UPSC Prelims 2018 Question:

Consider the following statements:

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?

Explanation: 

• General relativity is Einstein's understanding of how gravity affects the fabric of space-time. 
  • Einstein spent the decade determining that particularly massive objects (matter) warp the fabric of space-time, a distortion that manifests as gravity. So, statement 3 is correct.
  • Light bends around a massive object, such as a black hole, causing it to act as a lens for the things that lie behind it. Astronomers routinely use this method to study stars and galaxies behind massive objects. Einstein predicted that light should be bent by gravity. So, statement 1 is correct.
  • One of the most important applications of the theory is in describing the cosmic expansion of the universe since the Big Bang. The speed of this expansion is determined by the amount of energy in the universe. So, statement 2 is correct.
    
    

Therefore, option (4) is the correct answer.

Subject: Science & Technology | Physics