PUNE: Telling the story of ‘Ancient light: The microwave background radiation and cosmology’, Prof Mark Birkinshaw from the University of Bristol, UK, held the audience spell-bound on Wednesday during his lecture at Inter-University Centre for Astronomy and Astrophysics (IUCAA).
The lecture started with the story of microwave background radiation from the original idea in the 1940s to the latest easurements from satellites in orbit and telescopes in Antarctica.
Prof Birkinshaw said, “In 1964 Bob Wilson and Arno Penzias were working on a project when they heard a ‘hum’ sound coming to them from the sky. They checked out every possibility to find out where it was coming from. What they found out was about the cosmic microwave background radiation (CMB).”
Prof Birkinshaw added, “Alexander Friedmann, by using Albert Einstein equation wrote the first paper on how the universe would expand by using a mathematical model. The CMB is the oldest light in the universe. Shortly after the Big Bang, the cosmos was a seething-hot, opaque fog of plasma and energy. However, things changed about 3,80,000 years later, when temperatures dropped enough for electrically neutral atoms to form and the universe became transparent.”
The CMB is a uniform lending support to the theory of cosmic inflation, which says the universe expanded much faster than the speed of light just a few fractions of a second after the Big Bang. Talking about sound and gravity, he said the measurements of oscillations measure the key cosmological parameters from the properties of the noise.
The Planck (Planck is a European Space Agency space-based observatory observing the universe at wavelengths between 0.3 mm and 11.1 mm) spacecraft is busy scanning our skies picking up the light that created the universe after Big Bang. This ancient light travels billions of kilometres to reach us encountering gas, stars and galaxies,” he said.
“Neutrinos are one of the fundamental particles which make up the universe and there are only three key neutrinos,” Prof Birkinshaw said. Predicting the possibilities in future, he said, “Parameters describing the universe will be more precisely measured by CMB structure data using oscillations.”