(Spoiler alert for Interstellar). Contrary to popular opinion, the insides of black holes probably do not contain Matthew McConaughey's library. And even if they did contain Matthew McConaughey's library, which is pretty unlikely, it would be extremely difficult to confirm this one way or the other.
Black holes, you see, have a boundary called the event horizon, This is the point where gravity is strong enough to drag light back, and prevent it from escaping. And because nothing can travel faster than light, everything you could possibly think of (including Matthew McConaughey's library) would get dragged back into it.
Stephen Hawking once summarised the concept of a black hole when he said that "Falling through the event horizon, is a bit like going over Niagara Falls in a canoe." Grand mysteries such as black holes are feared by people because nothing, as far as we know, has ever entered one and lived to tell the tale.
With that in mind, you might be concerned to hear that a "monster" black hole has become active again after being dormant for 26 years. Now, we're not saying that it's time to panic, but it might be an idea to get in your garage and start converting your Volkswagen so that it's suitable for long-distance space travel (just in case).
Scientists, presumably in long white lab coats, have observed the black hole in V404 Cygni (a binary system that's some 8,000 light-years away from earth). Alarmingly, if you're an extraterrestrial that's living nearby, the black hole has started to eat a neighbouring star. This has resulted in a spectacular high-energy light show.
Gamma rays and X-rays picked up the black hole feasting upon, and simultaneously sucking up the leftovers of the star like your dad at an all-you-can-eat buffet. Basically, when it comes to feeding themselves, black holes are the polar opposites of fussy eaters. They literally devour all-forms of matter (including cauliflower omelettes).
As the proximity between the black hole and the star decreases, it's possible to briefly observe light emissions from the star heating up and shining brightly upon wavelengths across the electromagnetic spectrum before they disappear completely into the total darkness of this cosmic Camden goth (a.k.a. the black hole).
8,000 light-years might sound like a really long way away and, you'd be right, it is. That being said, the fact that this thing is out there has certainly made us think about our place in the universe all over again. It's also, as you might have guessed, put us in the mood to watch Interstellar one more time.