Page 18 - Dream 2047 June 2020

ANNULAR S LAR ECLIPSE
REVELATION
SRintu Nath
Solar eclipse and scientific discoveries
olar eclipses have offered opportunities for ground- breaking observations that have helped science progress. In this article, among many scientific advances that were made during past solar eclipses,
two notable observations are mentioned, namely experimental support for the general theory of relativity and the discovery of the element helium.
The general theory of relativity
In 1915, Elbert Einstein proposed the general theory of relativity. He explained gravity based on the way space could ʻcurveʼ in presence of mass and associated the force of gravity with the changing geometry of space-time. Newton had explained gravity as a force, pulling objects together. Einstein described gravity as a warping of time and space — a distortion in the fabric of the universe.
According to the general theory of relativity, light changes its path while travelling through the warped space-time. The more massive an object, the bigger the distortion, and the more its gravity can bend light. Einstein predicted that light rays from any distant star would bend while passing near any massive object like the Sun. As a result, the star would appear to be in a slightly different position in the sky during the day, compared to its position we see at night, when the Sun is in another part of the sky. Although according to Newton’s gravitational theory too, light would experience gravitational attraction towards the Sun, the degree of the
deviation was computed to be significantly higher according to Einstein’s theory. It was evident that general relativity theory could be validated experimentally if the bending of light is established through observation. The only problem was that the Sun needed to be blocked from the view; otherwise, stars would not be visible during the day in the dazzling light of the Sun. A total solar eclipse was the only option to establish a positional shift. If the same star were observed in the night sky and also during the day during totality, comparison of the
An artist's concept of the curved space-time around Earth
Image credit: https://science.nasa.gov/
18 dream2047/june2020