My understanding is that in a true vacuum light will not be reflected or bent by particles. However, due to gravity bending space time itself, light will follow the curvature of space. It would depend on the observer if the path if light is straight. If you look at the light passing by, it would not be straight under influence of gravity. If light itself is the observer, it will travel in a straight line :)
In the case of gravitational lensing the observer is looking at light coming in. An outside perspective.
I have been learning some database stuff today. Finally understand the drop table thing better.
You can have multiple users on android. Some plugin should be able to do such a thing.