How many smells can a smelly person smell? 1 trillion or 10?

Earlier this year, a paper in Science attempted to answer the question: how many smells can we actually smell? At least one trillion, they claimed. Recently, Markus Meister posted a paper on arxiv which made the bold claim that we can smell at least ten smells! Or at least that the data was just as consistent with ten smells as one trillion smells.

Let’s start with the original claim – that humans can differentiate between at least a trillion smells. These experimenters chose 128 molecules and mixed them together in differing amounts. A little bit of molecule A here, a dash of molecule B there. These delectable treats were then presented in pairs to subjects who were tasked with answering whether they were given the same delight from this perfumerie or given two different scents. By imagining these odors as balls of different smells; push them too near each other and…