Monday, June 24, 2013

Timescales, averaging, and baseball

Please pardon the summer blogging slowdown - it's been a surprisingly busy couple of weeks, between an instructor search, working on papers, proposal stuff, and trying to write more on my big long-term project. 

Thanks to an old friend for pointing me to this link, which does a great job looking at why a knuckleball is so erratic in its flight from pitcher to batter.  For non-Americans:  In baseball, a pitcher throws a ball to a catcher, while a batter attempts to hit the ball.  There are several types of pitches, depending on the pitcher's grip on the ball (which has seams due to the stitching that holds the leather cover on), the throwing motion, and the release.  A fastball can reach speeds in excess of 100 mph (161 kph) and typically spins more than 1000 rpm.  In contrast, a knuckleball can drift by the batter at a leisurely 70 mph yet be nearly unhittable because of its erratic motion.   A knuckleball barely spins, so that it may complete only 1-2 revolutions from leaving the pitcher's hand to reaching the batter.  This means that the positioning of the seams is absolutely critical to determing the aerodynamics of the motion, and no two knuckleballs move the same way.  In physics lingo, a knuckleball has almost none of the orientational averaging that happens in basically every other pitch.  I propose the definition of a new dimensionless parameter, the Wakefield number, \(W\), that is the ratio of the ball's period of revolution to its time-of-flight from pitcher to batter.   A knuckleball is a pitch with \(W \sim 1\).

Friday, June 14, 2013

Come on, PRL editors.

I rarely criticize papers.  I write this not to single out the authors (none of whom I know), nor to criticize the actual science (which seems very interesting) but to ask pointedly:  How did the editors of PRL, a journal that allegedly prizes readability by a general physics audience, allow this to go through in its current form?  This paper is titled "Poor Man’s Understanding of Kinks Originating from Strong Electronic Correlations".  A natural question would be, "Kinks in what?".  Unfortunately, the abstract doesn't say.  Worse, it refers to "the central peak".  Again, a peak in what?!   Something as a function of something, that's for sure. 

Come on, editors - if you are going to let articles be knocked from PRL contention because they're "more suitable for a specialized journal", that obligates you to make sure that the papers you do print at least have titles and abstracts that are accessible.  I'm even a specialist in the field and I wasn't sure what the authors were talking about (some spectral density function?) based on the title and abstract.

The authors actually do a good job explaining the issue in the very first sentence of the paper:  "Kinks in the energy vs. momentum dispersion relation indicate deviations from a quasiparticle renormalization of the noninteracting system."   That should have been the first sentence in the abstract.  In a noninteracting system, the relationship between energy and momentum of particles is smooth.  For example, for a free electron, \( E = p^{2}/2m \) where \(m\) is the mass.  In an ordinary metal (where Fermi liquid theory works), you can write a similar smooth relationship for the energy vs. momentum relationship of the quasiparticles. Kinks in that relationship, as the authors say, "provide valuable information of many-body effects".  

Wednesday, June 12, 2013

Academic self-sabotage

Ordinarily I wouldn't just post a link, but this article ("Self-Sabotage in the Academic Career: 15 ways in which faculty members harm their own futures, often without knowing it") from the Chronicle of Higher Education is exceptionally good advice for new faculty members.  While several of the points are specific to academia, some are generalizable to any career within a moderately large organization. 

Friday, June 07, 2013

The state of "molecular electronics"

For those interested in the history and current state of "molecular electronics", I refer you to the latest focus issue of Nature Nanotechnology.  Good news for those without subscription access - some good articles are available free of charge:

Wednesday, June 05, 2013

Rescheduled, Workshop on Surface Plasmons, Metamaterials, and Catalysis

Three of my colleagues and I are helping to organize a workshop at Rice University on October 21-23, 2013.   (This had originally been planned for May, but sequester-related travel restrictions on the government participants among other things forced a rescheduling.)  The goal of this ARO-sponsored workshop is to explore the opportunities for chemical catalysis arising from recent advances in the fields of metamaterials and plasmonics.  The workshop will bring together scientists from the disciplines of electrochemistry, catalysis, and plasmonics, which have not traditionally had a common platform.

The confirmed invited speakers are:

Rick Van Duyne - Northwestern University
Paul Bohn - University of Notre Dame
Martin Moskovits - University of California, Santa Barbara
Katherine Willets - University of Texas at Austin
Jennifer Dionne - Stanford University
Mark Brongersma - Stanford University
Louis Brus - Columbia University
Harry Atwater - California Institute of Technology
John Yates - University of Virginia
Mengyan Shen - University of Massachusetts, Lowell
Suljo Linic - University of Michigan
Mostafa El-Sayed –- Georgia Tech
Tom Mallouk –- Penn State

Topics include:

  • The state of the art in plasmonics, metamaterials, and chemical catalysis
  • Areas of catalysis that could benefit from enhanced optical/electromagnetic concepts
  • Concepts for nanophotonic- and metamaterials-driven catalysis and heat generation
  • Surface nanoengineering to merge nanophotonics and catalysis
  • Quantum plasmonics
  • Hot electrons driving chemistry
  • Chemical sensing using nanophotonic and plasmonic concepts
  • Nanophotonic characterization of catalytic structures:  Where do the reactions happen, and how fast?
The deadline for abstract submission is July 21, 2013, and space is limited.  The workshop website is here:  .

Please feel free to distribute this information to people that would be interested!