Back to New Jersey, where the universe began

A few miles away, Princeton University physicist Robert Dick and his students began to investigate the conditions under which the universe might have begun, if it really had a beginning. They concluded that any such large explosion would have to be hot enough to sustain thermonuclear reactions, at millions of degrees, in order to manufacture the heavy elements from primordial hydrogen.

They realized that this energy must still be there. But as the universe expanded, the primordial fireball would have cooled to a few degrees kelvin above absolute zero, which, they calculated, would place cosmic radiation in the microwave region of the electromagnetic spectrum. (The group didn’t know, or forgot, that the same calculation had been done twenty years earlier by physicist George Gamow and his collaborators at George Washington University.)

Dr. Dick has recruited two graduate students – David Wilkinson, a talented instrumentalist, and James Peebles, a theorist – to try to detect these microwaves. While the group was meeting to decide on a plan of action, the phone rang. It was Dr. Penzias. When Dr. Dick hung up, he turned to his team. He said, “Guys, we’ve just been targeted.”

The two teams met and wrote two papers, which have been published back-to-back in The Astrophysical Journal. The Bell Labs group described the radio noise, and the Princeton group suggested it could be leftover heat from the Big Bang — “maybe each side thinks, well, what we did is right but the other might not be,” says Dr. Wilson said.

“I think Arnaud and I wanted to leave open the idea of ​​another source of this noise,” he added. “But of course it didn’t work out.”