A pre-eminent scientist was recently asked what single piece of information he would preserve if some sort of Asimovian catastrophe destroyed all our scientific knowledge and only one idea could be preserved. The scientist neglected such profound insights as evolution by natural selection and instead favoured passing on the concepts of atomic theory to this hypothetical knowledge-impoverished society. The reason given was that there exists no other simple idea which provides such a wide scope of insight, that idea being that all matter is made up of irreducible units called atoms.
For those among us who chose not to pursue scientific education in later life, atomic theory most likely is one of several factoids that you vaguely remember learning in high school. You recall something about Neils Bohr, and that plum puddings were somehow important. Well your lack of recollection is perhaps more forgivable when we consider that the Ancient Greeks long debated this theory whose validity we now all take for granted.
Long before they decided to stop paying taxes and mooch off Germany, many great Greek minds devoted themselves to the question of whether all matter was a continuum, or whether it was made up of discrete units. In the case of the continuum, this would imply that you could divide any piece of matter into forever smaller parts and it would never fundamentally change. For example, say I had a piece of bread, then I could keep cutting it up and no matter how small I cut it, it would still be bread. The other school of thought took the position that there would come a point where you’d get to an irreducible element, so if you tried to divide that element the matter making up your bread would somehow be different. We now know that it was the latter school of thought who were correct in asserting that our universe is made up of many different types of discrete elements, called atoms.
The consequences of this knowledge are perhaps not readily apparent, what does it matter that if I divide up my sandwich a near infinite amount of times then I will eventually split a carbon atom into two lighter elements? Well this discovery has spawned off many significant fields of study, to name a few, nuclear, quantum and particle physics. Furthermore, this idea is the central tenet of chemistry, for which you can thank our current knowledge of fermentation, the process that drives brewing beer. So while the chances of all scientific knowledge being lost seems remote in the face of our tendency to ‘back up, early and often’; it is perhaps worthwhile reflecting on the power of simple ideas to radically shape our understanding of the universe in which we live.