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I don't keep tabs on quantum computing at all, but I get the distinct feeling that it isn't going to turn into anything important. Is there any reason to believ

I don't keep tabs on quantum computing at all, but I get the distinct feeling that it isn't going to turn into anything important. Is there any reason to believe this will be relevant to regular developers in the next 20 years?

vasco 7y ago
I'm also very unaware of actual papers coming out of the field but it does seem like it'll serve similar purposes to FPGA type work, where if you need to optimize a certain workload and you have the budget, you'll probably offload some code paths to a quantum computer / expansion-card. I do get the feeling that the "regular developer" won't have to deal with it or think about it any time soon.
roblabla 7y ago
Quantum computing won't be relevant to most regular developers, in the same way machine learning isn't relevant to most regular developers. Quantum computing might end up being useful for certain niche use-cases, such as heavy number crunching that can be made faster via quantum algorithms. As to whether it will be usable within 20 years, time will tell.
- XJ6 7y ago
  And just as every company is trying to work out how to "use AI" they'll be trying to work out how to "use Quantum" in future, with all the typical buzzword bullshit that comes with it.
  - deleted 7y ago
    [deleted]
- codesushi42 7y ago
  What is a "regular" developer then?
pulse7 7y ago
It depends on the number of qubits they will achieve. The larger the count, more relevant will it be. But if it stays low, the impact will be low...
- TallGuyShort 7y ago
  Yeah I was impressed that they had a fleet of quantum computers this size. Turns out I'm well over a decade behind on my sense of how many qubits one should have...
- GrayShade 7y ago
  What's a good number of qubits to have in order to outperform a classical computer in a useful application of quantum computing?
  - dtwhitney 7y ago
    my understanding is a qubit is roughly the equivalent of a transistor, so we've got a long way to go. That said, "53-qubit" seemed like a weird number and strayed from my understanding, so take my comment as a starting point for more investigation.
    - jacquesm 7y ago
      A committee was involved somewhere.
      - tw53bitquantum 7y ago
        53 bits is the significand in IEEE754 (Double precision FP).
thatcherc 7y ago
Maybe not to regular developers, but definitely to physicists[0], chemists[0][1], machine learning people[1], and cryptographers. [0] - https://www.nature.com/articles/nature23879 https://www.nature.com/articles/nature23879 [1] - https://ai.google/research/teams/applied-science/quantum/ https://ai.google/research/teams/applied-science/quantum/ - see 'Near-Term Applications'
- cooljacob204 7y ago
  Wouldn't the size different help with CPU density? I don't really know much about the topic but my understanding is that it could potentially be more dense then the theoretic limit of current transistor sizes.
  - jerf 7y ago
    It hard to know if that theory is going to translate into reality. The machinery required for isolating the qubits, configuring the qubits for a computation, and reading out the qubits at the end may prevent very much scaling. Science fiction has hypothesized about quantum computing that involves macroscopically-sized bits of carefully constructed matter running a number of qubits best described with scientific notation, but it's not clear how one would set up problems or read anything out of such a thing.
  - krastanov 7y ago
    Definitely not. Quantum computing building blocks do not have anything that makes them inherently easier to miniaturize: quite the opposite, there is enormous amount of classical hardware necessary to support a single quantum bit. Moreover, some form of "isolation" between the qubits is necessary, so you can not just pack them together. Current sizes of quantum bits: cavities are cm to mm scale; transmons and photonics can be much smaller, but nowhere near the size of modern transistors; ions need to be trapped in something and usually the scale is not better than the other options. There is the hope that qubits can be made in silicon and use lithographic technologies, but then at best we will reach the density of current CPUs (but such a thing is science fiction at the moment).
- 7y ago
asdfman123 7y ago
I'm not sure about the next 20 years, but quantum computers are really good at running calculations in parallel and finding a result. I'm not 100% sure I'm accurate, but I believe if an algorithm is a good candidate to run on, say, a Spark cluster, a quantum computer would be much better at it. I think the biggest change will be that quantum computing can really kill at machine learning, upping the numbers of nodes in neural networks with an exponential relationship to the number of qubits. It might turn neural nets into a neat toy that Facebook uses to show us sort-of good ad predictions to something that really cuts into a wide range of things that only humans are capable of doing.
- lacker 7y ago
  Quantum computers are not generically good at all parallel problems. They have better asymptotic runtime for “brute force search” type problems, where you know there is some answer but you have to guess-and-check repeatedly. Roughly they change a 2^n brute force algorithm to a 2^(n/2) algorithm in that case. The main area these problems are important is cryptography.
  - asdfman123 7y ago
    So what you're saying is I should short sell Bitcoin?
    - insulanus 7y ago
      You can read more about this issue here: https://en.bitcoin.it/wiki/Quantum_computing_and_Bitcoin https://en.bitcoin.it/wiki/Quantum_computing_and_Bitcoin
      - henryw 7y ago
        The article says "Attacking Bitcoin keys would require around 1500 qubits". So with 28 of these, Bitcoin is compromised?
        7y ago
hannob 7y ago
No, absolutely not. If quantum computers happen (which is still a big if) then mostly two things will happen: 1. Cryptographers will have to switch many of their algorithms and things like TLS will get a bit slower and will need a bit more data transmitted. 2. It's interesting for science, e.g. for simulations. For the regular dev I'm pretty sure it won't have any meaningful impact. Also even if quantum computers happen they won't be on our desks any time soon. It'll probably more like "you can rent a QC for specialized tasks in the cloud, but it will be relatively expensive and if you don't really need one you'll use something else".
- deleted 7y ago
  [deleted]
- ganzuul 7y ago
  You should already have switched to AES256 or better. The data can be captured and processed once a machine is available.
  - cyphar 7y ago
    The risk with quantum computers is with public-key cryptography (where all modern PK crypto is broken with a sufficiently-powerful quantum computers). It is believed that attacks with a quantum computer against symmetric-key cryptography (like AES) gain no better than a square-root improvement (meaning that doubling key sizes eliminates the risk).
    - ChrisLomont 7y ago
      >where all modern PK crypto is broken with a sufficiently-powerful quantum computers This isn't true - only methods based on Discrete Log are at risk, which includes RSA and ECC, but there are a lot of PK algos that are not at risk, like NTRU. Here's a bunch of stuff related https://en.wikipedia.org/wiki/Post-quantum_cryptography https://en.wikipedia.org/wiki/Post-quantum_cryptography
      - 7y ago

vasco 7y ago

I'm also very unaware of actual papers coming out of the field but it does seem like it'll serve similar purposes to FPGA type work, where if you need to optimize a certain workload and you have the budget, you'll probably offload some code paths to a quantum computer / expansion-card. I do get the feeling that the "regular developer" won't have to deal with it or think about it any time soon.

roblabla 7y ago

Quantum computing won't be relevant to most regular developers, in the same way machine learning isn't relevant to most regular developers. Quantum computing might end up being useful for certain niche use-cases, such as heavy number crunching that can be made faster via quantum algorithms. As to whether it will be usable within 20 years, time will tell.

XJ6 7y ago
And just as every company is trying to work out how to "use AI" they'll be trying to work out how to "use Quantum" in future, with all the typical buzzword bullshit that comes with it.
- deleted 7y ago
  [deleted]
codesushi42 7y ago
What is a "regular" developer then?

pulse7 7y ago

It depends on the number of qubits they will achieve. The larger the count, more relevant will it be. But if it stays low, the impact will be low...

TallGuyShort 7y ago
Yeah I was impressed that they had a fleet of quantum computers this size. Turns out I'm well over a decade behind on my sense of how many qubits one should have...
GrayShade 7y ago
What's a good number of qubits to have in order to outperform a classical computer in a useful application of quantum computing?
- dtwhitney 7y ago
  my understanding is a qubit is roughly the equivalent of a transistor, so we've got a long way to go. That said, "53-qubit" seemed like a weird number and strayed from my understanding, so take my comment as a starting point for more investigation.
  - jacquesm 7y ago
    A committee was involved somewhere.
    - tw53bitquantum 7y ago
      53 bits is the significand in IEEE754 (Double precision FP).

thatcherc 7y ago

Maybe not to regular developers, but definitely to physicists[0], chemists[0][1], machine learning people[1], and cryptographers. [0] - https://www.nature.com/articles/nature23879 https://www.nature.com/articles/nature23879 [1] - https://ai.google/research/teams/applied-science/quantum/ https://ai.google/research/teams/applied-science/quantum/ - see 'Near-Term Applications'

cooljacob204 7y ago
Wouldn't the size different help with CPU density? I don't really know much about the topic but my understanding is that it could potentially be more dense then the theoretic limit of current transistor sizes.
- jerf 7y ago
  It hard to know if that theory is going to translate into reality. The machinery required for isolating the qubits, configuring the qubits for a computation, and reading out the qubits at the end may prevent very much scaling. Science fiction has hypothesized about quantum computing that involves macroscopically-sized bits of carefully constructed matter running a number of qubits best described with scientific notation, but it's not clear how one would set up problems or read anything out of such a thing.
- krastanov 7y ago
  Definitely not. Quantum computing building blocks do not have anything that makes them inherently easier to miniaturize: quite the opposite, there is enormous amount of classical hardware necessary to support a single quantum bit. Moreover, some form of "isolation" between the qubits is necessary, so you can not just pack them together. Current sizes of quantum bits: cavities are cm to mm scale; transmons and photonics can be much smaller, but nowhere near the size of modern transistors; ions need to be trapped in something and usually the scale is not better than the other options. There is the hope that qubits can be made in silicon and use lithographic technologies, but then at best we will reach the density of current CPUs (but such a thing is science fiction at the moment).
7y ago

asdfman123 7y ago

I'm not sure about the next 20 years, but quantum computers are really good at running calculations in parallel and finding a result. I'm not 100% sure I'm accurate, but I believe if an algorithm is a good candidate to run on, say, a Spark cluster, a quantum computer would be much better at it. I think the biggest change will be that quantum computing can really kill at machine learning, upping the numbers of nodes in neural networks with an exponential relationship to the number of qubits. It might turn neural nets into a neat toy that Facebook uses to show us sort-of good ad predictions to something that really cuts into a wide range of things that only humans are capable of doing.

lacker 7y ago
Quantum computers are not generically good at all parallel problems. They have better asymptotic runtime for “brute force search” type problems, where you know there is some answer but you have to guess-and-check repeatedly. Roughly they change a 2^n brute force algorithm to a 2^(n/2) algorithm in that case. The main area these problems are important is cryptography.
- asdfman123 7y ago
  So what you're saying is I should short sell Bitcoin?
  - insulanus 7y ago
    You can read more about this issue here: https://en.bitcoin.it/wiki/Quantum_computing_and_Bitcoin https://en.bitcoin.it/wiki/Quantum_computing_and_Bitcoin
    - henryw 7y ago
      The article says "Attacking Bitcoin keys would require around 1500 qubits". So with 28 of these, Bitcoin is compromised?
      - 7y ago

hannob 7y ago

No, absolutely not. If quantum computers happen (which is still a big if) then mostly two things will happen: 1. Cryptographers will have to switch many of their algorithms and things like TLS will get a bit slower and will need a bit more data transmitted. 2. It's interesting for science, e.g. for simulations. For the regular dev I'm pretty sure it won't have any meaningful impact. Also even if quantum computers happen they won't be on our desks any time soon. It'll probably more like "you can rent a QC for specialized tasks in the cloud, but it will be relatively expensive and if you don't really need one you'll use something else".

deleted 7y ago
[deleted]
ganzuul 7y ago
You should already have switched to AES256 or better. The data can be captured and processed once a machine is available.
- cyphar 7y ago
  The risk with quantum computers is with public-key cryptography (where all modern PK crypto is broken with a sufficiently-powerful quantum computers). It is believed that attacks with a quantum computer against symmetric-key cryptography (like AES) gain no better than a square-root improvement (meaning that doubling key sizes eliminates the risk).
  - ChrisLomont 7y ago
    >where all modern PK crypto is broken with a sufficiently-powerful quantum computers This isn't true - only methods based on Discrete Log are at risk, which includes RSA and ECC, but there are a lot of PK algos that are not at risk, like NTRU. Here's a bunch of stuff related https://en.wikipedia.org/wiki/Post-quantum_cryptography https://en.wikipedia.org/wiki/Post-quantum_cryptography
    - 7y ago