I am a Professor in the physics department at
UCSD, and the Associate Director of
CASS, the Center for
Astrophysics and Space Sciences.
From 2003–2020, I led the APOLLO project
as an ultra-precise test of General Relativity using the technique of lunar
laser ranging. My interests are transitioning to quantitative assessment of
the challenges associated with long-term human success on a finite planet.
See also the more polished bio on the CASS Website.
In 2014, I started a company (Aircraft Avoidance Systems) to provide
safety devices for observatories using lasers for scientific research.
Energy And Human Ambitions on a Finite Planet
I released a new textbook in March 2021 addressing the challenges facing
humanity this century relating to growth, energy resources, and human factors.
The book is available as a free PDF at eScholarship, and as a paperback (at print-cost) at
A page on this site is also provided for submitting corrections and other feedback.
Selected Publications (PDF)
BASH Compendium: collection of CASS e-mails from Nathan Johnson about weekly social hour
- Review of Lunar Laser Ranging: Reports on Progress in Physics, 76, p. 076901 (2013)
- Description of the APOLLO instrument: P.A.S.P., 120, p. 20 (2008)
- Millimeter Range Performance: Classical and Quantum Gravity, 29, 184005 (2012)
- Absolute Calibration System for APOLLO: Classical and Quantum Gravity, 34, 245008 (2017)
- Gravitomagnetism in the lunar orbit: Phys. Rev. Lett., 98, 071102 (2007)
- Gravitomagnetism perspective: Space Science Reviews, 148, 217, (2009)
- Finding the lost Lunokhod 1 rover: Icarus, 211, 1103, (2011)
- Degraded lunar reflector performance: Icarus, 208, 31, (2010)
- Eclipse observations confirm reflector dust: Icarus, 231, 183, (2014)
- Thermal effects on corner cube reflectors: Applied Optics, 51, 8793, (2012)
- Diffraction and polarization properties of corner cube reflectors: Applied Optics, 52, 117, (2013)
- A transponder-based aircraft detector (TBAD): P.A.S.P., 124, 42, (2012)
Do the Math Blog on Energy, Growth, Options
Have a Revolutionary Idea?
If you are contemplating sending your physics idea to me, first
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