Question

According to the station clocks, two babies are born at the same instant, one in Howrah and other in Delhi. (a) Who is elder in the frame of 2301 Up Rajdhani Express going from Howrah to Delhi? (b) Who is elder in the frame of 2302 Dn Rajdhani Express going from Delhi to Howrah.

Answer 1

Explanation:

• In a moving train, the recorded time interval, that is, proper time is lesser than the improper time as per the recording in ground frame.
• The station clocks verify the birth timings and as it is the ground frame, it is the proper time interval.
• Additionally, in the moving train, the time recorded is improper as it archives time at two various sites.
• So, the improper time interval is more than that of proper time interval.  So,  

• (a) In the 2301 Up Rajdhani Express’s frame, which goes from Howrah to Delhi, the Delhi child is elder.
• (b) Howrah child is elder in the 2302 Dn Rajdhani express’s frame, which goes to Howrah from Delhi