Curious Link Between the Fly-By Anomaly and the “Impossible” EmDrive Thruster
Photons must behave as if they have mass. From TFA:<p>McCulloch’s theory could help to change that, although it is hardly a mainstream idea. It makes two challenging assumptions. The first is that photons have inertial mass.<p>When I was taking college physics, there was a question on the exam about radiation pressure. I missed that day, so had no idea how to solve it. "a 5mW laser is reflected off a mirror (perpendicular) what is the force exerted on the mirror"? Later looking it up in the book there was a page on this and a derivation using electromagnetic theory. In the exam however, I decided to convert 1 second of laser energy to mass, bounce it off the mirror at speed=c, compute the force and change in momentum (over change in time which was 1s). I got the right answer of course.<p>The logic is simple. If we can convert back and forth between matter and energy, any experimental setup must obey conservation of momentum and it's CG must not move. So a laser inside a closed spaceship would actually be tranfering mass (as energy) from one end to the other. The net effect must be the same as if that mass was moved any other way.<p>I derived a general expression for radiation pressure after the exam and it's identical to the EM one from the book. Photons behave - and must behave - as if they have mass with a velocity of c. By the same reasoning, gravity must bend light rays, though I have not compared this prediction to that of relativity.