Universe born out of Big Bang — Indian scientist

Now, a Pune scientist has come up with what is being called a “convincing test” that the universe indeed has been cooling down ever since the Big Bang happened many billion years ago.

Raghundhan Srianand of the Inter University Center for Astronomy and Astrophysics (JUCAA) in Pune, India, and his colleagues have measured the temperature of the Universe when it was just one-fifth of its current age. And their findings, which were reported in this week’s British journal Nature, are consistent with the predictions of the Big Bang model.

The Big Bang Theory implies that the Universe has been cooling since its formation in a cosmic fireball. Its remanants can still be seen as the cosmic microwave background radiation, which is the glow of empty space today at a temperature of about 2.73 Kelvin (a measure of temperature used by scientists). Srianand’s team show that about three billion years after the Big Bang the temperature of the Universe was between 6 and 14 K. The theory predicts a value of 9.1 K. Thus making this is the best estimate so far. The research was carried out at the 8.2-m giant telescope of the European Southern Observatory at a remote mountain called Paranal in Chile in South America and was supported by the Indo-French Center for the Promotion of Advanced Research.

It was n 1948 that the Russian-American physicist George Gamow put forward the Big Bang theory of the origin of the universe. Gamow propsed that the universe was created in a single gigantic explosion and that the various elements obserbved today were produced within the first few minutes after the Big Bang, when the extremely high temperature and density of the universe would fuse sub-atomic particles into the chemical elements of today.

The prime scientist led a team of three astronomers from Germany and France and studied the absorption of light from a distant, bright astrophysical object called a quasar — possibly one of the brightest objects in the universe — by a gas cloud that lies along the line of sight. Because of the expansion of the universe, the more distant objects are, the older they are. The background radiation heats up the atoms and molecules in the cloud in a way that allows the temperature of the gas to be estimated.

Calling the Pune researchers finding a “tremendous achievement” which provide fist evident that the “Big Bang is bang on”, John Bachali of the Institute for Advanced Study and Natural Sciences at Princeton in Now Jersey, USA says in the accompanying editorial that the results reported by Srianand represent “a landmark result”.