16 ms·

Quantum winter is coming

297 points by nsoonhui 4y ago

rippercushions 4y ago
Did we even have a quantum summer? The hype is nowhere near what we've seen for (say) blockchain, AI or self-driving cars.
- tambourine_man 4y ago
  Oh yes, we did. Remember Google announcing quantum supremacy? At the very least a spring.
- jhpankow 4y ago
  There was as far as marketing. My family members stopped asking me about ads they saw on TV for IBM's quantum computers.
  - CarbonCycles 4y ago
    I've started to adopt a hedging strategy (i.e. short plays) with IBM marketing...seems like everything they touch dies (horrendously). ETA..in case anyone is interested, the author of the article is a theoretical physicist, which lends more credibility to the article. https://en.wikipedia.org/wiki/Sabine_Hossenfelder https://en.wikipedia.org/wiki/Sabine_Hossenfelder
- mathattack 4y ago
  The hype is smaller, though I’ve seen my share of grifters in the market. It’s also not a vote of confidence to see IBM behind much of the research.
- rusticpenn 4y ago
  I think that is a good thing. There are usecases being found for quantum computers, but nothing that can’t be done with normal computers yet.
- indymike 4y ago
  That hype was back in the 00's. This one could be like AI, where it had a huge hype cycle in the 80s, and exploded over the last decade. Or not.
- moffkalast 4y ago
  The problem with quantum computers is that every time someone thinks of a good application, there's a scientist dropping in with an "ackchyually that's not how any of this works". At this point I'm convinced that RNG is the only thing quantum effects are actually usable for.
  - JanisErdmanis 4y ago
    Already in winter mentality :)
sdgdfgsfdfgsdfg 4y ago
Two things can be true at the same time: We know that an ideal quantum computer provides an exponential speed-up in commercially relevant applications. There is a significant amount of smoke and mirrors in the quantum space. Unless there is some unknown fundamental reason why we cannot realize a good-enough quantum computer with sufficient knowledge and engineering, governments and business are well-advised to invest into R&D of quantum computers.
- sweezyjeezy 4y ago
  > We know an ideal quantum computer provides an exponential speed-up in commercially relevant applications Do we know that though?
  - civilized 4y ago
    We don't. Here's a survey paper from quantum computing expert Scott Aaronson, posted to arXiv just a couple months ago: https://arxiv.org/pdf/2209.06930.pdf https://arxiv.org/pdf/2209.06930.pdf From the abstract: > I survey, for a general scientific audience, three decades of research into which sorts of problems admit exponential speedups via quantum computers -- from the classics (like the algorithms of Simon and Shor), to the breakthrough of Yamakawa and Zhandry from April 2022. [...] I make some skeptical remarks about widely-repeated claims of exponential quantum speedups for practical machine learning and optimization problems. Through many examples, I try to convey the "law of conservation of weirdness," according to which every problem admitting an exponential quantum speedup must have some unusual property to allow the amplitude to be concentrated on the unknown right answer(s). I am very confused at how so many people are absolutely convinced that quantum computing is known to do, or already does, all sorts of things it is not known to do. There's a sister comment here saying exponentially superior quantum computers are available in AWS! It's like an urban legend that circulates among software engineers.
    - sdgdfgsfdfgsdfg 4y ago
      You're wrong, we do know that, and the paper you cite doesn't refute that in any way. Integer factorization and quantum simulation would be two examples of commercially highly relevant applications where an exponential speed-up applies.
robg 4y ago
Seems like true neuromorphoric computing has more of future than quantum computing. We assume processing power and iterations go together, but what happens when we get better at self-learning software like our wetware?
- tsimionescu 4y ago
  A sfar as we know, the problem of solving the Schrodinger equation would be exponentially faster on a quantum computer than the fastest possible non-quantum computer. Given that "neuromorphic" computers are classical computers, we don't know of any way to achieve a similar speedup for this problem, so we can at least say that there are applications for which we need a QC if we want to solve them. Of course, it's possible that those are far fewer than "neuromorphic" computers, so it may make more sense to invest more in the latter. Note that I'm putting neuromorphic in quotes because it's mostly a marketing term, the resemblance between memirstors and neurons is at best symbolic.
laurentoget 4y ago
"Problem is, a lot of CEOs in industry and the financial sector can’t tell a bra from a ket" i do not know enough about quantum computing to judge whether this article is accurate or not, but it certainly is well written and entertaining
- lkoolma 4y ago
  I agree that many in the financial sector do not know much about quantum computing, but it also does not seem that some in the quantum that do not understand the details of the problems that the financial sector has either. For instance, those in the capital markets/trading floors in Europe and North America do significant risk calculations with hundreds or a thousand variables on up to 100,000 positions with a certain confidence. Many of these risk calculations need to be reported nightly to regulators. These financial companies are paying many millions per year to AWS, Azure, or Google to do these calculations on classical computers. However, many parts of these calculations could be done with quantum computers relatively instantly, given enough qubits. I realize that the technology and reliability is not there today, but hopefully it will come soon. I would not be surprised if by 2035 using quantum computers to do many variable risk calculations would become (almost) mandatory for major European and North American financial companies.
  - tsimionescu 4y ago
    What makes you say this? Which particular quantum algorithm do you think gives an exponential speedup for multi-variate risk predictions? And why do you think there is any chance in hell that a quantum computer would exist by 2035 that could even store an input of the size you're talking about, nevermind have spare qubits to actually process it?
- vitiral 4y ago
  I'm familiar with bras I think... what is a "ket"?
  - hprotagonist 4y ago
    https://en.wikipedia.org/wiki/Bra%E2%80%93ket_notation https://en.wikipedia.org/wiki/Bra%E2%80%93ket_notation a ket is |v>
sandworm101 4y ago
People also forget that analogue computers, mechanical devices to perform calculations, can also be faster than digital computers in some situations. That doesn't make them commercially viable. Seems to me that most all of the quantum computing community is trying to be in the right place when they can start cracking current encryption standards at a commercial scale. At that moment, anyone with a functional quantum computer will drown in money. Then a few weeks later new quantum-resistant algorithms will appear and the gold rush will end. All the other quantum projects seem like attempts to keep ones foot in the market while waiting for that day.
- ahelwer 4y ago
  Cracking encryption is basically irrelevant as a quantum computing application. Post-quantum encryption algorithm development proceeds apace and the messaging is already "if you want this to still be encrypted 30 years from now, start using post-quantum encryption today." Anybody caught with their pants down the day quantum computers can actually crack 4096-bit RSA simply isn't serious about security.
  - tsunamifury 4y ago
    “Anyone who doesn’t have weaponized anthrax isn’t serious about home defense.” This forum gets more and more detached from reality every day.
    - thadt 4y ago
      Not this forum, but rather the US government: “NSA intends that all NSS will be quantum-resistant by 2035, in accordance with the goal espoused in NSM-10.” Source: https://media.defense.gov/2022/Sep/07/2003071836/-1/-1/0/CSI_CNSA_2.0_FAQ_.PDF https://media.defense.gov/2022/Sep/07/2003071836/-1/-1/0/CSI...
    - ahelwer 4y ago
      The list of things that have to be encrypted 30 years from now is very, very small. I doubt any (many?) people here have contact with any of it. I don't understand your analogy at all, sorry.
ahelwer 4y ago
As someone who has spent a fair bit of time figuring out how to explain quantum computing to people I've come to the conclusion that there are only two possible ways for people to understand it: (1) mathematically (2) as a finite list of things quantum computers can and cannot do and most people are not going to understand it mathematically, least of all money people who have to watch and evaluate 10 powerpoint pitches in a day or whatever. Without the math you cannot possibly explain how superposition and entanglement work, and even that explanation requires your audience already understand how classical computers work. So you are often reduced to saying "Here is what we think quantum computers will be able to do. The timeline for accomplishing this is at least a decade out. Here are some other things that people have said quantum computers can do which they definitely will not be able to do." But then you're purely relying on your audience believing you based on your credentials rather than following their own reasoning from a place of understanding. Someone else can come in with different credentials and say different things, motivated by money or simple ignorance mixed with hope, and now your audience is playing the credential evaluation game rather than the quantum computing capability evaluation game. Mix in low interest rates and a few people who have learned what to say to get attention, and you get the current state of things. There is a quiet core of real quantum computing research happening, surrounded by a moat of noise and hype that is required to interface with investors and the public. My sincere hope is that this quiet core accomplishes real advances before the music stops.
- afiori 4y ago
  The wrong explanation I like about QC works is to describe it as 2^n many computers doing the same computations on related data, with the caveat that you can only query one at random. Sprinkle some hand waiving around how you can "average them all together" or have them "check the answer with each other" before querying them.
  - naasking 4y ago
    I was just thinking about this analogy to parallel computation. It works well enough, and gives a better intuition than a list of things a QC can and cannot do, as long as they can understand that these aren't regular computers and so reading the result has some restrictions which is why it only provide exponential speedup on some problems.
NiceKeeb 4y ago
It constantly amazes me how much attention Hossenfelder, a simple research fellow, manages to attract.
- kittiepryde 4y ago
  Do you have an educational youtube channel? Will definitely take a look if you do.
  - JBits 4y ago
    PBS Space Time seems pretty good. He gives good explanations and gives a balanced perspective to both sides when there's debate.
- starkd 4y ago
  Intelligently communicating complex topics to the masses is a valuable skill in itself. She gains a lot of credibility with her humble attitude and willingness to admit what she does not know.
  - JBits 4y ago
    Sabine isn't very accurate though and pushes her own fringe ideas while criticising everybody else.
    - starkd 4y ago
      Even if that's the case, she seems able to differentiate opinion from fact.
- guender 4y ago
  Hossenfelder has been in Physics for more than 25 years and is a seasoned researcher and communicator. Her “academic rank” shouldn’t and in fact doesn’t have any bearing on her impact.
- in3d 4y ago
  She opines on a lot of things she has very little knowledge about and her writing style is terrible. But it’s crack for HN readers who mistake skepticisms and snark for insight.
propter_hoc 4y ago
I studied experimental condensed-matter physics and this article is spot on. The PIs at my university were holding clouds of rubidium atoms with laser tweezers at microkelvins in ultra-high vacuum, agitating them with a laser beam, and publishing papers saying "look it responds sort of like a qubit!" If you have seen the kind of equipment required to perform these experiments, it's absolutely unimaginable that these concepts could be miniaturized enough that someone would be able to put them in a desktop size box, and to do so usefully and safely within a timeline that is competitive with the advancement of microelectronics.
- peteradio 4y ago
  How much of that size is cryo-equipment though?
  - propter_hoc 4y ago
    That's my point; how do you propose to miniaturize cryogenic equipment (and make it safe for the general public to use)? The UHV equipment is pretty intense too, fwiw.
    - peteradio 4y ago
      I'm not sure, I wonder if there are some back of the envelope estimates that could be done to see how small you could theoretically shrink that portion. At least when you make it small the materials cost is minimized!! Could make it out of exotic materials and it might still be cost effective. I wouldn't worry too much about safety once its small, there is minimal amount of harm caused by ultra cold or ultra high vacuum.
      - logifail 4y ago
        > I wouldn't worry too much about safety once its small, there is minimal amount of harm caused by ultra cold or ultra high vacuum In a previous life I worked with NMR machines, the ones with superconducting magnets cooled by liquid helium which is itself cooled by liquid nitrogen. I would dispute "minimal amount of harm", part of the our training involved what to do if the magnet quenches, I recall "run for the exit before you suffocate" was basically the SOP... Anyway, they were loads of fun to work with, I won't ever forget that time I nearly had my house keys snatched out of my hand by one, but back then (25 years ago) they occupied entire rooms. AFAIK they still do. OT but I had an MRI a couple of weeks ago, and forgot to take off my gold wedding band. I could distinctly feel the magnetic field pulsing in my ring as the scan started. After a brief moment of sheer panic I realised it wasn't a problem ... and as I lay there I was idly wondering about just how much gold was in my ring :)
est 4y ago
This reads like some thing like IBM® Watson. There was indeed an AI boom at the moment, just not Watson.
BoppreH 4y ago
Unfortunately I work in cryptography, and breaking our algorithms is one of the tasks that requires the least number of qubits. And that doesn't depend on having a desktop quantum computer either, but only that a single state actor anywhere has a sufficiently large quantum computer. I'm a bit bitter that physics handed us this magical tool, and the best we managed so far is using it to invalidate decades of security research.
- lupire 4y ago
  How many qubits vs larger keys?
  - BoppreH 4y ago
    I'm afraid the number of qubits doesn't grow fast enough. Here's[1] a tongue in cheek "Post-Quantum RSA" with 2 Terabit keys. [1] https://cr.yp.to/papers/pqrsa-20170419.pdf https://cr.yp.to/papers/pqrsa-20170419.pdf
- JanisErdmanis 4y ago
  It's rather easy to produce qubits and place them in a box. The hard part is to make them interact with each other in a controlled fashion thus, adding one qubit to a large system is substantially harder than adding it to a small one. The only true benchmark is a factorisation of numbers. Number 21 has been factorised with nudging. Let's wait for a number 45 in the coming next decade.
- hannob 4y ago
  > Unfortunately I work in cryptography, and breaking our algorithms is one of the tasks that requires the least number of qubits I don't think that is true (or maybe I'm underestimating how many qbits other uses of QCs take). Estimates are still in the many millions: https://cacm.acm.org/news/237303-how-quantum-computer-could-break-2048-bit-rsa-encryption-in-8-hours/fulltext https://cacm.acm.org/news/237303-how-quantum-computer-could-...
  - BoppreH 4y ago
mrkramer 4y ago
I'm sick and tired of this pop science. Write research papers don't clot my YT feed.
adelarsq 4y ago
> director of research at Bank of America said that quantum computing will be “bigger than fire”. The only way in I can see this coming true is that it’ll produce more carbon emissions. I laugh so hard on this. But it's true.
ouid 4y ago
The biggest obstacle to the realization of quantum computing is not technical, imo, but theoretical. it is well known, but not to laypeople, that a quantum computer is efficiently (quadratic overhead) simulable if it only operates on the eigenstates of the generalized Pauli matrices with the so called Clifford operators. This is a really fancy way of saying that this group action is not dense in the unitary operators, which is itself a fancy way of saying that it behaves like rolling a die, instead of like rolling a ball. In order to achieve density in the unitaries it suffices to construct a single state that is not one of these magic states (their language, not mine), to a sufficiently high level of purity. The much touted paper which claims to do this only succeeds in showing that the problem is equivalent to some other problem which we also do not know how to solve, (creating many, worse separable copies of this state) and there is no particular reason to believe that it can be. Moreover given what it would be able to do, it seems much more likely to me that there is a proof, waiting to be discovered, that there is a fundamental obstruction to harvesting such a state without at least waiting as long as you would have to wait to do your computation the old fashioned way.
- Strilanc 4y ago
  Could you cite the "much touted paper" you're talking about? In my view, making the noisy physical magic states is the easy part of the distillation process. You reset a qubit, then rotate it 90° around the Y axis, then 45° around the Z axis. That's the magic state. Note that the tolerance on those rotations is forgiving: getting them to within 10°, 95% of the time, is sufficient. All the error correcting code stuff that follows has fidelity requirements an order of magnitude stricter. As you note, there'd need to be some unforeseen obstacle for state prep to be the showstopper. Given how apparently easy it is to make these states, I think any obstacle like that would basically have to falsify quantum mechanics as we know it. It would be like finding out that light can't be diagonally polarized.
  - ouid 4y ago
    The ability to rotate 45 degrees is equivalent to the construction of a magic state, as you have correctly identified, as it is not a clifford operator, and adding it to your generators gives universal quantum computation on its own. You have pushed the problem sideways. This is the paper, https://arxiv.org/abs/quant-ph/0403025 https://arxiv.org/abs/quant-ph/0403025, and it is well understood by the paper that the independence of the noisy magic states is necessary for the distillation process to proceed. Note that the probability of having some entanglement between your partial states goes up rather dramatically with the number of them that you have, and not obviously in a way that you can do anything about.
UIUC_06 4y ago
> Quantum computers are promising technology, yes, but the same can be said about nuclear fusion and look how that worked out. I've been following Sabine for quite a while. She's really working on her snark.
c7b 4y ago
Not the first article on HN to make that point [0]. Feels a bit like whistleblowers starting to come out. [0] https://news.ycombinator.com/item?id=32722374 https://news.ycombinator.com/item?id=32722374
stevefan1999 4y ago
Guys stop saying there is winter this and winter that, it's all part of the Gartner hype cycle: 1. it all started with a technology trigger (much to the like of early AI development by Turing and McCarthy) 2. then we reach the Peak of Inflated Expectations (trying to solve real world hard problems like Travelling Salesman) 3. and swamp through the Trough of Disillusionment (Death of LISP machine and overall major AI projects halts) 4. until the Slope of Enlightenment (accidental discovery of using GPU to accelerate AI computation) 5. and finally reaching the Plateau of Productivity (developing Tensorflow, PyTorch, and the overall AI democratization though the use of DL and AutoML). We have just barely in between the stage of Peak of Inflated Expectations and going to Trough of Disillusionment for Quantum Computing and very much likely to stay for a while. Don't you worry child, It's all part of the cycle.
- pessimizer 4y ago
  Guys, stop saying Gartner hype cycle this and Gartner hype cycle that. Not every failing overhyped idea is secretly a future winner. Sometimes, there's actually a 3D TV winter.
- JamesianP 4y ago
  #4. will be more like: "someone uses some new advance from another field to actually make it work... then they get crushed in court by patent trolls who acquired all the failed IP."
hackandthink 4y ago
Quantum Computers are a great research field. The physics and engineering problems are exciting. It's a case for research money. I wouldn't invest in it but billionaires could spend their money worse.
- galaxyLogic 4y ago
  Yeah, they could buy Twitter :-)
photochemsyn 4y ago
Quantum computation plays a starring role in some of my favorite recent sci-fi novels (Hannu Rajaniemi's Quantum Thief, for example), but like the William Gibson's Neuromancer world (powered by Eastern Seaboard Fusion Reactors), it's just interesting and speculative sci-fi. Happily, there are many fields beside computing where quantum technology comes into play - better and cheap chip fabrication, semiconductor lasers and diodes, all kinds of materials science research, and of course, solar energy conversion systems modeled on the photosynthetic apparatus: https://sci-hub.se/10.1038/nature22012 https://sci-hub.se/10.1038/nature22012 Romero, et al. (2017). Quantum design of photosynthesis for bio-inspired solar-energy conversion. Nature As far as what today's working scientists will pursue, the silly popular notion that researchers are free to explore whatever they find exciting and interesting is mostly nonsense; successful researchers in the modern science system are as keen as hounds on the scent for new funding disbursements from the major federal agencies (and some private sponsors). If the money dries up, they turn their attention to other things, except perhaps for a few back-burner projects handed off to some hopelessly naive yet charmingly enthusiastic grad student.
- benreesman 4y ago
  Eastern Seabord Fission Authority ;) Gibson got some stuff wrong, but it’s borderline scary how much he got right. Book is like 43 years old or something.
TheRealPomax 4y ago
is there a tl;dr? This is a very long post that doesn't seem to want to get to point by the time you made it halfway through.
mabbo 4y ago
> They just produced a random distribution that would take a really long time to calculate by any other means. It’s like this this guy stapling 5 M&M. That’s a world record, hurray, but what are you going to do with it? And this is why I keep coming back to Sabine Hossenfelder.
quantum_mcts 4y ago
> weather is a non-linear system whereas quantum mechanics is a linear theory This lady have no idea what she is talking about.
- im-a-baby 4y ago
  I believe the point is that quantum computers allow you to manipulate a linear combination of bits, whereas simulating the weather would require non-linear combinations. It's unclear how a QC would help simulate something like that better than a classical computer.
  - quantum_mcts 4y ago
    Quantum algorithms are nonlinear. If someone is saying "quantum mechanics is a linear theory" as a counterargument to anything QC related. Then that person has no idea what they are talking about. Because they likely never cared to learn event the basics of QC.
    - raziel2701 4y ago
      Quantum mechanics is a linear theory. That's not an erroneous statement. Quantum computing and quantum mechanics, not the same thing.
    - fauigerzigerk 4y ago
      I don't think it's quite as simple as that: "New Quantum Algorithms Finally Crack Nonlinear Equations. Two teams found different ways for quantum computers to process nonlinear systems by first disguising them as linear ones." https://www.quantamagazine.org/new-quantum-algorithms-finally-crack-nonlinear-equations-20210105/ https://www.quantamagazine.org/new-quantum-algorithms-finall...
- mikewarot 4y ago
  I believe that she was using the term "linear" in the computational/signal processing sense, not that of computing. In electronics, in a linear system, you can decompose a complex waveform and analyze its response to each frequency discretely, and when you recompose them, you get a correct answer. In a non-linear system, such as a mixer, no such analysis is possible, you have to consider all of the frequencies, and their levels at the same time. Also consider that most algorithms are founded on a deterministic computational method.
gaze 4y ago
Broad strokes this article raises some ok points. She’s wrong about SC qubit coherence times and she’s wrong about refrigeration being any kind of bottleneck. You could buy a dilution fridge from bluefors off the shelf. The microwave hardware and optics and all this stuff costs an order of magnitude more. Just kind of a low effort article. If you want to beat on SC qubits, bring up cosmic rays. She’d know that if she passed this by an expert, which I guess she’s too smart to do. Either quantum computers pan out over the time investors stay interested or they don’t. It’s not unlike any other technology. As far as physicists feeling embarrassment, why should we? One, we’re largely incapable of feeling it, and two, we tried and that’s cool. You have these VCs who have a very narrow view of how the future should be (chiefly being that which makes them richer) so you can only pitch so many technologies that fit that mold. To be blunt, find me a better technology that could potentially push the boundaries of human capability or understanding or whatever that VCs will invest in. Beats the hell out of VR. Is it cooler than shooting stuff into orbit? Seems on par to me.
- JBits 4y ago
  I would also say that Sabine is wrong on a number of points, like coherence times, but I thought that the problems with cooling were correct. Since I don't know much about cooling, would you be happy to elaborate?
  - gaze 4y ago
    See my other response
- raziel2701 4y ago
  Cooling is definitely a problem is your aim is to cool down the millions of physical qubits required to get the thousands of logical qubits needed to do an actually useful quantum computation. No one has scaled up their qubit technology to achieve millions of physical qubits, and this is going to be a very big computer with tons of thermal mass that needs to be cooled down sub-kelvin. That is a substantial engineering challenge.
  - 4y ago
Animats 4y ago
From the article: "The record breaking “useful” calculation for quantum computers is the prime-number factorization of 21. That’s the number, not the number of digits. Yes, the answer is 3 times 7, but if you do it on a quantum computer you can publish it in Nature. In case you are impressed by this achievement, please allow me to clarify that doing this calculation with the standard algorithm and error correction is way beyond the capacity of current quantum computers. They actually used a simplified algorithm that works for this number in particular." Oh. I thought things were further along than that.
- mirekrusin 4y ago
  Apparently that's what it is and noise seems to be a huge problem - as it seems to be growing exponentially? Think crazy cool fridges that need to be orders of magnitude better, not just linearly better, if you want to entangle more qubits.
- csande17 4y ago
  There have been a lot of claims of larger numbers, but they all rely on some combination of (a) "classical preprocessing", where you find the answer on a normal computer first and use it as an input to the quantum algorithm, and/or (b) selecting numbers with extremely specific mathematical properties.
- time_to_smile 4y ago
  It's wild that I've a seen a few linkedin invites and even job posting for "quantum computing AI". The tone is always along the lines of building up your quantum computing software development skills since it will be the next big thing in industry. I've worked with quantum computing researchers before (I mean in the same building not doing the work), it's interesting work, but we're still at the stage where a focused background in physics doing research in is the prereq, not skills with quantum algorithms and their implementations. "Programming quantum computers" is still physics not software engineering.
  - throwoutway 4y ago
    They’re evidently selling shovels for the gold rush, before the gold is found
stephc_int13 4y ago
The Quantum Computing fiasco is fascinating and underline quite few human nature flaws. - We're collectively less smart/rational than we think - People with money/power are not much better than average - We tend to be very gullible when we don't understand the underlying principles The same human flaws can be seen in UFO/Conspiracy theories and to some extent in the crypto/NFT scene. A lot of this is amplified to several orders of magnitude by incompetent journalism.
- logifail 4y ago
  > - People with money/power are not much better than average I think it's way worse than that, the only things that people with money/power are better at ... is getting / hanging on to money and/or power. They're not better at anything apart from that, by any objective measure.
  - stephc_int13 4y ago
    From my experience, people with higher social status (and thus money/power) tend on average to be somewhat smarter, but not by a large margin.
    - SQueeeeeL 4y ago
      A lot of that is correlated with more recreational time, better family lives (probably no one in jail), and higher quality education. This is the same logic the French aristocrats used to justify the oppression of the peasants, reading novels made them "better"
- deleted 4y ago
  [deleted]
- seibelj 4y ago
  Bitcoin is money the government doesn’t control. I like it but statists don’t.
  - 4y ago
nobodyandproud 4y ago
Can slow neutrinos, in principle, be used to build qubits?
seydor 4y ago
Because there was a spring?
thom 4y ago
The main application of quantum computing is Cunningham’s Law. Any time someone shows something is faster on a quantum computer, then you know it’s worth spending some time proving that actually the classical algorithms could have been faster in the first place.
Animats 4y ago
The "next big thing" isn't coming along well. * 2017 - the year of 3D TV. * 2019 - the year of VR * 2021 - the year of the Metaverse. All duds, or no more than niche products. Related duds include quantum computing, fusion power, and self-driving cars. (There are self-driving cars that work, from Waymo and Cruise, but they're a long way from being cost-effective.) On the other hand, there's lots of work to be done deploying the stuff that works. Solar. Wind. Batteries. Electric cars. Desalination plants. Automated manufacturing. Electrical transmission infrastructure to get power to where it's needed. All are profitable. None has either huge margins or monopolization potential. This discourages the Silicon Valley funding model.
- alerighi 4y ago
  Let's add to the list crypto currencies and all the related stuff, such as NFT, that already made a lot of people loose a lot of money.
  - legulere 4y ago
    Sadly crypto currencies aren't dead yet like 3D television and is causing massive CO2 emissions.
- mclightning 4y ago
  >> On the other hand, there's lots of work to be done deploying the stuff that works. Solar. Wind. Batteries. Electric cars. Desalination plants. Automated manufacturing. Electrical transmission infrastructure to get power to where it's needed. All are profitable. None has either huge margins or monopolization potential. This discourages the Silicon Valley funding model. Honestly, this should be in all caps, and heard by everyone. I am regularly disturbed by this fact. I am lead/senior software engineer working with frontend development. I could easily do embedded software engineering, automation or any other more pressing field for humanity. But economics are simply not there to justify. I would be getting a %60 pay-cut if I chose to work on anything that actually matters.
  - effie 4y ago
bodhiandphysics 4y ago
One thing to note is while there are not a lot of quantum algorithms (though wikipedia's list is very incomplete!), some of them are massively useful. Grover's algorithm provides a quadratic improvement in black box search (which is a subroutine in many many many many algorithms). Solving a system of sparse linear equations can be solved log(n) time on a quantum computer, compared to n on a classical computer. This is the single most important problem in scientific computing.
- lisper 4y ago
  > Solving a system of sparse linear equations ... is the single most important problem in scientific computing. I think this is arguable. To be sure, a lot of linear-system solving goes on in science, but you cannot conclude from this that it is the "single most important problem", it's just the one that we happen to know how to solve, and so that's where the compute power goes. It's like looking for your keys under the street light because it's easier to see rather than because it's where you lost your keys. Protein folding and the Navier-Stokes equation are arguably "more important", we just have no idea how to solve those problems.
  - bodhiandphysics 4y ago
    The navier stokes equation is quite literally solved using the diagonalization of large matrixes!
    - lisper 4y ago
      As an approximation, because we don't know how to find exact solutions.
deepburner 4y ago
As a person who works in Quantum Computing, I can concur that there's hype in the field; one of the professors in my university has a quantum machine learning (TM) startup that seems to be performing well, even though most of the faculty and grad students can tell you that it's bullshit. However. This paragraph straight up displays a fundamental lack of understanding by Hossenfelder: > Last time I looked, no one had any idea how to do a weather forecast on a quantum computer. It’s not just that no one has done it, no one knows if it’s even possible, because weather is a non-linear system whereas quantum mechanics is a linear theory. Unitary evolution generated by the Schrödinger equation is a linear map on _probability amplitudes_, just like how classical (probabilistic) computing performs linear operations on _probability distributions_. The commonly used quantum circuit model is a superset of classical logic gates and can accomplish anything a probabilistic classical computer can, so if anything is possible in a classical computing scheme, it's also possible in the quantum circuit scheme. I don't have much sympathy for her since this is not the first time Hossenfelder has displayed a lack of understanding, recently she has published a paper criticizing another one [1], now replaced with a much shorter text due to being told [2] by the authors of the original paper. Yeah I get it, it's dumb when the president of BofA is talking about how QC is "the next big thing", I know it's not coming Soon^TM, but saying "we will never have a quantum computer because the current ones suck" has the same energy as "the world doesn't need more than 5 computers" imo.
- sfpotter 4y ago
  > Unitary evolution generated by the Schrödinger equation is a linear map on _probability amplitudes_, just like how classical (probabilistic) computing performs linear operations on _probability distributions_. The commonly used quantum circuit model is a superset of classical logic gates and can accomplish anything a probabilistic classical computer can, so if anything is possible in a classical computing scheme, it's also possible in the quantum circuit scheme. To predict weather on a computer, we need to run large CFD simulations. When we do this on a classical computer, this involves a discretization of a system of PDEs with millions or billions of degrees of freedom, requiring 4 or 8 bits per floating point number. It may be possible to do the same CFD simulations on a quantum computer, but this is several constrained by the small number of qubits currently available on quantum computers. And clearly, even if you could run the same algorithm, presumably the point of using a quantum computer would be reap the "quantum advantage" in order to do something algorithmically superior to what's possible on a classical computer. I think this is a pretty small point to get hung up on. The rest of her article is perfectly reasonable.
DebtDeflation 4y ago
The obligatory: https://scottlocklin.wordpress.com/2019/01/15/quantum-computing-as-a-field-is-obvious-bullshit/ https://scottlocklin.wordpress.com/2019/01/15/quantum-comput...
- JanisErdmanis 4y ago
  > You’re better off reading ancient Greek than studying a ‘technical’ subject that eventually involves bringing a public school kid like me a steak. Love it!
g42gregory 4y ago
Can somebody name one practical application of QC? Perhaps not right now, but within 3-5 years? It can’t be prime number factorization in encryption, since people will just switch (and already have) to elliptic curves.
deleted 4y ago
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mgraczyk 4y ago
The video mostly seems reasonable, but the economic arguments toward the end seem off base to me. Hossenfelder describes a situation in which universities rent equipment from large companies, but fits this into a worldview in which quantum computing as an industry will not be commercially viable. But isn't this exactly what happened with the internet and other new forms of large scale computation? Initially demand came largely from academia (or government via defense), companies competed on cost and usability. After a few years or decades of competition and scaling, the technology became so commercially useful that it's now ubiquitous. Why won't that happen with quantum computers, why would that be a bad thing, and why shouldn't academics want to be working on that?
- rini17 4y ago
  Classical computers were solving all kinds of useful problems since the beginning. Quantum computers on the other hand, don't appear to be good for anything now and in foreseeable future.
meinersbur 4y ago
> Unfortunately, I have to inform you that Moore’s law isn’t a law of nature. It worked for conventional computers because those could be miniaturized. However, you can’t miniaturize ions or the Compton wavelength of electrons. They’re already as small as it gets. I think this is a mischaracterization. Moore's law is the result of many individual multiplicative advances that stack in each other (many of them allowing further miniaturization, but alternatively can also go into the direction of larger chips: chiplets, 450mm wafers, wafer-scale chips). There isn't a reason this stacking couldn't also be possible for Quantum Computers. Indeed, the number of qubits seems to grow exponentially [1]: 1 -> 2 -> 5 -> 17 -> 49 -> 76 -> 127 -> 216 -> thousands. If anything, the iterative miniaturization of classic circuits made the first steps more approachable compared to quantum computers that had to start on the atomic level. However, the existence of more and more stackable advances is indeed no law of nature that some authors seem to assume [2]. [1] https://en.wikipedia.org/wiki/List_of_quantum_processors https://en.wikipedia.org/wiki/List_of_quantum_processors [2] https://en.wikipedia.org/wiki/Accelerating_change#Kurzweil.27s_The_Law_of_Accelerating_Returns https://en.wikipedia.org/wiki/Accelerating_change#Kurzweil.2...
LarsDu88 4y ago
That was a great fucking read
mondayp 4y ago
I took Computers in high school, some might even say I’m a computer guy, and this article is absolutely correct. Believe me.

297 points by nsoonhui 4y ago

Did we even have a quantum summer? The hype is nowhere near what we've seen for (say) blockchain, AI or self-driving cars.

tambourine_man 4y ago
Oh yes, we did. Remember Google announcing quantum supremacy? At the very least a spring.
jhpankow 4y ago
There was as far as marketing. My family members stopped asking me about ads they saw on TV for IBM's quantum computers.
- CarbonCycles 4y ago
  I've started to adopt a hedging strategy (i.e. short plays) with IBM marketing...seems like everything they touch dies (horrendously). ETA..in case anyone is interested, the author of the article is a theoretical physicist, which lends more credibility to the article. https://en.wikipedia.org/wiki/Sabine_Hossenfelder https://en.wikipedia.org/wiki/Sabine_Hossenfelder
mathattack 4y ago
The hype is smaller, though I’ve seen my share of grifters in the market. It’s also not a vote of confidence to see IBM behind much of the research.
rusticpenn 4y ago
I think that is a good thing. There are usecases being found for quantum computers, but nothing that can’t be done with normal computers yet.
indymike 4y ago
That hype was back in the 00's. This one could be like AI, where it had a huge hype cycle in the 80s, and exploded over the last decade. Or not.
moffkalast 4y ago
The problem with quantum computers is that every time someone thinks of a good application, there's a scientist dropping in with an "ackchyually that's not how any of this works". At this point I'm convinced that RNG is the only thing quantum effects are actually usable for.
- JanisErdmanis 4y ago
  Already in winter mentality :)

sdgdfgsfdfgsdfg 4y ago

Two things can be true at the same time: We know that an ideal quantum computer provides an exponential speed-up in commercially relevant applications. There is a significant amount of smoke and mirrors in the quantum space. Unless there is some unknown fundamental reason why we cannot realize a good-enough quantum computer with sufficient knowledge and engineering, governments and business are well-advised to invest into R&D of quantum computers.

sweezyjeezy 4y ago
> We know an ideal quantum computer provides an exponential speed-up in commercially relevant applications Do we know that though?
- civilized 4y ago
  We don't. Here's a survey paper from quantum computing expert Scott Aaronson, posted to arXiv just a couple months ago: https://arxiv.org/pdf/2209.06930.pdf https://arxiv.org/pdf/2209.06930.pdf From the abstract: > I survey, for a general scientific audience, three decades of research into which sorts of problems admit exponential speedups via quantum computers -- from the classics (like the algorithms of Simon and Shor), to the breakthrough of Yamakawa and Zhandry from April 2022. [...] I make some skeptical remarks about widely-repeated claims of exponential quantum speedups for practical machine learning and optimization problems. Through many examples, I try to convey the "law of conservation of weirdness," according to which every problem admitting an exponential quantum speedup must have some unusual property to allow the amplitude to be concentrated on the unknown right answer(s). I am very confused at how so many people are absolutely convinced that quantum computing is known to do, or already does, all sorts of things it is not known to do. There's a sister comment here saying exponentially superior quantum computers are available in AWS! It's like an urban legend that circulates among software engineers.
  - sdgdfgsfdfgsdfg 4y ago
    You're wrong, we do know that, and the paper you cite doesn't refute that in any way. Integer factorization and quantum simulation would be two examples of commercially highly relevant applications where an exponential speed-up applies.

robg 4y ago

Seems like true neuromorphoric computing has more of future than quantum computing. We assume processing power and iterations go together, but what happens when we get better at self-learning software like our wetware?

tsimionescu 4y ago
A sfar as we know, the problem of solving the Schrodinger equation would be exponentially faster on a quantum computer than the fastest possible non-quantum computer. Given that "neuromorphic" computers are classical computers, we don't know of any way to achieve a similar speedup for this problem, so we can at least say that there are applications for which we need a QC if we want to solve them. Of course, it's possible that those are far fewer than "neuromorphic" computers, so it may make more sense to invest more in the latter. Note that I'm putting neuromorphic in quotes because it's mostly a marketing term, the resemblance between memirstors and neurons is at best symbolic.

laurentoget 4y ago

"Problem is, a lot of CEOs in industry and the financial sector can’t tell a bra from a ket" i do not know enough about quantum computing to judge whether this article is accurate or not, but it certainly is well written and entertaining

lkoolma 4y ago
I agree that many in the financial sector do not know much about quantum computing, but it also does not seem that some in the quantum that do not understand the details of the problems that the financial sector has either. For instance, those in the capital markets/trading floors in Europe and North America do significant risk calculations with hundreds or a thousand variables on up to 100,000 positions with a certain confidence. Many of these risk calculations need to be reported nightly to regulators. These financial companies are paying many millions per year to AWS, Azure, or Google to do these calculations on classical computers. However, many parts of these calculations could be done with quantum computers relatively instantly, given enough qubits. I realize that the technology and reliability is not there today, but hopefully it will come soon. I would not be surprised if by 2035 using quantum computers to do many variable risk calculations would become (almost) mandatory for major European and North American financial companies.
- tsimionescu 4y ago
  What makes you say this? Which particular quantum algorithm do you think gives an exponential speedup for multi-variate risk predictions? And why do you think there is any chance in hell that a quantum computer would exist by 2035 that could even store an input of the size you're talking about, nevermind have spare qubits to actually process it?
vitiral 4y ago
I'm familiar with bras I think... what is a "ket"?
- hprotagonist 4y ago
  https://en.wikipedia.org/wiki/Bra%E2%80%93ket_notation https://en.wikipedia.org/wiki/Bra%E2%80%93ket_notation a ket is |v>

sandworm101 4y ago

People also forget that analogue computers, mechanical devices to perform calculations, can also be faster than digital computers in some situations. That doesn't make them commercially viable. Seems to me that most all of the quantum computing community is trying to be in the right place when they can start cracking current encryption standards at a commercial scale. At that moment, anyone with a functional quantum computer will drown in money. Then a few weeks later new quantum-resistant algorithms will appear and the gold rush will end. All the other quantum projects seem like attempts to keep ones foot in the market while waiting for that day.

ahelwer 4y ago
Cracking encryption is basically irrelevant as a quantum computing application. Post-quantum encryption algorithm development proceeds apace and the messaging is already "if you want this to still be encrypted 30 years from now, start using post-quantum encryption today." Anybody caught with their pants down the day quantum computers can actually crack 4096-bit RSA simply isn't serious about security.
- tsunamifury 4y ago
  “Anyone who doesn’t have weaponized anthrax isn’t serious about home defense.” This forum gets more and more detached from reality every day.
  - thadt 4y ago
    Not this forum, but rather the US government: “NSA intends that all NSS will be quantum-resistant by 2035, in accordance with the goal espoused in NSM-10.” Source: https://media.defense.gov/2022/Sep/07/2003071836/-1/-1/0/CSI_CNSA_2.0_FAQ_.PDF https://media.defense.gov/2022/Sep/07/2003071836/-1/-1/0/CSI...
  - ahelwer 4y ago
    The list of things that have to be encrypted 30 years from now is very, very small. I doubt any (many?) people here have contact with any of it. I don't understand your analogy at all, sorry.

ahelwer 4y ago

As someone who has spent a fair bit of time figuring out how to explain quantum computing to people I've come to the conclusion that there are only two possible ways for people to understand it: (1) mathematically (2) as a finite list of things quantum computers can and cannot do and most people are not going to understand it mathematically, least of all money people who have to watch and evaluate 10 powerpoint pitches in a day or whatever. Without the math you cannot possibly explain how superposition and entanglement work, and even that explanation requires your audience already understand how classical computers work. So you are often reduced to saying "Here is what we think quantum computers will be able to do. The timeline for accomplishing this is at least a decade out. Here are some other things that people have said quantum computers can do which they definitely will not be able to do." But then you're purely relying on your audience believing you based on your credentials rather than following their own reasoning from a place of understanding. Someone else can come in with different credentials and say different things, motivated by money or simple ignorance mixed with hope, and now your audience is playing the credential evaluation game rather than the quantum computing capability evaluation game. Mix in low interest rates and a few people who have learned what to say to get attention, and you get the current state of things. There is a quiet core of real quantum computing research happening, surrounded by a moat of noise and hype that is required to interface with investors and the public. My sincere hope is that this quiet core accomplishes real advances before the music stops.

afiori 4y ago
The wrong explanation I like about QC works is to describe it as 2^n many computers doing the same computations on related data, with the caveat that you can only query one at random. Sprinkle some hand waiving around how you can "average them all together" or have them "check the answer with each other" before querying them.
- naasking 4y ago
  I was just thinking about this analogy to parallel computation. It works well enough, and gives a better intuition than a list of things a QC can and cannot do, as long as they can understand that these aren't regular computers and so reading the result has some restrictions which is why it only provide exponential speedup on some problems.

NiceKeeb 4y ago

It constantly amazes me how much attention Hossenfelder, a simple research fellow, manages to attract.

kittiepryde 4y ago
Do you have an educational youtube channel? Will definitely take a look if you do.
- JBits 4y ago
  PBS Space Time seems pretty good. He gives good explanations and gives a balanced perspective to both sides when there's debate.
starkd 4y ago
Intelligently communicating complex topics to the masses is a valuable skill in itself. She gains a lot of credibility with her humble attitude and willingness to admit what she does not know.
- JBits 4y ago
  Sabine isn't very accurate though and pushes her own fringe ideas while criticising everybody else.
  - starkd 4y ago
    Even if that's the case, she seems able to differentiate opinion from fact.
guender 4y ago
Hossenfelder has been in Physics for more than 25 years and is a seasoned researcher and communicator. Her “academic rank” shouldn’t and in fact doesn’t have any bearing on her impact.
in3d 4y ago
She opines on a lot of things she has very little knowledge about and her writing style is terrible. But it’s crack for HN readers who mistake skepticisms and snark for insight.

propter_hoc 4y ago

I studied experimental condensed-matter physics and this article is spot on. The PIs at my university were holding clouds of rubidium atoms with laser tweezers at microkelvins in ultra-high vacuum, agitating them with a laser beam, and publishing papers saying "look it responds sort of like a qubit!" If you have seen the kind of equipment required to perform these experiments, it's absolutely unimaginable that these concepts could be miniaturized enough that someone would be able to put them in a desktop size box, and to do so usefully and safely within a timeline that is competitive with the advancement of microelectronics.

peteradio 4y ago
How much of that size is cryo-equipment though?
- propter_hoc 4y ago
  That's my point; how do you propose to miniaturize cryogenic equipment (and make it safe for the general public to use)? The UHV equipment is pretty intense too, fwiw.
  - peteradio 4y ago
    I'm not sure, I wonder if there are some back of the envelope estimates that could be done to see how small you could theoretically shrink that portion. At least when you make it small the materials cost is minimized!! Could make it out of exotic materials and it might still be cost effective. I wouldn't worry too much about safety once its small, there is minimal amount of harm caused by ultra cold or ultra high vacuum.
    - logifail 4y ago
      > I wouldn't worry too much about safety once its small, there is minimal amount of harm caused by ultra cold or ultra high vacuum In a previous life I worked with NMR machines, the ones with superconducting magnets cooled by liquid helium which is itself cooled by liquid nitrogen. I would dispute "minimal amount of harm", part of the our training involved what to do if the magnet quenches, I recall "run for the exit before you suffocate" was basically the SOP... Anyway, they were loads of fun to work with, I won't ever forget that time I nearly had my house keys snatched out of my hand by one, but back then (25 years ago) they occupied entire rooms. AFAIK they still do. OT but I had an MRI a couple of weeks ago, and forgot to take off my gold wedding band. I could distinctly feel the magnetic field pulsing in my ring as the scan started. After a brief moment of sheer panic I realised it wasn't a problem ... and as I lay there I was idly wondering about just how much gold was in my ring :)

est 4y ago

This reads like some thing like IBM® Watson. There was indeed an AI boom at the moment, just not Watson.

BoppreH 4y ago

Unfortunately I work in cryptography, and breaking our algorithms is one of the tasks that requires the least number of qubits. And that doesn't depend on having a desktop quantum computer either, but only that a single state actor anywhere has a sufficiently large quantum computer. I'm a bit bitter that physics handed us this magical tool, and the best we managed so far is using it to invalidate decades of security research.

lupire 4y ago
How many qubits vs larger keys?
- BoppreH 4y ago
  I'm afraid the number of qubits doesn't grow fast enough. Here's[1] a tongue in cheek "Post-Quantum RSA" with 2 Terabit keys. [1] https://cr.yp.to/papers/pqrsa-20170419.pdf https://cr.yp.to/papers/pqrsa-20170419.pdf
JanisErdmanis 4y ago
It's rather easy to produce qubits and place them in a box. The hard part is to make them interact with each other in a controlled fashion thus, adding one qubit to a large system is substantially harder than adding it to a small one. The only true benchmark is a factorisation of numbers. Number 21 has been factorised with nudging. Let's wait for a number 45 in the coming next decade.
hannob 4y ago
> Unfortunately I work in cryptography, and breaking our algorithms is one of the tasks that requires the least number of qubits I don't think that is true (or maybe I'm underestimating how many qbits other uses of QCs take). Estimates are still in the many millions: https://cacm.acm.org/news/237303-how-quantum-computer-could-break-2048-bit-rsa-encryption-in-8-hours/fulltext https://cacm.acm.org/news/237303-how-quantum-computer-could-...
- BoppreH 4y ago

mrkramer 4y ago

I'm sick and tired of this pop science. Write research papers don't clot my YT feed.

adelarsq 4y ago

> director of research at Bank of America said that quantum computing will be “bigger than fire”. The only way in I can see this coming true is that it’ll produce more carbon emissions. I laugh so hard on this. But it's true.

ouid 4y ago

The biggest obstacle to the realization of quantum computing is not technical, imo, but theoretical. it is well known, but not to laypeople, that a quantum computer is efficiently (quadratic overhead) simulable if it only operates on the eigenstates of the generalized Pauli matrices with the so called Clifford operators. This is a really fancy way of saying that this group action is not dense in the unitary operators, which is itself a fancy way of saying that it behaves like rolling a die, instead of like rolling a ball. In order to achieve density in the unitaries it suffices to construct a single state that is not one of these magic states (their language, not mine), to a sufficiently high level of purity. The much touted paper which claims to do this only succeeds in showing that the problem is equivalent to some other problem which we also do not know how to solve, (creating many, worse separable copies of this state) and there is no particular reason to believe that it can be. Moreover given what it would be able to do, it seems much more likely to me that there is a proof, waiting to be discovered, that there is a fundamental obstruction to harvesting such a state without at least waiting as long as you would have to wait to do your computation the old fashioned way.

Strilanc 4y ago
Could you cite the "much touted paper" you're talking about? In my view, making the noisy physical magic states is the easy part of the distillation process. You reset a qubit, then rotate it 90° around the Y axis, then 45° around the Z axis. That's the magic state. Note that the tolerance on those rotations is forgiving: getting them to within 10°, 95% of the time, is sufficient. All the error correcting code stuff that follows has fidelity requirements an order of magnitude stricter. As you note, there'd need to be some unforeseen obstacle for state prep to be the showstopper. Given how apparently easy it is to make these states, I think any obstacle like that would basically have to falsify quantum mechanics as we know it. It would be like finding out that light can't be diagonally polarized.
- ouid 4y ago
  The ability to rotate 45 degrees is equivalent to the construction of a magic state, as you have correctly identified, as it is not a clifford operator, and adding it to your generators gives universal quantum computation on its own. You have pushed the problem sideways. This is the paper, https://arxiv.org/abs/quant-ph/0403025 https://arxiv.org/abs/quant-ph/0403025, and it is well understood by the paper that the independence of the noisy magic states is necessary for the distillation process to proceed. Note that the probability of having some entanglement between your partial states goes up rather dramatically with the number of them that you have, and not obviously in a way that you can do anything about.

UIUC_06 4y ago

> Quantum computers are promising technology, yes, but the same can be said about nuclear fusion and look how that worked out. I've been following Sabine for quite a while. She's really working on her snark.

c7b 4y ago

Not the first article on HN to make that point [0]. Feels a bit like whistleblowers starting to come out. [0] https://news.ycombinator.com/item?id=32722374 https://news.ycombinator.com/item?id=32722374

stevefan1999 4y ago

Guys stop saying there is winter this and winter that, it's all part of the Gartner hype cycle: 1. it all started with a technology trigger (much to the like of early AI development by Turing and McCarthy) 2. then we reach the Peak of Inflated Expectations (trying to solve real world hard problems like Travelling Salesman) 3. and swamp through the Trough of Disillusionment (Death of LISP machine and overall major AI projects halts) 4. until the Slope of Enlightenment (accidental discovery of using GPU to accelerate AI computation) 5. and finally reaching the Plateau of Productivity (developing Tensorflow, PyTorch, and the overall AI democratization though the use of DL and AutoML). We have just barely in between the stage of Peak of Inflated Expectations and going to Trough of Disillusionment for Quantum Computing and very much likely to stay for a while. Don't you worry child, It's all part of the cycle.

pessimizer 4y ago
Guys, stop saying Gartner hype cycle this and Gartner hype cycle that. Not every failing overhyped idea is secretly a future winner. Sometimes, there's actually a 3D TV winter.
JamesianP 4y ago
#4. will be more like: "someone uses some new advance from another field to actually make it work... then they get crushed in court by patent trolls who acquired all the failed IP."

hackandthink 4y ago

Quantum Computers are a great research field. The physics and engineering problems are exciting. It's a case for research money. I wouldn't invest in it but billionaires could spend their money worse.

galaxyLogic 4y ago
Yeah, they could buy Twitter :-)

photochemsyn 4y ago

Quantum computation plays a starring role in some of my favorite recent sci-fi novels (Hannu Rajaniemi's Quantum Thief, for example), but like the William Gibson's Neuromancer world (powered by Eastern Seaboard Fusion Reactors), it's just interesting and speculative sci-fi. Happily, there are many fields beside computing where quantum technology comes into play - better and cheap chip fabrication, semiconductor lasers and diodes, all kinds of materials science research, and of course, solar energy conversion systems modeled on the photosynthetic apparatus: https://sci-hub.se/10.1038/nature22012 https://sci-hub.se/10.1038/nature22012 Romero, et al. (2017). Quantum design of photosynthesis for bio-inspired solar-energy conversion. Nature As far as what today's working scientists will pursue, the silly popular notion that researchers are free to explore whatever they find exciting and interesting is mostly nonsense; successful researchers in the modern science system are as keen as hounds on the scent for new funding disbursements from the major federal agencies (and some private sponsors). If the money dries up, they turn their attention to other things, except perhaps for a few back-burner projects handed off to some hopelessly naive yet charmingly enthusiastic grad student.

benreesman 4y ago
Eastern Seabord Fission Authority ;) Gibson got some stuff wrong, but it’s borderline scary how much he got right. Book is like 43 years old or something.

TheRealPomax 4y ago

is there a tl;dr? This is a very long post that doesn't seem to want to get to point by the time you made it halfway through.

mabbo 4y ago

> They just produced a random distribution that would take a really long time to calculate by any other means. It’s like this this guy stapling 5 M&M. That’s a world record, hurray, but what are you going to do with it? And this is why I keep coming back to Sabine Hossenfelder.

quantum_mcts 4y ago

> weather is a non-linear system whereas quantum mechanics is a linear theory This lady have no idea what she is talking about.

im-a-baby 4y ago
I believe the point is that quantum computers allow you to manipulate a linear combination of bits, whereas simulating the weather would require non-linear combinations. It's unclear how a QC would help simulate something like that better than a classical computer.
- quantum_mcts 4y ago
  Quantum algorithms are nonlinear. If someone is saying "quantum mechanics is a linear theory" as a counterargument to anything QC related. Then that person has no idea what they are talking about. Because they likely never cared to learn event the basics of QC.
  - raziel2701 4y ago
    Quantum mechanics is a linear theory. That's not an erroneous statement. Quantum computing and quantum mechanics, not the same thing.
  - fauigerzigerk 4y ago
    I don't think it's quite as simple as that: "New Quantum Algorithms Finally Crack Nonlinear Equations. Two teams found different ways for quantum computers to process nonlinear systems by first disguising them as linear ones." https://www.quantamagazine.org/new-quantum-algorithms-finally-crack-nonlinear-equations-20210105/ https://www.quantamagazine.org/new-quantum-algorithms-finall...
mikewarot 4y ago
I believe that she was using the term "linear" in the computational/signal processing sense, not that of computing. In electronics, in a linear system, you can decompose a complex waveform and analyze its response to each frequency discretely, and when you recompose them, you get a correct answer. In a non-linear system, such as a mixer, no such analysis is possible, you have to consider all of the frequencies, and their levels at the same time. Also consider that most algorithms are founded on a deterministic computational method.

gaze 4y ago

Broad strokes this article raises some ok points. She’s wrong about SC qubit coherence times and she’s wrong about refrigeration being any kind of bottleneck. You could buy a dilution fridge from bluefors off the shelf. The microwave hardware and optics and all this stuff costs an order of magnitude more. Just kind of a low effort article. If you want to beat on SC qubits, bring up cosmic rays. She’d know that if she passed this by an expert, which I guess she’s too smart to do. Either quantum computers pan out over the time investors stay interested or they don’t. It’s not unlike any other technology. As far as physicists feeling embarrassment, why should we? One, we’re largely incapable of feeling it, and two, we tried and that’s cool. You have these VCs who have a very narrow view of how the future should be (chiefly being that which makes them richer) so you can only pitch so many technologies that fit that mold. To be blunt, find me a better technology that could potentially push the boundaries of human capability or understanding or whatever that VCs will invest in. Beats the hell out of VR. Is it cooler than shooting stuff into orbit? Seems on par to me.

JBits 4y ago
I would also say that Sabine is wrong on a number of points, like coherence times, but I thought that the problems with cooling were correct. Since I don't know much about cooling, would you be happy to elaborate?
- gaze 4y ago
  See my other response
raziel2701 4y ago
Cooling is definitely a problem is your aim is to cool down the millions of physical qubits required to get the thousands of logical qubits needed to do an actually useful quantum computation. No one has scaled up their qubit technology to achieve millions of physical qubits, and this is going to be a very big computer with tons of thermal mass that needs to be cooled down sub-kelvin. That is a substantial engineering challenge.
- 4y ago

Animats 4y ago

From the article: "The record breaking “useful” calculation for quantum computers is the prime-number factorization of 21. That’s the number, not the number of digits. Yes, the answer is 3 times 7, but if you do it on a quantum computer you can publish it in Nature. In case you are impressed by this achievement, please allow me to clarify that doing this calculation with the standard algorithm and error correction is way beyond the capacity of current quantum computers. They actually used a simplified algorithm that works for this number in particular." Oh. I thought things were further along than that.

mirekrusin 4y ago
Apparently that's what it is and noise seems to be a huge problem - as it seems to be growing exponentially? Think crazy cool fridges that need to be orders of magnitude better, not just linearly better, if you want to entangle more qubits.
csande17 4y ago
There have been a lot of claims of larger numbers, but they all rely on some combination of (a) "classical preprocessing", where you find the answer on a normal computer first and use it as an input to the quantum algorithm, and/or (b) selecting numbers with extremely specific mathematical properties.
time_to_smile 4y ago
It's wild that I've a seen a few linkedin invites and even job posting for "quantum computing AI". The tone is always along the lines of building up your quantum computing software development skills since it will be the next big thing in industry. I've worked with quantum computing researchers before (I mean in the same building not doing the work), it's interesting work, but we're still at the stage where a focused background in physics doing research in is the prereq, not skills with quantum algorithms and their implementations. "Programming quantum computers" is still physics not software engineering.
- throwoutway 4y ago
  They’re evidently selling shovels for the gold rush, before the gold is found

stephc_int13 4y ago

The Quantum Computing fiasco is fascinating and underline quite few human nature flaws. - We're collectively less smart/rational than we think - People with money/power are not much better than average - We tend to be very gullible when we don't understand the underlying principles The same human flaws can be seen in UFO/Conspiracy theories and to some extent in the crypto/NFT scene. A lot of this is amplified to several orders of magnitude by incompetent journalism.

logifail 4y ago
> - People with money/power are not much better than average I think it's way worse than that, the only things that people with money/power are better at ... is getting / hanging on to money and/or power. They're not better at anything apart from that, by any objective measure.
- stephc_int13 4y ago
  From my experience, people with higher social status (and thus money/power) tend on average to be somewhat smarter, but not by a large margin.
  - SQueeeeeL 4y ago
    A lot of that is correlated with more recreational time, better family lives (probably no one in jail), and higher quality education. This is the same logic the French aristocrats used to justify the oppression of the peasants, reading novels made them "better"
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seibelj 4y ago
Bitcoin is money the government doesn’t control. I like it but statists don’t.
- 4y ago

nobodyandproud 4y ago

Can slow neutrinos, in principle, be used to build qubits?

seydor 4y ago

Because there was a spring?

thom 4y ago

The main application of quantum computing is Cunningham’s Law. Any time someone shows something is faster on a quantum computer, then you know it’s worth spending some time proving that actually the classical algorithms could have been faster in the first place.

Animats 4y ago

The "next big thing" isn't coming along well. * 2017 - the year of 3D TV. * 2019 - the year of VR * 2021 - the year of the Metaverse. All duds, or no more than niche products. Related duds include quantum computing, fusion power, and self-driving cars. (There are self-driving cars that work, from Waymo and Cruise, but they're a long way from being cost-effective.) On the other hand, there's lots of work to be done deploying the stuff that works. Solar. Wind. Batteries. Electric cars. Desalination plants. Automated manufacturing. Electrical transmission infrastructure to get power to where it's needed. All are profitable. None has either huge margins or monopolization potential. This discourages the Silicon Valley funding model.

alerighi 4y ago
Let's add to the list crypto currencies and all the related stuff, such as NFT, that already made a lot of people loose a lot of money.
- legulere 4y ago
  Sadly crypto currencies aren't dead yet like 3D television and is causing massive CO2 emissions.
mclightning 4y ago
>> On the other hand, there's lots of work to be done deploying the stuff that works. Solar. Wind. Batteries. Electric cars. Desalination plants. Automated manufacturing. Electrical transmission infrastructure to get power to where it's needed. All are profitable. None has either huge margins or monopolization potential. This discourages the Silicon Valley funding model. Honestly, this should be in all caps, and heard by everyone. I am regularly disturbed by this fact. I am lead/senior software engineer working with frontend development. I could easily do embedded software engineering, automation or any other more pressing field for humanity. But economics are simply not there to justify. I would be getting a %60 pay-cut if I chose to work on anything that actually matters.
- effie 4y ago

bodhiandphysics 4y ago

One thing to note is while there are not a lot of quantum algorithms (though wikipedia's list is very incomplete!), some of them are massively useful. Grover's algorithm provides a quadratic improvement in black box search (which is a subroutine in many many many many algorithms). Solving a system of sparse linear equations can be solved log(n) time on a quantum computer, compared to n on a classical computer. This is the single most important problem in scientific computing.

lisper 4y ago
> Solving a system of sparse linear equations ... is the single most important problem in scientific computing. I think this is arguable. To be sure, a lot of linear-system solving goes on in science, but you cannot conclude from this that it is the "single most important problem", it's just the one that we happen to know how to solve, and so that's where the compute power goes. It's like looking for your keys under the street light because it's easier to see rather than because it's where you lost your keys. Protein folding and the Navier-Stokes equation are arguably "more important", we just have no idea how to solve those problems.
- bodhiandphysics 4y ago
  The navier stokes equation is quite literally solved using the diagonalization of large matrixes!
  - lisper 4y ago
    As an approximation, because we don't know how to find exact solutions.

deepburner 4y ago

As a person who works in Quantum Computing, I can concur that there's hype in the field; one of the professors in my university has a quantum machine learning (TM) startup that seems to be performing well, even though most of the faculty and grad students can tell you that it's bullshit. However. This paragraph straight up displays a fundamental lack of understanding by Hossenfelder: > Last time I looked, no one had any idea how to do a weather forecast on a quantum computer. It’s not just that no one has done it, no one knows if it’s even possible, because weather is a non-linear system whereas quantum mechanics is a linear theory. Unitary evolution generated by the Schrödinger equation is a linear map on _probability amplitudes_, just like how classical (probabilistic) computing performs linear operations on _probability distributions_. The commonly used quantum circuit model is a superset of classical logic gates and can accomplish anything a probabilistic classical computer can, so if anything is possible in a classical computing scheme, it's also possible in the quantum circuit scheme. I don't have much sympathy for her since this is not the first time Hossenfelder has displayed a lack of understanding, recently she has published a paper criticizing another one [1], now replaced with a much shorter text due to being told [2] by the authors of the original paper. Yeah I get it, it's dumb when the president of BofA is talking about how QC is "the next big thing", I know it's not coming Soon^TM, but saying "we will never have a quantum computer because the current ones suck" has the same energy as "the world doesn't need more than 5 computers" imo.

sfpotter 4y ago
> Unitary evolution generated by the Schrödinger equation is a linear map on _probability amplitudes_, just like how classical (probabilistic) computing performs linear operations on _probability distributions_. The commonly used quantum circuit model is a superset of classical logic gates and can accomplish anything a probabilistic classical computer can, so if anything is possible in a classical computing scheme, it's also possible in the quantum circuit scheme. To predict weather on a computer, we need to run large CFD simulations. When we do this on a classical computer, this involves a discretization of a system of PDEs with millions or billions of degrees of freedom, requiring 4 or 8 bits per floating point number. It may be possible to do the same CFD simulations on a quantum computer, but this is several constrained by the small number of qubits currently available on quantum computers. And clearly, even if you could run the same algorithm, presumably the point of using a quantum computer would be reap the "quantum advantage" in order to do something algorithmically superior to what's possible on a classical computer. I think this is a pretty small point to get hung up on. The rest of her article is perfectly reasonable.

DebtDeflation 4y ago

The obligatory: https://scottlocklin.wordpress.com/2019/01/15/quantum-computing-as-a-field-is-obvious-bullshit/ https://scottlocklin.wordpress.com/2019/01/15/quantum-comput...

JanisErdmanis 4y ago
> You’re better off reading ancient Greek than studying a ‘technical’ subject that eventually involves bringing a public school kid like me a steak. Love it!

g42gregory 4y ago

Can somebody name one practical application of QC? Perhaps not right now, but within 3-5 years? It can’t be prime number factorization in encryption, since people will just switch (and already have) to elliptic curves.

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mgraczyk 4y ago

The video mostly seems reasonable, but the economic arguments toward the end seem off base to me. Hossenfelder describes a situation in which universities rent equipment from large companies, but fits this into a worldview in which quantum computing as an industry will not be commercially viable. But isn't this exactly what happened with the internet and other new forms of large scale computation? Initially demand came largely from academia (or government via defense), companies competed on cost and usability. After a few years or decades of competition and scaling, the technology became so commercially useful that it's now ubiquitous. Why won't that happen with quantum computers, why would that be a bad thing, and why shouldn't academics want to be working on that?

rini17 4y ago
Classical computers were solving all kinds of useful problems since the beginning. Quantum computers on the other hand, don't appear to be good for anything now and in foreseeable future.

meinersbur 4y ago

> Unfortunately, I have to inform you that Moore’s law isn’t a law of nature. It worked for conventional computers because those could be miniaturized. However, you can’t miniaturize ions or the Compton wavelength of electrons. They’re already as small as it gets. I think this is a mischaracterization. Moore's law is the result of many individual multiplicative advances that stack in each other (many of them allowing further miniaturization, but alternatively can also go into the direction of larger chips: chiplets, 450mm wafers, wafer-scale chips). There isn't a reason this stacking couldn't also be possible for Quantum Computers. Indeed, the number of qubits seems to grow exponentially [1]: 1 -> 2 -> 5 -> 17 -> 49 -> 76 -> 127 -> 216 -> thousands. If anything, the iterative miniaturization of classic circuits made the first steps more approachable compared to quantum computers that had to start on the atomic level. However, the existence of more and more stackable advances is indeed no law of nature that some authors seem to assume [2]. [1] https://en.wikipedia.org/wiki/List_of_quantum_processors https://en.wikipedia.org/wiki/List_of_quantum_processors [2] https://en.wikipedia.org/wiki/Accelerating_change#Kurzweil.27s_The_Law_of_Accelerating_Returns https://en.wikipedia.org/wiki/Accelerating_change#Kurzweil.2...

LarsDu88 4y ago

That was a great fucking read

mondayp 4y ago

I took Computers in high school, some might even say I’m a computer guy, and this article is absolutely correct. Believe me.