UPSC Prelims 2015 Question:

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?

Explanation:

The IceCube Neutrino Observatory is the first detector of its kind, designed to observe the cosmos from deep within the South Pole ice. An international group of scientists responsible for the scientific research makes up the IceCube Collaboration.

• Encompassing a cubic kilometer of ice, IceCube searches for nearly massless subatomic particles called neutrinos. So, statement 1 is correct.
  
  
• IceCube collaborators address several big questions in physics, like the nature of dark matter and the properties of the neutrino itself.  Roughly 4% of the universe is made up of regular matter like atoms and molecules. The other 96% of the universe is made of a material that can’t be seen and that is barely understood. It is composed of dark matter (23%) and dark energy (73%). Neutrinos may give a better understanding of dark matter and dark energy. So, statement 2 is correct.
  
  
• It is buried beneath the surface, extending to a depth of about 2,500 meters. IceCube not only needs clear, pure, and stable ice to make its discoveries; it also needs to be shielded from radiation at the Earth’s surface. IceCube’s individual sensors, called digital optical modules, or DOMs, are buried in the ice beginning at a depth of about 1,500 meters (4,920 feet, almost a mile) below the surface. The 1,500 meters of ice above the detector help to shield it from natural radiation at the Earth’s surface. So, statement 3 is correct.
  
  

Therefore, option (4) is the correct answer.  

Subject: Science & Technology | Recent Developments