It was no less a luminary than Isaac Newton who taught us that for every action, there is an equal and opposite reaction. Push on the wall, and it pushes back. With that in mind, cosmic “white holes” make a lot of sense — they seem inevitable, even.
We all know about black holes, those cosmic vacuum cleaners that suck in anything (including light) that gets too close. Well, what about the opposite? Might the vast unending cosmos also feature white holes, which emit matter and energy into the void, but could never be entered?
It’s appealing to our sense that things often come in binaries — if there’s an off switch, there’s probably an on switch somewhere. And white holes also feel like a necessary balance to the finality of black holes: Where does all that sucked-up stuff go?