Prelims 2018 · Q62
MediumConsider the following phenomena:
- 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?
Answer & explanation
Answer: (d) 1, 2 and 3
All three follow from Einstein's General Theory of Relativity (1915-16). It treats gravity as the curving of space-time by matter, so matter warps space-time, and light, which follows that curved space, is bent by gravity. Applied to the whole universe, the same equations allow an expanding universe.
- ✓ 1. A massive body such as the Sun curves space-time, so light passing it no longer travels in a straight line. This bending was tested during the solar eclipse of 29 May 1919.
- ✓ 2. Einstein's theory suggested that the universe expands. Einstein himself doubted this and added a 'cosmological constant' to avoid it; Friedmann's solutions of the equations and Hubble's observations supported expansion.
- ✓ 3. This is the core idea: mass and energy curve the space-time around them, and objects, including light, move along that curvature.
Remember · General Relativity: matter curves space-time, and that curvature is gravity. It bends light and allows an expanding universe.
Sources
- NASA Science: 10 Things Einstein Got Right ↗ “A massive object such as the Sun bends the spacetime blanket with its gravity, such that light no longer travels in a straight line as it passes by the Sun.”
- NASA Goddard (Imagine the Universe): Cosmic Times 1929, Universe is Expanding ↗ “It says that gravity curves this space-time and that the curvature controls the natural motions of objects in space. Einstein's theory also suggested the expansion of the Universe, but Einstein didn't believe this could be correct.”
Question and answer: UPSC's official GS Paper I (2018, Series A) — paper ↗ · answer key ↗. Explanation: Minimalist IAS, checked 30 Sept 2026 (how we verify). Permalink ·