Visiting LBNL

I’ve been traveling this week, giving a talk at Lawrence Berkeley National Laboratory, so this will be a short post.

In my experience, most non-scientists don’t know about the national labs. In the US, the majority of scientists work for universities, but a substantial number work at one of the seventeen national labs overseen by the Department of Energy. It’s a good gig, if you can get it: no teaching duties, and a fair amount of freedom in what you research.

Each lab has its own focus, and its own culture. In the past I’ve spent a lot of time at SLAC, which runs a particle accelerator near Stanford (among other things). Visiting LBNL, I was amused by some of the differences. At SLAC, the guest rooms have ads for Stanford-branded bed covers. LBNL, meanwhile, brags about its beeswax-based toiletries in recyclable cardboard bottles. SLAC is flat, spread out, and fairly easy to navigate. LBNL is a maze of buildings arranged in tight terraces on a steep hill.


I forgot to take a picture, but someone appears to have drawn one.

While the differences were amusing, physicists are physicists everywhere. It was nice to share my work with people who mostly hadn’t heard about it before, and to get an impression of what they were working on.


4 thoughts on “Visiting LBNL

  1. kashyap vasavada

    Hi! I understand you are Amplitudeologist and do calculations involving novel field theories on gravitons. Recently, from links on Motls’ blog, I saw two u-tube talks: one by Nima and the other by Paddilla. Both mentioned an elegant Virasoro-Shapiro type gamma function formula for two graviton scattering which is still standing firm after 45 years of research! I would like to know if your calculations, agree with this formula in some limits or are higher order corrections to it etc.


    1. 4gravitonsandagradstudent Post author

      So, the version you’re talking about is the answer from string theory. It’s also the only one we know of that behaves sensibly at high energies. It’s also a first-order thing: if you’ve seen my posts talking about loops, that nice amplitude with the gamma functions is just at tree level, the loop corrections make things more complicated.

      I’ve done a little work involving theories with gravitons, but not a lot, most of the theories I work with aren’t theories of gravity. I am working on a gravity-related project now, but it’s a bit of a weird case: using amplitudes to do calculations for classical (not quantum, but still general relativity) gravity.

      In general, the low-energy limits of string theory amplitudes like that one give amplitudes in gravity theories. Whether it’s easy to take that limit from the string theory amplitude varies depending on what you’re trying to do. Once loops start getting involved, the gravity answer has divergences which the string theory answer cures.


  2. Doug C.

    Sorry, but the overwhelming majority of scientists work for industry, not academia or DOE labs. Perhaps you mean physicists when you say scientist.


    1. 4gravitonsandagradstudent Post author

      Fair enough. In retrospect I was probably thinking about high energy physics. That said, it’s not obvious to me that the majority of scientists in general work in industry: there are certain fields where industry employs a lot of scientists (chemistry, molecular biology, any physics that deals with materials) but others where it’s a much smaller presence (industrial psychology is a thing, but I can’t imagine it employs more people than academia). On the other hand, the fields with an industry presence are typically larger ones, so eh.



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