Postby Sableagle » Mon Mar 28, 2016 9:53 pm UTC
I think the transfer of mass from Earth to Moon would increase the rate at which the Moon is slowing the Earth's rotation and increasing day length, but I don't think jumping straight up would do that no matter how unevenly they were distributed. If they all set off sprinting east when they saw the zap coming and all jumped at the last moment before it hit them, then it would affect the Earth's rotation.
There would be a tiny lurch as the orbits of the Earth and Moon around a point between their centres had to shift slightly to adjust for the change in mass ratio, and if they were tightly clustered in some small area at the time and jumped vertically then whether the Moon was "up" or "down" for them would affect whether Earth and Moon got pushed apart or together just before that transfer. If the Moon's rising or setting when they go they'd accelerate or slow that mutual orbit instead ... if they're in Nyahururu. If they're in some gods-forsaken, corrupt, third-world backwater like the Palace of Westminster, though, out past the 45' latitude line ... they'd actually induce a slight movement relative the the Earth's orbital plane around the Sun, wouldn't they? That'd make launching robots to Mars trickier.
Lesson learned: always anaesthetise Justin Bieber fans before teleporting them to the Moon.
Oh, Willie McBride, it was all done in vain.