You've probably seen the above image everywhere today. The first ever photograph of a black hole. BFD right? It looks like a blurry SpeghettiO smashed against the side of a can. Wrong.
Up until day, the evidence for black holes was indirect. Scientists could see their gravitational influence from the way stars behaved, or from gravitational waves which were only recently detected. But today was the first time in human history that a black hole had been observed.
This sucker is enormous. It exists about 55 million light-years away and could comfortably fit our entire solar system. It's hard to wrap your head around it, but I'm here to give you four fun facts you can "well actually..." your friends with this weekend. And what feels better than flexing on your friends with knowledge. Not a whole lot.
1. Black holes are dead stars
You've probably heard that when our sun dies, it'll swell up to a red giant and vaporize the inner planets before exploding. Pleasant. But that's not what happens with massive stars much larger than our sun. Once their fuel runs out, they collapse under their own gravity. The remaining matter is flung into space and what remains is a singularity of infinite density.
2. Time is bonkers near a black hole
The larger an object is, the more gravity it has. The more gravity an object has, the slower time moves. Think of it like this. You and three of your friends are holding a bed sheet by the corners. The sheet is the spacetime fabric. Someone drops a ping pong ball in the center of your sheet. That represents Earth. The sheet slightly warps. Now imagine someone drops a 100 lb iron ball in the middle of your sheet. The spacetime fabric would severely warp compared to the ping pong ball. So if you were unlucky enough to be falling into a black hole, time would move much slower for you compared to your luckier friends back on Earth.
3. There's a super massive black hole at the center of our galaxy
Has anyone seen it? No. We're at a bad angle. But we can see its influence in the behavior of surrounding stars. Not too worry. We're way too far away to get sucked in. You can go back to worrying about everything that can kill you on this planet alone.
4. Two of them crashed into each other a billion years ago, and we heard it in 2015
You may remember the big news a few years back about gravitational waves. Well what happened was a team of astrophysicists built two facilities to detect gravitational waves which hadn't been observed before. Basically they turned the machines on and BAM! Event detected. The waves rippling through spacetime were the result of a violent collision between two black holes over a billion light-years away. It even recorded the noise it made!
I write the words I'm too uncomfortable to say.