How can photon have energy, but no mass if “m=E/c^2” (E= mc^2)

Question

How can photon have energy, but no mass if “m=E/c^2” (E= mc^2)

In: 42

Answer 1

In certain scenarios, a photon can behave as if it has (or had) a mass equivalent to E/c^2. For example if it hits a surface and is absorbed, like on a solar sail, the momentum of the object it hits will change as if the photon had mass.