Thursday, March 27, 2014

Letter from Middletown

I'm in Middletown, CT, this evening having just given the mathematics department colloquium at Wesleyan University.

Wesleyan is a medium sized liberal arts college which supports a PhD-granting science and math program.  My invitation was an unusual one.  It said, "We'd like to hear about your research in geometry and we'd also like to hear about your ideas on sustainability education." So I tried to come up with a one-hour talk that would combine both themes into some kind of conceptual unity.  In the end I just went with a one-word title: Growth.

I started off talking about the old chessboard legend: you know, the one where the king promises to reward the inventor of chess by granting him whatever he may desire, and the savvy inventor asks with pretended modesty for just one grain of rice on the first square of the chessboard, two on the second, four on the third, and so on.  That and so on conceals the terrifying power of exponential growth which by the 64th square would demand a rice mountain five miles high - half a trillion tons of rice or about 1000 times the amount produced each year everywhere on earth.

I went on to consider the superficial geometry of exponential growth: the fact that there is no "deep inside"   an exponentially growing system, it is all "on the surface", and the expression of this through uniformly bounded homology and Ponzi schemes.  I talked about some research mathematics here, with a bit of discussion of the index theorems that showed up in my thesis.   But then I veered back to talk about growth in the usual "economic" sense, and my perception that mathematical educators owe it to our students to give them the conceptual tools to consider whether or in what sense growth can go on for ever, and what (if anything) might come afterwards.

I've never tried to give a talk like this before.  I felt that it went pretty well, and I made some good connections; I need to let it settle though.  Meanwhile here is a link to the slides.  And if any other math department would like to invite me to give some version of this talk, I'm happy to do so!

Photo of Wesleyan University by Flickr user AmandaB3, licensed under Creative Commons

Monday, March 24, 2014

Penn State Zero

Jon Brockopp and Sylvia Neely from PAIPL have gotten involved in a new initiative - Penn State Zero.

Reposting from the blog "Spring Creek Homesteading":

A group of five faculty members including Brockopp (History and Religious Studies), Neely (History, retired), Ray Najjar (Meteorology), Andy Lau (Engineering Design) and Leland Glenna (Rural Sociology)  began meeting monthly in October 2013 to discuss two key questions:
  1. “Why isn’t Penn State’s president a signatory to the American College & University Presidents’ Climate Commitment?”
  2. “How can our small committee get more faculty and administrators interested in and educated about climate change so that they can influence the president to sign on?”
Read the rest here

Thursday, March 20, 2014

Book Review: "Atomic Accidents"

Points of Inflection has been silent for nearly two months.

I'm sorry about that.  It's been a helpful discipline to try to blog here regularly, but several unpredictable things have combined to consume a bit too much of my time recently.  I'm trying now to get back to a more regular (but probably still slow) posting schedule.

I recently read the book Atomic Accidents by James Mahaffey.  Mahaffey was a senior researcher at Georgia Tech and his book is a clear-sighted, technically detailed and yet also readable and witty account of the quest to obtain safe, clean energy from nuclear fission and the numerous ways in which safety mechanisms carefully devised by human beings have been circumvented, undermined or just messed up by other human beings (or sometimes even the same ones); quite often with fatal consequences.  From the disasters of the radium-dial factories, through the Manhattan Project and the early attempts at civilian nuclear power, to the headline-grabbing accidents at Chernobyl and Fukushima, this book covers a lot of historical ground.  Many accidents are described in extensive technical detail - though nuclear processes have many frightening features, Mahaffy believes that the instinct for secrecy, arising from military nuclear programs, has not helped teh civilian nuclear industry, and that more information may reduce unfounded anxiety.  I wonder whether he is right?

Because, for all his encyclopedic knowledge of nuclear accidents and foolishnesses, Mahaffy is a (carefully qualified) proponent of nuclear energy.  His thoughts on this can be found throughout the book, especially in its final chapter, Caught in the Rickover Trap.  Admiral Hyman Rickover devised the propulsion system for US nuclear submarines and his water-cooled reactor design, scaled up by two orders of magnitude or so, is the basis for most nuclear power stations today.  "There have been trillions of problem-free watt-hours generated by scaled-up Rickover plants", writes Mahaffy, "but there may be a problem area that was not evident when submarine reactors were tiny 12-megawatt machines but that was revealed when the Rickover model was enlarged multiple times over for industrial use.  The reactor core, the uranium fuel pellets lined up in zirconium tubes and neatly separated from each other, is terribly sensitive  for such an otherwise robust machine... There have been many engineering fixes and modifications to correct these problems, but, ironically, these fixes can present new issues as they are complex add-ons, cluttering up an otherwise simple design... most of the plumbing in a nuclear plant has nothing to do with generating electricity.  It is part of the fix." 

The message of this final chapter is that the sheer bigness of the nuclear project may have led the nuclear industry to focus prematurely on one apparently effective design.  Perhaps there are other possibilities?  Mahaffy can tell us about the exotic reactor designs of the 1950s and 1960s (some arising from the crazy project to build a nuclear airplane).  Could these be revived as an alternative?  Some of them indeed do form the basis for the futuristic Generation IV nuclear plant proposals.   Some could perhaps be made much smaller - a large power plant would consist of many identical "modules" rather than one giant reactor.  Indeed, the message I took away from this book is that the major issues with nuclear power seem less technical than political: the size and complexity of the nuclear power process in relation to the societal "containment" within which it must necessarily operate.