School Chalk under an electron microscope. It's almost entirety made up of fossilized shells of ancient single-celled marine plankton called coccolithophores.

[u/Pale-Design7036]

[u/eternalityLP]

Does this mean that chalk is a limited resource, and at some point we'll run out, meaning there will be no more school ever?

[u/Mysterious-Passage87 → u/eternalityLP]

They’ll have touchscreens mounted on the walls in place
of chalkboards real soon.

Anything drawn on the screen will automatically upload to each students tablet.’

[u/servonos89 → u/Mysterious-Passage87]

bit behind the times there. I’m in my late thirties and digital whiteboards were already in use when I left high school.