Ramanujan Auditorium

The 150th anniversary of fingerprinting the Universe - the discovery of Helium from Andhra Pradesh

Niruj Mohan Ramanujam

Public Outreach and Education Committee, Astronomical Society of India

18 August 2018 marks the 150th anniversary of the discovery of
the element Helium. This event happened during a Total Solar Eclipse seen by European astronomers from Machilipatnam and Guntur in Andhra Pradesh in 1868. The
story of this discovery itself is fascinating. The truth behind who among
Janssen, Lockyer and Pogson (of Madras Observatory) should get the credit,
was cleared up only a few years ago. Helium remains the only element to
have been discovered first in space, before being found on Earth. More
importantly, this discovery truly marks the beginning of modern Astrophysics, whereby we gained the confidence and the knowledge of how to fingerprint the Universe. This beginning is intricately linked with the history of thermodynamics, atomic theory, and chemistry.

This talk will attempt to tell this story.