By Kevin Fitzsimons As the speaker of the annual Alpheus Smith lecture in May, Riccardo Giacconi, designer of the Uhuru X-ray satellite that found the first-ever evidence of a black hole, told students to take a broad view and be persistent in pursuing their contribution to the fields of physics and astronomy.

A new view of the universe

Nobelist, father of X-ray astronomy gives lecture

By PAM FROST GORDER, Research Communications

When face-to-face with a Nobel Prizewinner, you just have to ask certain questions. Chief among them: "So, how'd you do it?"

Students who attended an informal chat with Riccardo Giacconi before he gave the Alpheus Smith Lecture, which is sponsored annually by the Department of Physics, were privy to such information. They found that Giacconi earned the 2002 physics Nobel by simply doing what he thought was right, and not taking no for an answer.

He had no idea that his efforts to study the heavens in the late 1950s and early '60s would spawn a new branch of astronomy, he explained. He and his cohorts at the Massachusetts research firm American Science and Engineering didn't dwell on the long-term consequences as they pressed government agencies for funding to build the first X-ray telescopes.

"We didn't then fully understand the significance of what we were doing," he said. "We were young -- I was 29, and I was the old man of the group."

When he began his endeavor, the Russian satellite Sputnik had just challenged American supremacy in the sky, and the United States government had created NASA with the primary goal of beating the Russians to the moon.

NASA wasn't interested in Giacconi's proposal to survey the sky for far-off sources of X-ray radiation. Because the sun emitted X-rays, he was convinced that the radiation must be present elsewhere in space -- perhaps emanating from distant stars and galaxies. Undeterred by NASA's rejection, he took out a contract with the Air Force to study X-rays reflected off the lunar surface. His team designed better X-ray detection instruments for that project, and in 1962 they were the first to discover X-rays from other parts of the universe. NASA took notice.

The rest, as Giacconi explained, is history. He designed NASA's Uhuru X-ray satellite, which found the first-ever evidence of a black hole. He and his team then created the Einstein X-ray Observatory, the first imaging X-ray telescope. The ultimate achievement of Giacconi's work -- the Chandra X-Ray Observatory -- circles the Earth today.

But, Giacconi asked, why give a history lesson when you can relate a detective mystery? His Smith Lecture recounted some of the questions raised by his early X-ray research -- where do cosmic X-rays come from, and what do they tell us about the objects that emit them?

As 40 years of astronomy have revealed, wherever atoms collide in high-energy reactions in space, X-rays can be found. Exploding stars and colliding galaxies whose visible light can barely be seen from Earth shine in vivid detail when viewed by X-ray telescopes. And the main sources of X-rays in the universe appear to be black holes, tucked within the heart of galaxies. As doomed gas and dust is sucked into a black hole, the super-heated material glows bright with X-rays.

Will Saam, chair of the Department of Physics, was "struck by the fact that X-ray astronomy now contributes to one third of all academic papers published in the discipline, especially since the first such publication was only in 1962."

To students who dream of making their own similar mark in physics or astronomy, Giacconi suggested that they take a broad view of their discipline, one that goes beyond the super-specialization that pervades science today. "I worry sometimes that we are training many people who know how to use telescopes, but few who know how to build them," he commented.

And don't give up, Giacconi said.

"When Galileo said 'try and try again,' he didn't mean 'try twice,'" he added, smiling.

The Smith Lecture began in 1960 and honors Alpheus Smith, former chair of Ohio State's Department of Physics and dean of the Graduate School. The lecture is funded by a gift from the Smith family, and is given yearly to physicists renowned not only for their scientific achievements but also for the ability to communicate their scientific breakthroughs to the general public. Giacconi is the 18th Nobel Prizewinner to give the lecture.

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