31 October, 2004

Time Travel

Today we will calculate time difference between Pune and Kolkata using longitude information. We will also try to calculate the approximate distance based on longitude and lattitude.


LattitudeLongitude
Kolkata22 30' N88 20' E
Pune18 34' N73 58' E



Difference in the Longitude = 88 20 E - 73 58 E = 14 22' ~= 14.37 degrees.

1 degree of Longitude = 4 Minutes (of your wristwatch)
14.37 d = 14.37 * 4 = 57.48 Minutes

Conclusion I am 1 Hr ahead in time :-) In Kolkata it gets dark at 5.30 PM.

Nows lets try distance d between Pune and Kolkata.

1 degree of Longitude = 111 Kms on equator.

The line joining Pune to Kolkata is no equator, so we have consider lattitude. We will take the average of lattitudes at two places i.e. 20.

d = 111 * cos(20) * 14.37 (Kms)
= 104.3 * 14.37 (Kms)
= 1498.87 (Kms)

The train ticket shows distance as 2020 Kms which makes sense because 'd' is straight line distance.