# Flight time

October 29, 2008

“Will it take the same time for a plane to fly from Shanghai to Chicago as to fly back?” My friend Jiayin just asked.
“Of course the same” I answered almost spontaneously.
“Why? The rotation of the Earth affects the time.”
“No, as my physics teacher taught….” However, I failed to persuade her anyway, so I went to fetch some evidence, the airline information from American Airline. Then I was shocked.
It takes 13 hours and 45 minutes for a plane to fly from Shanghai to Chicago and 14 hours and 30 minutes back, which is 45 minutes’ different!
So, maybe Jiayin was right? The rotation of the Earth does affect the flight time? No! Newton’s First Law shouldn’t be false; planes are subject to the inertia the same as the Earth. What accounts for the difference in time?
“I have no idea“I told Jiayin.
But why? What makes the difference? I need an answer. I searched Google for an hour, but found no answer. The answers Google supplied were either too abstract or too plausible.
Confused, I attempted some calculations myself.
I first considered the rotation of the earth. As Newton’s First Law declares, since the atmosphere is in the same reference system as earth, they have the same inertia and the rotation of the Earth should not affect the plane. However, Einstein already proved that Newton was sometimes wrong. Maybe he was wrong again?
A Boeing 777 only gets a cruising speed of 272m/s; However, the linear velocity of a point riding on the surface of the rotating Earth is as high as (2âˆ/(3600*24)*6378100=ï¼‰463.8m/s . That is ridiculous, which just mean the plane can’t move forward on the equator. Newton was right ---- the rotation of the earth won’t influence the flight time of the plane.
I considered the electronic-magnetic force, the time difference and even the routine difference, but no answer came out.