Why is the water boiling?

Because it’s hot.

Because I put the kettle on.

Because electricity flows through a high-resistance metal coil inside the kettle and converts electrical energy into heat energy according to the formula ΔE = I*R*Δt.

Because water at roughly one atmosphere of pressure undergoes a gas-liquid phase transition at 100° Celcius.

Because I want coffee, because I always want coffee at this time in the morning.

Because if an invisible scientist was secretly living in my house, recording everything I do and plotting graphs, she would be able to predict my water boiling behaviour to within ±20 minutes’ accuracy, four times out of five.

How could it not be boiling? To imagine that is to imagine an alien universe.


Water phase diagram. Y-axis=Pressure in pascals (10n). X-axis=Temperature in kelvins. S=Solid; L=Liquid; V=Vapour, CP=Critical Point, TP=Triple Point. Graph by Eurico Zimbres, licensed CC BY-SA.

Because hydrogen bonding.

Because caffeine.

Because we only see little pieces of our universe, we never see the whole picture. When we find a connection between two of the little pieces we call that Cause and Effect. We think we have achieved Understanding, and we think that since our Understanding is true all other understandings must be false. We don’t think about all the other little pieces and all the other connections that we don’t see, that must be out there.

A bright purple banner with the text: 'Cause and Effect: it's complicated'