Popular accounts of quantum computing

[VantagePoint72]

I have never—and I really do mean never—seen an article in the mainstream press about quantum computing that didn't get it completely wrong. I don't just mean "over simplified"—physics is highly technical and ignoring important details for lay audiences is just a fact of life. I mean that they always say the same thing, and it's always simply, non-negotiably wrong. Take the following article published today: http://www.thestar.com/news/insight...y-grail-for-university-of-waterloo-scientists

Now, at one point there's an unnecessary, but largely inconsequential, confusing of the uncertainty and superposition principles—but that's not the issue. The offending piece is this:

It turns out that classical computers are not very good at factoring large numbers, a weakness that has long been exploited by cryptographers to safeguard data on the Internet. It is easy to multiply two prime numbers in order to produce a much larger number, but it turns out to be horrendously difficult to engineer the same process in reverse, to find the two prime divisors of a large number, a process called factoring.

The only way classical computers can address the challenge is by systematic trial and error — trying out two numbers to see if they work, discarding them, trying out two different numbers, and so on. There’s no shortcut.
...
By contrast, a quantum computer could crack such privacy barriers in an instant, by the dazzling expedient of testing every possible combination of divisors, not one by one, but all at once, something no conventional computer could do. The right answer would reveal itself almost immediately.

This is not an oversimplification, it's quite simply wrong. Shor's algorithm, and every other quantum algorithm, does not run in a single step. Yes, technically every possible input is operated on simultaneously—but at the cost of getting every possible output simultaneously! Extracting useful results out of a quantum computer is considerably less straightforward and uses the fact that the quantum amplitude is what obeys superposition but its norm-squared is what gives the probabilities. Maybe this is too difficult to explain non-technically, but that's no excuse for saying something objectively false in its place. And yet, every article I've ever seen about quantum computing contains this same misinformation. The result is that to the extent quantum computers are a part of the public imagination, their potential computing power is grossly over stated in people's minds.

I'm curious about the origin of this problem. Notice that in this article, the offending piece doesn't actually quote the researcher, Ray Laflamme. Still, I wonder if the journalist who wrote this got his awful description directly one of the other researchers he spoke to. I wouldn't be too surprised since I have, on some occasions, heard physicists—ones who should know better—saying things similar to what this article says. So, for those of you who work in quantum information: where do you think the blame falls? Do you think your colleagues generally give reasonably accurate explanation of quantum computing to lay audiences, but the message gets lost in translation? Or do they give into the temptation to give lazy, wrong answers because it's a difficult subject to explain? If it's the former, do you think there are steps the scientific community can take to remedy the problem? If the latter, is there any way to get the message to other physicists that this sort of thing is not OK?

Right now, there exists a serious barrier of understanding between those who study quantum information and everyone else. I think we need to try to understand the origin of this barrier; hopefully, doing so will help us take it down. Appropriately enough, this article gets one thing right when it says that "no matter how difficult they might be to fabricate, quantum computers are even more difficult to explain." But that's no excuse for not trying.

 

[Zarqon]

Describing physics that requires decades of learning/think, to someone that has none is always going to be difficult (read impossible) no matter how you explain it.

When I explain it (I work with quantum information too) I typically look at my target audience and then try to maximize their understanding at their level. Sometimes that requires me to use phrases such as "Keep in mind that the following is not 100% accurate, but to make it understandable consider the following scenario...". Of course, if they later retell what I said, they are going to omitt the "not 100% accurate" part for sure, because they don't know anything about this at all, and thus inaccuracies are born. I think this is just inherent in the fact that it's impossible to understand given so little time, and I think sometimes an inaccurate description, where they can at least understand something may serve the purpose better than an accurate one, which was not understood at all.