Sean Carroll

Physics is, by far, the simplest science. It doesn’t seem that way, because we know so much about it, and the required knowledge often seems esoteric and technical. But it is blessed by this amazing feature: we can very often make ludicrous simplifications—frictionless surfaces, perfectly spherical bodies—ignoring all manner of ancillary effects, and nevertheless get results that are unreasonably good. For most interesting problems in other sciences, from biology to psychology to economics, if you modeled one tiny aspect of a system while pretending all the others didn’t exist, you would just end up getting nonsense.