IT SOUNDS like a creature from a sci-fi movie, but yocto is both more and less exotic than that: it’s a numerical prefix denoting an extremely small number.
To save writing all those zeros when noting very small or large amounts, scientists devised some short-cut prefixes. But while we’ve all heard of a milligram (a thousandth of a gram), a kilometre (a thousand metres) and perhaps a gigawatt (a billion watts), what about a yoctogram? It is 10-24 of a gram, about 60 per cent of the mass of a neutron. And yocto, along with yotta (1024…
