In the context of modern scientific research, consider the following statements about ‘IceCube’, a particle detector located at South Pole, which was recently in the news : 1. It is the world's largest neutrino detector, encompassing a cubic kilometre of ice. 2. It is a powerful telescope to search for dark matter. 3. It is buried deep in the ice. Which of the statements given above is/are correct?
- (a) 1 only
- (b) 2 and 3 only
- (c) 1 and 3 only
- (d) 1, 2 and 3 ✓ UPSC's answer
Why the answer is (d)
• IceCube, completed in 2010 at the Amundsen–Scott South Pole Station, is the world's largest neutrino observatory, with 5,160 optical sensors spread through a cubic kilometre of Antarctic ice (statement 1).
• Its sensors are buried 1.5–2.5 km deep in the ice (statement 3), which shields them from cosmic rays.
• Besides detecting cosmic neutrinos, it searches for dark-matter particles by looking for neutrinos from their annihilation in the Sun and Earth (statement 2).
• Hence 1, 2 and 3, option (d).
Why the other options are wrong
- (a) 1 only
- Statements 2 and 3 are also correct.
- (b) 2 and 3 only
- Statement 1 is also correct: it is the largest neutrino detector.
- (c) 1 and 3 only
- Statement 2 on dark-matter search is also correct.
Asked in the GS Paper I of the UPSC Civil Services Preliminary Examination 2015, held on 23 August 2015. Question and answer key: Union Public Service Commission. Explanation: UPSC Answer Check.