| Birth Name: | James Roger Prior Angel |
| Birth Date: | 7 February 1941[1] |
| Birth Place: | St Helens, Lancashire, England |
| Nationality: | American, British |
| Fields: | Astrophysics, Optics |
| Workplaces: | Columbia University University of Arizona |
| Education: | Oxford (B.A., Ph.D.) |
| Known For: | Spin casting Lobster-eye optics Space sunshade |
James Roger Prior Angel (born February 7, 1941) is a British-American astrophysicist known for his contributions to astronomy and the design and fabrication of large optics for telescopes, solar power and other applications. He developed the spin casting and stressed lap polishing techniques used at the University of Arizona Richard F. Caris Mirror Lab to produce mirrors for some of the largest optical telescopes in the world.[1] [2] He is a Regents' Professor of Astronomy and Optical Sciences at the University of Arizona.[3]
Angel graduated from St Peter's College, Oxford, with a BA, in 1963, from California Institute of Technology, with an MS, in 1966, and from the University of Oxford, with a D Phil, in 1967.[1] While at Oxford's Clarendon Laboratory he built an early computer to allow for the first direct measurement an atom's quadrupole moment.[4]
He has taught at Columbia University. He is a Fellow of the Royal Society. He was elected a Fellow of the American Academy of Arts and Sciences in 1990.[5]
In 1979, he proposed the lobster-eye optics principle for X-rays.[6]
In 2006, Angel proposed assembling a space sunshade to mitigate global warming by placing trillions of 0.6-meter, 1-gram disks of refractive material into stable orbit between the Earth and the Sun (Lagrange point 1, or). The disks would be launched in stacks of 800,000 by electromagnetic acceleration and transported to (1.5 Gm from Earth) via ion propulsion. After separation the individual disks would remain in place by autonomously modulating solar radiation pressure. Together the cloud of disks would deflect 2% of solar radiation onto the Earth, enough to counteract the warming effect of a 100% increase in atmospheric carbon dioxide from pre-industrial levels. He concluded that such a sunshield "could be developed and deployed in ≈25 years at a cost of a few trillion dollars, <0.5% of world gross domestic product (GDP) over that time."[7]
On August 23, 2012, Angel and his inventions were the subject of a story on NPR's Morning Edition.[8]