How many planes
What is the largest number
of airplanes that could in blindly
random flight, over the continental US
between 15000 and 30000 feet altitude,
without risking more than 1 fatality
per billion passenger miles as
a result of midair collision?
units
1 plane = 200 passengers
total volume of us = 10^17 meters
volume of plane = 10^4 meters
plance spaces = 10^13
1 crash per 4*10^17 passenger/meters
number of spaces
