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.
Unless the light is in a vacuum like space
I asked my good friend gravitational lensing about light in space, and they said that light can go and get bent
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.