image: This is Roger Angel of the University of Arizona. view more
Credit: The University of Arizona
Roger Angel, director of the University of Arizona Steward Observatory Mirror Lab and Regents' Professor of Astronomy and Optical Sciences, will receive the Kavli Prize during a ceremony in Oslo, Norway, on Sept. 7. The eight laureates each will receive a scroll, a gold medal and their share of the $1 million prize for each of the three fields, astrophysics, nanoscience and neuroscience.
The Kavli gold medals were minted at Northwest Territorial Mint in Dayton, Nev., not far from Angel's home institution, the UA in Tucson, Ariz.
Each medallion measures just under 3 inches and is fashioned from 10 ounces of pure gold.
"It is very uncommon for a prize medal to be cast from pure, 24-karat gold," said Rob Vugteveen, a UA alumnus and project manager at Northwest Territorial Mint. "This means the gold used for the Kavli medal is 99.9 percent pure. Anything beyond that is only used for highly technical applications such as space missions."
The medal started out as an oversized sketch of Fred Kavli's portrait on the front side. Because of its intricate geometry, a computer design program was used to generate the design for the reverse side of the medal.
Using oil clay, the artist then handcrafted the portrait on a 9-inch circular base. A plaster "negative" was created, followed by a plaster "positive" for more finely finishing the portraiture.
The design was transferred and scaled down to actual size.
"Starting with an oversized mold and then reducing it enhances the detail in the finished medal," said Vugteveen, who graduated from the UA with a master's in geophysics in 1980 and served as director of marketing and outreach at the UA's Flandrau Science Center from 2002-07.
Similar in principle to a phonograph, a slowly rotating machine with a stylus called a pantograph scanned the oversized mold. The device simultaneously shrank and cut the design into a steel block to make a die of the proper size.
Using a hand-operated press, the medal dies were pressed into a lead blank for the resulting impression to be inspected. After minor touchups, the dies were heat-treated to harden them and mounted in a powerful hydraulic press to strike the gold medals.
"In this process, the blank that will become the medal is created by melting small bars of gold cast into a graphite mold to ensure the correct diameter," Vugteveen said. "This results in a blank, flat disk of pure gold."
"Because pure gold is very soft, much softer than say, a wedding band, the press does not need to use as muich pressure or as many blows as a bronze medal would require," Vugteveen said.
In addition to the Kavli Prize medals and numerous other high-end medallic art projects by Northwest Territorial Mint, its sister company, the Medallic Art Company, struck the inauguration medals for 11 American presidents – Theodore Roosevelt, Richard Nixon, George H.W. Bush, George W. Bush and Bill Clinton, to name a few.
Angel shares the Kavli astrophysics prize with Jerry Nelson of the University of California, Santa Cruz and Ray Wilson of the European Southern Observatory "for respective innovations in the field of telescope design that have allowed us glimpses of ever more distant and ancient objects and events in the remote corners of the universe," according to the foundation.
"Roger has revolutionized many fields in astronomy," said Peter Strittmatter, director of the UA's Steward Observatory. "He has pioneered techniques for measuring polarized light, resulting in discoveries like strong magnetic fields in white dwarfs, and he was the first to use optical fibers to allow astronomers to observe and analyze hundreds of objects in the sky at the same time."
As director of the Steward Observatory's Mirror Lab, Angel pioneered a revolutionary approach of producing mirrors for ground-based telescopes.
Angel created mirrors made of inexpensive borosilicate glass and molded them to incorporate a honeycomb pattern of holes, to reduce their weight and increase their rigidity, allowing the building of larger telescopes.
"Roger's great accomplishment in mirror design led to telescope mirrors that are lightweight and stiff and can quickly adjust to the cooler temperatures of an observing night," Strittmatter said.
"He also pioneered mirrors with a very steep curve," he said. "This shortens the telescope's focal length and allows for more compact telescopes that can be housed in smaller, cheaper buildings. In summary, Roger has optimized ground-based telescope design."
"He combines the courage to attempt new things with a deep understanding of physical principles, and this combination brings the success," Strittmatter said. "And, he does it all with great modesty."
Mirrors designed according to Angel's specifications have been or are about to be installed in more than 12 telescopes, including the Giant Magellan Telescope, whose first of seven 8.4-meter mirrors is currently being polished at the Steward Observatory Mirror Lab.
Angel is part of the second group of recipients of the biannual Kavli Prizes, following the successful launch of the awards in 2008. They were set up to recognize outstanding scientific research, honor highly creative scientists, promote public understanding of scientists and their work and to encourage international scientific cooperation. The prizes are a partnership of the Norwegian Academy of Science and Letters, The Kavli Foundation and the Norwegian Ministry of Education and Research.
The Kavli Prize was initiated by and named after Fred Kavli, founder of The Kavli Foundation, which is dedicated to advancing science for the benefit of humanity, promoting public understanding of scientific research, and supporting scientists and their work.