Why in news?
Nobel Prize in Physics 2019 has been awarded to James Peebles “for theoretical discoveries in physical cosmology” and to Michel Mayor and Didier Queloz “for the discovery of an exoplanet orbiting a solar-type star”.
Evolution of universe:
- James Peebles’ theoretical framework, developed since the mid-1960s, is the basis of our contemporary ideas about the universe.
- The importance of the cosmic radiation during birth of the Big Bang was realized by him.
- Barely 400,000 years after the Big Bang, the universe became transparent and light rays were able to travel through space.
- Using his theoretical tools and calculations, James Peebles interpreted traces from the infancy of the universe and discovered new physical processes.
- The universe in which just five per cent of its content is known constitutes stars, planets, trees and us.
- The remaining 95 per cent is unknown dark matter and dark energy.
- This dark energy helps the universe’s increasingly rapid and constant expansion.
Discovery of exoplanet:
- In October 1995, Michel Mayor and Didier Queloz announced the first discovery of a planet outside our solar system, an exoplanet, orbiting a solar-type star in the Milky Way.
- At the Haute-Provence Observatory in Southern France, using custom-made instruments, they were able to see the planet 51 Pegasi b.
- It is a gaseous ball comparable with the solar system’s planet, Jupiter.
- With this discovery, we now know that a quarter of all stars have a planet of Earth’s size and surface temperature, with the potential of hosting liquid water and the chemistry of life on its surface.
- Over 4,000 exoplanets have since been found in the Milky Way.
