Thibault Damour and I have just put out a new paper on using Lunar Laser Ranging to test for spatial variations of the fundamental couplings. Recently there has been a paper which claims to find a spatial gradient in the fine structure constant. If the fine structure constant has a gradient, the mass of objects will be different in different locations since the mass depends on alpha, leading to a force in the direction of the gradient. And this effect will be different for different objects because of their different compositions. Amazingly, Lunar Laser Ranging is competitive for finding the gradient in alpha by measuring the differential forces on the earth and the moon, as they can now measure the distances to millimeter level precision! This work was a quick project using our past work on composition dependence. It was fun to learn many new aspects of the orbit problem from Thibault.

I recently had some nice news – also noted here. I would like to thank all my students and collaborators for sharing their work with me, and also thank the people who nominated me for this, and those eminent folks who wrote letters on my behalf.