> Is there a part of the second spacetime in which some of the light is trapped in the WH? No. Nothing can get into a white hole from the outside. > where is

> Is there a part of the second spacetime in which some of the light is trapped in the WH? No. Nothing can get into a white hole from the outside. > where is it if the initial conditions are a Bonnor beam at large spacelike separation from the white hole? You are mistakenly thinking of a white hole as a "thing". It isn't. It's a region of spacetime that nothing can get inside. Or, to put it another way, it is a region of spacetime that is to the past of something else: either a black hole (if you are talking about the maximally extended Schwarzschild spacetime) or an object like a star that the white hole expanded into. So if you "aim" anything at a white hole, you won't hit the white hole; you'll hit whatever thing the white hole is to the past of. Either a black hole, or an object that the white hole expanded into. That is what the Bonnor beam in your scenario would actually intersect. Similar remarks would apply to your other scenarios; the actual objects you would end up dealing with would not be white holes, but whatever the white holes were to the past of.