42 ideas
21943 | Since Kant, self-criticism has been part of philosophy [Gutting] |
21944 | Structuralism describes human phenomena in terms of unconscious structures [Gutting] |
10859 | A set is 'well-ordered' if every subset has a first element [Clegg] |
10857 | Set theory made a closer study of infinity possible [Clegg] |
10864 | Any set can always generate a larger set - its powerset, of subsets [Clegg] |
10872 | Extensionality: Two sets are equal if and only if they have the same elements [Clegg] |
10875 | Pairing: For any two sets there exists a set to which they both belong [Clegg] |
10876 | Unions: There is a set of all the elements which belong to at least one set in a collection [Clegg] |
10878 | Infinity: There exists a set of the empty set and the successor of each element [Clegg] |
10877 | Powers: All the subsets of a given set form their own new powerset [Clegg] |
10879 | Choice: For every set a mechanism will choose one member of any non-empty subset [Clegg] |
10871 | Axiom of Existence: there exists at least one set [Clegg] |
10874 | Specification: a condition applied to a set will always produce a new set [Clegg] |
10880 | Mathematics can be 'pure' (unapplied), 'real' (physically grounded); or 'applied' (just applicable) [Clegg] |
10860 | An ordinal number is defined by the set that comes before it [Clegg] |
10861 | Beyond infinity cardinals and ordinals can come apart [Clegg] |
10854 | Transcendental numbers can't be fitted to finite equations [Clegg] |
10858 | By adding an axis of imaginary numbers, we get the useful 'number plane' instead of number line [Clegg] |
10853 | Either lack of zero made early mathematics geometrical, or the geometrical approach made zero meaningless [Clegg] |
10866 | Cantor's account of infinities has the shaky foundation of irrational numbers [Clegg] |
10869 | The Continuum Hypothesis is independent of the axioms of set theory [Clegg] |
10862 | The 'continuum hypothesis' says aleph-one is the cardinality of the reals [Clegg] |
21181 | Relativity and Quantum theory give very different accounts of forces [Hesketh] |
21183 | Thermodynamics introduced work and entropy, to understand steam engine efficiency [Hesketh] |
21191 | Photons are B and W° bosons, linked by the Higgs mechanism [Hesketh] |
21199 | Spinning electric charge produces magnetism, so all fermions are magnets [Hesketh] |
21189 | Electrons may have smaller components, bound by a new force [Hesketh] |
21180 | Electrons are fundamental and are not made of anything; they are properties without size [Hesketh] |
21182 | Quantum mechanics is our only theory, and is very precise, and repeatedly confirmed [Hesketh] |
21184 | Physics was rewritten to explain stable electron orbits [Hesketh] |
21187 | Virtual particles can't be measured, and can ignore the laws of physics [Hesketh] |
21185 | Colour charge is positive or negative, and also has red, green or blue direction [Hesketh] |
21194 | The Standard Model omits gravity, because there are no particles involved [Hesketh] |
21195 | In Supersymmetry the Standard Model simplifies at high energies [Hesketh] |
21197 | Standard Model forces are one- two- and three-dimensional [Hesketh] |
21188 | Quarks and leptons have a weak charge, for the weak force [Hesketh] |
21186 | Quarks rush wildly around in protons, restrained by the gluons [Hesketh] |
21192 | Neutrinos only interact with the weak force, but decays produce them in huge numbers [Hesketh] |
21196 | To combine the forces, they must all be the same strength at some point [Hesketh] |
21190 | 'Space' in physics just means location [Hesketh] |
21193 | The universe is 68% dark energy, 27% dark matter, 5% regular matter [Hesketh] |
21198 | If a cosmic theory relies a great deal on fine-tuning basic values, it is probably wrong [Hesketh] |