You are in an infinite grid with side a and at each corner you have a sphere of radius r < a/2. What is the % of area of the "sky" that is not eventually terminating in a sphere as function of your position?
Just one more since it's one of my favorites and most of you likely have never heard this Cuban big-band. I was incredibly lucky to see them about 15 years ago when they performed in Scottsdale when on tour from Cuba. Best concert ever.:
Last edited by Howard Beale; 06-20-2017 at 11:23 PM.
Reason: 2nd best: Mahler's 9th.