Brookhaven’s National Synchrotron Light Source, we would discover, is just that — a light source. And despite the differences in scale and the methods of production, it isn’t so different from the studio lights used by photographers. In each case, the way to get the best image is to shine a really bright light on the subject and take a picture of it. Indeed, the only respect in which the light source’s name can be misleading is that it does not confine itself to the visible light spectrum, but uses everything between infrared and x-rays.
Of course, the NSLS is not just a more-powerful-than-usual bulb. Rather, it consists of two rings, the larger of which isn’t much smaller than a football field, which house beams of electrons accelerated to high speeds. The main byproduct of this process is a fantastic excess of energy that radiates out from the ring in the form of bright light. Dozens of beamlines lead away from the ring at tangents, dividing the enormous building into discrete workspaces. When it’s running, scientists from nearly every discipline place detectors in the path of the illuminating rays so as to image a wide range of samples.
Only about 5% of the NSLS was dedicated to physics research in 2008. The highest concentration of users were in the life sciences, and we poked our head into an earth sciences lab working to recreate the conditions in our planet’s mantle. My impression is that this is the continuation of a pattern that began at least with the electron microscope: tools that were initially invented for work in physics or chemistry often turn out to be more heavily used by other disciplines.
When we visited, the NSLS was gearing up for the groundbreaking of the heavily publicized NSLS-II, which is exactly what it sounds like. This new light source will be the brightest on the planet – bright enough to properly expose a moving object on a tiny scale. Presently, the exposures required for a good image are on the order of minutes, not the fractions of a second required to observe processes that unfold over time (which is to say, almost all of them). This is particularly exciting for life scientists, who will finally be able to directly observe things like protein construction as they happen.