UPSC Prelims 2015 · Question 30 of 98

UPSC Prelims 2015 question on Icecube Neutrino Detector

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?

  1. 1 only
  2. 2 and 3 only
  3. 1 and 3 only
  4. 1, 2 and 3
Show answer

Answer: D. 1, 2 and 3

Verdict

The answer is 1, 2 and 3. IceCube is the world's largest neutrino detector, it is a powerful tool in the search for dark matter, and it is buried deep in the ice.

Analysis

Statement 1 is CORRECT. IceCube instruments a full cubic kilometre of Antarctic ice, making it the largest neutrino detector built. Statement 2 is CORRECT. Besides recording astrophysical neutrinos from exploding stars, gamma ray bursts and black hole phenomena, the array is used as a telescope in the search for dark matter. Statement 3 is CORRECT. The optical sensors are frozen into the ice at depths reaching around two and a half kilometres, using the ice itself as the detecting medium.

Source

The Hindu report on high energy neutrinos from alien sources, and the IceCube observatory's own material.

How to crack it

When a news item names an instrument, log what it detects, where it is, and what makes it unusual. Here all three statements are simply those three facts restated, which is why all of them stand. The reasoning shortcut is that a detector for a nearly massless particle needs enormous volume and heavy shielding from cosmic rays, and burying a cubic kilometre in polar ice satisfies both requirements at once. Physical necessity confirms statements 1 and 3 together.

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