Our Mathematical Universe: My Quest for the Ultimate Nature of Reality

by Max Tegmark

there are also quantities encoded in nature that aren’t whole numbers, but require decimals to write out. Nature encodes 32 such fundamental numbers according to my latest count. Does the number shown when you stand on your bathroom scale count as such a number? No, that number doesn’t count, because it’s measuring something (your mass) that changes from day to day and therefore isn’t a basic property of our Universe. What about the mass of a proton, 1.672622 × 10−27kg, or the mass of an electron, 9.109382 × 10−31kg, which seem to stay perfectly constant over time? They don’t count either, because they’re measuring the number of kilograms, and that’s just a rather arbitrary unit of mass that we humans have made up. But if you divide one of these last two numbers by the other, then you get something truly fundamental: the proton is about 1836.15267 more massive than the electron.1 1836.15267 is a pure number, just as π or , in the sense that it’s a quantity that doesn’t involve any human units of measurement such as grams, meters, seconds or volts. Why is it close to 1836? Why not 2013? Why not 42? The short answer is that we don’t know, but that we think we can in principle calculate this number and every other fundamental constant of nature ever measured from just the 32 numbers listed in Table 10.1.