[ujzkawfu] 45 minutes from now, the human race could be extinct

two clocks, one labeled "Time now" and the other set and labeled "45 minutes into the future".  above them, a sign reading "45 minutes from now, the human race could be be extinct."  in between the clocks, a button with a cover over it labeled "LAUNCH".

more fancy: the T+45min clock stops once the launch button is pressed.  the launch button remains depressed -- it does not retract -- once pushed, indicating it has been pressed.  the T-0 clock runs for 45 minutes until its time agrees with the stopped T+45min clock, then it too stops.  the clocks resume and the button resets after 12 hours (for art).

too fancy: graphical display of missiles in flight.

(low earth orbit = 90 minutes, so max 45 minutes for an ICBM to reach anywhere on earth.  extinction could be quicker than that if we strategically position nukes all over the earth, which we do (sigh).  although it will be difficult to directly kill submarine crews, they are doomed to die from starvation or radiation poisoning after salted nuclear weapons.)