The Physics Nobel Goes to the Big Bang and Exoplanets

At 93 billion light years across, our observable universe seems full of unfathomable possibility. Today, the Nobel Prize Committee awarded the physics prize to three researchers whose scientific discoveries have framed this cosmic vastness into a more comprehensible picture.

This year’s award goes to a Canadian physicist, James Peebles, whose theoretical work underpins the current understanding of the universe’s beginnings, and two Swiss astronomers, Michel Mayor and Didier Queloz, who discovered the first planet orbiting a sun-like star. The three will split 9 million Swedish kronor, equal to about 910,000 dollars, with Peebles receiving half the prize, and Queloz and Mayor sharing the remaining half.

“This year’s Nobel Laureates in physics have painted a picture of a universe far stranger and more wonderful than what we ever could have imagined,” said Ulf Danielsson, a member of the Nobel committee, during the press conference. “Our view and place in the universe will never be the same again.”

James Peebles, a researcher at Princeton University, helped to develop the theory behind the Big Bang model, which describes an extremely hot and dense early universe that rapidly cooled and expanded 13.8 billion years ago. Starting in the 1960s, Peebles translated the implications of the model into observations scientists could actually make. Other researchers used his insights to find evidence of the Big Bang in fluctuations in the cosmic microwave background, the faint ubiquitous glow that is the oldest radiation in the universe. More recent missions such as the European Space Agency’s Planck satellite, which released its last batch of data in 2018, have mapped this radiation at a much higher resolution, leading to a more detailed understanding of the early universe.

In a phone call during the press conference, Peebles highlighted the synergy between theory and observation that led to these deeper scientific insights. “I was, at regular intervals, startled at the great power of advances in technology to test these ideas,” he said.

Queloz and Mayor received the award for their 1995 detection of a planet orbiting a sun-like star, the first discovery of its kind. Working from an observatory in southeast France, they observed the planet 50 light years away, in the constellation Pegasus. This planet, now dubbed 51 Pegasus b, was about the size of Jupiter. It was more than five times closer to its star than Mercury is to the Sun, and its entire orbit was only four days long.