I have two main questions about light, one does gravity affect it? Two, does it have mass? I have read lots of posts and articles and many say that light is directly affected by gravity while others say that gravity "bends" the spacetime arround it so the light appears to be curved but is in reality travelling straight through the curved spacetime. Also for the question about mass I have read that light has no mass but it has momemntum? My understanding of momentum is that is it mass x velocity so I do not understand how it can have no mass but have momentum.