Notice the difference between ‘science in the making’ and ‘ready made science’ as described by Bruno Latour1. The first involves debate and discussion about matters which are uncertain, with a lot of speculative talk about possibilities and how to design an experimental test or what to search for as crucial observations. It is full of argument over how to interpret evidence and what can be taken as acceptable evidence. It is driven by a desire for insight into ‘what might be going on’—that is, some mental model of how things work. Practical activity is embedded in animated talk about all those things, and because no one definitely possesses ‘the’ right answer yet, there is an equality of status amongst the talkers.