#it from qubit

[art-of-mathematics]

Thought experiment regarding non-linear causal nets using an analogy of "dynamical chess"

Imagine a flexible chess board where each move of the chess figures alters the board. And each alteration of the board has effects on the figures as well, causing alteration in the behavior of the figures [a.k.a. the rules each figure has as a pre-defined rule]. | (That's entanglement of feedback-loops.) - This leads to chaotic behavior, making predictions even more difficult and "turbulent".

[This sort of chess is like the interaction between spacetime and matter.]

Following a helpful quote by John Wheeler:

"Spacetime tells matter how to move; matter tells spacetime how to curve."

- John Archibald Wheeler, Geons, Black Holes and Quantum Foam: A Life in Physics

---

Why do I use the neologism "non-linear causal nets"?

There is a kind of idiom-like brabble, called "causal chains". It states a linear string of cause-and-effect. This is often far too simplified for explaining real-life phenomena, because often there are far more causes to an effect than just one. There happen many "causal chains" simultaneously, so to speak. These causal chains are entangled. Multiple of such linear cause-and-effects are entangled, until they are no longer a linear-string or multiple linear strings, but a complex web. Each causal chain alters each other. That is basically a fundamental principle often recognized in quantum mechanics - interference.

It describes conservation of momentum in an analogy-based and merely imagination-based language of knots and loops, similar to some approaches of string theory and (loop) quantum gravity.

Information weaving

"Information weaving" might be the silly name I would use for that collection of conceptions and re-interpretations.

"Information transforms" in this conception are weaving patterns. In concrete, these are interaction patterns like

- replication of interaction pattern (like law of inertia)

- and interference/alteration of interaction pattern (momentum).

These two transforms are the two primary transforms. You can combine them and create all possible sorts of patterns.

Furthermore,... these relate to addition and multiplication of imaginary numbers, resulting in either a translation or a rotation in the complex plane... These might relate to the information transforms stated above.

But the research regarding this is really difficult and curently my mind is too sluggish and too over-crowded to compute it well enough.

It might take some years until it's less mad nonsense.

...

Spacetime as emergent property of entanglement

I enjoy the project It from Qubit and Polymath Vijay's interpretation that spacetime is emergent due to entanglement.

In my interpretation/analogy of "information weaving" time is a string, and space is the web consisting of that string. Space and time are hence "two aspects of one and the same thing".

This is especially interesting if you consider the difference between a time and a space dimension.

A space dimension has two ways of propagation, so to speak: left-right, top-down, before-behind... (to put it in plain words)

When it comes to the time dimension, I consider it to have only one propagation direction: The future, like in the conception of the arrow of time.

But here it becomes complex. Since time is "mono-directional", say, it has only one direction to propagate towards, it might interact with itself - via feedback-loops. This results in literal entanglement if you consider the arrow of time to be a simple string. Loop, knot and weave that string/arrow with itself and you might have spacetime as a complex result, so to speak.

In regards to quantum entanglement and superposition this interpretation might make sense as well, but I am not far enough with my research about that topic to summarize it coherently.

Furthermore, you can also define quantum gravity as the "degree of clotting": or, say: Let's interpret gravity as a principle of clustering: Areas with more density gain density, and areas with less density lose even more density, to reduce gravity to its primary principle.

Gravity is hence a re-distribution, a re-ordering of matter, or information, so to speak...

In regards to my information weaving conception, quantum gravity defines the density of information. It also defines how information re-distributes itself over time.

How the clustering happens depends on the patterns of interaction. And the patterns of interaction are affected by clustering as well. (Leading us back to Wheeler's quote above... )

What is "information"?

I regard information as an interaction pattern, a pattern in the web of causal nets, so to speak.

...

This is all a bit difficult to summarize. I will visualize it once I have summarized the parts of it well enough.

---

That was my literally chaotic thoughts as of today. It's a bit (/very much) incoherent.

[foone]

there are 6 flavors of qubits (using the names from quarks, for some reason) and thus 36 possible configurations. So every time you have a successful decode, it randomizes, and you have to iterate through all the configurations again to find the correct one.

why would you do this to your players? do you hate them? do you want them to go mad building endless logic networks?

[mindblowingscience]

An experiment by a group of physicists led by University of Rochester physics professor Regina Demina has produced a significant result related to quantum entanglement—an effect that Albert Einstein called "spooky action at a distance." Entanglement concerns the coordinated behavior of miniscule particles that have interacted but then moved apart. Measuring properties—like position or momentum or spin—of one of the separated pair of particles instantaneously changes the results of the other particle, no matter how far the second particle has drifted from its twin. In effect, the state of one entangled particle, or qubit, is inseparable from the other. Quantum entanglement has been observed between stable particles, such as photons or electrons. But Demina and her group broke new ground in that they found, for the first time, entanglement to persist between unstable top quarks and their antimatter partners at distances farther than what can be covered by information transferred at the speed of light. Specifically, the researchers observed spin correlation between the particles.

Continue Reading.

[as-if-and-only-if]

ok, there’s NO WAY this means what it says. Classic case of sensationalized science journalism! Right?

In the recent research, pulsing a laser periodically at the 10 ytterbium qubits kept them in a quantum state—meaning entangled—for 1.5 seconds. But when the researchers pulsed the lasers in the pattern of the Fibonacci sequence, they found that the qubits on the edge of the system remained in a quantum state for about 5.5 seconds, the entire length of the experiment (the qubits could have remained in a quantum state for longer, but the team ended the experiment at the 5.5-second mark). Their research was published this summer in Nature.

oh WHAT??

ok, ok, sure. but what do they mean by “blasting it with the Fibonacci sequence”?

Shooting the qubits with laser pulses with a periodic (a simple A-B-A-B) pattern didn’t prolong the system’s quantum state. But by pulsing the laser in a Fibonacci sequence (A-AB-ABA-ABAAB, and so on), the researchers gave the qubits a non-repeating, or quasi-periodic, pattern.

“With this quasi-periodic sequence, there’s a complicated evolution that cancels out all the errors that live on the edge,” Dumitrescu said in a Simons Foundation release. By on the edge, he’s referring to the qubits farthest from the center of their configuration at any one time. “Because of that, the edge stays quantum-mechanically coherent much, much longer than you’d expect.” The Fibonacci-pattern laser pulses made the edge qubits more robust.

ah, ok; take the Fibonacci recursion relation F(i+2) = F(i+1) + F(i), but + is concatenation (note the order), and start with B, A. but what do B and A represent? unfortunately scihub doesn’t seem to have the article, so I’m guessing…laser frequencies and/or polarizations?

in any case, yeah. I guess they really did get it to work by blasting it with the Fibonacci sequence. incredible.

[mysticstronomy]

WHAT IS A QUANTUM COMPUTER??

Blog#313

Wednesday, July 12th, 2023

Welcome back,

It’s fascinating to think about the power in our pocket—today’s smartphones have the computing power of a military computer from 50 years ago that was the size of an entire room. However, even with the phenomenal strides we made in technology and classical computers since the onset of the computer revolution, there remain problems that classical computers just can’t solve. Many believe quantum computers are the answer.

Now that we have made the switching and memory units of computers, known as transistors, almost as small as an atom, we need to find an entirely new way of thinking about and building computers. Even though a classical computer helps us do many amazing things, “under the hood” it’s really just a calculator that uses a sequence of bits—values of 0 and 1 to represent two states (think on and off switch) to makes sense of and decisions about the data we input following a prearranged set of instructions.

Quantum computers are not intended to replace classical computers, they are expected to be a different tool we will use to solve complex problems that are beyond the capabilities of a classical computer.

Basically, as we are entering a big data world in which the information we need to store grows, there is a need for more ones and zeros and transistors to process it. For the most part classical computers are limited to doing one thing at a time, so the more complex the problem, the longer it takes.

A problem that requires more power and time than today’s computers can accommodate is called an intractable problem. These are the problems that quantum computers are predicted to solve.

When you enter the world of atomic and subatomic particles, things begin to behave in unexpected ways. In fact, these particles can exist in more than one state at a time. It’s this ability that quantum computers take advantage of.

Instead of bits, which conventional computers use, a quantum computer uses quantum bits—known as qubits. To illustrate the difference, imagine a sphere. A bit can be at either of the two poles of the sphere, but a qubit can exist at any point on the sphere. So, this means that a computer using qubits can store an enormous amount of information and uses less energy doing so than a classical computer.

By entering into this quantum area of computing where the traditional laws of physics no longer apply, we will be able to create processors that are significantly faster (a million or more times) than the ones we use today. Sounds fantastic, but the challenge is that quantum computing is also incredibly complex.

The pressure is on the computer industry to find ways to make computing more efficient, since we reached the limits of energy efficiency using classical methods. By 2040, according to a report by the Semiconductor Industry Association, we will no longer have the capability to power all of the machines around the world.

That’s precisely why the computer industry is racing to make quantum computers work on a commercial scale. No small feat, but one that will pay extraordinary dividends.

Originally published on forbes.com

COMING UP!!

(Saturday, July 15th, 2023)

"DOES MASS INCREASE WHEN NEARING THE SPEED OF LIGHT??"

[yanban-san]

Alright but they way that my tiny touch-starved being is, I can imagine how comfy hugs are from each set of twins-

Plain ol’ twins; just barely hiding in their coats as they hug you from the front-

Droids; might be a lil cold from the metal but I bet they got some heat core tomfoolery to warm the both of us up-

Eldritch; I’ve always wanted to know what hugs from shadows and feathers both feel like, just being lost in their innumerable wings, claws, scales and whatnot- every hug could be different depending on the day!

Driders; fluffy back and legs + the little clicks and buzzes they make when they’re happy, sign me up-

Hydreigons; wrapped up in their six wings to the point where you can’t tell human from hybrid-

I want ALL OF THEM to help my attention-starved existence. Thank you for listening to my Ted talk.

-lemon tea anon 🍋 🍵

Honest to god that's how I feel 🥲 Lemme just have hugs from my boys, pretty please-

I always thought the image of the twins having a small darling would be really cute- Like Emmet is hugging you and then he just wraps his long coat around you and you're squirming trying to escape while he's laughing- A Depot agent comes up to see what all the commotion is about and Emmet shushes them, telling them to be real quiet like- Before he asks the Depot Agent if they'd like... to purchase... a Darling- And swishing his coat open to reveal you glaring at him. Woe be unto the Depot Agent that actually tries to purchase you though. You're priceless to your sweethearts, after all. Ingo loves hugging you, or using you in the middle of the day as a pillow to squeeze while he rests his head. He'll wrap both of you in his coat- It makes a lovely impromptu blanket.

I decided to say the 'droids have quantum computers inside of them- But if you don't know, quantum computers... In their current states require temperatures as close to absolute zero as we can possibly get in order for them to work. So if they do have qubits running their brains, they are probably venting a lot of heat all the time- Especially because they have a generator inside of them as well. Hugging them is toasty, and during the Summer they are extra toasty. Of course they also run on pokemon-logic, so maybe they just have some NeverMeltIce jammed into those processors of theirs. I have also been playing around with some- Dare I say, body horror- that might get invoked with their physical interactions with their darling. But I digress; Their hugs are generally toasty, and they will grab you from afar to pull you in for one.

Eldritch boys just constantly hold you. The rare times you're alone, you can almost always feel their presence- Lurking in the shadows and out of sight- And sometimes you get pulled into darkness when you step into the shadows- Only to find yourself in Gear Station, being held by Ingo. "I missed you," He explains, tendrils and shadows coiling around you. His body dripping with the inky void that makes up his true form. Emmet grows jealous, and takes you away the moment he can. Whining as he holds you against him, a thousand voices wondering why you didn't ask him to come cuddle you too? He wants your affections- He's far softer than his brother, and prettier too! And then they spend your sleeping hours curled around you, a bed of fluffy feathers and scales and ink and light, cradling you in their claws and arms- Their precious soulmate. Their darling soulmate.

Driders have a difficult time with the hugging thing- Humans are much shorter than them, and though they have their four arms and their pedipalps, it's difficult for them to hug you- But you can hug them easily, especially if you're riding on their back. It's a place of honor, really- To be allowed on their fluffy back side, cuddling them while being carried everywhere. Their only complaint is that they cannot look at you. Though that is easily fixed. They can hug you easily by placing you in a hammock of webbing, or trapping you under them... They can also carry you- Supporting you in one set of arms and hugging you close with the other pair, kissing you with their spider mouths.

The hydreigon boys have an easy time hugging you- You just have to avoid being nommed on by them. Being bitten is their love language. Bite them back. They'll bite you in their sleep, they'll bite you while they're awake- They'll trap you in a cage of their wings, enjoying the fright on your face- That looks to them like adoration. Together, the six wings become twelve, and they lock you against them- Snapping at each other if they think the other is causing you discomfort. They kiss you, nursing on your skin, refusing to let up- Nesting with you in a lovely bed they've prepared of furs and moss and bones and flowers, while your feet are wrapped up in their tails.

[rydiathesummoner]

I've seen FFXVI's ambiguous ending compared to Schrodinger's Cat. CBU3 has already officially stated they will not be elaborating on a "correct" ending, thus the ending is officially up to player interpretation. I don't like the comparison to Schrodinger's Cat for two reasons:

That cat did nothing to you, you fucking monster.

In a fictional story, it's completely possible for characters to be both alive and dead at the same time. Valisthea is not bound by our laws of reality or any observer's paradox.

I prefer to look at the ending at a qubit. If you don't know what a qubit is, very simply put it's a computing term that goes beyond 0 and 1. We know computers are run with 0s and 1s right? So let's take a coin and say heads is 0 and tails is 1. Flip the coin, it's heads or tails right? OK what happens if you spin the coin on its side? Is it heads or tails now? That state of spinning coin is called superposition. It's both heads and tails at the same time. A qubit goes beyond typical bits in a computer by accommodating the spinning coin state along with 0s and 1s.

Using this spinning coin analogy, because CBU3 has said they will not be clarifying the ending, it means that Clive is officially both alive and dead. Both Clive and Joshua wrote the book in the ending. Clive is both dead on a beach and reuniting with Jill. Dion lived, but also was the first dragoon in the series to die from fall damage like a little bitch. Joshua is dead in Origin but also revived by Clive. The ending was carefully crafted to allow for any of these possibilities, reflecting the story's theme of giving people the freedom to live and die on their own terms. That freedom was extended to us, the players, to determine the outcome of the characters. Therefore ALL of the possibilities listed above are all correct at the same time.

You can have a qubit that is a 0 or a 1. You can also have a qubit that's both 0 and 1. Same with the ending.

I'm sure the internet can handle something not being black and white and where opposing sides are both correct with grace and maturity, right? ...right? ...hello?

[mysteriousquantumphysics]

Circuit Cutting for Efficient Quantum Circuit Simulation

In previous blog posts [1, 2] we talked about quantum circuit cutting - a technique to "cut" quantum circuits into pieces to run them on smaller quantum devices. In particular, for NISQ devices this is a nice method to run larger quantum circuits than usually possible with the limited number of qubits as well as diminishing the effects of noise during the computation [3]. However, such techniques come with the cost of having an exponential sampling overhead in the number of cut wires or gates. Thus, such methods are limited in applicability - namely they work best for shallow, easy to partition, circuits.

"Cutting" for Classical Simulation

No matter the (dis)advantages, the idea of "cutting" circuits into pieces cannot only be applied as a "compilation" step to run cut algorithms on real quantum devices. In contrast, "cutting" can also make classical simulations of quantum circuits of suitable classes more efficient. Why might it be desirable to simulate smaller circuits on a classical computer? The simple answer is that storing statevectors on classical computers requires an exponential amount of RAM, i.e., 2^n amplitudes for n qubits. As only limited RAM is available - similar to the limited number of qubits in NISQ devices - running smaller simulations/computations is desirable. However, there is no free lunch here as well, since cutting also induces an exponential overhead in the classical simulation case - meaning that an exponential amount of smaller subcircuits has to be run and subsequently reassembled again. Thus, the reason why one wants to cut circuits for classical simulations is a bit more intricate: Reducing the RAM requirements can also decrease the runtime of simulating gates (i.e. by matrix-vector multiplication) but as pointed out before, one has to run an exponential amount of circuits which is increasing the time cost again. Therefore, cutting quantum circuits for classical simulation is not always useful; instead, there is a tradeoff between reducing runtime by reducing RAM and the exponential overhead - thus, such techniques are usually only useful for quantum circuits with limited connectivity such that only a manageable number of cuts must be performed. In the literature this cutting is usually denoted as Hybrid Schrödinger Feynman Technique (HSF) [4, 5, 6] - still, the underlying ideas are quite similar to quantum circuit cutting. Let's look at the core idea of cutting circuits for classical simulation and where this aforementioned exponential overhead comes from.

How to Cut Circuits for Simulation

Conceptually, classical cutting of quantum gates (contrasting quantum circuit cutting, one is usually not considering wire cuts for HSF simulation) merely requires performing a Schmidt-Decomposition on the gate(s) to be cut. Considering the CNOT gate, this can be done quite easily by just factoring out properly as follows

where we just wrote down the CNOT gate in Dirac notation and factored out the projector P_0 and P_1 respectively. This can be represented graphically in a circuit diagram as

With this illustration it becomes more apparent what is meant by cutting. We decomposed the CNOT gate, which originally acts on two qubits jointly, into a representation with two contributions (terms) in which each one is bipartite: The first term is just the projector onto the zero state on the first qubit and nothing on the other. The second term is the projector onto the other computational basis state as well as a separate Pauli X gate on the other qubit. You can see that the qubit wires are not connected anymore in the separate contributions that constitute the cut.

If you have a larger circuit that you want to partition into two smaller parts which should be simulated separately and they are connected by a single CNOT gate, cutting would give you two pairs of bipartite circuits. Each of them is smaller than before, thus, faster to simulate. This toy example has a pretty small overhead in the number of simulations, often also denoted as "paths", namely only two. If more gates are cut, this grows exponentially as the number of paths per gate has to be multiplied. Mathematically speaking, this number of paths is determined by the Schmidt-rank of each cut gate. As mentioned before, the Schmidt Decomposition is the core tool to perform cutting and thus, we briefly look into how this Schmidt Decomposition is done in general.

Classical Cutting in General by Schmidt-Decompositions

In order to spare you tedious notation with a lot of confusing indices, let's consider the general case in graphical notation only. Any quantum circuit can be represented as a tensor network [7]. Each quantum wire can be interpreted as leg of a tensor with physical dimension 2 (since qubits have a basis with 2 vectors). Consider some operator A with n=6 qubits (the logic applies for arbitrarily many qubits) as shown in the figure below. Assume that we want to cut this operator in the middle. Originally, operator A has 2n legs , but we can reshape those legs/wires according to the desired cut location as shown on the right-hand side - resulting in two "big" legs with higher dimensions than before. The dimension of the upper and lower big leg is determined by the number of qubits n_a in the upper partition and n_b in the lower partition respectively, in our example n_a=n_b=3. The upper big leg has dimension 2^(2n_a) and the lower 2^(2n_b).

Doing this not only fixes the cut position but is a way of matricizing the previously higher rank object - allowing to perform a Singular Value Decomposition (SVD), which can be applied on matrices (having 2 legs) only. An SVD decomposes a matrix into three parts, two isometries, U and V as well as the diagonal matrix σ containing the singular values (shown diagramatically below). The number of singular values fixes the aforementioned Schmidt-rank [8] of the original operator/gate A which, in turn, determines the aforementioned overhead, the number of paths in the simulation. The isometries can be absorbed into the top and bottom and the remaining sum can be made explicit such that we end up with a bipartite representation, similar to the one shown for the CNOT gate. This allows to decompose the gate into two parts, at the cost of a higher number of paths for the simulation.

Conclusion

Now you know how circuit cutting can be applied for classical simulations as well - it merely requires performing a Schmidt Decomposition in order to find bipartite representations of gates to be cut. Interestingly, performing cuts for classical simulation induces an exponential overhead - similar to quantum circuit cutting for real quantum devices. Even though conceptual differences are present between both approaches, this parallel neatly shows that one can never avoid the exponential complexity of quantum systems: We can merely shift the complexity (e.g. memory complexity into time complexity as for HSF simulation), to hope for nice tradeoffs and computing advantages - but no method can get rid of the inherent exponential complexity of quantum systems.

References

[1] Blog Post "Cutting Quantum Circuits into Pieces - Why and How?"

[2] Blog Post "Quantum Circuit Cutting - with Randomly Applied Channels"

[3] Bechtold, M., Barzen, J., Leymann, F., Mandl, A., Obst, J., Truger, F., & Weder, B. (2023). Investigating the effect of circuit cutting in QAOA for the MaxCut problem on NISQ devices. In Quantum Science and Technology (Vol. 8, Issue 4, p. 045022). IOP Publishing. https://doi.org/10.1088/2058-9565/acf59c

[4] Aaronson, S., & Chen, L. (2016). Complexity-Theoretic Foundations of Quantum Supremacy Experiments (Version 2). arXiv. https://doi.org/10.48550/ARXIV.1612.05903

[5] Markov, I. L., Fatima, A., Isakov, S. V., & Boixo, S. (2018). Quantum Supremacy Is Both Closer and Farther than It Appears. arXiv. https://doi.org/10.48550/ARXIV.1807.10749

[6] Burgholzer, L., Bauer, H., & Wille, R. (2021). Hybrid Schrödinger-Feynman Simulation of Quantum Circuits With Decision Diagrams. In 2021 IEEE International Conference on Quantum Computing and Engineering (QCE). 2021 IEEE International Conference on Quantum Computing and Engineering (QCE). IEEE. https://doi.org/10.1109/qce52317.2021.00037

[7] Blog Entry Pennylane, "Tensor Network Quantum Circuits"

[8] Nielsen, M. A., Dawson, C. M., Dodd, J. L., Gilchrist, A., Mortimer, D., Osborne, T. J., Bremner, M. J., Harrow, A. W., & Hines, A. (2003). Quantum dynamics as a physical resource. In Physical Review A (Vol. 67, Issue 5). American Physical Society (APS). https://doi.org/10.1103/physreva.67.052301

[materialsscienceandengineering]

Physicists propose time crystal-based circuit board to reduce quantum computing errors

A trio of physicists, two with Uniwersytet Jagielloński in Poland and one with Swinburne University of Technology in Australia, are proposing the use of temporal printed circuit boards made using time crystals as a way to solve error problems on quantum computers. Krzysztof Giergiel, Krzysztof Sacha and Peter Hannaford have written a paper describing their ideas, which is currently available on the arXiv preprint server. Quantum computers promise to revolutionize computing—unfortunately, they are still in their infancy, and no one has yet been able to build one that could be used in a truly meaningful way. Efforts to build the desired types have been stymied by various hurdles, most of which are deemed likely solvable. However, one major hurdle that worries researchers is the enormous number of errors that are generated on such computers along with the good results. Errors on quantum computers happen when qubits interact while running calculations. Such interactions lead to the degradation of their quantum states and the information they hold. In this new effort, the research trio has developed an idea that would allow the qubits to work together in a way that prevents their interactions from leading to degradation.

Read more.

[muzzleroars]

Is v1 scared of death ?

it wasn't, at the start of everything - v1 boots to a dying world, its corroded mind immediately clinging to corrupted ideas about its purpose, knowing it is for war but instead thinking it must forever cause it into perpetuity instead of just fighting when called for. it is not yet a self, consciousness a faint flicker in a mind vast and filling fast with so much information its damaged computer can't fully process the data before it weaves into twisted code. when it meets v2, a shift occurs in recognition of the self, a mirrored image that it cannot copy - what's wrong? mirage is the emerging sentience, the understanding that it is v1, it is made for war, and it is in hell. it is here to end everything, and it cannot stop even if it had other wishes. to create war is its fundamental self and should it stop, everything it is would unravel. fear has no place but it feels it as an unnamed presence in the back of its mind. it has a self now, but the self can't project forward in concrete terms. confidence low. simulation unstable. cancel and move on.

but what happens when its self keeps growing, what happens when v1 follows whims instead of a directive? a new self is fostered, it is fed on curiosity instead of blood, it wants to learn instead of make war - these sides do not reconcile until it meets with gabriel. like v2, something is tripped again and in gabriel, its curiosity and bloodthirst are woven together, they fasten into a solid core of being, into what must be v1's soul. v1 is still not regularly existential but it has the capacity, endless in fact, which would only result in an abyss of inaction should it give way to it. it's a by-product of how its mind works, how easily it could be overtaken by the inevitability of death, unending loops of thoughts that lead nowhere or back into each other...and so v1 doesn't actively engage it, and in fact protects against it.

yet the fear grows, directly proportional to the life v1 gains in and outside of itself - it develops interests, it wants to see more, know more, do more than what it was made for, and it wants to stay with gabriel, learn about him and love him, have a whole life with him. it has so much to lose now and when it stops, it will be the end of everything, no spirit inhabiting the flesh...or maybe not. it wonders if it could have a ghost in some way, if the quantum particles that make up its mind are forever impressed with who it is, with what it has become, and if they would carry it on in some way. it would be caught in chaos it knows, the only reason it thinks now because its mind is so well-controlled, the particles so slow or directed that they can be turned into a thinking machine - without the computer, who would it express, experience? even if those particles remember, who would it be in a volatile outside world, separated from one another and scattered so far they could never meet again? would quantum strings still entangle them, too enmeshed to truly be apart? would its consciousness then be a web strung far and wide across space, echoing with who v1 was but unable to attain any cohesion without the deep frozen crystals that turn prisms into qubits? it thinks, somehow, this could be worse than nothing, so it continues to avoid thinking on it.

this avoidance is what i think ultimately causes the issues it and gabriel need to confront as it begins to fail though. they're not totally unprepared, but with the layers of protective coding against contemplating its own death, they're also not in the best position they could be. and as they attempt to figure things out now, as v1's code degrades and those restrictions are lifted, gabriel sees the full extent of its thoughts, the existential depth he knew it was capable of but had never heard at length. something in its mind was obviously given over to this a long time ago and has thought on nothing else while the rest of it ran unaware of the dread it was spinning. it is highly tuned to its demise, and it has considered inanimation at length (it still thinks about some of the first words gabriel said to it) or the possibility of its echo remaining in the quantum particles that have housed its consciousness for so long, they know nothing else. it asks gabriel several times where it will go, what will happen to it, and over and over he needs to admit he doesn't know. it tells him it doesn't want either, it doesn't want to shut off but it doesn't want to be a quantum ghost stretched thin and unthinking. it wants answers it can't compute, it wants answers gabriel can't divine. and it is very afraid.

[esotericworld]

“Physicists have purportedly created the first-ever wormhole, a kind of tunnel theorized in 1935 by Albert Einstein and Nathan Rosen that leads from one place to another by passing into an extra dimension of space.

The wormhole emerged like a hologram out of quantum bits of information, or “qubits,” stored in tiny superconducting circuits. By manipulating the qubits, the physicists then sent information through the wormhole, they reported today in the journal Nature.

The team, led by Maria Spiropulu of the California Institute of Technology, implemented the novel “wormhole teleportation protocol” using Google’s quantum computer, a device called Sycamore housed at Google Quantum AI in Santa Barbara, California. With this first-of-its-kind “quantum gravity experiment on a chip,” as Spiropulu described it, she and her team beat a competing group of physicists who aim to do wormhole teleportation with IBM and Quantinuum’s quantum computers.

When Spiropulu saw the key signature indicating that qubits were passing through the wormhole, she said, “I was shaken.”

The experiment can be seen as evidence for the holographic principle, a sweeping hypothesis about how the two pillars of fundamental physics, quantum mechanics and general relativity, fit together. Physicists have strived since the 1930s to reconcile these disjointed theories — one, a rulebook for atoms and subatomic particles, the other, Einstein’s description of how matter and energy warp the space-time fabric, generating gravity. The holographic principle, ascendant since the 1990s, posits a mathematical equivalence or “duality” between the two frameworks. It says the bendy space-time continuum described by general relativity is really a quantum system of particles in disguise. Space-time and gravity emerge from quantum effects much as a 3D hologram projects out of a 2D pattern.

Indeed, the new experiment confirms that quantum effects, of the type that we can control in a quantum computer, can give rise to a phenomenon that we expect to see in relativity — a wormhole...” 

[art-of-mathematics]

"The red thread of time"

The thread forms a sort of self-looping helix (with alternating diameters) - resembling a somewhat torus-like shape, and also the resulting shape looks like an egg.

[thestalwartheart]

WIP Wednesday

A snippet from the next chapter of my ongoing 00Q fic, the age of change. So many of you have been lovely about it this week. I can't thank you enough ❤️

They were watching the map on Q’s screen with dogged helplessness. Q’s smart blood was doing its job, but this far from a city, there was no CCTV to rely on; Q was blind. The only discernable figure on his screen was Bond, who was represented by his usual bright blue symbol: Poseidon’s trident, that everlasting reminder of strength, stability and control. The symbol of God of the sea, and now, the mark of a man who fell into rivers and lochs with death knocking at his door, only to resurrect himself from the watery depths stronger than before.

Psi hadn’t quite been an unbiased assignation. Q was just glad his branch colleagues assumed it was a nod to qubits.

@mi6-cafe

[nunuslab24]

Understanding The World of Quantum Computers

Imagine a computer so powerful that it could solve problems in seconds that would take our current machines millions of years. No, it's not science fiction—it's the exciting world of quantum computing, where bits become qubits and the impossible becomes possible. Let's dive into this technological marvel that might one day be as common as your smartphone!

A quantum computer is a supercomputer that exploits quantum mechanical phenomena or in other words, a quantum computer uses tiny particles to perform complex calculations. Unlike regular computers, quantum computers use qubits instead of bits!

A qubit means that it is either neither 0 or 1, think of it as a wave; it can go up and down at any given moment! This ability to be in multiple states simultaneously is known as superposition. At the same time, a bit in a classical computer is like a simple switch that can be either off (0) or on (1), a qubit can be both off and on simultaneously, providing an incredible amount of computational power. But how do they really work?

How Quantum Computers Actually Work

Superposition: As mentioned, qubits can exist in multiple states at once. This allows quantum computers to process a vast amount of information simultaneously.

Entanglement: This is a phenomenon where qubits become intertwined, so the state of one qubit can depend on another, no matter how far apart they are. This can massively increase computational power.

Quantum Gates: Similarto logic gates (a device that acts as a building block for digital circuits) in classical computers, quantum gates manipulate qubits. but because of superposition and entanglement, quantum gates can perform complex operations much faster than classical gates (smartphones, tablets, etc).

What Do Quantum Computers Look Like?

Unlike the sleek laptops and smartphones we use today, quantum computers look very different. They are usually large (5ft wide & 20ft long), complex machines housed in specialized laboratories. A typical quantum computer setup includes:

Cryogenic Systems: Quantum computers need extremely low temperatures to function, often close to absolute zero (kelvin or -273.15 degrees Celsius or -460 degrees Fahrenheit). This requires sophisticated cooling systems.

Quantum Processor: The heart of a quantum computer, where qubits are manipulated.

Control Systems: These are used to manage and operate the quantum processor, often involving complex electronics and software.

In other words, quantum computers are not something you can slip into your pocket or place on your desk. They currently require a highly controlled environment and are far from being household items.

Why Does This Matter?

The potential of quantum computers is amazing. Here are a few areas where they could make a significant impact:

Cryptography: Quantum computers could break current encryption methods, making our data vulnerable. However, they could also create unbreakable encryption.

Drug (Health) Discovery: They can simulate molecular structures much more efficiently than classical computers, speeding up the process of drug discovery and development.

Optimization: Quantum computers can solve complex optimization problems that are currently unsolvable, impacting industries from logistics to finance.

Pros and Cons of Quantum Computers:

Pros:

Speed: Quantum computers can solve problems in seconds that would take classical computers millions of years.

Power: Their ability to handle complex calculations could revolutionize fields like cryptography, material science, and artificial intelligence (AI).

Innovation: They could lead to new discoveries and advancements in technology that we can’t even imagine yet.

Cons:

Complexity: Quantum computers are incredibly complex and difficult to build and maintain.

Cost: The technology is expensive and currently out of reach for most organizations.

Security Risks: The potential to break current encryption methods poses a significant security threat.

Will We Ever Have Quantum Computers in Our Homes?

Given their current state, quantum computers are unlikely to become household items anytime soon. The technology is still in its infancy, and the machines are expensive and complex. However, as research progresses and technology advances, it’s possible that we could see more accessible forms of quantum computing in the future.

For now, the most practical application for everyday users will likely come through cloud-based quantum computing services provided by tech companies. This means you could potentially access the power of a quantum computer over the internet, without having to own one.

Quantum computers represent a leap forward in computing technology, with the potential to transform numerous fields and solve problems that are currently intractable. However, they also come with significant challenges and risks. As this technology develops, it will be crucial to balance its immense potential with the necessary safeguards to ensure it benefits humanity as a whole.

[tanadrin]

@adzolotl

Since you seem to want to make this a Real Science vs Not Science thing, does it change your mind at all if I tell you the most respected physicists at Stanford and Princeton are all (afaict) Everettians? It's very very widely accepted among the "it from qubit" set.

All of the physicists who actually think hard about quantum cosmology end up being Everettians (except Penrose, I don't know what that guy's problem is).

i want to post about stargate sg-1; i suppose i should have remembered that @official-kircheis is an mwi stan and also physically incapable of letting anything go, but here we are

i will happily admit i do not have the mathematics or physics background to weigh the relative merits of different interpretations of quantum mechanics. but i think the whole concept of “interpretations” of physics is a bit silly! as i understand it, the physics people do on blackboards and in books is the business of the mathematical models which make predictions, against which we test observations; i do not see why that requires “interpretation,” bc either the math works or it doesn’t. so insofar as i have an opinion on interpretations of qm, i think that interpretations of qm which can’t be experimentally distinguished from one another are essentially a kind of detached philosophy, a bit like those string theories that nobody has found a way to experimentally test yet.

from that standpoint, the idea that people get really attached to certain philosophical ideas about what physics means (beyond, like, what the math says you should observe) is interesting, and also not surprising, but also not, like... persuasive? in the sense that you cannot experimentally disprove people’s philosophical manias, and also in the sense that yeah, if you need to believe (or at least tacitly accept) in the likelihood of mwi to be taken seriously as a physicist at stanford and princeton, there might be some external/social reasons why those interpretations prevail, in addition to or aside from a kind of aesthetic or philosophical appeal. the university of chicago is famous for producing a very particular kind of economist, with a very particular kind of philosophical view on what is “correct’ economics. i do not have to be an economist to work out that this might be an institutional bias rather than an objective feature of economics.

mwi might very well be true, but most of the evidence people trot out seems to be more of the “this makes the theory more elegant” kind rather than the “oh yeah we ran such-and-such experiment, and we could not have gotten the result we did if objective collapse theories were true.” and sure, sometimes physics is quite elegant. but sometimes it isn’t! and from what i can tell aesthetic or philosophical judgements are not a very reliable guide to physics.

[jcmarchi]

Toward a code-breaking quantum computer

New Post has been published on https://thedigitalinsider.com/toward-a-code-breaking-quantum-computer/

Toward a code-breaking quantum computer

The most recent email you sent was likely encrypted using a tried-and-true method that relies on the idea that even the fastest computer would be unable to efficiently break a gigantic number into factors.

Quantum computers, on the other hand, promise to rapidly crack complex cryptographic systems that a classical computer might never be able to unravel. This promise is based on a quantum factoring algorithm proposed in 1994 by Peter Shor, who is now a professor at MIT.

But while researchers have taken great strides in the last 30 years, scientists have yet to build a quantum computer powerful enough to run Shor’s algorithm.

As some researchers work to build larger quantum computers, others have been trying to improve Shor’s algorithm so it could run on a smaller quantum circuit. About a year ago, New York University computer scientist Oded Regev proposed a major theoretical improvement. His algorithm could run faster, but the circuit would require more memory.

Building off those results, MIT researchers have proposed a best-of-both-worlds approach that combines the speed of Regev’s algorithm with the memory-efficiency of Shor’s. This new algorithm is as fast as Regev’s, requires fewer quantum building blocks known as qubits, and has a higher tolerance to quantum noise, which could make it more feasible to implement in practice.

In the long run, this new algorithm could inform the development of novel encryption methods that can withstand the code-breaking power of quantum computers.

“If large-scale quantum computers ever get built, then factoring is toast and we have to find something else to use for cryptography. But how real is this threat? Can we make quantum factoring practical? Our work could potentially bring us one step closer to a practical implementation,” says Vinod Vaikuntanathan, the Ford Foundation Professor of Engineering, a member of the Computer Science and Artificial Intelligence Laboratory (CSAIL), and senior author of a paper describing the algorithm.

The paper’s lead author is Seyoon Ragavan, a graduate student in the MIT Department of Electrical Engineering and Computer Science. The research will be presented at the 2024 International Cryptology Conference.

Cracking cryptography

To securely transmit messages over the internet, service providers like email clients and messaging apps typically rely on RSA, an encryption scheme invented by MIT researchers Ron Rivest, Adi Shamir, and Leonard Adleman in the 1970s (hence the name “RSA”). The system is based on the idea that factoring a 2,048-bit integer (a number with 617 digits) is too hard for a computer to do in a reasonable amount of time.

That idea was flipped on its head in 1994 when Shor, then working at Bell Labs, introduced an algorithm which proved that a quantum computer could factor quickly enough to break RSA cryptography.

“That was a turning point. But in 1994, nobody knew how to build a large enough quantum computer. And we’re still pretty far from there. Some people wonder if they will ever be built,” says Vaikuntanathan.

It is estimated that a quantum computer would need about 20 million qubits to run Shor’s algorithm. Right now, the largest quantum computers have around 1,100 qubits.

A quantum computer performs computations using quantum circuits, just like a classical computer uses classical circuits. Each quantum circuit is composed of a series of operations known as quantum gates. These quantum gates utilize qubits, which are the smallest building blocks of a quantum computer, to perform calculations.

But quantum gates introduce noise, so having fewer gates would improve a machine’s performance. Researchers have been striving to enhance Shor’s algorithm so it could be run on a smaller circuit with fewer quantum gates.

That is precisely what Regev did with the circuit he proposed a year ago.

“That was big news because it was the first real improvement to Shor’s circuit from 1994,” Vaikuntanathan says.

The quantum circuit Shor proposed has a size proportional to the square of the number being factored. That means if one were to factor a 2,048-bit integer, the circuit would need millions of gates.

Regev’s circuit requires significantly fewer quantum gates, but it needs many more qubits to provide enough memory. This presents a new problem.

“In a sense, some types of qubits are like apples or oranges. If you keep them around, they decay over time. You want to minimize the number of qubits you need to keep around,” explains Vaikuntanathan.

He heard Regev speak about his results at a workshop last August. At the end of his talk, Regev posed a question: Could someone improve his circuit so it needs fewer qubits? Vaikuntanathan and Ragavan took up that question.

Quantum ping-pong

To factor a very large number, a quantum circuit would need to run many times, performing operations that involve computing powers, like 2 to the power of 100.

But computing such large powers is costly and difficult to perform on a quantum computer, since quantum computers can only perform reversible operations. Squaring a number is not a reversible operation, so each time a number is squared, more quantum memory must be added to compute the next square.

The MIT researchers found a clever way to compute exponents using a series of Fibonacci numbers that requires simple multiplication, which is reversible, rather than squaring. Their method needs just two quantum memory units to compute any exponent.

“It is kind of like a ping-pong game, where we start with a number and then bounce back and forth, multiplying between two quantum memory registers,” Vaikuntanathan adds.

They also tackled the challenge of error correction. The circuits proposed by Shor and Regev require every quantum operation to be correct for their algorithm to work, Vaikuntanathan says. But error-free quantum gates would be infeasible on a real machine.

They overcame this problem using a technique to filter out corrupt results and only process the right ones.

The end-result is a circuit that is significantly more memory-efficient. Plus, their error correction technique would make the algorithm more practical to deploy.

“The authors resolve the two most important bottlenecks in the earlier quantum factoring algorithm. Although still not immediately practical, their work brings quantum factoring algorithms closer to reality,” adds Regev.

In the future, the researchers hope to make their algorithm even more efficient and, someday, use it to test factoring on a real quantum circuit.

“The elephant-in-the-room question after this work is: Does it actually bring us closer to breaking RSA cryptography? That is not clear just yet; these improvements currently only kick in when the integers are much larger than 2,048 bits. Can we push this algorithm and make it more feasible than Shor’s even for 2,048-bit integers?” says Ragavan.

This work is funded by an Akamai Presidential Fellowship, the U.S. Defense Advanced Research Projects Agency, the National Science Foundation, the MIT-IBM Watson AI Lab, a Thornton Family Faculty Research Innovation Fellowship, and a Simons Investigator Award.