Context:
The European Space Agency’s Euclid mission recently discovered an Einstein ring in the galaxy NGC 6505, which is about 590 million light-years away from Earth.
Einstein Ring:
- Einstein Ring – A ring-shaped image that occurs when light from a distant galaxy is bent around a massive object in the foreground (gravitational lensing).
- Appears around celestial objects like dark matter, galaxies, or clusters of galaxies.
- A full ring appears only if the observer (Euclid telescope), lensing object, and background galaxy are nearly perfectly aligned.
- 1st noticed by – Bruno Altieri (Astronomer) [nicknamed Altieri’s Ring]
- Albert Einstein’s general theory of relativity predicted this phenomenon.
- General relativity predicts that the path of light will follow the curvature of space-time as it passes near a massive object.
- The gravity of the foreground object bends light rays, similar to how a magnifying lens bends light.
- GAL-CLUS-022058s: Largest and one of the most complete Einstein rings ever discovered.
- Also known as Einstein–Chwolson ring or Chwolson ring.
- Significance – Einstein rings are valuable for studying expansion of the universe, Dark matter, Dark energy etc.
Source: The Hindu
Previous Year Question
Consider 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?
[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)