39 ideas
17884 | Mathematical set theory has many plausible stopping points, such as finitism, and predicativism [Koellner] |
17893 | 'Reflection principles' say the whole truth about sets can't be captured [Koellner] |
17894 | We have no argument to show a statement is absolutely undecidable [Koellner] |
17518 | Counting 'coin in this box' may have coin as the unit, with 'in this box' merely as the scope [Ayers] |
17516 | If counting needs a sortal, what of things which fall under two sortals? [Ayers] |
17890 | There are at least eleven types of large cardinal, of increasing logical strength [Koellner] |
17887 | PA is consistent as far as we can accept, and we expand axioms to overcome limitations [Koellner] |
17891 | Arithmetical undecidability is always settled at the next stage up [Koellner] |
17520 | Events do not have natural boundaries, and we have to set them [Ayers] |
17519 | To express borderline cases of objects, you need the concept of an 'object' [Ayers] |
17510 | Speakers need the very general category of a thing, if they are to think about it [Ayers] |
17522 | We use sortals to classify physical objects by the nature and origin of their unity [Ayers] |
17515 | Seeing caterpillar and moth as the same needs continuity, not identity of sortal concepts [Ayers] |
17511 | Recognising continuity is separate from sortals, and must precede their use [Ayers] |
17517 | Could the same matter have more than one form or principle of unity? [Ayers] |
17513 | If there are two objects, then 'that marble, man-shaped object' is ambiguous [Ayers] |
17523 | Sortals basically apply to individuals [Ayers] |
17521 | You can't have the concept of a 'stage' if you lack the concept of an object [Ayers] |
17514 | Temporal 'parts' cannot be separated or rearranged [Ayers] |
17509 | Some say a 'covering concept' completes identity; others place the concept in the reference [Ayers] |
17512 | If diachronic identities need covering concepts, why not synchronic identities too? [Ayers] |
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] |
20628 | The electric and magnetic are tightly linked, and viewed according to your own motion [Close] |
20622 | All motions are relative and ambiguous, but acceleration is the same in all inertial frames [Close] |
20635 | The general relativity equations relate curvature in space-time to density of energy-momentum [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] |
20630 | Light isn't just emitted in quanta called photons - light is photons [Close] |
20627 | Electric fields have four basic laws (two by Gauss, one by Ampère, one by Faraday) [Close] |
20637 | In general relativity the energy and momentum of photons subjects them to gravity [Close] |
20642 | Photon exchange drives the electro-magnetic force [Close] |
20639 | Quantum fields contain continual rapid creation and disappearance [Close] |
20631 | Dirac showed how electrons conform to special relativity [Close] |
20641 | Electrons get their mass by interaction with the Higgs field [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] |