11/10/2019 Opinion

Roger Cabré Rodon, Physicist and Professor of the Department of Electronic, Electrical and Automatic Engineering of the URV

Discovering the universe

The Nobel Prize for Physics has been awarded twice to three leading scientists pioneers in the field of exoplanets.

James Peebles, Michel Mayor and Didier QuelozIll. / Niklas Elmedhed © Nobel Media.

This year the Nobel Prize for Physics has been awarded twice to three leading scientists. Why do we say twice if there are three of them? Well, because as happens sometimes, after the jury’s deliberations there are many deserving candidates and, to be fair, the prize is shared. This year it has been divided into two parts: one for the now veteran Canadian astrophysicist James Peebles from the University of Princeton; and the other for two members of the same team from the University of Geneva, Michel Mayor (the veteran) and Didier Queloz, whose work he supervised.

In the 1990s, Mayor and Queloz were pioneers in the field of exoplanets. They used a new detection technique (radial velocities) with which they discovered, in 1995, the first confirmed exoplanet in orbit around 51-Pegasi, a star like our sun. The planet, a gas giant like Jupiter, was called 51 Pegasi b. Since then, this technique and other newer ones have been used to discover as many as 4,000 exoplanets in the nearest region of our galaxy, some of whose atmospheric conditions are even similar to Earth’s. All these discoveries have led to a wealth of understanding of what we and the Earth represent in the Universe and they pave the way to finding life beyond the solar system.

As far as James Peebles is concerned I simply cannot be clearer: it was he who theorised about the universe’s background radiation, which had been detected a few years before (1964) by Penzias and Wilson, identifying it as the remnant of a wave of immense and extremely hot light that some 350,000 years after the Big Bang finally managed to cross our universe after being imprisoned within it. Nowadays, these microwaves are reaching us from all directions but are much colder. The detection of this background radiation with large radio telescopes, and particularly its extremely small irregularities, have enabled scientists to deduce what the universe was like in its infancy and how it has evolved over time. Some say that background radiation is for the history of the universe what fossils are for the history of the Earth.

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