UCLA's Andrea Ghez, Terence Tao elected to American Philosophical Society
Renowned UCLA scientists Andrea Ghez, a professor of physics and astronomy, and Terence Tao, a professor of mathematics, have been elected to the American Philosophical Society, the country's oldest learned society, which recognizes extraordinary achievements in science, letters and the arts.
Founded in 1743 by Benjamin Franklin, the society's members have included George Washington, John Adams, Thomas Jefferson, James Madison, Charles Darwin, Marie Curie, Albert Einstein, Thomas Edison, Louis Pasteur, Linus Pauling and Margaret Mead.
Next week, Ghez and Tao will be in Lund, Sweden, for another honor: Each will receive the Royal Swedish Academy of Sciences' prestigious Crafoord Prize in the presence of the king and queen of Sweden. The prize recognizes extraordinary achievements in mathematics, astronomy and other fields.
Joseph Rudnick, dean of the UCLA Division of Physical Sciences, has called Ghez and Tao "two of UCLA's true superstars — indeed, two of the world's intellectual superstars."
Since 1995, Ghez has used the W.M. Keck Observatory, which sits atop Hawaii's dormant Mauna Kea volcano and houses the two largest telescopes in the world, to study the rotational center of the Milky Way and the movement of hundreds of stars close to this galactic center. She holds UCLA's Lauren B. Leichtman and Arthur E. Levine Chair in Astrophysics.
Tao, who holds the James and Carol Collins Chair in the UCLA College of Letters and Science, has said that we are living in a "golden age for mathematics" and that mathematics has become much more collaborative and interdisciplinary than in the past. He also said he learns much from the feedback he receives from other mathematicians on his mathematics blog.
Ghez, who was selected as a 2008 MacArthur Fellow, among many other prestigious honors, uses novel, ground-based telescopic techniques to identify thousands of new star systems and illuminate the role of supermassive black holes in the evolution of galaxies.
In 1998, she answered one of astronomy's most important questions, showing that a monstrous black hole resides at the center of our Milky Way, some 26,000 light-years away from Earth, with a mass more than 3 million times that of the sun. The question had been a subject of raging debate among astronomers for more than a quarter of a century.
One reason astronomers had been unable to determine whether a black hole was at the galactic center is that the Earth's atmosphere distorts the images of stars.
Ghez used a technique she refined known as speckle interferometry, which involves taking thousands of very quick, high-resolution snapshots that correct for these distortions. She has developed algorithms — specific computer commands based on sophisticated mathematics — and software for analyzing the data.
While traditional imaging techniques at the center of the galaxy cause the stars closest to the galactic center to look fuzzy and indecipherable, Ghez's technique improves the resolution by a factor of at least 20.
In 2000, Ghez and colleagues reported that for the first time astronomers had seen stars accelerate around a supermassive black hole. Their research demonstrated that three stars had accelerated by more than 250,000 mph a year as they orbited the black hole at the center of the Milky Way. They also reported, based on five years of measurements, that the star closest to the black hole had turned a corner in its orbit.
In 2005, Ghez and her colleagues took the first clear picture of the center of the Milky Way, including the area surrounding the black hole, using laser guide star adaptive optics technology at the Keck Observatory.
She said of the Keck Observatory, "it is why I came to UCLA and why I stay at UCLA."
She and her research team have benefited significantly from the Preston Family Endowed Graduate Fellowship in Astrophysics, supported by Howard and Astrid Preston.
Tao, the first faculty member in UCLA's history to win the prestigious Fields Medal, often described as the Nobel Prize in mathematics, is widely considered one of the world's leading mathematicians.
He has received numerous national and international honors, including a MacArthur Fellowship and the National Science Foundation's Alan T. Waterman Award, the highest honor the NSF bestows. He was named among the "Best Brains in Science" by Discover magazine, which praised him as "one of the most prolific and esteemed mathematicians in the nation," and was honored as one of science's "Brilliant 10" by Popular Science magazine, which called him "math's great uniter," to whom "the traditional boundaries between different mathematical fields don't seem to exist."
Discover magazine praised Tao's research on prime numbers, conducted with Ben Green, a professor of mathematics at the University of Bristol in England, as one of the 100 most important discoveries in all of science for 2004. A number is prime if it is larger than one and divisible by only itself and one. The primes begin with 2, 3, 5, 7, 11, 13 and 17.
Euclid proved that the number of primes is infinite. Tao and Green proved that the set of prime numbers contains infinitely many progressions of all finite lengths. An example of an equally spaced progression of primes, of length three and space four, is 3, 7, 11; the largest known progression of prime numbers is length 23, with each of the numbers containing 16 digits. Green and Tao's discovery revealed that somewhere in the prime numbers, there is a progression of length 100, one of length 1,000, and one of every other finite length, and that there are an infinite number of such progressions in the primes.
To prove this, Tao and Green spent two years analyzing all four proofs of a theorem named for Hungarian mathematician Endre Szemerédi. Very few mathematicians understand all four proofs, and Szemerédi's theorem does not apply to prime numbers.
"We took Szemerédi's theorem and goosed it so that it handles primes," Tao said. "To do that, we borrowed from each of the four proofs to build an extended version of Szemerédi's theorem. Every time Ben and I got stuck, there was always an idea from one of the four proofs that we could somehow shoehorn into our argument."
Tao is also well-known for his work on the Kakeya conjecture, a perplexing set of five problems in harmonic analysis. One of Tao's proofs extends more than 50 pages, in which he and two colleagues obtained the most precise known estimate of the size of a particular geometric dimension in Euclidean space. The issue involves the most space-efficient way to fully rotate an object in three dimensions, a question of interest to theoretical mathematicians.
Tao found a surprising result to an applied mathematics problem involving image processing with California Institute of Technology mathematician Emmanuel Candès; their collaboration was forged while they were taking their children to UCLA's Fernald Child Care Center. Chan said that Tao and Candès' work is providing important insights into how to compress images, which has applications for medical imaging.
UCLA is California's largest university, with an enrollment of nearly 38,000 undergraduate and graduate students. The UCLA College of Letters and Science and the university's 11 professional schools feature renowned faculty and offer 337 degree programs and majors. UCLA is a national and international leader in the breadth and quality of its academic, research, health care, cultural, continuing education and athletic programs. Six alumni and five faculty have been awarded the Nobel Prize.