All That Space
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LMR-006 · Stars

Fusion

How to make sunlight: squeeze hydrogen until it gives up.
§ 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.
Deep inside the Sun, it is so unbelievably hot and the squeeze is so unbelievably strong that the tiniest pieces of hydrogen get smashed into each other so hard they actually stick together — and become a slightly bigger thing called helium. Every time two of them stick, a tiny burst of energy is set free. The Sun is doing this trick about a million billion billion billion times every second, and has been for 4.6 billion years without taking a single day off. That warmth on your face when you step outside? It's hydrogen losing a fight. Sunlight is just the cheering.
§ Strange but true
  1. 01When you press hydrogen together, the result weighs slightly less than the pieces. That missing weight is the sunlight.
  2. 02Iron is the dead end. Stars can't fuse past it for profit — so every atom of gold in your jewelry was born in a colliding neutron star.
  3. 03Fusion needs 100 million °C. Quantum tunneling lets the Sun cheat and do it at a chilly 15 million.
§ From the field journal
Fusion

"How to make sunlight: squeeze hydrogen until it gives up."

— observed, sketched, not yet fully understood.

field sketch · graphite & gold leaf
§ Nearby

Constellations near Fusion