2012 Many-Core Developer’s Conference

On 5 December, I attended the UK Many Core Developer’s Conference (UKMAC 2012), a supercomputing conference organized by Simon McIntosh-Smith. I gave a presentation & demo of danceroom Spectroscopy, with emphasis on the algorithms and heterogeneous parallelization strategies we’ve implemented to build it (see video above). There were several interesting presentations, including: Adapteva’s Andreas Olofsson keynote lecture about designing small, energy-efficient parallel architectures; Alan Gray (Edinburgh, EPCC) talking about scaling soft matter physics code to more than one thousand (!) GPUs; Zheng Wang (Edinburgh) talking about auto-generating OpenCL code from OpenMP pragmas; and Pedro Gonnet (Durham) talking about task-based parallelization algorithms applied to molecular dynamics simulations.

London Art Premier!

So here’s a funny thing for a scientist to announce… My premier on the London arts scene! It takes place over the 3rd-4th November at the Barbican Arts Centre! The interactive quantum dynamics project that I dreamed up almost two years ago, danceroom Spectroscopy (dS for short), is headlining a (FREE!) Barbican-wide arts festival called Natural Circuits. The installation will run both days from 11 am – 7 pm. Interspersed throughout will be six performances of Hidden Fields (three each day), our genre-defying dance performance – where the movement of dancers’ energy fields actually control the sounds and graphics generated within the piece. If you’re in town, drop by!

Non-equilibrium quantum states in atmospheric chemistry

O2 “intercepting” an atmospheric pollutant molecule. Hot orange and cool blue colors show molecules in high and low energy quantum states, respectively.

Today’s issue of Science magazine includes a report I wrote with an international team based across Leeds, Cambridge, and Chicago.

Earth’s atmosphere is a huge chemical reactor where sunlight (rather than heat) starts off chemical chain reactions that ultimately control the fate of greenhouse gases and atmospheric pollutants.

Within the atmosphere, one of the most important classes of chemical reactions are so-called “association reactions”, where one molecule (call it A) reacts with another molecule (call it B). Chemical physicists have known for a long time that molecules can exist in both high energy and low energy quantum states, oftentimes referred to as “equilibrium” and “non-equilibrium” states, respectively. For arbitrary A + B reactions taking place in the Earth’s atmosphere, the nearly universal assumption is that, prior to reaction, both A and B are in their equilibrium states.

Earth’s atmosphere is composed of lots of O2, meaning that O2 participates in most atmospheric reaction sequences. Contrary to the assumption that atmospheric association reactions always involve reactants in equilibrium states, our paper shows that, for association reactions of the type O2 + B (leading to peroxy radicals), there is a high probability that O­2 “intercepts” B before its non-equilibrium quantum states have relaxed to equilibrium. Our paper shows that this occurs during the atmospheric degradation of acetylene, which is an important tracer of atmospheric pollution and also participates in formation of atmospheric particulates. Interestingly, the products produced when O2 intercepts another molecule’s non-equilibrium quantum states are different from those produced when the states are in equilibrium.

Using a detailed mathematical model to calculate how fast non-equilibrium quantum states relax to equilibrium, our paper speculates that the interception of non-equilibrium quantum states by O2 is likely important for a range of chemical reactions in Earth’s atmosphere, with possibly unexpected chemical reaction outcomes.

Ultimately, this work improves our fundamental understanding of the microscopic chemical physics driving peroxy radical formation – amongst the most textbook reactions in atmospheric chemistry. It also paves the wave for further studies of how nature harnesses non-equilibrium effects.

London 2012 Olympic Art Installation

The team and I just got back from running our interactive quantum mechanics art installation “danceroom Spectroscopy” as part of the London 2012 Olympic events! It was awesome! We put it in an immersive 360 degree projection dome (19 meter diameter). Professor Vader, our custom-built 12-core supercomputer (who also has 2048 graphics cores) managed to run seven 3d capture cameras and talk to six graphics outputs, meanwhile doing sonic analysis, graphics rendering, and solving equations of motion for 10,000 quantum particles – all in real-time!  We also ran a dance performance of Hidden Fields, which is the show that we’ve been developing using the danceroom Spectroscopy technology. Stay tuned for some video footage…

Faraday Discussion 157 – Assisi, Italy

I just got back from Assisi (the famous birthplace of St. Francis), having attended a Faraday Discussion on “Molecular Reaction Dynamics in Gases, Liquids, and Interfaces”. Faraday discussions have a rather unique format, and I enjoyed this one. I met several people I’d never met before, including Martin Gruebele, Stephen Bradforth, Kopin Liu, and Don Truhlar. I also got to chat with some of the fathers of the field of reaction dynamics: Dick Zare, and Nobel Prize Winner John Polanyi!