Sis is a god.

She takes the form of an extremely fat, humorless crow.

Sis created a quark nine billion years ago.

If you believe in Sis, she will visit you to thank you.

If you do not believe in Sis, she will destroy your favourite planet.

Sis' most sacred site is Brechfa in Wales.

Sis' Holy Commandments

1. Never think about quantum field theory near nematodes while wearing red hats and balancing six tin spheres on your hands.

2. Never write about black holes.

3. Never feed nuts to snakes while wearing white rings.

4. Do not dye your hair fawn.

5. Never pour water over plants.