Consider the following statements:

1. Light is affected by gravity.
2. The Universe is constantly expanding.
3. Matter warps its surrounding space-time.

Which of the above is/are the prediction/predictions of Albert Einstein’s General Theory of Relativity, often discussed in media?

[UPSC Civil Services Exam – 2018 Prelims]

(a) 1 and 2 only

(b) 3 only

(c) 1 and 3 only

(d) 1, 2 and 3

Answer: (d)        

Explanation:

• The bending of light by gravity can lead to the phenomenon of gravitational lensing, in which multiple images of the same distant astronomical object are visible in the sky.
• Gravity, Einstein asserted, is caused by a warping of space and time. Gravity is the curvature of spacetime caused by massive objects.
• In 1917, Einstein applied the general theory of relativity to the structure of the universe as a whole. He found that the general field equations predicted a universe that was dynamic, either contracting or expanding. Since observational evidence for a dynamic universe was not known at the time, Einstein introduced a new term, the cosmological constant, for the field equations to allow him to predict a static universe.