A: Four:
- One to actually change the darn thing.
- One to operate the CCD camera to measure the number of photons it emits
whilst his friend operates the computer to do the task (bit techie)
- And another to complain about how the CCD is out of focus and how the
light bulb actually looks like a polo mint.
Taken from the electronic bulletin of the Network of Student
Physical Societies, 1994.