LMR-092 · Black Holes
Accretion Disk
The brightest things in the universe are made of stuff falling.
§ A first look
§ Depths
Six ways into the same idea — from bedtime story to chalkboard. No order required.
L1 · Crayon
Told like a bedtime story.
For a curious 10-year-old. No jargon. Just a picture in your head.
When water drains down a bathtub, it usually doesn't go straight in — it whirls around and around the drain in a little swirling disc on its way down. The exact same thing happens when gas falls toward a very heavy thing in space, like a black hole. The gas spirals in instead of plunging straight, and as it whirls it rubs against itself and gets fantastically hot — millions of degrees hot — and so it glows extremely brightly. That flat, hot, glowing whirlpool of in-falling gas is called an accretion disk. Most of what we 'see' from a black hole is actually the gas getting upset about being eaten.
§ Strange but true
- 01Material spirals in at nearly the speed of light, heated by friction to millions of degrees — bright enough to outshine a galaxy.
- 02Quasars are accretion disks around supermassive black holes. We can see them across 13 billion light-years.
- 03The disk is flatter than a vinyl record relative to its size. Spin organizes everything.
§ From the field journal
Accretion Disk
"The brightest things in the universe are made of stuff falling."
— observed, sketched, not yet fully understood.
§ Nearby