Archive for the ‘Democritus’ Category

Quantum Computing Since Democritus now out in the US! 20% discount for Shtetl-Optimized readers

Saturday, April 27th, 2013

OK, this will be my last blog post hawking Quantum Computing Since Democritus, at least for a while.  But I do have four pieces of exciting news about the book that I want to share.

  1. Amazon is finally listing the print version of QCSD as available for shipment in North America, slightly ahead of schedule!  Amazon’s price is $35.27.
  2. Cambridge University Press has very generously offered readers of Shtetl-Optimized a 20% discount off their list price—meaning $31.99 instead of $39.99—if you click this link to order directly from them.  Note that CUP has a shipping charge of $6.50.  So ordering from CUP might either be slightly cheaper or slightly more expensive than ordering from Amazon, depending (for example) on whether you get free shipping from Amazon Prime.
  3. So far, there have been maybe 1000 orders and preorders for QCSD (not counting hundreds of Kindle sales).  The book has also spent a month as one of Amazon’s top few “Quantum Physics” sellers, with a fabulous average rating of 4.6 / 5 stars from 9 reviews (or 4.9 if we discount the pseudonymous rant by Joy Christian).  Thanks so much to everyone who ordered a copy; I hope you like it!  Alas, these sales figures also mean that QCSD still has a long way to go before it enters the rarefied echelon of—to pick a few top Amazon science sellers—Cosmos, A Brief History of TimeProof of Heaven (A Neurosurgeon’s Journey into the Afterlife), Turn On Your SUPER BRAIN, or The Lemon Book (Natural Recipes and Preparations).  So, if you believe that QCSD deserves to be with such timeless classics, then put your money where your mouth is and help make it happen!
  4. The most exciting news of all?  Luboš Motl is reading the free copy of QCSD that I sent him and blogging his reactions chapter-by-chapter!  So, if you’d like to learn about how mathematicians and computer scientists simply lack the brainpower to do physics—which is why we obsess over kindergarten trivialities like the Church-Turing Thesis or the Axiom of Choice, and why we insist idiotically that Nature use only the mathematical structures that our inferior minds can grasp—then check out Luboš’s posts about Chapters 1-3 or Chapters 4-6.  If, on the other hand, you want to see our diacritical critic pleasantly surprised by QCSD’s later chapters on cryptography, quantum mechanics, and quantum computing, then here’s the post for you.  Either way, be sure to scroll down to the comments, where I patiently defend the honor of theoretical computer science against Luboš’s hilarious ad hominem onslaughts.

Pigs sprouted wings, Hell froze over, and I guest-posted on Luboš Motl’s blog

Monday, April 8th, 2013

Furthermore, the last of those things actually happened.  What won’t I do to promote Quantum Computing Since Democritus?  Enjoy!

Update: I submitted the following response to the comments over on Lubos’s blog.  Since it has some bits of general interest, I thought I’d crosspost it here while it awaits Lubos’s moderation.

Since Lubos “officially invited” me to respond to the comments here, let me now do so.

1. On “loopholes” in quantum mechanics: I completely agree with Lubos’s observation that the actual contents of my book are “conservative” about the truth of QM. Indeed, I predict that, when Lubos reads his free copy, he’ll agree with (or at least, have no objections to) the vast majority of what’s in the book. On the other hand, because I was guest-blogging about “the story of me and Lubos,” I found it interesting to highlight one area of disagreement regarding QM, rather than the larger areas of agreement.

2. On Gene Day’s patronizing accusation that I don’t “get the basics of QM or even comprehend the role of mathematics in physics”: his misreading of what I wrote is so off-base that I don’t know whether a response is even necessary.  Briefly, though: of course two formulations of QM are mathematically equivalent if they’re mathematically equivalent!  I wasn’t asking why we don’t use different mathematical structures (quaternions, the 3-norm, etc.) to describe the same physical world.  I was asking why the physical world itself shouldn’t have been different, in such a way that those other mathematical structures would have described it.  In other words: if you were God, and you tried to invent a theory that was like QM but based on those other structures, would the result necessarily be less “nice” than QM?  Would you have to give up various desirable properties of QM?  Yes?  Can you prove it?  The ball’s in your court, Mr. Day — or else you can just read my book! :-)

3. On Lord Nelson’s accusation that I’m a “poseur”: on reflection, someone who only knew me from blog stunts like this one could easily be forgiven for getting that impression! :-) So it might be worth pointing out for the record that I also have a “day job” outside the blogosphere, whose results you can see here if you care.

4. On my political views: I wish to clarify for Tom Vonk that I despise not only “Communists,” but the ideology of Communism itself. One of the formative experiences of my life occurred when I was an 8-year-old at Wingate Kirkland summer camp, and all the campers had to relinquish whatever candy they’d brought into a communal “bunk trunk.” The theory was that all the campers, rich and poor alike, would then share the candy equally during occasional “bunk parties.” What actually happened was that the counselors stole the candy. So, during a meeting of the entire camp, I got up and gave a speech denouncing the bunk trunk as Communism. The next day, the camp director (who had apparently been a fellow-traveler in the 1950s) sat with me at lunchtime, and told me about a very evil man named Joe McCarthy who I was in danger of becoming like. But the truth was that I’d never even heard of McCarthy at that point — I just wanted to eat candy.  And I’d give exactly the same speech today.

Like (I suppose) several billion of the world’s people, I believe in a dynamic market-based capitalist society, and also in strong environmental and other regulations to safeguard that society’s continued existence. And I don’t merely believe in that as a cynical compromise, since I can’t get the “dictatorship of the proletariat” that I want in my heart of hearts. Were I emperor of the world, progressive capitalism is precisely what I would institute. In return, perhaps, for paying a “candy tax” to keep the bunk functioning smoothly, campers could keep their remaining candy and eat or trade it to their heart’s delight.

5. On climate change: I’m not a professional climatologist, but neither is Lubos, and nor (correct me if I’m wrong) is anyone else commenting here. Accordingly, I refuse to get drawn into a debate about ice cores and tree rings and hockey sticks, since my experience is that such debates tend to be profoundly unilluminating when not conducted by experts. My position is an incredibly simple one: just like with the link between smoking and cancer, or the lack of a link between vaccines and autism, or any other issue where I lack the expertise to evaluate the evidence myself, I’ll go with what certainly looks like an overwhelming consensus among the scientists who’ve studied the matter carefully. Period. If the climate skeptics want to win me over, then the way for them to do so is straightforward: they should ignore me, and try instead to win over the academic climatology community, majorities of chemists and physicists, Nobel laureates, the IPCC, National Academies of Science, etc. with superior research and arguments.

To this, the skeptics might respond: but of course we can’t win over the mainstream scientific community, since they’re all in the grip of an evil left-wing conspiracy or delusion!  Now, that response is precisely where “the buck stops” for me, and further discussion becomes useless.  If I’m asked which of the following two groups is more likely to be in the grip of a delusion — (a) Senate Republicans, Freeman Dyson, and a certain excitable string-theory blogger, or (b) virtually every single expert in the relevant fields, and virtually every other chemist and physicist who I’ve ever respected or heard of — well then, it comes down to a judgment call, but I’m 100% comfortable with my judgment.

Quantum Computing Since Democritus: The Buzz Intensifies

Thursday, March 21st, 2013

Update (March 22): The Kindle edition of Quantum Computing Since Democritus is now available, for the low price of $15.40!  (Not factorial.)  Click here to get it from, or here to get it from  And let me know how it looks (I haven’t seen it yet).  Another Update: Just saw the Kindle edition, and the figures and formulas came out great!  It’s a product I stand behind with pride.

In the meantime, I regret to say that the marketing for this book is getting crasser and more exploitative by the day.



It seems like wherever I go these days, all anyone wants to talk about is Quantum Computing Since Democritus—the sprawling new book by Scott Aaronson, published by Cambridge University Press and available for order now.  Among leading figures in quantum information science—many of them well-known to Shtetl-Optimized readers—the book is garnering the sort of hyperbolic praise that would make Shakespeare or Tolstoy blush:

“I laughed, I cried, I fell off my chair – and that was just reading the chapter on Computational Complexity.  Aaronson is a tornado of intellectual activity: he rips our brains from their intellectual foundations; twists them through a tour of physics, mathematics, computer science, and philosophy; stuffs them full of facts and theorems; tickles them until they cry ‘Uncle’; and then drops them, quivering, back into our skulls.  Aaronson raises deep questions of how the physical universe is put together and why it is put together the way it is.  While we read his lucid explanations we can believe – at least while we hold the book in our hands – that we understand the answers, too.” –Seth Lloyd

“Scott Aaronson has written a beautiful and highly original synthesis of what we know about some of the most fundamental questions in science: What is information? What does it mean to compute? What is the nature of mind and of free will?” –Michael Nielsen

“Not since Richard Feynman’s Lectures on Physics has there been a set of lecture notes as brilliant and as entertaining.  Aaronson leads the reader on a wild romp through the most important intellectual achievements in computing and physics, weaving these seemingly disparate fields into a captivating narrative for our modern age of information.  Aaronson wildly runs through the fields of physics and computers, showing us how they are connected, how to understand our computational universe, and what questions exist on the borders of these fields that we still don’t understand.   This book is a poem disguised as a set of lecture notes.  The lectures are on computing and physics, complexity theory and mathematical logic and quantum physics.  The poem is made up of proofs, jokes, stories, and revelations, synthesizing the two towering fields of computer science and physics into a coherent tapestry of sheer intellectual awesomeness.” –Dave Bacon

After months of overhearing people saying things like the above—in the halls of MIT, the checkout line at Trader Joe’s, the bathroom, anywhere—I finally had to ask in annoyance: “is all this buzz justified?  I mean, I’m sure the book is as deep, hilarious, and worldview-changing as everyone says it is.  But, after all, it’s based off lecture notes that have long been available for free on the web.  And Aaronson, being the magnanimous, open-access-loving saint that he is, has no plans to remove the online notes, even though he could really use the royalties from book sales to feed his growing family.  Nor does Cambridge University Press object to his principled decision.”

“No, you don’t understand,” they told me.  “Word on the street has it that the book is extensively updated for 2013—that it’s packed with new discussions of things like algebrization, lattice-based cryptography, the QIP=PSPACE theorem, the ‘quantum time travel controversy,’ BosonSampling, black-hole firewalls, and even the Australian models episode.  They say it took years of painstaking work, by Aaronson and his student Alex Arkhipov, to get the notes into book form: fixing mistakes, clarifying difficult points, smoothing out rough edges, all while leaving intact the original’s inimitable humor.  I even heard Aaronson reveals he’s changed his mind about certain things since 2006.  How could you not want such a labor of love on your bookshelf?”

Exasperated, I finally exclaimed: “But the book isn’t even out yet in North America! says it won’t ship until April 30.”

“Sure,” one gas-station attendant replied to me, “but the secret is, it’s available now from  Personally, I couldn’t wait a month, so I ordered it shipped to me from across the pond.  But if you’re a less hardcore quantum complexity theory fan, and you live in North America, you can also preorder the book from, and they’ll send it to you when it arrives.”

Much as the hype still grated, I had to admit that I’d run out of counterarguments, so I looked into ordering a copy for myself.

Quantum Computing Since Democritus Lecture 21: Ask Me Anything

Monday, September 1st, 2008

In the final Democritus installment, I entertain students’ questions about everything from derandomization to the “complexity class for creativity” to the future of religion.  (In this edited version, I omitted questions that seemed too technical, which surprisingly was almost half of them.)  Thanks to all the readers who’ve stuck with me to this point, to the students for a fantastic semester (if they still remember it) as well as their scribing help, to Chris Granade for further scribing, and to Waterloo’s Institute for Quantum Computing for letting me get away with this.  I hope you’ve enjoyed it, and only wish I’d kept my end of the bargain by getting these notes done a year earlier.

A question for the floor: some publishers have expressed interest in adapting the Democritus material into book form.  Would any of you actually shell out money for that?

Quantum Computing Since Democritus Lecture 20: Cosmology and Complexity

Thursday, August 21st, 2008

Come watch me attempt to explain the implications of a positive cosmological constant for computational complexity theory.  If this blog is about anything, it’s about me talking about subjects I don’t understand sufficiently well and thereby making a fool of myself.  But it’s also about experts taking the time to correct me.  The latter is the primary saving grace.

Quantum Computing Since Democritus Lecture 19: Time Travel

Thursday, July 31st, 2008

A visitor from the year 2006, this time travel lecture appears before you now due to a blip in the space/time/procrastination continuum.  No grandfathers were harmed in the writing of it.  I’m looking backward to your comments.

(Alas, these forehead-bangingly obvious lines can now never be unwritten … or can they?)

Quantum Computing Since Democritus Lecture 18: Free Will

Monday, July 28th, 2008

If you don’t like this latest lecture, please don’t blame me: I had no choice! (Yeah, yeah, I know. You presumably have no choice in criticizing it either. But it can’t hurt to ask!)

Those of you who’ve been reading this blog since the dark days of 2005 might recognize some of the content from this post about Newcomb’s Paradox, and this one about the Free Will Theorem.

Quantum Computing Since Democritus Lecture 17: Fun With The Anthropic Principle

Thursday, July 24th, 2008

Here it is. There was already a big anthropic debate in the Lecture 16 comments — spurred by a “homework exercise” at the end of that lecture — so I feel absolutely certain that there’s nothing more to argue about. On the off chance I’m wrong, though, you’re welcome to restart the debate; maybe you’ll even tempt me to join in eventually.

The past couple weeks, I was at Foo Camp in Sebastopol, CA, where I had the opportunity to meet some wealthy venture capitalists, and tell them all about quantum computing and why not to invest in it hoping for any short-term payoff other than interesting science. Then I went to Reed College in Portland, OR, to teach a weeklong course on “The Complexity of Boolean Functions” at MathCamp’2008. MathCamp is (as the name might suggest) a math camp for high school students. I myself attended it way back in 1996, where some guy named Karp gave a talk about P and NP that may have changed the course of my life.

Alas, neither camp is the reason I haven’t posted anything for two weeks; for that I can only blame my inherent procrastination and laziness, as well as my steadily-increasing, eminently-justified fear of saying something stupid or needlessly offensive (i.e., the same fear that leads wiser colleagues not to start blogs in the first place).

Quantum Computing Since Democritus Lecture 16: Interactive Proofs

Tuesday, July 8th, 2008

In which I try to give a non-rigorous taste of the interactive proofs revolution that rocked the complexity world in the 1990′s, as well as its consequences for circuit lower bounds. I argue that these results matter because they offer a tiny glimpse of how one can exploit the structure of problems like 3SAT to prove lower bounds—something we know will eventually be needed for the P vs. NP question. If you got off the train before its latest tour through the Complexity Badlands, don’t worry: it will double back into Philosophers’ Valley (where everyone has an opinion and no one has a result) by Lecture 17 (“Fun With Anthropic Principles”).

Quantum Computing Since Democritus Lecture 15: Learning

Thursday, June 26th, 2008

Lektur iz heer.

This week I explain Valiant’s PAC-learning model (previously covered in GITCS Lectures 19, 20, 21), and also — in response to a question from the floor — take a swipe at Bayesian fundamentalism.  When you only know one formalism to describe some phenomenon (in this case, that of choosing hypotheses to fit data), it’s easy to talk yourself into believing that formalism is the Truth: to paraphrase Caliph Omar, “if it agrees with Bayesianism, it is superfluous; if it disagrees, it is heresy.”  The antidote is to learn other formalisms.  Enter computational learning theory: an account of learning that’s clear, mathematically rigorous, useful, nontrivial, and completely different from the Bayesian account (though of course they have points of contact).  The key idea is to jettison the notoriously-troublesome notion of a prior, replacing it by a concept class (about which one makes no probabilistic assumptions), as well as a probability distribution over sample data rather than hypotheses.

Incidentally, I’d say the same thing about complexity theory.  If you think (for example) that Turing machines are the only way to reason about computational efficiency, then you’re overdue for a heaping helping of communication complexity, circuit complexity, query complexity, algebraic complexity…

Ah yes, complexity.  This week I was at the Conference on Computational Complexity at the beautiful University of Maryland in College Park: home of the Terrapins, as one is reminded by signs placed roughly every three inches.  I heard some great talks (ask in the comments section if you want details), gave two talks myself, and during the business meeting, was elected to the CCC Steering Committee.  This being a complexity conference, my declared campaign motto was “No We Can’t!”  It was inspiring to see how this simple yet hopeful motto united our community: from derandomization to circuit lower bounds, from quantum computing to proof complexity, we might have different backgrounds but we all worry about shrinking grant sizes and the rising costs of conference registration; we all face common challenges to which we want to prove that no solutions exist.  Rest assured, I will treat my duties as a steering committee member (mostly helping to select PC chairs, who in turn select the program committees who select the conference papers) with the awesome gravity they deserve.