Flying west, what will happen exactly?

Question

OK so this has been bugging me for a while, lets say I'm in a plane flying west over the equator at the same speed as the rotation of the earth, the time on my watch is 12 noon local time when I begin. I fly completely around the world in 24 hours at a constant speed, how should I adjust my watch for the different time zones?

Answer 1

the answer depends on the speed you are flying. if you are flying at a geosynchronical speed it should stay noon all the time and your watch should reflect that.

Answer 2

The easiest thing to do is just stop your watch.  If you are flying west at the same speed the earth is rotating under you to the east, then it is always noon wherever you are.  24 hours later the place you took off from will be under you again.  It will still be noon, but the next day.  By the way, at the equator, the speed you need is about 1038 mph.  The Concorde was the only passegner jet to fly that fast (and even faster) but it does not fly any longer

Answer 3

You would have to put your watch back an hour roughly once an hour as you entered each time zone. When you crossed the international date line, the point at which the time zones change from GMT-12 to GMT+12, you would have to move the watch's date on by a day. So you would arrive back at your starting point 24 hours later, having put your watch back an hour 24 times, but forward a day at the international date line.

Let's illustrate this - say you set off at 08:00 from London on the 1st of the month. An hour later, it's 09:00 London time, but you have to put your watch back an hour because you've just moved into the GMT-1 time zone, so it's now 08:00 local time again. The same happens another hour later - it's now 10:00 London time, but you're now in the GMT-2 time zone, so it's 08:00 local time again. This carries on until you cross the international date line, when you have to move the date on your watch forward to the 2nd. It's now 12 hours later, and it's 20:00 in London, still on the 1st, but for you, the local time is 08:00 in the morning on the 2nd. You carry on west, and four hours later it turns midnight in London, and the date there changes to the 2nd. By this point you're in the GMT+8 time zone, and you've just set your watch back to 08:00 (again) on the 2nd. Eight hours later you arrive back in London, and it's 08:00 on the 2nd there; at last, your watch is back on GMT time, and reading, as you would expect, a complete day later than the time you started, having taken a day to circumnavigate the globe. And having been through twenty-four eight o'clocks, you are now heartily sick of the airline breakfasts.