pcalau12i

quantum nature of the randomly generated numbers helped specifically with quantum computer simulations, but based on your reply you clearly just meant that you were using it as a multi-purpose RNG that is free of unwanted correlations between the randomly generated bits

It is used as the source of entropy for the simulator. Quantum mechanics is random, so to actually get the results you have to sample it. In quantum computing, this typically involves running the same program tens of thousands of times, which are called “shots,” and then forming a distribution of the results. The sampling with the simulator uses the QRNG for the source of entropy, so the sampling results are truly random.

Out of curiosity, have you found that the card works as well as advertised? I ask because it seems to me that any imprecision in the design and/or manufacture of the card could introduce systematic errors in the quantum measurements that would result in correlations in the sampled bits, so I am curious if you have been able to verify that is not something to be concerned about.

I have tried several hardware random number generators and usually there is no bias either because they specifically designed it not to have a bias or they have some level of post-processing to remove the bias. If there is a bias, it is possible to remove the bias yourself. There are two methods that I tend to use that depends upon the source of the bias.

To be “random” simply means each bit is statistically independent of each other bit, not necessarily that the outcome is uniform, i.e. 50% chance of 0 and 50% chance of 1. It can still be considered truly random with a non-uniform distribution, such as 52% chance of 0 and 48% chance of 1, as long as each successive bit is entirely independent of any previous bit, i.e. there is no statistical analysis you could ever perform on the bits to improve your chances of predicting the next one beyond the initial distribution of 52%/48%.

In the case where it is genuinely random (statistical independence) yet is non-uniform (which we can call nondeterministic bias), you can transform it into a uniform distribution using what is known as a von Neumann extractor. This takes advantage of a simple probability rule for statistically independent data whereby Pr(A)Pr(B)=Pr(B)Pr(A). Let’s say A=0 and B=1, then Pr(0)Pr(1)=Pr(1)Pr(0). That means you can read two bits at a time rather than one and throw out all results that are 00 and 11 and only keep results that are 01 or 10, and then you can map 01 to 0 and 10 to 1. You would then be mathematically guaranteed that the resulting distribution of bits are perfectly uniform with 50% chance of 0 and 50% chance of 1.

I have used this method to develop my own hardware random number generator that can pull random numbers from the air, by analyzing tiny fluctuations in electrical noise in your environment using an antenna. The problem is that electromagnetic waves are not always hitting the antenna, so there can often be long strings of zeros, so if you set something up like this, you will find your random numbers are massively skewed towards zero (like 95% chance of 0 and 5% chance of 1). However, since each bit still is truly independent of the successive bit, using this method will give you a uniform distribution of 50% 0 and 50% 1.

Although, one thing to keep in mind is the bigger the skew, the more data you have to throw out. With my own hardware random number generator I built myself that pulls the numbers from the air, it ends up throwing out the vast majority of the data due to the huge bias, so it can be very slow. There are other algorithms which throw out less data but they can be much more mathematically complicated and require far more resources.

In the cases where it may not be genuinely random because the bias is caused by some imperfection in the design (which we can call deterministic bias), you can still uniformly distribute the bias across all the bits so that not only would be much more difficult to detect the bias, but you will still get uniform results. The way to do this is to take your random number and XOR it with some data set that is non-random but uniform, which you can generate from a pseudorandom number generator like the C’s rand() function.

This will not improve the quality of the random numbers because, let’s say if it is biased 52% to 48% but you use this method to de-bias it so the distribution is 50% to 50%, if someone can predict the next value of the rand() function that would increase their ability to make a prediction back to 52% to 48%. You can make it more difficult to do so by using a higher quality pseudorandom number generator like using something like AES to generate the pseudorandom numbers. NIST even has standards for this kind of post-processing.

But ultimately using this method is only obfuscation, making it more and more difficult to discover the deterministic bias by hiding it away more cleverly, but does not truly get rid of it. It’s impossible to take a random data set with some deterministic bias and trulyget rid of the deterministic bias purely through deterministic mathematical transformations,. You can only hide it away very cleverly. Only if the bias is nondeterministic can you get rid of it with a mathematical transformation.

It is impossible to reduce the quality of the random numbers this way. If the entropy source is truly random and truly non-biased, then XORing it with the C rand() function, despite it being a low-quality pseudorandom number generator, is mathematically guaranteed to still output something truly random and non-biased. So there is never harm in doing this.

However, in my experience if you find your hardware random number generator is biased (most aren’t), the bias usually isn’t very large. If something is truly random but biased so that there is a 52% chance of 0 and 48% chance of 1, this isn’t enough of a bias to actually cause much issues. You could even use it for something like cryptography and even if someone does figure out the bias, it would not increase their ability to predict keys enough to actually put anything at risk. If you use a cryptographysically secure pseudorandom number generator (CSPRNG) in place of something like C rand(), they will likely not be able to discover the bias in the first place, as these do a very good job at obfuscating the bias to the point that it will likely be undetectable.

I’m not sure what you mean by “turning into into a classical random number.” The only point of the card is to make sure that the sampling results from the simulator are truly random, down to a quantum level, and have no deterministic patterns in them. Indeed, actually using quantum optics for this purpose is a bit overkill as there are hardware random number generators which are not quantum-based and produce something good enough for all practical purposes, like Intel Secure Key Technology which is built into most modern x86 CPUs.

For that reason, my software does allow you to select other hardware random number generators. For example, you can easily get an entire build (including the GPU) that can run simulations of 14 qubits for only a few hundred dollars if you just use the Intel Secure Key Technology option. It also supports a much cheaper device called TrueRNGv3 which is a USB device. It also has an option to use a pseudorandom number generator if you’re not that interested in randomness accuracy, and when using the pseudorandom number generator option it also supports “hidden variables” which really just act as the seed to the pseudorandom number generator.

For most most practical purpose, no, you do not need this card and it’s definitely overkill. The main reason I even bought it was just because I was adding support for hardware random number generators to my software and I wanted to support a quantum one and so I needed to buy it to actually test it and make sure it works for it. But now I use it regularly for the back-end to my simulator just because I think it is neat.

I own a quantum random number generator on a PCie card that uses optical effects for random number generation. It cost me over $2000. I use it for quantum computer simulations.

By applying both that and the many worlds hypothesis, the idea of quantum immortality comes up, and thats a real mind bender. Its also a way to verifiably prove many worlds accurate(afaik the only way)

MWI only somewhat makes sense (it still doesn’t make much sense) if you assume the “branches” cannot communicate with each other after decoherence occurs. “Quantum immortality” mysticism assumes somehow your cognitive functions can hop between decoherent branches where you are still alive if they cease in a particular branch. It is self-contradictory. There is nothing in the mathematical model that would predict this and there is no mechanism to explain how it could occur.

Imagine creating a clone which is clearly not the same entity as you because it is standing in a different location and, due to occupying different frames of reference, your paths would diverge after the initial cloning, with the clone forming different memories and such. “Quantum immortality” would be as absurd as saying that if you then suddenly died, your cognitive processes would hop to your clone, you would “take over their body” so to speak.

Why would that occur? What possible mechanism would cause it? Doesn’t make any sense to me. It seems more reasonable to presume that if you die, you just die. Your clone lives on, but you don’t. In the grand multiverse maybe there is a clone of you that is still alive, but that universe is not the one you occupy, in this one your story ends.

It also has a problem similar to reincarnation mysticism. If MWI is correct (it’s not), then there would be an infinite number of other decoherent branches containing other “yous.” Which “you” would your consciousness hop into when you die, assuming this even does occur (it doesn’t)? It makes zero sense.

To reiterate though, assuming many worlds is accurate, the expiriment carries no risk to you. Due to the anthropic principle, you will always find yourself in the reality in which you survive.

You see the issue right here, you say the reality in which you survive, except there would be an infinite number of them. There would be no the reality, there would be a reality, just one of an infinitude of them. Yet, how is the particular one you find yourself in decided?

MWI is even worse than the clone analogy I gave, because it would be like saying there are an infinite number of clones of you, and when you die your cognitive processes hop from your own brain to one of theirs. Not only is there no mechanism to cause this, but even if we presume it is true, which one of your infinite number of clones would your cognitive processes take control of?

Isn’t the quantum communication (if it were possible) supposed to be actually instantaneous, not just “nearly instantaneous”?

There is no instantaneous information transfer (“nonlocality”) in quantum mechanics. You can prove this with the No-communication Theorem. Quantum theory is a statistical theory, so predictions are made in terms of probabilities, and the No-communication Theorem is a relativity simple proof that no physical interaction with a particle in an entangled pair can alter the probabilities of the other particle it is entangled with.

(It’s actually a bit more broad than this as it shows that no interaction with a particle in an entangled pair can alter the reduced density matrix of the other particle it is entangled with. The density matrix captures more than probabilities, but also the ability for the particle to exhibit interference effects.)

The speed of light limit is a fundamental property of special relativity, and if quantum theory violated this limit then it would be incompatible with special relativity. Yet, it is compatible with it and the two have been unified under the framework of quantum field theory.

There are two main confusions as to why people falsely think there is anything nonlocal in quantum theory, stemming from Bell’s theorem and the EPR paradox. I tried to briefly summarize these two in this article here. But to even more briefly summarize…

People falsely think Bell’s theorem proves there is “nonlocality” but it only proves there is nonlocality if you were to replace quantum theory with a hidden variable theory. It is important to stress that quantum theory is not a hidden variable theory and so there is nothing nonlocal about it and Bell’s theorem just is not applicable.

The EPR paradox is more of a philosophical argument that equates eigenstates to the ontology of the system, which such an equation leads to the appearance of nonlocal action, but this is just because the assumption is a bad one. Relational quantum mechanics, for example, uses a different assumption about the relationship between the mathematics and the ontology of the system and does not run into this.

Depends upon what you mean by “consciousness.” A lot of the literature seems to use “consciousness” just to refer to physical reality as it exists from a particular perspective, for some reason. For example, one popular definition is “what it is like to be in a particular perspective.” The term “to be” refers to, well, being, which refers to, well, reality. So we are just talking about reality as it actually exists from a particular perspective, as opposed to mere description of reality from that perspective. (The description of a thing is always categorically different from the ontology of the thing.)

I find it bizarre to call this “consciousness,” but words are words. You can define them however you wish. If we define “consciousness” in this sense, as many philosophers do, then it does not make logical sense to speak of your “consciousness” doing anything at all after you die, as your “consciousness” would just be defined as reality as it actually exists from your perspective. Perspectives always implicitly entail a physical object that is at the basis of that perspective, akin to the zero-point of a coordinate system, which in this case that object is you.

If you cease to exist, then your perspective ceases to even be defined. The concept of “your perspective” would no longer even be meaningful. It would be kind of like if a navigator kept telling you to go “more north” until eventually you reach the north pole, and then they tell you to go “more north” yet again. You’d be confused, because “more north” does not even make sense anymore at the north pole. The term ceases to be meaningfully applicable. If consciousness is defined as being from a particular perspective (as many philosophers in the literature define it), then by logical necessity the term ceases to be meaningful after the object that is the basis of that perspective ceases to exist. It neither exists nor ceases to exist, but no longer is even well-defined.

But, like I said, I’m not a fan of defining “consciousness” in this way, albeit it is popular to do so in the literature. My criticism of the “what it is like to be” definition is mainly that most people tend to associate “consciousness” with mammalian brains, yet the definition is so broad that there is no logical reason as to why it should not be applicable to even a single fundamental particle.

This problem presupposes metaphysical realism, so you have to be a metaphysical realist to take the problem seriously. Metaphysical realism is a particular kind of indirect realism whereby you posit that everything we observe is in some sense not real, sometimes likened to a kind of “illusion” created by the mammalian brain (I’ve also seen people describe it as an “internal simulation”), called “consciousness” or sometimes “subjective experience” with the adjective “subjective” used to make it clear it is being interpreted as something unique to conscious subjects and not ontologically real.

If everything we observe is in some sense not reality, then “true” reality must by definition be independent of what we observe. If this is the case, then it opens up a whole bunch of confusing philosophical problems, as it would logically mean the entire universe is invisible/unobservable/nonexperiential, except in the precise configuration of matter in the human brain which somehow “gives rise to” this property of visibility/observability/experience. It seems difficult to explain this without just presupposing this property arbitrarily attaches itself to brains in a particular configuration, i.e. to treat it as strongly emergent, which is effectively just dualism, indeed the founder of the “hard problem of consciousness” is a self-described dualist.

This philosophical problem does not exist in direct realist schools of philosophy, however, such as Jocelyn Benoist’s contextual realism, Carlo Rovelli’s weak realism, or in Alexander Bogdanov’s empiriomonism. It is solely a philosophical problem for metaphysical realists, because they begin by positing that there exists some fundamental gap between what we observe and “true” reality, then later have to figure out how to mend the gap. Direct realist philosophies never posit this gap in the first place and treat reality as precisely equivalent to what we observe it to be, so it simply does not posit the existence of “consciousness” and it would seem odd in a direct realist standpoint to even call experience “subjective.”

The “hard problem” and the “mind-body problem” are the main reasons I consider myself a direct realist. I find that it is a completely insoluble contradiction at the heart of metaphysical realism, I don’t think it even can be solved because you cannot posit a fundamental gap and then mend the gap later without contradicting yourself. There has to be no gap from the get-go. I see these “problems” as not things to be “solved,” but just a proof-by-contradiction that metaphysical realism is incorrect. All the arguments against direct realism, on the other hand, are very weak and people who espouse them don’t seem to give them much thought.