31 ideas
| 8755 | Maddy replaces pure sets with just objects and perceived sets of objects [Maddy, by Shapiro] |
| 13733 | Frege considered definite descriptions to be genuine singular terms [Frege, by Fitting/Mendelsohn] |
| 9874 | Contradiction arises from Frege's substitutional account of second-order quantification [Dummett on Frege] |
| 18252 | Real numbers are ratios of quantities, such as lengths or masses [Frege] |
| 18271 | We can't prove everything, but we can spell out the unproved, so that foundations are clear [Frege] |
| 10623 | Frege defined number in terms of extensions of concepts, but needed Basic Law V to explain extensions [Frege, by Hale/Wright] |
| 9975 | Frege ignored Cantor's warning that a cardinal set is not just a concept-extension [Tait on Frege] |
| 10718 | A natural number is a property of sets [Maddy, by Oliver] |
| 8756 | Intuition doesn't support much mathematics, and we should question its reliability [Maddy, by Shapiro] |
| 17733 | We know mind-independent mathematical truths through sets, which rest on experience [Maddy, by Jenkins] |
| 18165 | My Basic Law V is a law of pure logic [Frege] |
| 9190 | A concept is a function mapping objects onto truth-values, if they fall under the concept [Frege, by Dummett] |
| 13665 | Frege took the study of concepts to be part of logic [Frege, by Shapiro] |
| 20624 | Work degrades into heat, but not vice versa [Close] |
| 20623 | First Law: energy can change form, but is conserved overall [Close] |
| 20625 | Third Law: total order and minimum entropy only occurs at absolute zero [Close] |
| 20622 | All motions are relative and ambiguous, but acceleration is the same in all inertial frames [Close] |
| 20628 | The electric and magnetic are tightly linked, and viewed according to your own motion [Close] |
| 20635 | The general relativity equations relate curvature in space-time to density of energy-momentum [Close] |
| 20642 | Photon exchange drives the electro-magnetic force [Close] |
| 20627 | Electric fields have four basic laws (two by Gauss, one by Ampère, one by Faraday) [Close] |
| 20630 | Light isn't just emitted in quanta called photons - light is photons [Close] |
| 20637 | In general relativity the energy and momentum of photons subjects them to gravity [Close] |
| 20629 | Electro-magnetic waves travel at light speed - so light is electromagnetism! [Close] |
| 20632 | In QED, electro-magnetism exists in quantum states, emitting and absorbing electrons [Close] |
| 20639 | Quantum fields contain continual rapid creation and disappearance [Close] |
| 20641 | Electrons get their mass by interaction with the Higgs field [Close] |
| 20631 | Dirac showed how electrons conform to special relativity [Close] |
| 20626 | Modern theories of matter are grounded in heat, work and energy [Close] |
| 20633 | The Higgs field is an electroweak plasma - but we don't know what stuff it consists of [Close] |
| 20640 | Space-time is indeterminate foam over short distances [Close] |