What Radio Telescopes Reveal about the Universe

Astronomer Farhad Zadeh to deliver April 18 Science Café talk

By Roger AndersonApril 3, 2018

Farhad Zadeh, physics and astronomy, is adept at detecting the unseen and will share his cosmic insights this month during the latest installment of Science Café, an engaging public forum that brings Northwestern research into the community.

“The universe is not emitting only visible light that humans can see,” says Zadeh, a member of Northwestern’s Center for Interdisciplinary Exploration and Research in Astrophysics. “It also radiates invisible light and I’m hoping to relate how this invisible light was first discovered.”

What Zadeh discovers can surprise even him, as was the case last year when he and colleagues reported on gas clouds near the Milky Way’s center. The clouds have the right amount of mass to be planetary systems with small, young stars.

The finding was a shock, because it means the infant stellar systems are developing in the “shadow” of the galaxy’s supermassive black hole at it’s center — a hostile environment with intense gravity and ultraviolet radiation.

“Nature is very clever. It finds ways to work in extreme environments,” says Zadeh.

Zadeh and colleagues relied on ALMA, the Atacama Large Millimeter/submillimeter Array, in Chile to study the gas clouds and the research team will use ALMA for additional studies.

ALMA — 66 radio telescopes in northern Chile at an elevation of more than 16,000 feet — began scientific observations in the second half of 2011 and has provided insight on star birth during the early universe and detailed imaging of local star and planet formation.

Radio telescopes have been used since the 1940s, when scientists discovered that radio waves come not only from manmade inventions, but from natural sources far beyond our planet, too.

Each generation of stronger and stronger radio telescopes has led to major discoveries. In 1964, scientists used a radio telescope to reveal that Mercury rotates three times for every two revolutions around the Sun. In 2008, the Arecibo Observatory in Puerto Rico detected prebiotic molecules in a starburst about 250 million light-years from Earth. The presence of these molecules suggests that there may be living organisms in other solar systems.

“The universe is not emitting only visible light that humans can see,” says Zadeh. “It also radiates invisible light and I’m hoping to relate how this invisible light was first discovered.”

Join Zadeh at Science Café to learn more about his latest research and about the history of radio astronomy. The event is open to the public and takes place April 18 from 6:30 to 8 p.m. at the Firehouse Grill, 750 Chicago Ave. in Evanston.