Bell Labs: The development of gravitational lens mass tomography
The dark matter mass in a cluster of galaxies, reconstructed via gravitational strong and weak lensing data. The primary amazing result was that most of the dark matter mass is in a broad gaussian distribution, which is the same as the diffuse light in the cluster, not galaxies, showing that the dark matter dynamics had stripped stars from the galaxies.
Source: J. A. Tyson, G. P. Kochanski, and I. P. Dell’Antonio, “Detailed Mass Map of CL0024+1654 from Strong Lensing,” Astrophysical Journal 498, 1998, L107-110.
Reflections by J. Anthony Tyson
J. Anthony Tyson, “The Development of Gravitational Lens Mass Tomography” (.pdf, 383 kb)This article by Tony Tyson recounts the story of the “cosmic mirage,” in which he and colleagues at Bell Labs in the early 1980s leveraged new technology to image dark matter and probe the physics of the mysterious “dark energy.” Tyson obtained his PhD from the University of Wisconsin in 1967, undertook superfluid helium research at the University of Chicago from 1964 to 1967, and was offered a permanent position at Bell Labs as member of technical staff in 1969 after two years as postdoc at Chicago. At Bell Labs, he and others were given freedom to explore novel ideas.
In the early 1970s, Tyson and Bell Labs colleagues Laurie Miller, Allen Mills, and Ron Decker built a sensitive experiment to detect gravitational waves. This ignited an interest in astronomy. From the 1970s to the 1990s, Tyson applied charge-coupled devices (CCDs) to astronomy, undertaking the first deep optical surveys of the universe, together with John Jarvis. He discovered a population of distant galaxies (the “faint blue galaxies”) and then used their systematically distorted shapes to produce the first images of foreground dark matter concentrations: gravitational lens mass tomography. He pioneered this technique of weak gravitational lensing, publishing the first evidence of galaxy cluster mass measurement in 1990 with Bell Labs colleagues Frank Valdes and Rick Wenk. In 1996, Tyson proposed a new international facility to map tens of billions of galaxies with the goal of precision cosmology. This idea was ranked highly by the 2000 astronomy and astrophysics decadal survey, and the facility was named the “Large Synoptic Survey Telescope.” In 2007, Tony was elected to the National Academy of Sciences, and in 2000 the American Philosophical Society.
Tony Tyson left Bell Labs in 2003 to lead a new research group at University of California, Davis. He became founding director of the LSST, promoting the idea internationally. In 2007, he raised funds from Microsoft colleagues enabling fabrication of the special optics for LSST. In 2013, Tyson stepped down as LSST project director, assuming the job of Rubin Observatory chief scientist—-that year, the facility was renamed after astronomer Vera Rubin. Supported by the National Science Foundation and the Department of Energy Office of Science, in 2025 the observatory construction project was completed, and the first data revealed an unprecedented deep view of our Universe. The Legacy Survey of Space and Time sky survey began in 2026.
Cite this resource
J. Anthony Tyson, “The Development of Gravitational Lens Mass Tomography,” History of Bell Labs Physical Research, 1980–2006 collection, edited by Arthur Ramirez, Cherry Murray, and David Bishop, American Institute of Physics, 2026, https://www.aip.org/history/bell-labs-physical-research-1980-2006/gravitational-lens-mass-tomography.
