What are some commonly known facts that are too bizarre for you to believe to be true?
For me it is the fact that our blood contains iron. I earlier used to believe the word stood for some 'organic element' since I couldn't accept we had metal flowing through our supposed carbon-based bodies, till I realized that is where the taste and smell of blood comes from.
I might be misremembering but I believe our sun can't go nova, it's too small. It will, however, expand and swallow the Earth towards the end of its life.
Space aliens could teleport in next to sun, fling a bunch of Star Trek red matter at it like Spock did to the Romulan star, destabilize the star, and cause a, I think it was a black hole? where the star was. And we wouldn't know for 8-ish minutes.