toddverrone,
It is indeed possible to see photons in motion. This new technology will explain it for you.
http://www.popsci.com/science/article/2011-12/trillion-frame-second-camera-captures-photons-moving-through-space-slow-mo
You asked, "if photons have zero rest mass, Mo, does that mean they have mass when they’re moving?
What logic leads you to ask this? If photons have no mass that means they have no mass under all conditions. They do not suddenly acquire mass then magically lose that mass. This defies logic -- unless there are laws at work of which I am unaware.
It is indeed possible to see photons in motion. This new technology will explain it for you.
http://www.popsci.com/science/article/2011-12/trillion-frame-second-camera-captures-photons-moving-through-space-slow-mo
You asked, "if photons have zero rest mass, Mo, does that mean they have mass when they’re moving?
What logic leads you to ask this? If photons have no mass that means they have no mass under all conditions. They do not suddenly acquire mass then magically lose that mass. This defies logic -- unless there are laws at work of which I am unaware.

