spiderweb

speed of light is limit for propulsion of solar sail I guess, however no one could test the speed limit of any object yet. A Photon generate electricity by hitting solar panel that it releases electron. interaction of photon causes mechanical force in a solar sail propulsion. it must has mass.

some web pages called second, some third. you could figure it out by looking formula F=m*a. it's the most famous one of newton

if I continue to write answer for your comment. you do the same thing for me. thus it keeps in cycle that not relevant with topic.

comment is not about topic I wrote there. it's a judgement about something else that causes to be less productive, fruitless etc... if there is no idea about the topic please do not write comment.

When an object hit another, molecular bonds are forced to leave each other(tear) Inner dynamic of it come from Kinetic energy which was provided by Newton's third law. F=m*a. What if there is no third law. Nothing can be damaged physically by crash or hit. If you punch of an object, no acceleration force. At the moment of hit, there is no deceleration force too which causes damage. Let say gravity pulls 1 ton iron downward. it falls however acceleration of iron is at light speed? or faster.(there is no unlimited speed) When it hits, no deceleration force to damage. It's like a photon. It would not has any weight so gravity somehow has link to 3rd law of Newton. World has constant acceleration 9.81 Solar sail is the way of pushing force of photons and black hole swallows the light. They are under the influence of Newton's 3rd law of it so they have a mass. If gravity pull masses, it also pulls photons. World pulls photons. Gravity bends the light. Actual question is what causes to 3rd law of Newton.