If photons are massless, how do solar sails provide thrust?
How are light sails propelled by light, if photons have no mass?
Physics: Why don’t photons have mass? Does a moving photon have mass? Does light have kinetic energy? Is light made up only of photons? How is it possible that a photon is massless? Can a photon be at rest or does it have to travel at the speed of light? Does laser light have mass? What is the mass of photon? Is light really a type of energy? Does Light attract Light? Light is energy therefore E=mc^2. If it has mass it has gravity? Where do photons appear from when mass and energy are combined? How can massless particles (photons) have momentum? How is light produced? Why does light have energy? How are photons created? How can photons have no mass and yet still have energy given that [math]E=mc^2[/math]? Does energy have mass or light (as in light beam) have mass? How is light a form of energy? How does a photon lose energy? If light is made of particles, how does it pass through glass? Why does light posses a dual nature of both wave and particle only and nothing else? Given that photons have no mass and the speed of light cannot be exceeded, could there be a negative mass that exceeds the speed of light? Can a single photon behave as a wave. If yes, how? In what medium does light (photon) travel? What are photons? How are visible light waves produced? What Is the Photon Theory of Light? Photons are 'bend' downwards by mass; what does this say about the relation between photons and gravity (tons) and which particles would bend upwards? Do massless particles have to travel at the speed of light? Does light moves? What is the definition of energy of a photon?