Predicting and discovering in chemistry

While in common parlance ‘prediction’ concerns claims about things that have not happened yet, this is not how it is construed in science. Paleontology makes predictions about animals and plants that existed millions of years ago. Astrochemistry makes predictions about things that are happening now but to which we have no direct observable access, such as the chemical composition of the atmosphere of distant stars or planets. More generally, scientific predictions are claims about objects, processes or phenomena that have not yet been sufficiently corroborated through reliable empirical means. The ability of a theory, model or scientific hypothesis to correctly predict how an object, process or phenomenon unfolds is considered not just a virtue but also empirical evidence that it says something correct about the world.

As with prediction, discovery can also mean different things. A scientific discovery is often associated with acquiring new insight. In this context it can refer to the discovery of an object (such as a planet, element or form of energy) or to the discovery of a previously unknown property or process (such as that the earth moves around the sun). What is important in cases of purported scientific discoveries is that they carry considerable epistemic weight: the discovery is not perceived as a conjecture but as an empirically well-established fact.