3 ms·

For an extreme example, there are finite patterns behind the lava lamps at Cloudfare or the chaos of Jupiter's storms. These are sufficiently random for any cur

by meroes 5y ago

For an extreme example, there are finite patterns behind the lava lamps at Cloudfare or the chaos of Jupiter's storms. These are sufficiently random for any current need I can currently imagine though. But then I also see that "classical computers can never be built big enough to explore more than 400, actually more than, probably 100 qubits, 100 qubits doesn’t seem like very much. No classical computer can do the calculation of following what 100 qubits do" https://blog.ycombinator.com/leonard-susskind-on-richard-feynman-the-holographic-principle-and-unanswered-questions-in-physics/ https://blog.ycombinator.com/leonard-susskind-on-richard-fey... Are we really in no danger of quantum computers being able decipher patterns behind these traditional sources of noise? There is no pattern to quantum randomness. Aren't we going to have switch to truly random sources of noise eventually, instead of pseudorandom ones (anything non quantum)?

mikewarot 5y ago
A lava lamp is a chaotic system. The same initial conditions, no matter how precisely measured, will not result in the same outcome, it will diverge. It is non-deterministic in the real world.
- meroes 5y ago
  Wait, let's be clear. In the real world a lava lamp is basically impossible predict as it evolves. And that is due to chaos. So far so good. But this chaos is deterministic. Chaos means highly sensitive to initial conditions and involves nonlinearity, but it is still entirely classical and deterministic. In the real world we do not measure things precise enough to keep track of a lava lamp's deterministic evolution, but it is there within the chaos. So I am wondering if a quantum computer, which Susskind says takes only 100 qubits to outperform any Turing Machine constructable ever, may one day do better at picking out the deterministic patterns behind the chaos of things like lava lamps. And if that happens, we may need more extreme versions of chaotic systems to keep secrets. And since quantum randomness is the only true randomness in the universe, forever indiscernable in principle; will one day all deterministic, chaotic means of adding "randomness" be replaced with quantum sources of randomness, due to how powerful quantum computers are? *Now you could say even the lava lamp involves quantum randomness because everything is ultimately quantum. But because it is so macroscopic, it behaves more classically the a smaller quantum system.
  - mikewarot 5y ago
    It might be possible to predict the pattern in the lava lamp, but to do so would require cutting it off from the rest of the universe. Light, heat, convection with room air, variations in local gravity all are going to effect the flow.
  - tsimionescu 5y ago
    > a quantum computer, which Susskind says takes only 100 qubits to outperform any Turing Machine constructable ever It's very important to understand that this only applies for a limited set of algorithms. QCs are not universal accelerators. In particular, if picking out this deterministic patterns from the apparent chaos were an NP problem, the QC would be just as slow as any other computing machine that we know so far. You're also misunderstanding how chaotic systems work. With a chaotic system, even if you know the precise time evolution rules, you're not going to be able to predict the outcome at time T, because a tiny difference in the initial conditions, or a tiny interference from the outside world, will mean vastly different outcomes. In fact, QCs would be particularly BAD at predicting the outcome of a chaotic system, because QCs can only give answers up to some error bound, unlike classical computers which can perform exact calculations. But the error introduced by the QC itself is probably going to compound the imprecision in the initial measurements of your chaotic system. One final note that is important to state: the problem with predicting chaotic systems is not physical or computational, it is mathematical. You can have even simple systems whose solution can vary orders of magnitude more than a variance in the parameters. Solving such a system is easy and fast, but the solution is physically meaningless: a 0.01% error in the measurements can mean that you solution is off by a factor of 100.
    - meroes 5y ago
      If chaos is not a problem for computation, why do we always hear weather simulations needing better and better supercomputers? If simulating/computing chaos is just about getting precise enough initial measurements, then that wouldn't seem to be a need for weather simulating right? I was thinking along the lines of running current observed data backwards to fine tuned initial conditions. That must require lots of computational power. Are we sure quantum computers and quantum algorithms wont speed this part up. That has to be somwewhat isomorphic to factoring large numbers, which I thought QC does have a potential advantage. But maybe chaos is distinct from factoring, I don't know much about how it would be modeled computationally. I realize most of the battle is getting proper initial conditions. But quantum computing is also coming at time when quantum sensing is growing. To me with quantum computing speed ups and quantum sensors, we have the two ingredients necessary to make progress on chaotic systems. Better initial conditions and better computational methods. That was my thought. Sorry for the ramble

by meroes 5y ago

mikewarot 5y ago

A lava lamp is a chaotic system. The same initial conditions, no matter how precisely measured, will not result in the same outcome, it will diverge. It is non-deterministic in the real world.

meroes 5y ago
Wait, let's be clear. In the real world a lava lamp is basically impossible predict as it evolves. And that is due to chaos. So far so good. But this chaos is deterministic. Chaos means highly sensitive to initial conditions and involves nonlinearity, but it is still entirely classical and deterministic. In the real world we do not measure things precise enough to keep track of a lava lamp's deterministic evolution, but it is there within the chaos. So I am wondering if a quantum computer, which Susskind says takes only 100 qubits to outperform any Turing Machine constructable ever, may one day do better at picking out the deterministic patterns behind the chaos of things like lava lamps. And if that happens, we may need more extreme versions of chaotic systems to keep secrets. And since quantum randomness is the only true randomness in the universe, forever indiscernable in principle; will one day all deterministic, chaotic means of adding "randomness" be replaced with quantum sources of randomness, due to how powerful quantum computers are? *Now you could say even the lava lamp involves quantum randomness because everything is ultimately quantum. But because it is so macroscopic, it behaves more classically the a smaller quantum system.
- mikewarot 5y ago
  It might be possible to predict the pattern in the lava lamp, but to do so would require cutting it off from the rest of the universe. Light, heat, convection with room air, variations in local gravity all are going to effect the flow.
- tsimionescu 5y ago
  > a quantum computer, which Susskind says takes only 100 qubits to outperform any Turing Machine constructable ever It's very important to understand that this only applies for a limited set of algorithms. QCs are not universal accelerators. In particular, if picking out this deterministic patterns from the apparent chaos were an NP problem, the QC would be just as slow as any other computing machine that we know so far. You're also misunderstanding how chaotic systems work. With a chaotic system, even if you know the precise time evolution rules, you're not going to be able to predict the outcome at time T, because a tiny difference in the initial conditions, or a tiny interference from the outside world, will mean vastly different outcomes. In fact, QCs would be particularly BAD at predicting the outcome of a chaotic system, because QCs can only give answers up to some error bound, unlike classical computers which can perform exact calculations. But the error introduced by the QC itself is probably going to compound the imprecision in the initial measurements of your chaotic system. One final note that is important to state: the problem with predicting chaotic systems is not physical or computational, it is mathematical. You can have even simple systems whose solution can vary orders of magnitude more than a variance in the parameters. Solving such a system is easy and fast, but the solution is physically meaningless: a 0.01% error in the measurements can mean that you solution is off by a factor of 100.
  - meroes 5y ago
    If chaos is not a problem for computation, why do we always hear weather simulations needing better and better supercomputers? If simulating/computing chaos is just about getting precise enough initial measurements, then that wouldn't seem to be a need for weather simulating right? I was thinking along the lines of running current observed data backwards to fine tuned initial conditions. That must require lots of computational power. Are we sure quantum computers and quantum algorithms wont speed this part up. That has to be somwewhat isomorphic to factoring large numbers, which I thought QC does have a potential advantage. But maybe chaos is distinct from factoring, I don't know much about how it would be modeled computationally. I realize most of the battle is getting proper initial conditions. But quantum computing is also coming at time when quantum sensing is growing. To me with quantum computing speed ups and quantum sensors, we have the two ingredients necessary to make progress on chaotic systems. Better initial conditions and better computational methods. That was my thought. Sorry for the ramble