11 ideas
| 6007 | If you know your father, but don't recognise your father veiled, you know and don't know the same person [Eubulides, by Dancy,R] |
| Full Idea: The 'undetected' or 'veiled' paradox of Eubulides says: if you know your father, and don't know the veiled person before you, but that person is your father, you both know and don't know the same person. | |
| From: report of Eubulides (fragments/reports [c.390 BCE]) by R.M. Dancy - Megarian School | |
| A reaction: Essentially an uninteresting equivocation on two senses of "know", but this paradox comes into its own when we try to give an account of how linguistic reference works. Frege's distinction of sense and reference tried to sort it out (Idea 4976). |
| 6006 | If you say truly that you are lying, you are lying [Eubulides, by Dancy,R] |
| Full Idea: The liar paradox of Eubulides says 'if you state that you are lying, and state the truth, then you are lying'. | |
| From: report of Eubulides (fragments/reports [c.390 BCE]) by R.M. Dancy - Megarian School | |
| A reaction: (also Cic. Acad. 2.95) Don't say it, then. These kind of paradoxes of self-reference eventually lead to Russell's 'barber' paradox and his Theory of Types. |
| 6008 | Removing one grain doesn't destroy a heap, so a heap can't be destroyed [Eubulides, by Dancy,R] |
| Full Idea: The 'sorites' paradox of Eubulides says: if you take one grain of sand from a heap (soros), what is left is still a heap; so no matter how many grains of sand you take one by one, the result is always a heap. | |
| From: report of Eubulides (fragments/reports [c.390 BCE]) by R.M. Dancy - Megarian School | |
| A reaction: (also Cic. Acad. 2.49) This is a very nice paradox, which goes to the heart of our bewilderment when we try to fully understand reality. It homes in on problems of identity, as best exemplified in the Ship of Theseus (Ideas 1212 + 1213). |
| 3449 | If parallelism is true, how does the mind know about the body? [Crease] |
| Full Idea: In parallelism, the idea that we have a body is like an astronaut hearing shouting on the moon, and reasoning that as this is impossible he must be simultaneously imagining shouting AND there is real shouting taking place! | |
| From: Jason Crease (works [2001]), quoted by PG - Db (ideas) | |
| A reaction: This seems to capture the absurdity of Leibniz's proposal. I experience what my brain is doing, but not because my brain is doing it. I would never know if God had made a slight error in setting His two 'clocks'; their accuracy is just a pious hope. |
| 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. |