My daughter just completed her class schedule for next semester, including an astronomy class which fulfills an earth sciences distribution requirement. She's not terribly excited about it, because she's not a science major, and the course has a reputation for difficulty.
This is a stark contrast with the astronomy class of my own college experience, renowned as a 'gut' (easy) course. Discussion sections primarily consisted of students imbibing now-legal but then-illicit substances and philosophizing about what might be floating around 'out there'. Comets, meteors, other sentient life? Black holes? And what WAS a black hole?
Black holes are newly topical this week, with the release of new photos from the Event Horizon Telescope, the first-ever actual images of a black hole. Black holes, a region of space with such a strong gravitational effect that nothing-including light-can escape it, are incredibly difficult to photograph because they are relatively tiny. Relatively. Because even though a black hole may be huge, like the one in the center of our own Milky Way, it is so relatively small that taking a photo of it is like "taking a photo of a DVD on the moon"*. So the EHT photos are a game-changer.
In that long-ago astronomy class, the pessimists thought black holes contained nothing. The optimists thought they might contain Nirvana. My version of Nirvana would include plenty of wine from pre-phylloxera, ungrafted vines. Some crazy old bottled in bond Bourbon, from before it became chic and limited. Bottles of Scotch from distilleries long-shuttered. A unicorn beer or three. Probably not, of course, but it's as good a guess as any.
So until the EHT photos show us exactly what that black hole contains, I'm taking the optimist's view.
*Dimitrios Psaltis, astrophysicist, University of Arizona