Coffee Cup Science

Welcome to that part of the website where we delve into anecdotes and experiments that relate the physics of coffee to the physics of the universe as a whole. Please click the links below to explore.

Coffee and wine

Tears of WineAll liquids have surface tension.  The surface tension of alcohol is weaker than that of coffee, watch what happens when the two are brought together.


A connection between coffee and exploding stars

Milk RingSmoke rings are in fact found throughout nature, not just in smoke.  This section shows how ‘smoke rings’ can be seen by adding drops of milk (or coffee) to water and then explores where else in nature ‘smoke rings’ are observed, in the aftermath of an exploding star for example.


Blue Sky Thinking

Blue sky, light scattering, Tyndall blueThe colour of the sky is caused by scattering of light from the air molecules in the atmosphere.  An analogue can be found in a glass of diluted milk. Explore why the sky is blue (and sunsets red) with equipment you can find in your kitchen.


Why coffee is a bad idea for your smart phone

CoffeeStainCoffee rings can be irritating, but have you ever stopped to wonder why these stains form the way that they do?  Explore the reasons for coffee ring formation and the consequences this has for today’s electronics industry.


Kelvin, Darwin and cooling coffee

pigeon, sun, sunbathing, age of the earthThe physics determining how hot objects cool is the same whether that object is a cup of coffee or the Sun.  One hundred and fifty years ago this observation led to problems reconciling theories based on the latest physics and the latest biology of the day.


Cafe Physics Reviews


Take time to slow down and to look around you. Many cafes are full of unexpected connections to different aspects of science, from the Giant’s Causeway through to the effects of rainforest deforestation, often with some interesting history thrown in.



More stories can be found in the Bean thinking blog “The Daily Grind“.  If you have a suggestion for a topic to include in “Coffee cup science” or you have any comments on the articles above please contact me.