View Full Version : Racing the Sun

Lord Jubjub
2011-Jan-23, 07:04 PM
In the northern winter, at about 1800 Greenwich Time, if you were to take a hypersonic flight from Iceland due south, you would see the Sun rise in the west (yeah, I know, about Mach 12).

In the northern summer, the same flight would see the Sun race across the sky and set with undue haste.

If the previous two statements are true, then making that flight on March or September 21st would see the sun do a perfectly normal sunset, right?

2011-Jan-24, 01:18 AM
My guess is (not perfectly) normal sun set on March 21 and September 21, shortly after takeoff, even if one or both of the first two are flawed. Your altitude makes at least a small difference. Possibly you need to takeoff about 1700, local time instead of 1800 Greenwich mean time = UT time. Your south bound speed can be much slower than Mach 12. Flying West from Iceland shortly after sunset at Mach 1.2 will produce a sunrise in the West, soon after take off, except near December 21, when possibly no sun rise occurs. Is Iceland inside the Arctic Circle? Neil