An artistic representation of a white hole. (Credit: NASA’s Goddard Space Flight Center/Discover)

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 opp