A school science refresher: the 3 primary states of matter, solids, liquids and gases and the transitions between each one. If you’re like me you probably forget about the more obscure sublimation and deposition directly between solids and gases. And vaporisation of a liquid is evaporation, occurring at the surface, if it is below boiling point, otherwise it’s boiling.

There are some more unusual states including plasma — seen in lightning and fluorescent lights — and Bose-Einstein condensates, but mostly we’re familiar with ice cubes, water and steam.

States of matter

Turns out a bunch of substances have the power to make you sleepy - tryptophan, vitamin B6, calcium, glycine, lactucarium and carbohydrates are some of the major ones. Some even interact with each other for maximum sleepiness. A few common foods with these compounds in good measure include:

turkey, walnuts - tryptophan
tuna, pistachios - vitamin B6
dairy - calcium
chamomile - glycine
lettuce - lactucarium

So an evening turkey or tuna, walnut, cheese and lettuce sandwich with a glass of milk and a side of pistachios or walnuts and you’ll be set for a good night.

Sleepy foods

How soap gets things clean is pretty amazing. What’s really nice is how the chemical properties generate such a simple mechanical solution.

The magic of soap

Whichever way you look at it, water is a remarkable substance.

Chemistry sketches