Flight time calculator
By looking at the clock.
,No, really, it is that simple.
,In bigger and heavier aircraft, there is sensor called the Weight On Wheels sensor (well, usually three of them), and when it registers weight off the wheels (ie the plane is airborne), the computer makes a note of the time on the clock.
When the sensors log weight on wheels again, it makes a note of the time, works out the difference between the take off time and the landing time, and proudly shows this to the crew.
,On a light aircraft you normally donu2019t have such complex devices, so the pilot has to look at his watch.
Time and distance calculator
s=1/2 at^2 , where s= distance, a= acceleration, t =time,Thereofore, a = 2s / (t^2)
Time zone duration calculator
I would retreat from society and live alone as far from civilization as possible, hoping for an early death.
Or perhaps find someone who can lobotomise me.
,For if the Earth is flat, I am the subject of such a massive global level conspiracy to fool me that everyone has to be on it.
,,I was a bit of an amateur astronomer in my past life.
Not that I was particularly good, mind you.
OK, scratch that u2014 I was so bad at observational astronomy that it was legendary at the olympiad camp.
,Still, I have observed the sky quite a bit.
Here are a few things that I have seen.
,The pole star stays fixed in the sky while the rest of the sky seems to rotate around it without distortion.
And as I travelled north from Calicut to Mumbai and then to Kanpur and Europe, the pole star kept getting higher and higher up in the sky.
And the rest of the rotating night sky kept moving with it u2014 once again, without getting distorted.
I could no longer see stars which were visible back home.
I have used spherical trigonometry to calculate when stars are supposed to rise and set, and obtained excellent results.
,I have also seen many lunar eclipses.
I have seen the shadow of earth fall on the moon.
I have also calculated the duration of lunar eclipses using the spherical earth model and seen that even a back-of-the-envelope calculation is exceptionally accurate.
I have also travelled to many parts of the world.
I have flown from New Delhi to New York and from Europe to Singapore, and seen the local time being completely different from what my watch says.
I have made video calls to my family while being in different time zones.
,I have also been part (admittedly a very small one) of a large effort to send a satellite up to orbit the earth.
And I have written code for it which works only on a spherical earth.
,,And I am not talking qualitative arguments here.
I have made hard numerical calculations which work exactly as they should on a spherical earth.
,So, if the flat earthers are correct, the round earth conspiracy is much bigger than they suggest.
Someone is tracking the times I do sky observations at different places across the world and modifying the visible stars to make it look just like it would on a round earth.
People are drugging me and modifying my watches while I am on long-distance flights to mess with my understanding of time zones.
My family is in on the conspiracy too, fooling me about the time zone back home.
,If I am living in such a Truman Show world, best to leave it all.
,That, or the earth is actually a sphere (to a near-perfect approximation) and the flat earthers are idiots, loonies or trolling jokers.