Review of Vivek Wadhwa’s Washington Post Column on Quantum Computing
scottaaronson.com
scottaaronson.com
From 4:30 Simmons brings out the laundry list of quantum computing misconceptions. These are that the TSP scales poorly for classical computers and implies it doesn't for QC, implies that there's an efficient quantum algorithm for list lookups because the list can be read in parallel, and says the power of QC is partially because you can store so much information in the superposition (which is, at the very least, misleading). Then she starts comparing the power of QC and classical computers, saying that a 300 bit QC would be more powerful than all the computers in the world put together. In a section that's about what quantum computers will be useful for she includes as examples economic and climate modelling, which is news to me. The slides even include the phrase - 'Quantum computer- can check many different possibilities in parallel'.
All in all, I'm not surprised that Wadhwa was confused.
These are just rather generic examples of computationally-expensive fields of study.
As it is, his main points seem to be:
- The Y2K comparison, which, eventually, he seems to agree may indeed be accurate.
- The "trying all possible solutions simultaneously" explanation of qc. This is a very common explanation, and from what I gather from Scott's comments is that it's inaccurate for TSP, but possibly right for problems that are better structured to use the technology(?)
- An off-topic criticism of the author's previous article calling bitcoin a Ponzi scheme. That article may have been premature in its predictions, but seems accurate on the facts. Who would be miffed of being warned of a ponzi scheme too early?
- That matrix multiplication bit, which indeed appears to be mostly gibberish. Although my take-away from the sentence would mostly be the existence of "quantum-resistant" algorithms, which seems accurate (and would also hint at the non-universality of the claims of speedups.)
I guess Scott may be unwilling to "do the author's work for them", so to speak. And it's laudable that he mentions some of the good work the WP has been doing, instead of succumbing to the nihilistic cynicism so common these days.
But for as long as someone is showing a good-faith effort to improve, I think it's worth for experts in a field to engage constructively with them. Quantum Computing is niche enough that it's entirely plausible that someone with plenty of expertise on computing and the best intentions could end up writing such an article just from a few misunderstandings in their communications with the experts they found.
From what I gather from Scott's comments (and the tagline of his entire blog), this common explanation is basically always incorrect. Quantum algorithms do not try all solutions simultaneously.
That's a description of the theoretical model of nondeterministic computing (like where "NP" comes from), not of quantum computing.
A nondeterministic computer halts in the "success" state if any of the individual threads halted succesfully. This turns out to be tremendously useful.
A quantum computer run on a quantum superposition of all possible inputs gives you a superposition of the outputs. If you we're to measure it directly you would just get one of the outputs chosen at random. This not useful. But sometimes (on particular problems with a suitable structure) further work can be done on the superposed state before measuring it, in such a way that the results of the measurement are useful.
The point is that not all the outputs are equally probable and (in the interesing cases) you will get the “right” answer with high probability.
In particular “factoring and other problems important for public-key cryptography,” which is the subject of the article.
Obviously, someone who's already bought in but hasn't cashed out yet.
I'd recommend reading the Washington Post with a bit more skepticism. You're only noticing their mistakes on this article because it's something you're familiar with, but they make many mistakes in their other articles too. You probably just don't pick it up as you're not an expert in those other fields, and it sticks out in this one like a sore thumb because you are.
"Briefly stated, the Gell-Mann Amnesia effect works as follows. You open the newspaper to an article on some subject you know well. In Murray’s case, physics. In mine, show business. You read the article and see the journalist has absolutely no understanding of either the facts or the issues. Often, the article is so wrong it actually presents the story backward-reversing cause and effect. I call these the “wet streets cause rain” stories. Paper’s full of them. In any case, you read with exasperation or amusement the multiple errors in a story-and then turn the page to national or international affairs, and read with renewed interest as if the rest of the newspaper was somehow more accurate about far-off Palestine than it was about the story you just read. You turn the page, and forget what you know." - Michael Crichton, Why Speculate (26 April 2002)
Regarding Seth Abramson, it's important to note that there is ample criticism of his rather sloppy methods. A nice summary of him and similar "independent journalists" is at https://thinkprogress.org/blue-detectives-collapse-trump-rus.... If ThinkProgress thinks some criticism of Trump may be too close to conspiracy theories than comfortable, it would seem to be rather suspect.
1. He's insane
2. 2016-2018 has been insane
3. They've often been materially insane in the same way. But sometimes not.
Russians are, in fact, under our collective beds, getting at our voting.
You ever see a Putin drink a glass of water?
Corrections are prominently added at the top of the article. See https://www.washingtonpost.com/news/made-by-history/wp/2018/... for an example.
The ability of people to point out factual errors should be kept for small details, not the all too common practice of posting articles without first getting them checked by experts. Why should unpaid experts have to go and spend hours posting corrections of the articles in Washington Post? Washington Post should be finding and paying experts to do this pre-publication.
There needs to be some level of quality control at the Washington Post if they want to keep their reputation -- which they have tarnished very poorly since their push for the Iraq War and the role they had to making that war happen.
The traveling salesman problem isn't hard. It's one of those things that's NP-hard only for pathological cases, as is linear programming. Solutions to the TSP which produce a near-optimum result, and the optimal result most of the time, are easy. (Connect nodes arbitrarily. Then randomly cut two links to split path into three sections, try all ways to reconnect the three sections, pick the best. Repeat until no improvement for a while. Bell Labs, 1960s.)
Now, if quantum computing could help with factoring, we'd have a problem.
[1] https://books.google.com/books?id=tTkEAAAAMBAJ&pg=PA40&lpg=P...
On the other hand, it is generally not believed that quantum computers would be able to solve NP-complete problems such as TSP in polynomial time.
Perhaps you are talking about Integer Linear Programming?
-------------
Scott, I just watched your fascinating and excellent TedX talk and really appreciate your perspectives. I’ll start by admitting that I struggle with the concepts of quantum computing and found it very hard to simplify these. I have read your criticisms of journalists who have had the same issue and your frustrations with the deficiency.
As far as the traveling salesman problem goes, the person I learned of this from, a few years ago is Michelle Simmons, director of the Centre for Quantum Computation & Communication Technology, University of NSW. This TedX talk that she gave was brilliant and I wrote to her to thank her for opening my eyes: https://www.youtube.com/watch?v=cugu4iW4W54. She repeated this example in a recent piece in ZDNet: http://www.zdnet.com/article/australias-ambitious-plan-to-wi... I also consulted a couple of other gurus and no one raised issue with this example.
If you give me a better way of explaining how quantum computers work I will surely use that. But I find your comparison of this to my criticism of Bitcoin’s demise as a digital currency to be unprofessional and petty. Surely you don’t have to resort to such nastiness.
-------------
That was a pretty great response, and he's right. Scott does come across as petty, and as someone you would never want to work with. Vivek might have been wrong, but he had done a reasonable amount of homework on this - far more than Scott had mistakenly assumed. This discussion would have been far more productive if Scott had dedicated a thousand words towards educating people about QC, rather than belittling someone personally.
Please don't let his (admittedly sometimes aggressive, unabashed) writing style detract from the man himself. From personal experience, he's unfailingly generous, kind, and amazing to work with.
In light of Vivek Wadhwa's responses, Aaronson's attack seems really petty. I'd love to read a technical summary of all mistakes made by Wadhwa though.
The cryptographic content of the article gets even worse from there.
I don't think it's "petty" to call out someone as high-profile as Vivek Wadhwa for apparently taking to the pages of the Washington Post to write about a topic he has no conversance with at all.
"Please give me 1-2 sentences that your children could understand that explains the possibilities of quantum computing and I will use these in future articles. I acknowledge that I am not as smart as most of you are. I struggle with the concepts of quantum computing, these just don’t make sense to me."
Is there any other field in which someone would profess complete ignorance about a topic, and go on to write about it in a national newspaper anyway?
There's also a difference between complete ignorance, and the ability to perfectly frame a field's possible impact in language that the general public can understand.
Considering that he is unlikely to be so humbled by this experience to immediately change careers, the wish to improve journalism may be best channeled not at trying to take this guy down, but to actually acquiesce and simply provide him that summary he is asking for. I, for one, would be interested.
Yes, this happens in every field. This isn't a problem specific to computing, it's specific to journalism.
This is what I'd explain to a child, and I believe it's more or less correct. Once they get more interested, they'll be able to consult more precise although less accessible descriptions.
He was one of the few people I recall following on Twitter. I was also surprised then by how accessible he was to chat with, as is shown in this.
This broad lack of education opens the door for people like Mr. Wadhwa to write articles about subjects like quantum computing that are wrong in many important ways, rankling people who actually know a lot about the subject, like Aaronson.
Every article in a mainstream publication I've read on a technical subject about which I actually know something is wrong in important ways.
I doubt there's a short-term solution for this problem.
[0] Crichton’s “Gell-Mann Amnesia” quote is fantastically apropos in this regard, and certain kinds of specialists ought to recall it so that it might temper snobbery and inspire a more charitable response. I can’t tell you how often specialists, often competent in their own narrow areas of expertise, produce some of the most absurd and ignorant nonsense ever put to paper when they falsely presume to have anything of value to say about topics outside of their fields.
Not on topic but since Scott had to mention it...
> Would you agree that the Washington Post has been a leader in investigative journalism exposing Trump’s malfeasance? Do you, like me, consider them one of the most important venues on earth for people to be able to trust right now?
No, no, I don't. They are better then MSNBC and CNN in that they do some actual legwork as opposed to talking about ice-cream scoops and extra long hand shakes, but certainly have gotten the "Russian hackers" fever and can't let go of it: https://theintercept.com/2017/01/04/washpost-is-richly-rewar...