mathematics

Multiverse Mania makes the big time this week, with a cover story Welcome to the Multiverse by Brian Greene in Newsweek. While the title indicates that the Multiverse is here and part of our scientific world-view, the subtitle is a bit cagier: “The latest developments in cosmology point toward the possibility that our universe is merely one of billions.”

The article is pretty uniformly a promotional piece for multiverse mania, although buried fairly deep in the piece is something a bit more skeptical:

because the proposal is unquestionably tentative, we must approach it with healthy skepticism and invoke its explanatory framework judiciously.

Imagine that when the apple fell on Newton’s head, he wasn’t inspired to develop the law of gravity, but instead reasoned that some apples fall down, others fall up, and we observe the downward variety simply because the upward ones have long since departed for outer space. The example is facetious but the point serious: used indiscriminately, the multiverse can be a cop-out that diverts scientists from seeking deeper explanations. On the other hand, failure to consider the multiverse can place scientists on a Keplerian treadmill in which they furiously chase answers to unanswerable questions.

Which is all just to say that the multiverse falls squarely in the domain of high-risk science. There are numerous developments that could weaken the motivation for considering it, from scientists finally calculating the correct dark-energy value, or confirming a version of inflationary cosmology that only yields a single universe, or discovering that string theory no longer supports a cornucopia of possible universes. And so on.

I don’t see how we’re anywhere near finding such a version of inflation or getting rid of the string theory landscape, so the only hope of getting any evidence against the multiverse seems to be to calculate the CC. The multiverse thus looks to be pretty much impregnable and immune to any conceivable scientific challenge. A few years ago, pieces like this would hold out hope that the LHC would discover something encouraging for the multiverse, but now the LHC isn’t even mentioned. The only possible positive evidence suggested is seeing remnants of bubble collisions in the CMB, but the very likely eventuality of not seeing such a thing doesn’t count as evidence against the multiverse idea.

So, I fear Brian is right: Welcome to the Multiverse, physics is going to be stuck with it for a very long time…

The announcement of new Higgs results from the LHC is now scheduled for about a month and a half from now, July 7th, 9:30 and 10am Melbourne time, at ICHEP2012. The LHC is performing well, with nearly 2.5 fb^-1 of integrated luminosity/experiment. With only 2-3 weeks more of data collection before the cutoff for what can be analyzed in time to be made public July 7, one can expect the July announcements to be based on perhaps 4-5 fb^-1 per experiment. Rough estimates show that, combining last year’s 5 fb^-1 at 7 TeV and this year’s expected data, if the SM Higgs really is there at 125 GeV, each experiment should see a signal of 4 sigma significance. This is not quite the 5 sigma significance traditionally set for a discovery claim, but very close.

It thus looks possible that a discovery claim will require combining the results from CMS and ATLAS. The LHC Higgs Combination Group has been hard at work for the last couple years, developing methods for combining results from the two experiments. This time, they will be ready to quickly combine all the data from the two experiments, and maybe this will be what gives the 5 sigma needed for CERN to claim discovery. I don’t know what the plan is for when they will be provided with the CMS/ATLAS data, or when they plan to announce a result.

The LHC-HCG is competing with Philip Gibbs, who today released a Higgs Combination Java Applet which allows anyone to produce their own data combinations. If the LHC-HCG can’t produce a combination by 10:30am July 7, CERN should perhaps consider getting Philip’s applet properly set up and having DG Heuer publicly press the right button, allowing CERN to claim the Higgs discovery before Philip does.

In June 11-14 will be a new workshop: Algorithmic Frontiers. How many venues do we have for meetings?

1. What the call themselves: Meetings (e.g., MATHFEST), Conferences (e.g., STOC), Workshops (Barriers), Seminars (e.g., Dagstuhl), Tutorials, Lunches. More? (six options)
2. Criteria for getting a paper in: Refereed (e.g., STOC): lightly refereed (I think MATHFEST), unrefereed, talks-by-invite-only (Algorithmic Frontiers, Barriers) (four options)
3. Participants: Open (most)or by-invite-only (Dagstuhl and Bertinoro) (two options)
4. Size: This is more informal. However, CCC is small (100), STOC is larger (around 400), FCRC larger still, and Supercomputing is expecting 11,000. Medical conventions can get around 20,000. (five options, though could be more or less depending on your mood.)
5. Variety of activities: A venue can have any combination of the following: contributed talks (unrefereed), refereed talks (typical STOC), invited talks, rump sessions, tutorials, workshops, short courses. (128 combinations, though in reality only about 5 options actually happen, so I'll take it as 5)
6. Length: Number of days can be anything from 1 day to 2 months. However, I don't think all 60 options really exist. I've seen 1,2,3,4,5 days, 1 week, 2 weeks, 1 month, and 2 months. nine options.
7. Expense: Either expensive or VERY expensive.

So that would be 6x4x2x5x5x9x2. That's a lot! Of course its far far less since, for example, an invite-only gathering can only have invited talks. I would guess its more like 5 types. And some are inconsistent (e.g., STOC sometimes has tutorials and sometimes doesn't). Algorithmic Frontiers seems to be a 4-day open workshop that has invited talks only. I don't know how big it will be but I would guess between 100 and 200. Do the gatherings that we go to work? As my Software engineering friend Jim Purtilo often says If you don't know your goals you are not going to achieve them. So, what are the goals? Ultimately to help both us as individuals and us as a community in our research. The hope is we learn things and get inspired to work on problems. And these can be done by the formal talks in the ballroom and informal talks in the hallways. Does this happen? Yes. Is it cost effective (not just money but time)? Debatable, as this and other blogs have debated. Here are my experiences. What are yours?

1. DAGSTUHL SEMINARS. These are specialized one-week long meetings by invitation only. The talks need not be on the latest/greatest thing and hence are understandable. (I've been to DAGSTUHL- Complexity 3 times.)
2. Bertinoro is similar to Dagstuhl. I've been to the RATLOCC 2011 and RATLOCC 2009 which are on Ramsey Theory and Logic. Here there were even more talks that were surveys or historical-perhaps because math moves slower than computer science. If the talks were on the INTERSECTION Of Ramsey Theory and Logic then it would be too specialized. (I've worked in both, but not quite together.) As is, its a nice mix. But the main point- I understood the talks.
3. The Center for Intractability sponsors workshops which anyone can go to but the speakers are picked by them. I've been to one of the Barriers workshops and it was very good. The speakers have more time then at conferences, which is a plus. The Algorithmic Frontiers workshop seems to be in this model.
4. The last few CCC's and STOC's that I've gone to I have enjoyed and gotten stuff out of, but not as much as the smaller venues. Partly because the talks are shorter. which is a plus. The Algorithmic Frontiers workshop seems to be in this model.
5. MATHFEST is nice in that there is a VARIETY Of activities- workshops, seminar, tutorials, invited talks. Very large which is both good (that's why they can have all of these things and bad (I never met the same person twice).
6. One of my colleagues, Jeff Hollingsworth, is organizing SC12, Supercomputing 2012. This will have 11,000 people at it. The program committee has over 100 people on it. This seems... large. They seem to have a variety of activities so it more like MATHFEST.
7. Of course the talks are only part of the reason to go to these things. Even so, for me they are a big reason.

What venues to YOU get the most out of? Why or why not?

There’s at least one thing about string theory that has changed dramatically since my book was written back in 2002 or so. At the time I accumulated various numbers showing the way hiring in particle theory at leading institutions in the US had been dominated by string theory hires. Overall, at that time about 20 people/year were getting tenure-track positions, roughly half in string theory half in phenomenology. This data came from the Theoretical Particle Physics Jobs Rumor Mill, and Erich Poppitz has done an excellent job of putting some statistics together based on this data (see here). In recent years Erich’s data shows a much lower number of such positions (10-15/year), due to some combination of the bad economy and lack of enthusiasm for particle theory by other physicists. The number of string theorists getting positions had come down to about 2/year, then down to only one last year.

The hiring season is not yet over and not all the data is in, but so far the Rumor Mill shows no job offers to string theorists at all. Job offers are going pretty exclusively to phenomenologists and cosmologists, with phenomenologists allowed to stray into formal theory if they work on topics related to N=4 SYM and its superconformal invariance (including the hot topic of amplitudes). Marcus at PhysicsForums has patched some of the Rumor Mill links for better accuracy.

One thing hasn’t changed though since 2002: there’s a much larger number of talented and accomplished candidates than there are jobs, and departments are playing it safe, offering the few jobs available only to people working in a small number of areas that are conventionally agreed to be “hot”. As always, if you’re working on some idea that’s not in the narrow mainstream, there’s no chance you’ll get hired into a permanent position at a US institution.

The implications of the failure to find SUSY at the LHC are beginning to sink into the particle physics community: the paradigm that dominated the subject for the past 30 years has collapsed in the face of experimental (non)-evidence, threatening to take down the life’s work of hundreds if not thousands of theorists. For some recent attempts to quantify what is going on, from some people with much more statistical expertise than me, see Philip Gibbs and Tommaso Dorigo. By now a significant number of SUSY analyses of the full 2011 dataset have been completed, with negative results. By the end of the year there will be more data, but just a factor of 2-3 more, at about 14% higher energy. To believe that these sorts of increases will turn no signal into a signal requires a willingness to engage in a rather large amount of wishful thinking. The 62% jump in 2014 to 6.5 TeV/beam is more significant, but it’s hard to see an argument for why this should do the trick, and the wait for these results will be discouragingly long, probably until 2015. How many SUSY enthusiasts will keep the faith?

A small number of theorists though still claim all is well, with one group producing a new paper claiming the full 5 inverse femtobarn results show Chanel No5 (fb^-1): The Sweet Fragrance of SUSY. Last year the same authors were claiming to detect Profumo di SUSY in the first inverse femtobarn, and argued that 5 times more data would be conclusive. To quantify the SUSY smells they are advertising, one can plot as a function of time their published predictions for the parameter $M_{1/2}$ which determines the gluino mass.

arXiv:1007.5100 455 GeV (“Golden Point”) arXiv:1009.2981 455-481 GeV (“Golden Strip”) arXiv:1111.0236 512 GeV (“Universe F-U2″) arXiv:1111.4204 518 GeV (“Profumo di SUSY”) arXiv:1203.1918 610 GeV (“Aroma of Stops and Gluinos”) arXiv:1205.3052 708 GeV (“The Sweet Fragrance of SUSY”)

It’s rather easy to extrapolate to the future what these authors will be claiming the SUSY masses are, harder to extrapolate how they’ll be describing the smell. The rest of the particle physics community I suspect is already using very different terms for this.

The ACM announced the 2012 Gödel Prize awardees, three seminal papers in algorithmic game theory. The prizes themselves will be presented at ICALP in Warwick in July. Elias Koutsoupias and Christos H. Papadimitriou: Worst-case equilibria, Computer Science Review, 3(2): 65-69, 2009. Tim Roughgarden and Éva Tardos: How Bad Is Selfish Routing?, Journal of the ACM, 49(2): 236-259, 2002. Noam Nisan and Amir Ronen: Algorithmic Mechanism Design, Games and Economic Behavior 35: 166-196, 2001. The first paper introduced the price of anarchy. The second applied price of anarchy to routing problems. The third applied algorithmic techniques and competitive analysis to auctions. Congrats to all the winners.

This week Yale is hosting a conference on Perspectives in Representation Theory, in honor of Igor Frenkel’s 60th birthday. I’m planning to take the train up there and attend some of the talks tomorrow and Wednesday. Frenkel has been a pioneer in the field of representation theory, especially in the area of infinite-dimensional algebras whose representations are significant for understanding low-dimensional QFT, string theory and topological QFT. He started his career in the early 1980s, with many important results relevant to understanding affine Lie algebras. These became central in the explosion of interest among physicists in 2d conformal QFTs after 1984 due to their importance in string theory. Frenkel’s later work has covered a wide variety of topics, with one theme that of trying to understand higher-dimensional generalizations of affine Lie algebras and their potential application to QFTs in higher space-time dimensions than 2. He has also promoted the themes of “categorification” and geometric incarnation of representations that are now central to much research in this area.

Pavel Etingof and other students and collaborators of Frenkel have put together a wonderful document, On the work of Igor Frenkel, which gives much more detail about the many topics of his mathematical research.

There is much blame to go around for JPMorgan Chase's two billion dollar loss last week but part of that blame came back to us. In a New York Times web piece, How Moore’s Law Affects Wall St. Trading, Quentin Hardy argues

Faster, cheaper computing makes it possible to create more and better models for calculating cash movements, which can be turned into trading instruments. Areas like leasing, mortgages and project finance have exploded – as has the entire financial derivatives market — thanks to cheap computing...

Soon, it becomes nearly impossible to say what is going on where, and you get events like the 1998 blow-up at Long Term Capital Management, the creation and destruction of the subprime mortgage market in 2008 and perhaps even the “flash crash” in 2010. JPMorgan’s loss seems to be the latest in that series.

I've argued the dangers of reducing computational friction before. But here computational complexity comes in a different way. A derivative is just a function of current and future security prices. But a derivative complex enough can have a behavior that even its creator cannot understand. The Clay Math Institute offers a million dollars to settle "P v NP" but it cost Chase two billion.

The MATLAB language has become ubiquitous in many fields of applied mathematics such as linear algebra, differential equations, control systems and signal processing among many others.  MATLAB is a great tool but it also costs a lot!  If you are not a student then MATLAB is a very expensive piece of software.  For example, my own academic licensed copy with just 4 toolboxes cost more than the rather high powered laptop I use it on.  If I left academia then there would be no chance of me owning a copy unless I found an employer willing to stump up the cash for a commercial license.  Commercial licenses cost a LOT more than academic licenses.

Octave – The free alternative

The good news is that there is a free alternative to MATLAB in the form of Octave.  Octave attempts to be source compatible with MATLAB which means that, in many cases, your MATLAB code will run as-is on Octave.  Many of the undergraduate courses taught at my university (The University of Manchester) could be taught using Octave with little or no modification and I imagine that this would be the case elsewhere.  One area where Octave falls down is in the provision of toolboxes but this is improving thanks to the Octave-Forge project.

Addi – The beginnings of MATLAB/Octave on Android

As Dillion said The Times They Are a-Changin’ and there is an ever-increasing segment of world-society that are simply skipping over the PC and going straight to mobile devices for their computing needs.  It is possible to get your hands on a functional Android mobile phone or tablet for significantly less than the cost of a PC.   These cheap mobile devices may be a lot less powerful than even the cheapest of PCs but they are powerful enough for many purposes and are perfectly capable of outgunning Cray supercomputers from the past.

There is, however, no MATLAB for Android devices.  The best we have right now is in the form of Addi, a free Android app that makes use of JMathLib to provide a very scaled-back MATLAB-like experience.  Addi is the work of Corbin Champion, an android developer from Portland in the US, and he has much bigger plans for the future.

Full Octave/GNUPlot on Android with no caveats

Corbin is working on a full Octave and GNUPlot* port for Android.  He has already included a proof of concept in the latest release of Addi which includes an experimental Octave interpreter.  To go from this proof of concept to a fully developed Android port, however, is going to take a lot of work.  Corbin is up to the task but he would like our help.

[* - GNUPLot is used as the plotting engine for Octave and include support for advanced 3D graphics]

Donate as little as $1 to help make this project possible

Corbin has launched a Kickstarter project in order to try to obtain funding for this project.  He feely admits that he’ll do the work whether or not it gets funded but will be able to devote much more of his time to the project if the funding request is successful.  After all, we all need to eat, even great sotware developers.

Although I have never met him, I believe in Corbin and strongly believe that he will deliver on his promise.  So much so that I have pledged $100 to the project out of my own pocket.

If, like me, you want to see a well-developed and supported version of Octave on Android then watch the video below and then head over to Corbin’s kickstarter page to get the full details of his proposal.  The minimum donation is only $1 and your money will only be taken if the full funding requirement is met.

• Click here to go to the Octave on Android kickstarter page

On November 30, 2009 I posted the famous 17x17 challenge:

(Paraphrase) Find a 4-coloring of the 17x17 grid that has no monochromatic rectangles. For $289.00. It was solved in 2012 by Bernd Steinbach and Christian Posthoff (I posted about it here and will post their paper when they make it it is public, which should be soon.) Even though it was solved, it seemed to be a hard problem.

On April 28, 2010 (before the problem was solved) I wondered WHY it was so hard and posted the following question:

(Paraphrase) Consider the following problem: Given (N,M,c,f) where f is a partial c-coloring of NxM, can f be extended to a total c-coloring of NxM (without mono rectangles)? Is this problem NP-complete?

Kevin Lawler emailed me a sketch of a proof recently! So YES, it is NP-complete! I cleaned it up, wrote it up, and put in a few other things, and the paper is here. (We will be posting to arXiv after we get comments from this blog.)

1. Does this really show why the 17x17 challenge was hard? Not really since the 17x17 challenge is just one instance.
2. Does this show that grid coloring problems are hard in general? Not really since the case we are really interesting in is where f is the empty function. While we do not believe this case is easy, we have not ruled this out.
3. What can we show about the algorithmic complexity? The problem is FPT. For fixed c its in time poly(N,M)+O(c^c4).

This is a problem for hardness-of-Ramseyian numbers in general. While it seems as if computing (say) Ramsey Numbers is hard, there is no real proof of this. Related problems have been studied by Marcus Shaefer here. While this work is very interesting it is NOT the same as showing that finding Ramsey Numbers is hard.I suspect that to prove such things we need a new framework for lower bounds.

A guest post by Ian Cottam (@iandavidcottam).

I have been a programmer for 40 years this month. I thought I would write a short essay on things I experienced over that time that went into the design of a relatively recent, small program: DropAndCompute. (The purpose and general evolution of that program were described in a blog entry here. Please just watch the video there if you are new to DropAndCompute.)

Once I had the idea for DropAndCompute –inspired equally by the complexity of Condor and the simplicity of Dropbox — I coded and tested it in about two days. (Typically, one bug lasted until it had a real user, but it was no big deal.) My colleague, Mark Whidby, later re-factored/re-coded it to better scale as it grew in popularity here at The University of Manchester. I expect Mark spent about two days on it too. The user interface and basic design did not change. (As the evolution blog discusses, we eventually made the use of Dropbox optional, but that does not detract from this tale.)

Physically dropping programs and their data: In the early to mid 1970s as well as doing my own programming work I helped scientists in Liverpool to run their code. One approach we used to make them faster was to drop the deck of cards into the input well of a card reader which was remotely connected to the regional supercomputer centre at Manchester. (I never knew what the communication mechanism was – probably a wet string given the technology of the time.) A nearby line printer was similarly connected and our results could be picked up, usually the next day. DropAndCompute is a 21st century version of this activity, without the leg work and humping of large boxes of cards about.

That this approach was worth the effort was made obvious with one of the first card decks I ever submitted. We had been running the code on an ICL 1903A computer in Liverpool; Manchester had a CDC 6600 (hopefully my memory has not let me down – it did become a CDC 7600 at some stage). Running the code locally in Liverpool, with typical data, took around 55 CPU minutes. Dropping it into that card reader so that it automatically ran in Manchester resulted in the jaw dropping time of 4 CPU seconds. (I still had to wait overnight to pick up the results, something that resonates with today’s DropAndCompute users and Manchester’s Condor Pool, which is only large and powerful overnight.)

Capabilities: Later, but still in the mid 1970s, I worked for Plessey on their System 250 high-reliability, multiprocessor system. It was the first commercial example of a capability architecture. With such there is no supervisor state or privileged code rings or similar. If you held the capability to do something (e.g. read, write or enter another code context) you could do it. If you didn’t hold the appropriate capability, you could not. The only tiny section of code in the System 250 that was special was where capabilities were generated. No one else could make them.

The server side of DropAndCompute generates capabilities to the user client side. They are implemented as zero length files whose information content is just in their names. For job 3159, you get 3159.kill, 3159.vacate and 3159.debug generated*. By dragging and dropping one or more of these zero length files (capabilities) onto the dropbox the remote lower level Condor command code is automatically executed. [* You could try to make your own capability, such as 9513.kill, but it won't work.]

UNIX and Shell Glue Code: My initial exposure to the UNIX tools philosophy in the late 1970s profoundly influenced me (and still does). In essence, it says that one should build new software by inventing ‘glue’ to stick existing components together. The UNIX Shell is often the language of choice for this, and was for me. DropAndCompute is a good example of where a little bit of glue produced a hopefully impressive synergy.

The Internet not The Web: DropAndCompute uses the Internet (clearly). It is not a Web application. I only mention this as some younger programmers, who have grown up with the Web always being there, seem to think the best/only architecture to use for a software system design is one implemented through a web browser using web services. I am grateful to be able to remember pre-Web days, as much as I love what Tim Berners-Lee created for us.

Client-Server: I’m not sure when I first became aware of client-server architecture. I know a famous computer scientist (the late David Wheeler*) once described it as simply the obvious way to implement software systems. For my part, I’m a believer in the less code the client side (user) needs to install the better (less to go wrong on strange environments one has no control over). In the case of DropAndCompute if the user had Dropbox, it was nothing to install, and just downloading Dropbox if they didn’t. [* As well as being a co-inventer of the subroutine, David Wheeler led the team that designed  the first operational capability-based computer: the Cambridge University CAP.]

Rosetta – Software as Magic: Around a decade ago I worked for Transitive, a University of Manchester spin-out, and the company that produced Rosetta for Apple. With apologies to Arthur C Clarke: all great software appears to be magic to the user. The simpler the user interface, often the more complex the underlying system is to implement the magic. This is true, for example, for Apple iOS and OS X and for Dropbox (simpler, and yet I would bet that it is internally more complex, than its many competitors). One small part of OS X I helped with is Rosetta (or was, as Apple dropped it from the Lion 10.7 release of OS X). Rosetta dynamically (i.e. on-the-fly) translates PowerPC applications into Intel x86 code. There is no noticeable user interface: you double click your desired application, like any other, and, if needed, Rosetta is invoked to do its job in the background.

I have read many interesting web based discussions about Rosetta, several say, or imply, that it is a relatively simple piece of software: nothing could be further from the truth. It’s likely still a commercial secret how it works, but if it were simple, Apple’s transition to Intel would likely have been a disaster. It took a lot of smart people a long time to make the magic appear that simple.

I tried to keep DropAndCompute’s interface to the user as simple as possible, even where it added some complexity to its implementation. The National Grid Service in the UK did their own version of DropAndCompute, but, for my taste, added too many bells and whistles.

In Conclusion: I hope this brief essay has been of interest and given some insight into how many years of software/system design experience come to be applied, even to small software systems, both consciously and subconsciously, and always, hopefully, with good taste. Hide complexity, keep it simple for the user, make them think it is simply magic!

With a lot of attention these days (see here for instance) going to an argument between philosophers and physicists about the “Why is there Something rather than Nothing?” question, this is the perfect time for Jim Holt’s new book Why Does the World Exist? An Existential Detective Story. While the argument between Krauss, Albert and their fellow combatants was mind-numbingly dumb, boring, narrow, petty and ill-mannered, Holt’s discussion of the topic is brilliant, entertaining, and wide-ranging as well as generous in spirit to all points of view. The only unfortunate thing here is that the book won’t be out until July. I’ve checked with him though, and he doesn’t mind if I write about it now, since I just read an advance copy. In July I’ll try to remember to repost this.

Holt first sets the stage by explaining some of the history of the question “Why is there Something rather than Nothing?” and why it’s one he finds compelling (as well as explaining why one might reasonably think otherwise…). He first ran across the question as a high school student fascinated by Existentialism and trying to read Heidegger’s Introduction to Metaphysics.

(Personal digression:

Around the same time I was also trying to read that book as a college freshman. I just found my old copy, where I underlined lots of things that seemed of significance at the time, as well as putting exclamation points around the paranoid nationalist ravings that appear at one point. I soon decided Heidegger wasn’t for me, and some years later learned of a personal reason to dislike him, see this from the Wikipedia entry on Heidegger and Nazism:

Heidegger also denounced or demoted several colleagues for being insufficiently committed to the Nazi cause.

On September 29, 1933, Heidegger leaked information to the local minister of education that the chemist Hermann Staudinger had been a pacifist during World War I. Heidegger knew this would cost Staudinger his job. The Gestapo investigated the matter and confirmed Heidegger’s tip. Asked for his recommendation as rector of the university, Heidegger secretly urged the ministry to fire Staudinger without a pension.

Hermann Staudinger was my great-uncle (on my father’s side of the family). Despite Heidegger’s efforts, he managed to keep his job, survived the war, and went on to win a Nobel prize. I never really got to know him since he died when I was rather young, but got to know very well his widow, my great-aunt Magda. Decades later, she was still quite upset by the Heidegger business.

End of personal digression.)

Holt then moves on to contemporary thinker’s takes on the subject, including entertaining descriptions of his trips to visit some of them, starting with some philosophers. These include Adolf Grünbaum who takes the position (to which I’m sympathetic…) that this is a pseudo-problem, and derisively refers to worries about Nothingness as the “ontopathological syndrome”. Another visit is to Richard Swinburne at Oxford, who goes for the “God did it” explanation.

The first physicist he visits is David Deutsch, also at Oxford, and Holt’s description of the experience and account of their conversation is quite wonderful. As you might expect, lots about the deep significance of quantum physics and Many-Worlds. After a discussion of Robert Nozick and his principle of fecundity (“all possible worlds are real”), it’s on to Alexander Vilenkin and the cosmological multiverse mania that has gotten so much attention from physicists in recent years. Here the sort of “something from nothing” that Krauss was discussing in his recent book comes into play.

The most intellectually powerful figure Holt talks to might be Steven Weinberg, who has this to say about the multiverse:

“Vilenkin is a really clever guy, and these are fascinating conjectures,” Weinberg said. “The problem is that we have no way, at present, of deciding whether they’re true or not. It’s not just that we don’t have the observational data – we don’t even have the theory.”

and this about string theory:

When I brought up string theory, a melancholy strain became detectable in Weinberg’s voice. “I was hoping that with string theory things would fall into place much more rapidly than they have,” he said. “But it’s been rather disappointing. I’m not one of those people who bad-mouth string theory. I still think it’s the best effort we’ve made to step beyond what we already know, but it hasn’t worked out the way we were expecting it would.”

About Susskind’s claims that the Many-Worlds and string theory multiverses may be one and the same, Weinberg is having none of it, describing the two ideas as “completely perpendicular” and saying:

“I found it [Susskind's claims] puzzling too,” he said. “I’ve spoken to other people about it, and they don’t understand it either”… “I don’t agree with Susskind on that,” Weinberg told me, “and I don’t know why he said it.”

The discussion with Weinberg brings up the whole question of a “Final theory”, a truly unified fundamental theory of physics, and what its significance for the question of existence might be. After Weinberg, Holt describes a meeting with Sir Roger Penrose, and explains Penrose’s “Platonism”, the philosophical point of view that mathematical objects actually are real things that exist (in some sense…). Penrose attempts to also bring the question of consciousness into this, which seems to me a mistake, but the questions raised here about the relation of mathematics and our fundamental ideas about the physical world are dear to my heart. To the extent that to me there’s a sensible question behind “Why is there Something rather than Nothing?”, it’s bound up with this great mystery of the origin of the fundamental laws of physics. Mathematics and physics have a completely unexpected and still not understood congruence at their deepest levels, and this mystery seems to me not only a very real one, but one that we can hope to further elucidate. I realized from Holt’s discussion that maybe my own mystical views on this subject are best described as “Pythagorean”. While he does a reasonable job of raising some of these issues, to me he dismisses them too quickly in favor of moving on to other topics much less worth taking seriously. But I would think that, wouldn’t I?

The later part of the book reverts to the philosophers. For his discussion with John Leslie about “axiarchism”, you can watch the two of them here on Bloggingheads. His final philosophical encounter is with Derek Parfit, in the imposing venue of All Souls at Oxford. Novelist John Updike is his last interviewee, and Updike also isn’t so happy with string theory:

“But this whole string theory business… There’s never any evidence, just mathematical formulas, right? There are men spending their whole careers working on a theory of something that might not even exist.”

Holt ends the book on a personal note, telling the story of the death of his mother and his return to the place he grew up. Throughout the book, he weaves in accounts of time spent in Paris, reading at Sartre’s Cafe de Flore, and wandering the city contemplating aspects of his great philosophical question, as well as life in general. Some might find this distracting and not so serious, but I enjoyed those parts of the book a lot. Of course, this may largely be due to the fact that I’m a sucker for Paris and know well and love the locations he was describing.

If you have even the slightest interest in the “Why is there Something rather than Nothing?” question, be sure to get yourself of a copy of this wonderful book when it comes out. My interest in the question has always been rather minimal (I got grief from some of my commenters recently for my dismissive attitude on the topic), but this didn’t keep me from getting a lot out of the book. It’s philosophy of a high level, pursued in an unusual and personal manner, and it’s a pleasure to follow along with the author as he tells a fascinating and thought-provoking story.

Baron Münchhausen is famous for his tall tales. My co-author Konstantin Knop wants to rehabilitate him and so invents problems where the Baron is proven to be truthful from the start. We already wrote a paper about one such problem. Here is a new problem by Konstantin:

Kostya has a black box, such that if you put in exactly 3 coins of distinct weights, the box will expose the coin of median weight. The Baron gave Kostya 5 coins of distinct weights and told him which coin has the median weight. Can Kostya check that the Baron is right, using the box not more than 3 times?

Actually, Konstantin designed a more complicated problem that was given at the Euler Olympiad, 2012 in Russia.

Let n be a fixed integer. Kostya has a black box, such that if you put in exactly 2n+1 coins of distinct weights, the box will expose the coin of median weight. The Baron gave Kostya 4n+1 coins of distinct weights and told him which coin has the median weight. Can Kostya check that the Baron is right, using the box not more than n+2 times?

Note that Kostya can’t just put 4n+1 coins in the box. The box accepts exactly 2n+1 coins. The problem that I started with is for n = 1. Even such a simple variation was a lot of fun for me to solve. So, have fun.

This week at the University of Pittsburgh the Phenomenology 2012 Symposium has talks reviewing the current situation in particle physics phenomenology. Not much new, but there is one plenary talk on string phenomenology, Cumrun Vafa’s Stringy Predictions for Particle Physics. Mostly this deals with Vafa’s ideas about F-theory “predictions” for the fermion mass and mixing matrices. Quite a few assumptions and rather little string theory (the predictions are “stringy”) goes into this, and except for the one recently measured neutrino mixing angle, these are all postdictions, not predictions. I suspect that most string theorists are no more sold on these as predictions of string theory than they are on Kane’s Higgs mass prediction. For example, Vafa’s colleague Andy Strominger in recent talks gives string theory an “F” in the area of making unambiguous testable predictions, and I assume he’s well aware of Vafa’s work.

Pre-LHC, Vafa had been claiming F-theory predictions for SUSY at the LHC (see for example here, here and here). The most dramatic one, the focus of the Harvard Gazette story, was for a stable stau. One of the papers linked to has various detailed calculations for what such an stau would look like, with typical masses around 200 GeV.

At the conference on Monday, this talk gives recent CMS results relevant to such an stau, listing new mass limits of 314 GeV for a “cascade-decay” scenario, 223 GeV for a “pair-produced” one. Vafa only briefly mentions SUSY at the end of his talk, with his final slide “We will wait to see if SUSY plays any role at the weak scale!” I’m guessing he’s getting resigned to the idea that the answer is probably No.

You proved a nice theorem, wrote up the paper and submitted it to a major computer science conference. Your paper was accepted! Congratulations. Now pay up. An author of every paper accepted at a CS conferences is expected to present that paper at the conference. To do so requires at the least paying the registration fees, travel and lodging to go the the meeting. That can easily run one to three thousand dollars (or more) depending mostly on how far you need to travel. You can use grant money for these expenses. Some conference offer support to those who need it, particularly students. CS departments will often help out if needed. Sometimes people pay out of their own pockets and, in any case, the funds come from limited pots that could have been used for other purposes. In the "old days" this was less of a problem. There were only one or two conferences relevant to one's field and you were probably going to those conferences anyway. Now as the field has grown and it has been harder to get your papers published in the strongest conferences, you may find yourself traveling just to give the talk. Even many major conferences don't draw many attendees who don't have papers in the conference. We haven't seen an outcry of these expenses, say compared to the outcry over the cost of digital library subscriptions. Perhaps we consider attending the conference a "reward" for getting published. We could just eliminate the conferences and publish the proceedings and post videos of talks, made at the home institutions, saving the field huge amounts of money. Then we could actually choose to attend conferences to meet people in our field instead of just talking at them.

Matt Strassler posts here about a recent panel discussion of phenomenologists talking about the implications of the latest results from the LHC. You can listen to the thing for yourself, and see what Matt has to say at his blog, but here are some things that I noticed from watching the discussion:

• I don’t recall string theory even getting mentioned once. The extent to which string theory is now agreed to be thoroughly irrelevant to LHC physics is kind of striking. The few people like Kane claiming otherwise are being ignored as an embarrassment. If evidence for SUSY or extra dimensions had shown up, this would be very, very different.
• Arkani-Hamed is probably the dominant personality in this field, and as Matt mentions, he embodies the conventional wisdom of the subject, expressing it at length and with brio. Back in 2005 he was claiming we would know whether SUSY solves the hierarchy problem within a year of LHC turn-on. Somewhat more than a year after LHC turn-on, in February 2011, he was saying that we’d have to wait until 2020. Now he’s putting it differently: it’s the “eleven and a halfth hour” for the idea of SUSY solving the hierarchy problem.

  The only remaining hope for this is that there’s a light stop, which has so far escaped detection, and gluinos just above the current bounds. He sounds willing to bet against this, and is arguing that the idea may soon be toast, to be finally put to bed as results from better stop searches come in over the next few months. If there’s no sign of SUSY in the 2012 data set, it sounds like he’s willing to concede that SUSY can’t be what stabilized the weak scale.

• On the other hand, he argues that a 125 GeV mass for the Higgs is evidence for SUSY. Here the argument is that such a low-mass Higgs must be an elementary scalar, not the sort of thing you get in technicolor or extra-dimensional models. “SUSY” is here equated with the SM, without comment. I’m not sure what the reason for this is other than the sociological reason that it’s the dominant remaining paradigm for BSM physics, I don’t see a positive scientific argument.

  The 125 GeV value is also described as uncomfortably inconclusive for the idea of SUSY explaining the hierarchy. It’s somewhat too high for this, but not so high as to make it impossible.

• If the SM continues unvanquished at LHC energies, it sounds like conventional wisdom will move to “it still has to be SUSY, even though our main motivation for SUSY is gone, since we don’t have any better ideas.” Best guess for the SUSY breaking scale will move up to be just high enough to be unobservable at the LHC.
• Clearly a lot of theorists are looking at the failure of the last quarter century of BSM ideas and trying to figure out what else they can work on. The idea of “back to working on QCD” was repeatedly mentioned. Arkani-Hamed has over the past few years dropped BSM work and moved to a radical speculative program about new ideas for QFT based on a different point of view about amplitudes. One of the speakers jokingly accused him of becoming a mathematician. Maybe that’s where things are going…

A LONG time (so long ago I was a guest poster, not a co-blogger) I posted about how calling things that are on You-Tube rare is odd since ITS ON YOU-TUBE! ANYONE in the world can look at it! I now have a Contrasting thought: Can something be well known if its not easily found on the web? Last week I posted a proof that the intersection of a CFL and a REG lang is CFL that did not use PDA's. I thought it was NOT new and indeed, the comments politely gave me the proper reference. So far, so good. But wait--- some of them called the proof Well Known. Can a proof be well known if its not on the web? The notion of a proof being well known has always been problematic since one wonders what the scope is.

1. Addition being commutative is well known but might not to my 5-year old niece. Someone emailed me that I should take this opp to teach her about noncommutative algebras.
2. Binary search is well known but might not be known to my (then) 8 year old great nephew. Some said I should use this opp to teach him logarithms.
3. Induction is a well known technique but it still puzzles some undergraduates.
4. The poly vdw theorem is well known among mathematically inclined high school students in Maryland but is not even that well known among combinatorists.

The point really is well known to who?. But now with the web we can ask a more focused question: Can you find it easily? The proof I posted was not one that I found on the web. So here is what I want your thoughts on:

1. Should we redefine our definition of well known to be that you can find it on the web easily?
2. If I were to make an article out of the three short notes on CFL's that I posted about, and submit to Math Archives, would that help the problem of what is easy to find or would it just clutter up Math Archives making things hard to find. (I would of course provide all references and make NO claim to originality.)
3. Should I post to Wikipedia?
4. Will the web ever replace asking someone who knows stuff?

A while ago I wrote here about a recent “conference of Nobel Laureates” convened by Jeffrey Epstein in the Virgin Islands. This was based upon stories in boston.com (Boston Globe) and marketwatch.com (Wall Street Journal), which were based upon this press release from Epstein’s foundation. The foundation also has stories about this on their web-site (see for instance here).

Looking into it more carefully, it appears that everything in the press release refers to something that happened not this spring, but back in 2006. More details about the 2006 event are in a piece by Lawrence Krauss at Edge.org. The pictures and quotes are the same as in the 2012 press release. Still available on-line here is a schedule of talks from the 2006 conference.

When I saw this I was wondering why it didn’t give a specific date for the conference, and how Epstein had gotten the same prominent people as in 2006 to return this year, despite his well-known problems with the law in the interim. I have no idea why the Epstein Foundation recently issued this peculiar press release.

Epstein is a rather curious story, for some background, see this New York Magazine profile from 2002, and this Harvard Crimson piece about him when he donated $30 million to establish a Program for Evolutionary Dynamics in the Harvard math department. At the time of the 2006 conference, Epstein was under investigation by the police for having hired under-aged women for sex, and he ended up serving 13 months in prison as a result. He was arrested soon after the conference. Some recipients of donations from Epstein returned the money, but not Harvard.

I started working with David Pennock on prediction markets back when we both were at the NEC Research Institute in New Jersey a decade ago. After a major reorganization the dropped basic research from their mission, I went back to academics but David stayed in industry research first at Overture which soon was swallowed up by Yahoo. He ended up at Yahoo Research New York in a small but amazingly strong research lab including machine learning theorist John Langford and social scientist Duncan Watts. But with a new Yahoo CEO and Prabhakar Raghavan and Andrei Broder's departures for Google, it  became clear that the days of Yahoo research were numbered. 

Once upon a time there was a land where the only antidote to a poison was a stronger poison, which needed to be the next drink after the first poison. In this land, a malevolent dragon challenges the country’s wise king to a duel. The king has no choice but to accept.

By bribing the judges, the dragon succeeds in establishing the following rules of the duel: Each dueler brings a full cup. First they must drink half of their opponent’s cup and then they must drink half of their own cup.

The dragon wanted these rules because he is able to fly to a volcano, where the strongest poison in the country is located. The king doesn’t have the dragon’s abilities, so there is no way he can get the strongest poison. The dragon is confident of winning because he will bring the stronger poison.

The only advantage the king has is that the dragon is dumb and straightforward. The king correctly predicts what the dragon will do. How can the king kill the dragon and survive?