In science fiction stories, we find space vehicles that consist of large sails that deflect light so that the recoil of the light propels the vehicle to amazing speeds. Suppose that the Department of Energy has funded such a project, and there is a sailship in free space that feels the push of a strong, steady laser beam of light directed at it from Earth. If the sail is perfectly reflecting, calculate the mass equivalent of light required to accelerate a vehicle of rest mass m0 up to a fixed γ.

In science fiction stories, we find space vehicles that consist of large sails that deflect light so that the recoil of the light propels the vehicle to amazing speeds. Suppose that the Department of Energy has funded such a project, and there is a sailship in free space that feels the push of a strong, steady laser beam of light directed at it from Earth. If the sail is perfectly reflecting, calculate the mass equivalent of light required to accelerate a vehicle of rest mass m0 up to a fixed γ.