33 ideas
13030 | Extensionality: ∀x ∀y (∀z (z ∈ x ↔ z ∈ y) → x = y) [Kunen] |
13032 | Pairing: ∀x ∀y ∃z (x ∈ z ∧ y ∈ z) [Kunen] |
13033 | Union: ∀F ∃A ∀Y ∀x (x ∈ Y ∧ Y ∈ F → x ∈ A) [Kunen] |
13037 | Infinity: ∃x (0 ∈ x ∧ ∀y ∈ x (S(y) ∈ x) [Kunen] |
13038 | Power Set: ∀x ∃y ∀z(z ⊂ x → z ∈ y) [Kunen] |
13034 | Replacement: ∀x∈A ∃!y φ(x,y) → ∃Y ∀X∈A ∃y∈Y φ(x,y) [Kunen] |
13039 | Foundation:∀x(∃y(y∈x) → ∃y(y∈x ∧ ¬∃z(z∈x ∧ z∈y))) [Kunen] |
13036 | Choice: ∀A ∃R (R well-orders A) [Kunen] |
13029 | Set Existence: ∃x (x = x) [Kunen] |
13031 | Comprehension: ∃y ∀x (x ∈ y ↔ x ∈ z ∧ φ) [Kunen] |
13040 | Constructibility: V = L (all sets are constructible) [Kunen] |
18465 | An 'equivalence' relation is one which is reflexive, symmetric and transitive [Kunen] |
20239 | Unlike us, the early Greeks thought envy was a good thing, and hope a bad thing [Hesiod, by Nietzsche] |
21181 | Relativity and Quantum theory give very different accounts of forces [Hesketh] |
21183 | Thermodynamics introduced work and entropy, to understand steam engine efficiency [Hesketh] |
21199 | Spinning electric charge produces magnetism, so all fermions are magnets [Hesketh] |
21191 | Photons are B and W° bosons, linked by the Higgs mechanism [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] |