This is the very reason he was in such a hurry to slow down the neutrons with deuterium. Alone, he could not force his colleagues to believe him. If he could get his reactor going for only a few seconds, and if he could get evidence of this event that was sufficiently clear that no one could accuse him of seeing only what he wanted to see, then Joliot would no longer be alone. With him, behind him, disciplined and supervised by his collaborators, and properly lined up, the neutrons of the reactor could be made visible in the form of a cross-sectional diagram. The experiment in the shed at Ivry was very expensive, but it  was precisely this expense that would force his esteemed colleagues to take his article in Nature seriously. Science studies, once again, does not take a position in a classical debate – is it rhetoric or proof that finally convinces scientists? – but reconfigures the whole question in order to understand this strange hybrid: a copper sphere built to convince. (Latour 1999:95-6)
For six months Joliot was the only one in the world who had at his disposal the material resources allowing him to mobilize both colleagues and neutrons around and inside a real reactor. Joliot’s opinion by itself could be swept aside with a wave of the hand; Joliot’ s opinion supported by Halban’s and Kowarski’s diagrams, diagrams obtained from the copper sphere in the shed at Ivry, could not so easily be cast aside – the proof being that three countries at war immediately set to work at building their own reactors. Disciplining men and mobilizing things, mobilizing things by disciplining men; this is a new way of convincing, sometimes called scientific research. (Latour 1999:96)
As we will see, the energy with which Joliot pushed Szilard, Kowarski, Dautry, and all the others is proportional to the number of resources and interests he had already mobilized. If the reactor fails, if each neutron liberates no more than one other neutron, then all these accumulated resources will scatter and disperse. It will no longer be worth going to all this trouble. This line of research will be seen as costly, useless, or premature, and Joliot’s words will begin to lie, to lack reference. What matters for science studies is that a heterogeneous assembly of hitherto unrelated elements now shares a common fate within a common collective, and that Joliot’s words will become true or false according to what circulates throughout this entire newly assembled collective. It is too late to claim that ontological and epistemological questions should be kept neatly distinct. Because of Joliot’s work these questions are now tied to one another, and the relevance of what he says to what the world is really like now hinges on what happens in the copper sphere at Ivry.(Latour 1999:98)
LATOUR, Bruno. 1999. Pandora’s Hope: essays on the reality of science studies. London: Harvard University Press.