Roger Angel, Regents' Professor of Astronomy and Optical Sciences at the University of Arizona, has been named as a fellow of the prestigious National Academy of Inventors.
"The University of Arizona is the only university capable of manufacturing mirrors for the largest telescope in the world, and that is because of the process developed here by Roger Angel several decades ago," said UA President Robert C. Robbins. "He is one of the greatest minds in space exploration and optical sciences, and his inventions have had an international impact. I am so proud to see his accomplishments honored in this way."
Angel began his professional career as an astrophysicist at Columbia University, studying collapsed stars and black holes. Shortly after joining the faculty of the UA, he developed an interest in large telescopes, inspired by the high-quality images produced by the Multiple Mirror Telescope on Mount Hopkins with its unique honeycomb mirrors. Angel began with professor Nick Woolf to explore innovations in large telescope construction.
Previous large telescope mirrors were very heavy and retained heat, with the warm air rising from them causing blurred images. Angel founded what is today the Richard F. Caris Mirror Lab, where he pushed the frontiers of large mirror making by using a honeycomb sandwich structure to greatly reduce the weight and using fans to keep the glass voids cool in operation. He perfected the art of spincasting molten glass into a honeycomb mold, allowing centrifugal force to spin out the glass to naturally form a deep paraboloidal shape. This reduced the many tons of glass that otherwise would need to be ground away to achieve the desired surface figure. The lab now makes the largest telescope mirrors on the planet, 27 feet in diameter.
Polishing such large mirror surfaces would take a long time using conventional techniques, so, along with Buddy Martin, Angel developed computer-controlled flexible polishing tools and high-precision testing methods that enable the Mirror Lab to achieve extremely accurate and smooth mirror surfaces. The sum of these advances has profoundly increased the ability to see farther into the universe with the greatest of clarity.
Angel also perfected the manufacture of very thin glass secondary telescope mirrors whose shape can be rapidly adjusted to compensate for the effects of atmospheric turbulence, a technique that is used in combination with the large primary mirrors to make the sharpest images from the ground — as much as 10 times sharper than those from the Hubble Space Telescope.
Angel's innovative spirit reaches beyond academia and into the realm of real-world problem solving. His graduate students and postdoctoral colleagues advanced scientific learning and discovery and have been inventive as well as entrepreneurial. Angel has inspired further improvements in astronomical telescopes and instruments, as well as in the field of optical science. For example, he and then-student John Hill pioneered a way to greatly speed up astronomical observations by using optical fibers to pick out hundreds of stars or galaxies and analyze them individually all at the same time. This method is widely used and played a central role in the recent discovery that the expansion of the universe is accelerating.
According to Buell Jannuzi, director of the UA's Steward Observatory, "Roger's ability to deliver transformative technological innovations through the application of his deep understanding of physics and engineering are awe-inspiring."
In the past decade, Angel's interests have turned to solving worldwide challenges, including global warming and sustainable clean energy. With his understanding of optics, he devised a more efficient method for photovoltaic solar energy generation, using mirrors to concentrate sunlight onto super-efficient PV cells.
In 2009, Angel founded a company, REhnu, to transform these inventive designs into commercially feasible power generation systems. All along the way, he has hired and inspired electronics engineers, mechanical engineers, technicians and students.
"It's been exciting working with Dr. Angel on commercializing his inventions and supporting REhnu," said Doug Hockstad, assistant vice president of Tech Launch Arizona, the office of the UA that commercializes inventions stemming from research. "We look forward to our ongoing collaboration with him to bring the results of his research to the market."
"Roger Angel is an inventor in a class by himself," said Kimberly Andrews Espy, the UA's senior vice president for research. “He exemplifies the creative spirit of research at the UA. Not being constrained by contemporary wisdom, he has developed countless innovative technologies that transform our scientific understanding. In the case of his design for the world's largest mirrors, we are unlocking the mysteries of the creation of the universe and will have the power to detect life on other planets. His insights into how to capture and harness light is generating the next generation of solar power innovation. The University of Arizona is very proud of Roger's boundless research accomplishments — and pleased to see his work recognized by NAI."
Angel continues to find solutions to problems, and many of his students have contributed to the novel aspects of those inventions. He is leading the next generation toward creative problem solving through commercially viable inventions, with more than a dozen U.S. patents issued or in process, mostly in the solar energy field.
Angel is a member of the National Academy of Sciences and the American Academy of Arts and Sciences, a fellow of the Royal Society, a MacArthur Fellow (1996-2001), an honorary fellow of St. Peter's College, Oxford University (1993) and a recipient of the Kavli Prize in Astrophysics (2010).