10 ideas
| 17813 | Löwenheim-Skolem says any theory with a true interpretation has a model in the natural numbers [White,NP] |
| Full Idea: The Löwenheim-Skolem theorem tells us that any theory with a true interpretation has a model in the natural numbers. | |
| From: Nicholas P. White (What Numbers Are [1974], V) |
| 17812 | Finite cardinalities don't need numbers as objects; numerical quantifiers will do [White,NP] |
| Full Idea: Statements involving finite cardinalities can be made without treating numbers as objects at all, simply by using quantification and identity to define numerically definite quantifiers in the manner of Frege. | |
| From: Nicholas P. White (What Numbers Are [1974], IV) | |
| A reaction: [He adds Quine 1960:268 as a reference] |
| 20653 | Six reduction levels: groups, lives, cells, molecules, atoms, particles [Putnam/Oppenheim, by Watson] |
| Full Idea: There are six 'reductive levels' in science: social groups, (multicellular) living things, cells, molecules, atoms, and elementary particles. | |
| From: report of H.Putnam/P.Oppenheim (Unity of Science as a Working Hypothesis [1958]) by Peter Watson - Convergence 10 'Intro' | |
| A reaction: I have the impression that fields are seen as more fundamental that elementary particles. What is the status of the 'laws' that are supposed to govern these things? What is the status of space and time within this picture? |
| 24162 | Planck introduced the idea that energy can be quantized [Baggott] |
| Full Idea: By deriving his radiation law, Planck had inadvertently introduced the idea that energy itself could be 'quantized'. | |
| From: Jim Baggott (The Quantum Story: 40 moments [2011], 01) | |
| A reaction: He earlier assumed energy is continuously variable. I presume this means that the older idea of energy is now subsumed into the concept of fields, which are quantized into particles. The powers of nature are found in the fields. |
| 21731 | Fields can be 'scalar', or 'vector', or 'tensor', or 'spinor' [Baggott] |
| Full Idea: Fields can be 'scalar', with no particular direction (pointing, but not pushing or pulling); or 'vector', with a direction (like magnetism, or Newtonian gravity); or 'tensor' (needing further parameters); or 'spinor' (depending on spin orientation). | |
| From: Jim Baggott (Farewell to Reality: fairytale physics [2013], 2 'Quantum') | |
| A reaction: [compressed] So the question is, why do they differ? What is it in the nature of each field the result in a distinctive directional feature? |
| 21730 | A 'field' is a property with a magnitude, distributed across all of space and time [Baggott] |
| Full Idea: A 'field' is defined in terms of the magnitude of some physical property distributed over every point in time and space. | |
| From: Jim Baggott (Farewell to Reality: fairytale physics [2013], 2 'Quantum') | |
| A reaction: If it involves a 'property', normal usage entails that there is some entity which possesses the property. So what's the entity? Eh? Eh? You don't know! Disappointed... |
| 24163 | Free electrons have clouds of virtual particles, arising from field interaction [Baggott] |
| Full Idea: A free electron doesn't simply persist as a point particle travelling along a predetermined, classical path; it is surrounded by a swarm of virtual particles arsising from self-interactions with its own magnetic field. | |
| From: Jim Baggott (The Quantum Story: 40 moments [2011], 19) | |
| A reaction: It seems to me important for amateurs and mere philosophers to hang on to this idea of virtual particles, because they undermine any attempt to impose a macro picture on sub-atomic events. |
| 24161 | Thermodynamics sees nature as a continuous flow of energy, as radiation and as substance [Baggott] |
| Full Idea: Thermodynamics reinforced a vision of nature as one of harmonious flow. Energy, which could be neither created nor destroyed, flowed continuously between radiation and material substance, in themselves unbroken continua. | |
| From: Jim Baggott (The Quantum Story: 40 moments [2011], 01) | |
| A reaction: Interestingly, Einstein's Special Relativity e = mc2 seems to endorse this view, by equation energy and mass. I've always wanted to know what energy is, but no one seems to know. |
| 21732 | The current standard model requires 61 particles [Baggott] |
| Full Idea: The current model requires 61 particles: three generations of two leptons and two flavours of quark, in three different colours (making 24); the anti-particles of all of these (48); 12 force particles (photon, W1, Z0, 8 gluons), and a Higgs boson. | |
| From: Jim Baggott (Farewell to Reality: fairytale physics [2013], 6 n) |
| 24160 | Particle measurements don't seem to reflect their reality [Baggott] |
| Full Idea: It seems that we can no longer assume that the particle properties we measure necessarily reflect or represent the properties of the particles as they really are. | |
| From: Jim Baggott (The Quantum Story: 40 moments [2011], Pref) | |
| A reaction: [He cites a 2006 experiment] This gives an interesting response to the Copenhagen Interpretation - that observers appear to be creating the reality they observe, because they only have 'observations', with no reality to correspond to them. I like it. |