Welcome!

Hello and welcome back to my little neck of timber!  If you’re coming here from scienceblogs, thanks for following me over here!  If your here because you started randomly surfing the internet like the teleportation portion of the PageRank algorithm, well, then, you are and odd duck, but welcome!
Not sure where this blog will take me this time, but right off the top I should warn you:

Picture of Dave playing tennis
Beware of Dave!

Test

This is a test.  I repeat this is only a test.  The emergency broadcast system’s got nothing on this test.

Dead Spins And The Dirty Ground

Yep, it’s that time again. Paper dance time!

arXiv:1006.4388
Making Classical Ground State Spin Computing Fault-Tolerant
Isaac J. Crosson, Dave Bacon, Kenneth R. Brown
We examine a model of classical deterministic computing in which the ground state of the classical system is a spatial history of the computation. This model is relevant to quantum dot cellular automata as well as to recent universal adiabatic quantum computing constructions. In its most primitive form, systems constructed in this model cannot compute in an error free manner when working at non-zero temperature. However, by exploiting a mapping between the partition function for this model and probabilistic classical circuits we are able to show that it is possible to make this model effectively error free. We achieve this by using techniques in fault-tolerant classical computing and the result is that the system can compute effectively error free if the temperature is below a critical temperature. We further link this model to computational complexity and show that a certain problem concerning finite temperature classical spin systems is complete for the complexity class Merlin-Arthur. This provides an interesting connection between the physical behavior of certain many-body spin systems and computational complexity.

Best Paper at STOC

Congrats to Rahul Jain, Zhengfeng Ji, Sarvagya Upadhyay, and John Watrous for being selected a best paper at STOC 2010 for their paper “QIP=PSPACE”. (The best paper award was shared with “An improved LP-based approximation for Steiner Tree” by Jaroslaw Byrka, Fabrizio Grandoni , Thomas Rothvoss and Laura Sanit√†)

Pr(Future Dave Bacons|Library Cuts) is Small

I grew up in the small town of Yreka, CA (“Yreka Bakery” backwards is…) that sits just minutes south of the Oregon-California border on Interstate 5. Yreka, population a little over 7000 brave souls, is the county seat of Siskiyou county. Siskiyou county is “god’s country” meaning, yes, (a) it votes strongly Republican 🙂 and (b) its scenery is awesome:
Siskiyou county is, however, not a wealthy part of the United States (yes, if you measure wealth in dollars :)) Unemployment in the county is currently 19 percent (not seasonally adjusted), the median income is $29,530, and about 18 percent of the population is below the poverty line. Most employment is in the services or retail trade, with government and agriculture/mining/timber being the next highest employers. The collapse of the timber industry during the 70s and 80s took a hard toll on the county and no industry has really arisen to take its place.
As you might imagine, given the above facts, the recent recession has cause some financial hardships for Siskiyou county. It comes as no surprise, then to read an article in the local newspaper, the Siskiyou Daily News, regarding drastic cuts in the funding of the Siskyou County library. The county is running a $3.7 million deficit, and many cuts are now on the county supervisor’s agenda. Among the cuts is one that hits dear to my heart, cutting the county library’s budget from $712,000 to $50,000, the later being enough to keep the utilities running at the library buildings. The county library in Siskiyou county is in danger of dying.
Read about this made me sad. Now I’m not a bystander without personal interest in this situation: my handicapped sister has worked or volunteered at the county library in Yreka for many many years. The “gainful” employment the library has given her has been a blessing for her and, I think, for those who get to spend time with someone who is much more wonderful than her oafish brother. It would be a shame if her job where to end, not because she costs the county much (she is a volunteer now) but because it brings great joy to her day, and I suspect, to many people who interact with her.
But I’m also sad for a different reason. I’m sad because of Spacetime Physics 1ST Edition. 1st edition, peoples, not the later editions! I picked up this book from the county library at who knows what age and learned all about special relativity (chapter 1 is available here: note the dog and spaceship.) Indeed learning about hyperbolic sine and hyperbolic cosine were of great use when I finally, years later, had to learn trigonometry (which I taught myself in order to calculate how the size of the moon’s shadow is changed by refraction in the earth’s atmosphere. NERD!)
I’m sad because of a county library Calculus book whose author I do not remember, but where I first learned about Newton’s (and friend’s) great discovery involving wacko ideas like limits and infinitesimals. It will come as no surprise to learn that I was led to this book by a book on quantum theory. The quantum theory book started out with a discussion of something called blackbody radiation, and it was very important that the big sigma (I new this stood for a sum) was used instead of a big flat “S.” A science teacher said “Ah that’s an integral sign from Calculus.” Ah the indignation of having to learn calculus before you could learn quantum theory (now we know better!)
I’m sad because of all of the back issues of Scientific American with their wonderful articles on the game of life, computer bugs that evolved, and tinkertoy machines for playing tic-tac-toe (and whose author, in later life, seems to have become rather sadly confused.)
I’m sad for all of the many popular science books on the “mysteries” of quantum theory that allowed me, when it came time to really learn quantum theory, to know exactly where the line to those mysteries lay and that crossing that line tonight at 2 a.m. was not going to help me solve my problem set by 10 a.m. I’m sad for A Brief History of Time, From the Big Bang to Black Holes where I learned that I disagreed with Hawking about many things, none of them involving physics.
Now I can’t say that I’ve been any great contribution to my country, given how big of a user of its library I once was. I live in Seattle and visit Yreka only occasionally now. But I do know with high certainty that a major factor in me ending up with a Ph.D. in theoretical physics and performing research on quantum computing can be traced back to that county library. And I’m guessing that for many others the library has provided a path towards their own self-education: may it be on black holes, sewing, or learning about the history of the world. If I had a soapbox I’d probably also go on about studies showing businesses not moving to the county due to it’s low literacy rate. But enough of the political whining. Tonight, I’m just going to be sad for the future kids who don’t even know that they just lost one more opportunity to expand and better their future world.

De Took Er DataBs Jrbs!

Over at Daily Speculations, Alan Corwin writes about database programming jobs that will never return. The gist of Alan’s piece is that the tools for databases are basically so turn-key and so easy that those who were trained to build their own database code by hand will be unlikely to see those job returns. He ends his article by noting: “For my friends in the programming community, it means that there are hard times ahead.”
Turn the page.
Here is a report from UCSD on “Hot Degrees for College Graduates 2010.” 3 of the top 5 are computer science related, and number 3 is “Data Mining.”
Now I know that database programming does not equal data mining. But it is interesting to contrast these two bits of data (*ahem*), especially giving the dire prediction at the end of Alan Corwin’s article. Besides my tinkering with iPhone apps, simulations for my research, and scirate, I’m definitely not a professional programmer. But I am surrounded by students who go on to be professional programmers, many of them being immensely successful (as witnessed by alumni I have met.) And when I talk to my CS students about job prospects, they are far from doom and gloom. So how to reconcile these two views?
Well, I think what is occurring here is simply that those who view themselves as a set of tools and languages they use to get their jobs are misunderstand what the role of a programmer should be. There are many variations on this theme, but one place to find a view of the programmer as different than someone whose skill set defines them is The Programmers Stone. And indeed, in this respect, I think a good CS degree resembles a good physics degree. Most people who come out of physics programs don’t list on their resume: “Expert in E&M, quantum theory, and statistical physics.” The goal of a good physics program is not to teach you the facts and figures of physics (which are, anyways, easily memorized), but to teach you how to solve new problems in physics. For computer science this will be even more severe, as it is pretty much guaranteed that the tools you will be using today will change in the next few years.
So doom and gloom for programmers? Only time will tell, of course, but I suspect this answer is a strong function of what kind of programmer you are. And by kind I don’t mean a prefix like “Java” or “C++”.
(And yes I realize that this is an elitist position, but I just find the myth of the commodity programming job as an annoying misrepresentation of why you should get a degree in computer science.)
Update: more here.

Dmitry Maslov, who is a program director at the NSF, made a good suggestion to me the other day that I’d like to follow up on (can you tell my full paternity leave is up?) In particular he noted that there is no central mailing list for announcements in quantum information science.

Google Hella Cool

Fellow Yrekan Austin Sendek’s quest to get “Hella” the official prefix for 1027 has scored a Googol-sized success. Err I mean a Google-sized success:
Austin also writes to inform me that there is an official petition, which can be found here.
Also I’m amused to note that the google-monster also recognizes smoots.

Portrait of a Reviewer as a Young Man

Science is dynamic. Sometimes this means that science is wrong, sometimes it means that science is messy. Mostly it is very self-correcting, given the current state of knowledge. At any given time the body of science knows a lot, but could be overturned when new evidence comes in. What we produce through all of this, however, at the end of the day, are polished journal articles. Polished journal articles.
Every time I think about this disparity, I wonder why different versions of a paper, the referee reports, the author responses, and all editorial reviews aren’t part of the scientific record. In an age where online archiving of data such as this is a minor cost, why is so much of the review process revealed to only the authors, the referees, and the editors?