A beam of light carries momentum and therefore the absorption of a beam of light results in an impulse. One could contemplate constructing a solar sail that catches light the way a regular sail catches wind. One could even imagine trying to escape the solar system this way.
The sun has a mass of 2 × 10^30 kg and emits 4 × 10^26 W of power.
a) If the sail absorbs all of the light that reaches it, what is the maximum surface density the sail could have and still escape to infinity?
b) What if the sail is a perfect reflector?
c) How feasible do you think these quantities are?
can anyone explain to me what requirements are needed in order to escape to infinity so I can tackle part a? Thanks.