I need to know why light has no mass

Question

Misty · Answer

The first point to make is that while photons (little packets of light energy) do not have mass, they do have momentum, and a change in momentum yields a force, so in actual fact light is able to physically interact with matter.Dec 26, 2013

Reed · Answer

hittp://www.indexmundi.com/map/?v=39&r=sa&l=en

Reed · Answer

Oops: http://www.indexmundi.com/map/?v=39&r=sa&l=en

Reed · Answer

No, that's not right! That's from another question. Here's what I meant for you: http://www.google.com/search?sourceid=navclient&ie=UTF-8&rlz=1T4VRHB_enUS648US649&q=characteristics+of+light