58 ideas
| 17774 | Definitions make our intuitions mathematically useful [Mayberry] |
| 17773 | Proof shows that it is true, but also why it must be true [Mayberry] |
| 17795 | Set theory can't be axiomatic, because it is needed to express the very notion of axiomatisation [Mayberry] |
| 17796 | There is a semi-categorical axiomatisation of set-theory [Mayberry] |
| 17800 | The misnamed Axiom of Infinity says the natural numbers are finite in size [Mayberry] |
| 17801 | The set hierarchy doesn't rely on the dubious notion of 'generating' them [Mayberry] |
| 17803 | Limitation of size is part of the very conception of a set [Mayberry] |
| 17786 | The mainstream of modern logic sees it as a branch of mathematics [Mayberry] |
| 17788 | First-order logic only has its main theorems because it is so weak [Mayberry] |
| 17791 | Only second-order logic can capture mathematical structure up to isomorphism [Mayberry] |
| 17787 | Big logic has one fixed domain, but standard logic has a domain for each interpretation [Mayberry] |
| 17790 | No Löwenheim-Skolem logic can axiomatise real analysis [Mayberry] |
| 17779 | 'Classificatory' axioms aim at revealing similarity in morphology of structures [Mayberry] |
| 17778 | Axiomatiation relies on isomorphic structures being essentially the same [Mayberry] |
| 17780 | 'Eliminatory' axioms get rid of traditional ideal and abstract objects [Mayberry] |
| 17789 | No logic which can axiomatise arithmetic can be compact or complete [Mayberry] |
| 17784 | Real numbers can be eliminated, by axiom systems for complete ordered fields [Mayberry] |
| 17782 | Greek quantities were concrete, and ratio and proportion were their science [Mayberry] |
| 17781 | Real numbers were invented, as objects, to simplify and generalise 'quantity' [Mayberry] |
| 17799 | Cantor's infinite is an absolute, of all the sets or all the ordinal numbers [Mayberry] |
| 17797 | Cantor extended the finite (rather than 'taming the infinite') [Mayberry] |
| 17775 | If proof and definition are central, then mathematics needs and possesses foundations [Mayberry] |
| 17776 | The ultimate principles and concepts of mathematics are presumed, or grasped directly [Mayberry] |
| 17777 | Foundations need concepts, definition rules, premises, and proof rules [Mayberry] |
| 17804 | Axiom theories can't give foundations for mathematics - that's using axioms to explain axioms [Mayberry] |
| 17792 | 1st-order PA is only interesting because of results which use 2nd-order PA [Mayberry] |
| 17793 | It is only 2nd-order isomorphism which suggested first-order PA completeness [Mayberry] |
| 17794 | Set theory is not just first-order ZF, because that is inadequate for mathematics [Mayberry] |
| 17802 | We don't translate mathematics into set theory, because it comes embodied in that way [Mayberry] |
| 17805 | Set theory is not just another axiomatised part of mathematics [Mayberry] |
| 17785 | Real numbers as abstracted objects are now treated as complete ordered fields [Mayberry] |
| 22717 | Self-interest can fairly divide a cake; first person cuts, second person chooses [Poundstone] |
| 22718 | Formal game theory is about maximising or minimising numbers in tables [Poundstone] |
| 22719 | The minimax theorem says a perfect game of opposed people always has a rational solution [Poundstone] |
| 22720 | Two prisoners get the best result by being loyal, not by selfish betrayal [Poundstone] |
| 22721 | The tragedy in prisoner's dilemma is when two 'nice' players misread each other [Poundstone] |
| 22722 | TIT FOR TAT says cooperate at first, then do what the other player does [Poundstone] |
| 22723 | Do unto others as you would have them do unto you - or else! [Poundstone] |
| 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] |