more!

[Tiste Simeon]

Haha thanks all. Plans were mostly food related as there are some decent restaurants nearby. It was a lovely relaxing time!

[Azath Vitr (D'ivers]

Good news about time (and basic research into quantum computing---hope for the future):

'Scientists have seen "time crystals" interacting for the first ever time.

[...]The breakthrough could lead to a host of new technological advances, from quantum computers to powerful GPS systems. [...]

Time crystals are so powerful because they remain together or "coherent" despite different conditions. Keeping coherence is the main difficulty that is stopping humanity from building powerful quantum computers, whose proponents argue could overcome a variety of technological problems.

[...] "Controlling the interaction of two time crystals is a major achievement. Before this, nobody had observed two time crystals in the same system, let alone seen them interact," [...]

"Controlled interactions are the number one item on the wish list of anyone looking to harness a time crystal for practical applications, such as quantum information processing."

Standard crystals like metals or rocks are made up of atoms, arranged in a regularly repeating pattern through space. Time crystals are different: they appear to be in constant, repeating motion through time, even without anything changing them from the outside.

[...] a rare isotype of helium. They cooled it down to almost absolute zero and then created the time crystals, allowing them to touch'

https://www.independ...k-a9674401.html

'Theories of time and time-travel have highlighted an apparent stumbling block: time travel requires changing the past, even simply by adding in the time traveller. The problem, according to chaos theory, is that the smallest of changes can cause radical consequences in the future. In this conception of time travel, it wouldn't be advisable to recover your unsaved document since this act would have huge knock-on effects on everything else.

New research in quantum physics from Los Alamos National Laboratory has shown that the so-called butterfly effect can be overcome in the quantum realm in order to "unscramble" lost information by essentially reversing time.

[...] the fact that the butterfly effect does not occur in quantum realms is not a surprising result, but demonstrating information unscrambling is both novel and important.

[...] This scenario is still hypothetical, but explores the mathematics of the actual quantum processor used by Google to demonstrate quantum supremacy in 2019.

[...] "Another potential application is to use this effect to protect information. A random evolution on a quantum circuit can make the qubit robust to perturbations. One may further exploit the discovered effect to design protocols in quantum cryptography."

[...] "Classical chaotic evolution magnifies any state damage exponentially quickly, which is known as the butterfly effect," explain Yan and Sinitsyn. "The quantum evolution, however, is linear. This explains why, in our case, the uncontrolled damage to the state is not magnified by the subsequent complex evolution. Moreover, the fact that Bob's measurement does not damage the useful information follows from the property of entanglement correlations in the scrambled state."

Hypothetical though this scenario may be, the result already has a practical use: verifying whether a quantum system has achieved quantum supremacy. Quantum processors can simulate time-reversal in a way that classical computers cannot'

https://www.vice.com...e-quantum-world

'Major quantum computational breakthrough is shaking up physics and maths

MIP* = RE is not a typo. It is a groundbreaking discovery and the catchy title of a recent paper in the field of quantum complexity theory. Complexity theory is a zoo of "complexity classes" – collections of computational problems – of which MIP* and RE are but two.

[...] That may seem like an insignificant detail in an abstract theory without any real-world application. But physicists and mathematicians are flocking to visit the zoo, even though they probably don't understand it all. Because it turns out the discovery has astonishing consequences for their own disciplines.

[...] RE stands for problems that can be solved by a computer. It is the zoo.

[...] In complexity theory, the interrogator is the person, with limited computational power, trying to solve the problem. The prover is the new computer, which is assumed to have immense computational power. An interactive proof system is a protocol that the interrogator can use in order to determine, at least with high probability, whether the prover should be believed. By analogy, these are crimes that the police may not be able to solve, but at least innocents can convince the police of their innocence. This is the class IP.

If multiple provers can be interrogated, and the provers are not allowed to coordinate their answers (as is typically the case when the police interrogates multiple suspects), then we get to the class MIP. [...] Entanglement – a quantum feature in which qubits are spookishly entangled, even if separated – makes quantum communication fundamentally different to ordinary communication. Allowing the provers of MIP to share an entangled qubit leads to the class MIP*.

It seems obvious that communication between the provers can only serve to help the provers coordinate lies rather than assist the interrogator in discovering truth. For that reason, nobody expected that allowing more communication would make computational problems more reliable and solvable. Surprisingly, we now know that MIP* = RE. This means that quantum communication behaves wildly differently to normal communication.

[...] Grossly simplified, this asked whether infinite matrices can be approximated by finite matrices. This new paper has now proved this isn't possible – an important finding for pure mathematicians.


[...] Tsirelson's Problem. This was about two different mathematical formalisms of a single situation in quantum mechanics – to date an incredibly successful theory that explains the subatomic world. Being two different descriptions of the same phenomenon it was to be expected that the two formalisms were mathematically equivalent.

But the new paper now shows that they aren't. Exactly how they can both still yield the same results and both describe the same physical reality is unknown, but it is why physicists are also suddenly taking an interest.'

https://theconversat...nd-maths-136634

This post has been edited by Azath Vitr (D'ivers: 18 August 2020 - 02:59 AM

[Azath Vitr (D'ivers]

'MIP*=RE [...] some of the major implications are as follows.

(1) There is a protocol by which two entangled provers can convince a polynomial-time verifier of the answer to any computable problem whatsoever (!!), or indeed that a given Turing machine halts.

[...] I can remember when the class MIP* was first defined and studied, back around 2003, and people made the point that we didn't know any reasonable upper bound on the class's power—not NEXP, not NEEEEXP, not even the set of all computable languages. Back then, the joke was how far our proof techniques were from what was self-evidently the truth. I don't remember a single person who seriously contemplated that two entangled provers could convince a polynomial-time verifier than an arbitrary Turing machine halts.

[...] we have two heuristics locked in direct conflict. On the one hand, nothing about interactive proofs relativizes, and MIP*=RE is about interactive proofs. On the other hand, everything in computability theory relativizes, and MIP*=RE is (ultimately) about computability theory.

In this case, I can prove that (as you guessed) the first heuristic has to win.
[...] The intuitive difficulty is that, if we're talking about Turing machines that run for arbitrary lengths of time, and which therefore (it seems) can only be simulated in a step-by-step manner anyway, what difference could it possibly make if those Turing machines also query an oracle?

The answer, I think, is that despite that intuition, nonrelativizing stuff happens (and needs to happen) in the "compression lemma" that's at the core of the new result. Indeed, the Time Hierarchy Theorem relativizes, while the compression lemma says informally that in the land of MIP*, the Time Hierarchy Theorem is as nothing … since at no cost to yourself, you can always just force the provers to go up another exponential in how many entangled qubits they use.

And indeed, the compression lemma is exactly where the authors bring in PCP and low-degree polynomial machinery—well-known sources of non-relativizing goodness.

If I'm right, then MIP*=RE is the first fully convincing example I've ever seen of a non-relativizing computability theorem.

(Update: In response to my inquiry, Thomas Vidick was kind enough to confirm the above understanding—adding that their proof uses NEXP⊆MIP* as an ingredient, which already fails to relativize—although that's almost certainly not the only non-relativizing part of the proof.)'

https://www.scottaar...om/blog/?p=4512

This post has been edited by Azath Vitr (D'ivers: 18 August 2020 - 03:59 AM

[Not-So-Great-Raven]

Todays first bright spot was definitely stumbling upon these forums, which I didn't know exist until a few hours ago.

And another one was the fact that there are still some active people here, a pleasant surprise! Did a short post to the introduction thread already.

[Macros]

Welcome, more people!

[QuickTidal]

This makes me happy.

[Mentalist]

YouTube linked me to a channel discussing new BlackBerry phones coming out next year.

The dream of phones with proper keyboards lives on!

[Malankazooie]

Hoping that hurricane remnants kick up here and bring relief to Rocky Mtn west fires and drought, and it looks like it might based on future weather predictions. Laura is quite a boring name for a hurricane though. They should have called that thing Hurcainzo the Vortex of Madness. That would get more people to evacuate.

As with all things ..... one man gathers what another man spills.