



At the time when astronomer Edwin Hubble discovered that the universe was expanding (by calculating the speeds at which the galaxies were receding), the Nobel Prize in physics did not recognize work done in astronomy. As a result, Hubble was not eligible despite making a crucial discovery in the field.





Hubble spent much of the latter part of his career attempting to have astronomy considered an area of physics. The campaign was unsuccessful during his lifetime but shortly after his death, the Nobel Prize Committee decided, that astronomical work would be eligible for the physics prize.

The Nobel Prize in 2019 has been announced, with one half going to Canadian astrophysicist James Peebles for theoretical discoveries in physical cosmology, and the other half jointly shared by Swiss astronomers Michel Mayor and Didier Queloz for their discovery of an exoplanet orbiting a solar-type star.









84-year-old Jim Peebles has made important contributions to the Big Bang model, like predicting the cosmic microwave background radiation, for example. He was also the leading pioneer in the theory of cosmic structure formation in the 1970s, long before it was considered a serious, quantitative branch of physics.





Peebles laid the foundations for almost all the modern investigations in cosmology, both theoretical and observational. For example, using theoretical tools and calculations, he drew a link between the temperature of the radiation emitted after the Big Bang and the amount of matter it created, and thus, he has a long record of innovating the basic ideas.







Mayor and Queloz, the teacher and student duo from the University of Geneva, have received the other half of the Prize, for their 1995 discovery. At the end of 1994, the pair noted a periodic variation in the Sun-like star, Mayor and Queloz, the teacher and student duo from the University of Geneva, have received the other half of the Prize, for their 1995 discovery. At the end of 1994, the pair noted a periodic variation in the Sun-like star, 51 Pegasi , (50 light-years from Earth), which could have been due to the presence of a large planet in orbit, but smaller in size than Jupiter.





Their technique ushered in the modern era of exoplanet discovery as it led to rapid detection of many more exoplanets. By observing the variation in a star's apparent luminosity as an orbiting planet transited in front of it, Mayor alone has discovered 200 exoplanets! More than four thousand exoplanets have been observed since, by using the same technique.





Queloz and Mayor





Mayor and Queloz's astronomical techniques have forever changed our conceptions of the world. That Earth is one among a plethora of planets in the universe, strange new worlds still waiting to be discovered, and more new planets means more possibilities of life elsewhere, which is simply extraordinary!





This year's Prizes celebrate the contributions of astronomers: while Peebles' theoretical work has added to our understanding of the evolution of the universe, Mayor and Queloz have explored our cosmic neighbourhoods. We also would like to remember Edwin Hubble on this day, who fought hard, not to make a new prize, but to make astronomy a part of physics.

The result this year also seems to show a welcome broadening of the Nobel criteria, "..their discoveries are revolutionary," the jury said. The trio will receive the prize at a formal ceremony in Stockholm on December 10 (the anniversary of the death of scientist and entrepreneur Alfred Nobel).



In a telephonic interview after the announcement, Jim Peebles has advised young people that, while the awards are charming and very much appreciated, they should do physics for the love of it, "That is what I did," he added. Mayor and Queloz declared the 1995 discovery the most exciting of their careers. Didier Queloz said, "I am gonna buy a new bike!"