One of the beauties of Stevin's setup is that it uses a familiar, everyday effect. The result of the test triggers the most basic characteristic of the brilliant researcher. This isn't curiosity, as is commonly thought, but perceptiveness: the ability to see what everyone else can see, too, only better, or more connected to other things, more cleverly abstracted from circumstantial clutter, or more broadly generalized.

As an example, consider the statement The sky is dark at night. This truism is, on closer inspection, quite remarkable and non-obvious. Another example of a fact that is so strange that it borders on the bizarre: I am not the average of my parents, especially if we see it together with the fact I resemble both of my parents. The darkness at night is due to a subtle combination of effects. The most prominent of these are: stars cannot emit more light than a certain maximum; the Universe expands; the Universe has a finite age. That people are not the average of their parents, even though they resemble both of them rather closely, turns out to be mostly due to the fact that we are built out of elementary particles.

Everyday phenomena are almost completely incomprehensible in their raw appearance, so they are a very bad guide to physics. The world is messy, and there is not a single observation – whether in the days of Archimedes or in the days of the European Extremely Large Telescope – that is free from the interference of side effects. To make matters worse, if we speak about physics, we are obliged to use words that have an established common meaning already, such as ‘energy’, ‘force’ or ‘symmetry’.

It is useful to return one final time to the subject of ‘laws of nature’. I will argue that these do not exist if, by ‘law’, we mean some sort of Ultimate Truth that will never change once we have discovered it. If science were a methodical process that zooms in on ‘natural laws’ by steps big and small, then we would expect that it would always be fairly clear what course to take. But the quest for the mechanisms of the Universe has led us to a point from which there is no visible road ahead.