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Think of quantum computing progress like this. There were fundamental problems keeping it from working, and those have been largely overcome. Now we have a path

Think of quantum computing progress like this. There were fundamental problems keeping it from working, and those have been largely overcome. Now we have a path and we are really just improving the technology until it’s useful, and that path is very clear. It’s just a matter of going down it, which is what’s really happening. The general consensus is that there will be a fault tolerant quantum computer by 2035-2040. So like silicon, it is going to take us a while to get there, but we are only talking about 11-16 years or so according to the best experts in the field (remember AI has similar longer terms before it rapidly accelerated). And quantum computers are profoundly powerful — as in civilization changing computer power.

Aardwolf 3y ago
> and that path is very clear How is the time of this clear path measured? I actually have the exact same question about fusion reactors (such as ITER with results planned decades ahead of time) What could speed up those decades? Letting more people work on it at the same time? Throwing more money at it? (e.g. for ITER, are we just waiting for them to pour concrete faster?) Or are these decades of planning also waiting for other technologies to appear in 10, 20, ... years? (Which would be some kind of unclear uncertainty after all)
- ghaff 3y ago
  One area in quantum that’s getting a lot of attention is dealing with noise. (Basically you want to decrease the number of qubits needed to make a reliable logical qubit to a reasonable number.) This has turned out to be a big problem (with some calling it potentially intractable.) But a lot of progress is being made in this area. There’s a good article in the current issue of Technology Review.) This is one area that could lead to outsized advances. More money and people can usually move but there’s a limit to which just throwing money at a problem can accelerate the outcome in part because of all the complex interconnection, some not even appreciated. Think ML with GPUs.
  - deleted 3y ago
    [deleted]
- antonvs 3y ago
  Assuming it's true that there's some clear path in the quantum computing case, then ITER is rather different because there's currently no clear path to commercially viable nuclear fusion. ITER itself isn't even intended to achieve that. It's a research facility to test and demonstrate large-scale fusion in a tokamak. It's not even designed to generate electricity as output - just heat energy. If ITER ends up demonstrating that its approach could be further improved in the direction of a commercial design - which is not at all clear (see reference below) - they'll have to start a new project to achieve that. And you can expect that project to take even more money and quite probably a longer time, since there will be a lot of advances that will still need to be made. You might be interested to read "ITER is a showcase … for the drawbacks of fusion energy": https://thebulletin.org/2018/02/iter-is-a-showcase-for-the-drawbacks-of-fusion-energy/ https://thebulletin.org/2018/02/iter-is-a-showcase-for-the-d... . I recommend reading the whole article. > Letting more people work on it at the same time? Throwing more money at it? There are 6500 people all told that work on ITER, and its total funding is projected to reach as much as $65 billion. More people and money for ITER is almost certainly not the answer. But other groups are also working on it, including 30+ fusion startups (see e.g. https://app.dealroom.co/lists/25184 https://app.dealroom.co/lists/25184). However, ITER's funding is about 10-15 times that of all those startups combined. The problem with the startup approach is they're more likely to be killed if they don't achieve results. > Or are these decades of planning also waiting for other technologies to appear in 10, 20, ... years? For fusion, that's certainly the case. Despite the existence of startups, which perhaps reflect the existence of either altruistic and/or gullible VCs, fusion power is still very much a research project. It's not even certain that commercial fusion power will ever be viable - the article I linked helps explain that.
- fastneutron 3y ago
  With ITER (and tokomaks more generally), the original assumption was that scaling laws would enable you to reach breakeven just by making the thing big enough. The problem is that "big enough" means throwing $25B at it, and when that's spread across a committee of a dozen countries, that's not a recipe for getting anything done quickly. With quantum error correction, we're not talking a $25B facility with many competing hands in the pie. Instead, we're talking about improving the spatial and timing precision of RF, optics, and photonic hardware. Unlike fusion, where basically everything needs to be a custom job, there are established industries around these quantum-adjacent technologies with decades of accumulated know-how and plenty of low-hanging fruit to get most of, if not all of the way there.
- happytiger 3y ago
  Well one important metric is this one: https://www.scmp.com/news/china/science/article/3246752/china-and-russia-test-hack-proof-quantum-communication-link-brics-countries https://www.scmp.com/news/china/science/article/3246752/chin... Read the quotes. Global financial systems are trying to harden themselves with quantum computers in anticipation of forecast technology advancements. Maybe this piece by 60 minutes is worth watching too to get a better sense: https://youtu.be/K4ssT6Dzmnw?si=FseoJawRowldaaPH https://youtu.be/K4ssT6Dzmnw?si=FseoJawRowldaaPH It directly addresses technology progress and explains the basics.
  - JoachimS 3y ago
    But that is just hedging the bets - it does not show that the path to practical quantum computers at scale to handle real problems is feasible. We see customers getting requirement requests for using PQ safe crypto algorithms to be used in systems that will be used 30+ years. But that too is also just hedging the bets. Quantum Key Distribution is feasible - esp for systems that don't need to move and where you own the medium. And can spend the 1000+ kUSD these machines costs. For most use cases (for example between a client and a server setting up a secure session over Internet) these machines does not solve anything. But they sure are very cool to own and deploy.
    - deleted 3y ago
      [deleted]
    - happytiger 3y ago
      Please see the comments at 7:30 and then look the guy up. He founded Google’s quantum lab.
iainmerrick 3y ago
And quantum computers are profoundly powerful — as in civilization changing computer power. How so? The main promise/fear I hear about is breaking cryptography, but then it sounds like we can switch to new post-quantum encryption and we’ll be essentially in the same place as before.
- regularfry 3y ago
  It's not the same place because access to quantum computers is (and likely will be for a while) heavily asymmetric. People who want to break encryption will be able to do so, while people who want unbreakable encryption will, except for the tiny overlap with the former set, not have access to the hardware.
  - iainmerrick 3y ago
    I don’t think you need a quantum computer to do post-quantum encryption. It’s just an encryption method that’s believed not to have any quantum shortcuts.
    - ghaff 3y ago
      Correct. At the moment seems to be mostly lattice-based approaches.
  - dmurray 3y ago
    No, post-quantum cryptography is focused on methods where encryption can be done with classical computers. Post-quantum methods have other disadvantages, primarily that they haven't been studied as deeply as traditional methods (especially RSA) so they may be vulnerable to classes of attack we haven't thought of yet. https://en.m.wikipedia.org/wiki/Post-quantum_cryptography https://en.m.wikipedia.org/wiki/Post-quantum_cryptography
  - JoachimS 3y ago
    AFAIK, this is basically the opposite of how it probably will pan out. Some organsations MAY someday have Quantum Computers capable of cracking some asymmetric keys (RSA). All of us will have access to cryptographic algorithms (inlcuding open source implementations) that can't be cracked by the Quantum Computers. These algorithms are executed on our normal, classical computers. We already have a first set of post quantum computer cryptographic algorithms. See the NIST competition for example. Their implementations still looks immature (some have fallen against classical attacks, including side channel issues). But we'll get there. We will also have to (yet again) deal with having algorithm agility, which adds complexity. Quantum Computers are not magical things. We can (and do) know type of problems, algorithms, operations they should be better than classical computers to solve (called quantum supremacy). Shor's algorithm, which provides exponential speedup of cracking RSA key is an example of such an algorithm. What we so far don't consider that much is the feasibility to perform these algorithms in reality. That is, we look at the asymptotic speedup, not the practical speedup. There is a really good paper by people from the MS PQ team that looked at this. Highly recommended: https://cacm.acm.org/magazines/2023/5/272276-disentangling-hype-from-practicality-on-realistically-achieving-quantum-advantage/fulltext https://cacm.acm.org/magazines/2023/5/272276-disentangling-h...
cvalka 3y ago
Quantum computers, fusion reactors, economically viable maglev trains. They've been around the corner for the last fifty years.
- Koshkin 3y ago
  As have EVs and AI…
- happytiger 3y ago
  Fusion is now a reality. Commercializing it is the next challenge, but we have working fusion: https://www.energy.gov/articles/doe-national-laboratory-makes-history-achieving-fusion-ignition https://www.energy.gov/articles/doe-national-laboratory-make... You can buy a quantum computer today. They are reality: https://quantumzeitgeist.com/how-to-buy-a-quantum-computer/ https://quantumzeitgeist.com/how-to-buy-a-quantum-computer/ They will likely only get better from here. Too early to take that promise to the bank, but human progress isn’t generally made by pessimists. To what level, we’ll see. They don’t call it the frontiers of innovation because of the security of outcome involved. Public transportation is a public good and doesn’t need to be profitable. If it needed to be profitable we have a word for that: private transportation. Maglev trains are obscenely expensive to build and may never be profitable. Brightline is showing that profitable high speed rail may be a commercial reality worth pursuing however. People bag on them, but they have already launched their first line and are working on their second. Tons of people betting against them and my goodness were there so many naysayers from day one, yet they are getting it done. Also: AI is a reality. That was science fiction. Wearable computers are a reality. Dick Tracy stuff. Also science fiction. Virtual reality is a reality. Also science fiction. Electric cars were a fantasty that had so many headwinds and scaling problems they were called impractical, but now in just a decade or so they are commonplace. Fully automated electronic pilots for both fixed wing and helicopters was science fiction just a few decades ago. Not autopilots but pilot replacements. Today: commercial reality. Just in time factories with robots running the lines were science fiction until just a few decades ago. Now people use old ones for making art and many factories are deeply automated headed towards even greater automation. Drones were also science fiction (the first cameras were on kites). Now they are so common we have to ban them from places. Everyone dogs on the progress these days, especially big projects, but we keep making progress in big ways and the negativity is just unjustified. It’s just that the progress is adsorbed into society in such a way that people don’t realize how remarkable their every day things are.
JoachimS 3y ago
This sounds very interesting, and at least to me very much news. Can you please provide some links that show that the path from what we have today in terms of number of qubits, handling of noise at the number of qubits, and keeping the qubits in a entanglement state long enough to, for example, factor a RSA 4096 key is clear and straight forward. We are talking 4,5,6 orders of magnitude for several vital physical properties. Silicon scaling the last 40 years seems to me as being much easier - and that have required enormous amount of R&D including physical theory, and is bumping into physical limits. We have gone from say 500 nm to 5 nm, basically three orders of magnitude. What makes it so clear that quantum computer technology are even possible to scale? And yes, Quantum computers may be profoundly powerful someday, for a set of problems. Not in general.
somat 3y ago
Quantium computers feel like they are in the mechanical computer era, they still need the equivalent of the electronic, thermionic and semiconductor revolutions to be useful. My gut tells me they may never end up being very useful. something about the intrinsic downsides to any analog computer. which if you are not familiar, is that analog computer components must be far more precise than their digital counterparts. If you really wanted to get pedantic you could call our everyday semiconductor based computers "quantum" as they operate on a distinctly quantum phenomena. However the term appears to be reserved for devices that are able to exploit analog quantum outcomes.
- CamperBob2 3y ago
  My gut tells me they may never end up being very useful. something about the intrinsic downsides to any analog computer. which if you are not familiar, is that analog computer components must be far more precise than their digital counterparts. Counterpoint: some of the most interesting classical algorithms, such as transformer-based neural nets, appear to work well with far less precision than expected. For that matter, the first perceptrons were analog... and of course, so is the one that everybody is trying to emulate. As a measure of signal-to-noise ratio, numerical precision in the classical domain may correspond to other attributes in other domains. It may not be a productive thing to focus on.

Aardwolf 3y ago

> and that path is very clear How is the time of this clear path measured? I actually have the exact same question about fusion reactors (such as ITER with results planned decades ahead of time) What could speed up those decades? Letting more people work on it at the same time? Throwing more money at it? (e.g. for ITER, are we just waiting for them to pour concrete faster?) Or are these decades of planning also waiting for other technologies to appear in 10, 20, ... years? (Which would be some kind of unclear uncertainty after all)

ghaff 3y ago
One area in quantum that’s getting a lot of attention is dealing with noise. (Basically you want to decrease the number of qubits needed to make a reliable logical qubit to a reasonable number.) This has turned out to be a big problem (with some calling it potentially intractable.) But a lot of progress is being made in this area. There’s a good article in the current issue of Technology Review.) This is one area that could lead to outsized advances. More money and people can usually move but there’s a limit to which just throwing money at a problem can accelerate the outcome in part because of all the complex interconnection, some not even appreciated. Think ML with GPUs.
- deleted 3y ago
  [deleted]
antonvs 3y ago
Assuming it's true that there's some clear path in the quantum computing case, then ITER is rather different because there's currently no clear path to commercially viable nuclear fusion. ITER itself isn't even intended to achieve that. It's a research facility to test and demonstrate large-scale fusion in a tokamak. It's not even designed to generate electricity as output - just heat energy. If ITER ends up demonstrating that its approach could be further improved in the direction of a commercial design - which is not at all clear (see reference below) - they'll have to start a new project to achieve that. And you can expect that project to take even more money and quite probably a longer time, since there will be a lot of advances that will still need to be made. You might be interested to read "ITER is a showcase … for the drawbacks of fusion energy": https://thebulletin.org/2018/02/iter-is-a-showcase-for-the-drawbacks-of-fusion-energy/ https://thebulletin.org/2018/02/iter-is-a-showcase-for-the-d... . I recommend reading the whole article. > Letting more people work on it at the same time? Throwing more money at it? There are 6500 people all told that work on ITER, and its total funding is projected to reach as much as $65 billion. More people and money for ITER is almost certainly not the answer. But other groups are also working on it, including 30+ fusion startups (see e.g. https://app.dealroom.co/lists/25184 https://app.dealroom.co/lists/25184). However, ITER's funding is about 10-15 times that of all those startups combined. The problem with the startup approach is they're more likely to be killed if they don't achieve results. > Or are these decades of planning also waiting for other technologies to appear in 10, 20, ... years? For fusion, that's certainly the case. Despite the existence of startups, which perhaps reflect the existence of either altruistic and/or gullible VCs, fusion power is still very much a research project. It's not even certain that commercial fusion power will ever be viable - the article I linked helps explain that.
fastneutron 3y ago
With ITER (and tokomaks more generally), the original assumption was that scaling laws would enable you to reach breakeven just by making the thing big enough. The problem is that "big enough" means throwing $25B at it, and when that's spread across a committee of a dozen countries, that's not a recipe for getting anything done quickly. With quantum error correction, we're not talking a $25B facility with many competing hands in the pie. Instead, we're talking about improving the spatial and timing precision of RF, optics, and photonic hardware. Unlike fusion, where basically everything needs to be a custom job, there are established industries around these quantum-adjacent technologies with decades of accumulated know-how and plenty of low-hanging fruit to get most of, if not all of the way there.
happytiger 3y ago
Well one important metric is this one: https://www.scmp.com/news/china/science/article/3246752/china-and-russia-test-hack-proof-quantum-communication-link-brics-countries https://www.scmp.com/news/china/science/article/3246752/chin... Read the quotes. Global financial systems are trying to harden themselves with quantum computers in anticipation of forecast technology advancements. Maybe this piece by 60 minutes is worth watching too to get a better sense: https://youtu.be/K4ssT6Dzmnw?si=FseoJawRowldaaPH https://youtu.be/K4ssT6Dzmnw?si=FseoJawRowldaaPH It directly addresses technology progress and explains the basics.
- JoachimS 3y ago
  But that is just hedging the bets - it does not show that the path to practical quantum computers at scale to handle real problems is feasible. We see customers getting requirement requests for using PQ safe crypto algorithms to be used in systems that will be used 30+ years. But that too is also just hedging the bets. Quantum Key Distribution is feasible - esp for systems that don't need to move and where you own the medium. And can spend the 1000+ kUSD these machines costs. For most use cases (for example between a client and a server setting up a secure session over Internet) these machines does not solve anything. But they sure are very cool to own and deploy.
  - deleted 3y ago
    [deleted]
  - happytiger 3y ago
    Please see the comments at 7:30 and then look the guy up. He founded Google’s quantum lab.

iainmerrick 3y ago

And quantum computers are profoundly powerful — as in civilization changing computer power. How so? The main promise/fear I hear about is breaking cryptography, but then it sounds like we can switch to new post-quantum encryption and we’ll be essentially in the same place as before.

regularfry 3y ago
It's not the same place because access to quantum computers is (and likely will be for a while) heavily asymmetric. People who want to break encryption will be able to do so, while people who want unbreakable encryption will, except for the tiny overlap with the former set, not have access to the hardware.
- iainmerrick 3y ago
  I don’t think you need a quantum computer to do post-quantum encryption. It’s just an encryption method that’s believed not to have any quantum shortcuts.
  - ghaff 3y ago
    Correct. At the moment seems to be mostly lattice-based approaches.
- dmurray 3y ago
  No, post-quantum cryptography is focused on methods where encryption can be done with classical computers. Post-quantum methods have other disadvantages, primarily that they haven't been studied as deeply as traditional methods (especially RSA) so they may be vulnerable to classes of attack we haven't thought of yet. https://en.m.wikipedia.org/wiki/Post-quantum_cryptography https://en.m.wikipedia.org/wiki/Post-quantum_cryptography
- JoachimS 3y ago
  AFAIK, this is basically the opposite of how it probably will pan out. Some organsations MAY someday have Quantum Computers capable of cracking some asymmetric keys (RSA). All of us will have access to cryptographic algorithms (inlcuding open source implementations) that can't be cracked by the Quantum Computers. These algorithms are executed on our normal, classical computers. We already have a first set of post quantum computer cryptographic algorithms. See the NIST competition for example. Their implementations still looks immature (some have fallen against classical attacks, including side channel issues). But we'll get there. We will also have to (yet again) deal with having algorithm agility, which adds complexity. Quantum Computers are not magical things. We can (and do) know type of problems, algorithms, operations they should be better than classical computers to solve (called quantum supremacy). Shor's algorithm, which provides exponential speedup of cracking RSA key is an example of such an algorithm. What we so far don't consider that much is the feasibility to perform these algorithms in reality. That is, we look at the asymptotic speedup, not the practical speedup. There is a really good paper by people from the MS PQ team that looked at this. Highly recommended: https://cacm.acm.org/magazines/2023/5/272276-disentangling-hype-from-practicality-on-realistically-achieving-quantum-advantage/fulltext https://cacm.acm.org/magazines/2023/5/272276-disentangling-h...

cvalka 3y ago

Quantum computers, fusion reactors, economically viable maglev trains. They've been around the corner for the last fifty years.

Koshkin 3y ago
As have EVs and AI…
happytiger 3y ago
Fusion is now a reality. Commercializing it is the next challenge, but we have working fusion: https://www.energy.gov/articles/doe-national-laboratory-makes-history-achieving-fusion-ignition https://www.energy.gov/articles/doe-national-laboratory-make... You can buy a quantum computer today. They are reality: https://quantumzeitgeist.com/how-to-buy-a-quantum-computer/ https://quantumzeitgeist.com/how-to-buy-a-quantum-computer/ They will likely only get better from here. Too early to take that promise to the bank, but human progress isn’t generally made by pessimists. To what level, we’ll see. They don’t call it the frontiers of innovation because of the security of outcome involved. Public transportation is a public good and doesn’t need to be profitable. If it needed to be profitable we have a word for that: private transportation. Maglev trains are obscenely expensive to build and may never be profitable. Brightline is showing that profitable high speed rail may be a commercial reality worth pursuing however. People bag on them, but they have already launched their first line and are working on their second. Tons of people betting against them and my goodness were there so many naysayers from day one, yet they are getting it done. Also: AI is a reality. That was science fiction. Wearable computers are a reality. Dick Tracy stuff. Also science fiction. Virtual reality is a reality. Also science fiction. Electric cars were a fantasty that had so many headwinds and scaling problems they were called impractical, but now in just a decade or so they are commonplace. Fully automated electronic pilots for both fixed wing and helicopters was science fiction just a few decades ago. Not autopilots but pilot replacements. Today: commercial reality. Just in time factories with robots running the lines were science fiction until just a few decades ago. Now people use old ones for making art and many factories are deeply automated headed towards even greater automation. Drones were also science fiction (the first cameras were on kites). Now they are so common we have to ban them from places. Everyone dogs on the progress these days, especially big projects, but we keep making progress in big ways and the negativity is just unjustified. It’s just that the progress is adsorbed into society in such a way that people don’t realize how remarkable their every day things are.

JoachimS 3y ago

This sounds very interesting, and at least to me very much news. Can you please provide some links that show that the path from what we have today in terms of number of qubits, handling of noise at the number of qubits, and keeping the qubits in a entanglement state long enough to, for example, factor a RSA 4096 key is clear and straight forward. We are talking 4,5,6 orders of magnitude for several vital physical properties. Silicon scaling the last 40 years seems to me as being much easier - and that have required enormous amount of R&D including physical theory, and is bumping into physical limits. We have gone from say 500 nm to 5 nm, basically three orders of magnitude. What makes it so clear that quantum computer technology are even possible to scale? And yes, Quantum computers may be profoundly powerful someday, for a set of problems. Not in general.

somat 3y ago

Quantium computers feel like they are in the mechanical computer era, they still need the equivalent of the electronic, thermionic and semiconductor revolutions to be useful. My gut tells me they may never end up being very useful. something about the intrinsic downsides to any analog computer. which if you are not familiar, is that analog computer components must be far more precise than their digital counterparts. If you really wanted to get pedantic you could call our everyday semiconductor based computers "quantum" as they operate on a distinctly quantum phenomena. However the term appears to be reserved for devices that are able to exploit analog quantum outcomes.

CamperBob2 3y ago
My gut tells me they may never end up being very useful. something about the intrinsic downsides to any analog computer. which if you are not familiar, is that analog computer components must be far more precise than their digital counterparts. Counterpoint: some of the most interesting classical algorithms, such as transformer-based neural nets, appear to work well with far less precision than expected. For that matter, the first perceptrons were analog... and of course, so is the one that everybody is trying to emulate. As a measure of signal-to-noise ratio, numerical precision in the classical domain may correspond to other attributes in other domains. It may not be a productive thing to focus on.