23 ideas
17824 | The master science is physical objects divided into sets [Maddy] |
17825 | Set theory (unlike the Peano postulates) can explain why multiplication is commutative [Maddy] |
17826 | Standardly, numbers are said to be sets, which is neat ontology and epistemology [Maddy] |
17828 | Numbers are properties of sets, just as lengths are properties of physical objects [Maddy] |
17827 | Sets exist where their elements are, but numbers are more like universals [Maddy] |
17830 | Number theory doesn't 'reduce' to set theory, because sets have number properties [Maddy] |
17823 | If mathematical objects exist, how can we know them, and which objects are they? [Maddy] |
17829 | Number words are unusual as adjectives; we don't say 'is five', and numbers always come first [Maddy] |
20239 | Unlike us, the early Greeks thought envy was a good thing, and hope a bad thing [Hesiod, by Nietzsche] |
21202 | The strong force has a considerably greater range than the weak force [Martin,BR] |
21211 | If an expected reaction does not occur, that implies a conservation law [Martin,BR] |
21209 | Electron emit and reabsorb photons, which create and reabsorb virtual electrons and positrons [Martin,BR] |
21212 | The Higgs field, unlike others, has a nozero value in a state without particles [Martin,BR] |
21201 | A 'field' is just a region to which points can be assigned in space and time [Martin,BR] |
21205 | Many physicists believe particles have further structure, if only we could see it [Martin,BR] |
21203 | Uncertainty allows very brief violations of energy conservation - even shorter with higher energies [Martin,BR] |
21207 | The Exclusion Principle says no two fermions occupy the same state, with the same numbers [Martin,BR] |
21204 | The standard model combines theories of strong interaction, and electromagnetic and weak interaction [Martin,BR] |
21208 | Eletrons don't literally 'spin', because they are point-like [Martin,BR] |
21210 | Virtual particles surround any charged particle [Martin,BR] |
21206 | The properties of a particle are determined by its quantum numbers and its mass [Martin,BR] |
21213 | String theory only has one free parameter (tension) - unlike the standard model with 19 [Martin,BR] |
21200 | An 'element' is what cannot be decomposed by chemistry [Martin,BR] |