if you had two space craft which had a solar sail as its means of Propulsion A & B, and were both identical. Spaceship A has light from the sun to push it along its way. Spaceship B has only gamma rays to push it along.(both craft have the whole of their sail surface covered with their respective radiation) now would spaceship A accelerate slower, faster or the same as spaceship B? and why? i know that both forms of radiation of course travel at the speed of light but does the higher energies that gamma rays possess hit the solar sail harder and make it accelerate quicker? if any readers could enlighten me on this matter i would be most grateful.