51 ideas
| 7950 | Philosophy tries to explain how the actual is possible, given that it seems impossible [Macdonald,C] |
| Full Idea: Philosophical problems are problems about how what is actual is possible, given that what is actual appears, because of some faulty argument, to be impossible. | |
| From: Cynthia Macdonald (Varieties of Things [2005], Ch.6) | |
| A reaction: [She is discussing universals when she makes this comment] A very appealing remark, given that most people come into philosophy because of a mixture of wonder and puzzlement. It is a rather Wittgensteinian view, though, that we must cure our own ills. |
| 7923 | 'Did it for the sake of x' doesn't involve a sake, so how can ontological commitments be inferred? [Macdonald,C] |
| Full Idea: In 'She did it for the sake of her country' no one thinks that the expression 'the sake' refers to an individual thing, a sake. But given that, how can we work out what the ontological commitments of a theory actually are? | |
| From: Cynthia Macdonald (Varieties of Things [2005], Ch.1) | |
| A reaction: For these sorts of reasons it rapidly became obvious that ordinary language analysis wasn't going to reveal much, but it is also a problem for a project like Quine's, which infers an ontology from the terms of a scientific theory. |
| 7933 | Don't assume that a thing has all the properties of its parts [Macdonald,C] |
| Full Idea: The fallacy of composition makes the erroneous assumption that every property of the things that constitute a thing is a property of the thing as well. But every large object is constituted by small parts, and every red object by colourless parts. | |
| From: Cynthia Macdonald (Varieties of Things [2005], Ch.5) | |
| A reaction: There are nice questions here like 'If you add lots of smallness together, why don't you get extreme smallness?' Colours always make bad examples in such cases (see Idea 5456). Distinctions are needed here (e.g. Idea 7007). |
| 17536 | If it can't be expressed mathematically, it can't occur in nature? [Heisenberg] |
| Full Idea: The solution was to turn around the question How can one in the known mathematical scheme express a given experimental situation? and ask Is it true that only such situations can arise in nature as can be expressed in the mathematical formalism? | |
| From: Werner Heisenberg (Physics and Philosophy [1958], 02) | |
| A reaction: This has the authority of the great Heisenberg, and is the ultimate expression of 'mathematical physics', beyond anything Galileo or Newton ever conceived. I suppose Pythagoras would have thought that Heisenberg was obviously right. |
| 7944 | Reduce by bridge laws (plus property identities?), by elimination, or by reducing talk [Macdonald,C] |
| Full Idea: There are four kinds of reduction: the identifying of entities of two theories by means of bridge or correlation laws; the elimination of entities in favour of the other theory; reducing by bridge laws and property identities; and merely reducing talk. | |
| From: Cynthia Macdonald (Varieties of Things [2005], Ch.3 n5) | |
| A reaction: [She gives references] The idea of 'bridge laws' I regard with caution. If bridge laws are ceteris paribus, they are not much help, and if they are strict, or necessary, then there must be an underlying reason for that, which is probably elimination. |
| 17545 | Quantum theory shows that exact science does not need dogmatic realism [Heisenberg] |
| Full Idea: It is only through quantum theory that we have learned that exact science is possible without the basis of dogmatic realism. | |
| From: Werner Heisenberg (Physics and Philosophy [1958], 05) |
| 17538 | Quantum theory does not introduce minds into atomic events [Heisenberg] |
| Full Idea: Certainly quantum theory does not contain genuine subjective features, it does not introduce the mind of the physicist as a part of the atomic event. | |
| From: Werner Heisenberg (Physics and Philosophy [1958], 03) | |
| A reaction: This should be digested by anyone who wants to erect some dodgy anti-realist, idealist, subjective metaphysics on the basis of the Copenhagen interpretation of quantum mechanics. |
| 7938 | Relational properties are clearly not essential to substances [Macdonald,C] |
| Full Idea: In statements attributing relational properties ('Felix is my favourite cat'), it seems clear that the property truly attributed to the substance is not essential to it. | |
| From: Cynthia Macdonald (Varieties of Things [2005], Ch.3) | |
| A reaction: A fairly obvious point, but an important one when mapping out (cautiously) what we actually mean by 'property'. However, maybe the relational property is essential: the ceiling is ('is' of predication!) above the room. |
| 7967 | Being taller is an external relation, but properties and substances have internal relations [Macdonald,C] |
| Full Idea: The relation of being taller than is an external relation, since it relates two independent material substances, but the relation of instantiation or exemplification is internal, in that it relates a substance with a property. | |
| From: Cynthia Macdonald (Varieties of Things [2005], Ch.6) | |
| A reaction: An interesting revival of internal relations. To be plausible it would need clear notions of 'property' and 'substance'. We are getting a long way from physics, and I sense Ockham stropping his Razor. How do you individuate a 'relation'? |
| 7965 | Does the knowledge of each property require an infinity of accompanying knowledge? [Macdonald,C] |
| Full Idea: An object's being two inches long seems to guarantee an infinite number of other properties, such as being less than three inches long. If we must understand the second property to understand the first, then there seems to be a vicious infinite regress. | |
| From: Cynthia Macdonald (Varieties of Things [2005], Ch.2) | |
| A reaction: She dismisses this by saying that we don't need to know an infinity of numbers in order to count. I would say that we just need to distinguish between intrinsic and relational properties. You needn't know all a thing's relations to know the thing. |
| 7934 | Tropes are abstract (two can occupy the same place), but not universals (they have locations) [Macdonald,C] |
| Full Idea: Tropes are abstract entities, at least in the sense that more than one can be in the same place at the same time (e.g. redness and roundness). But they are not universals, because they have unique and particular locations. | |
| From: Cynthia Macdonald (Varieties of Things [2005], Ch.3) | |
| A reaction: I'm uneasy about the reification involved in this kind of talk. Does a coin possess a thing called 'roundness', which then has to be individuated, identified and located? I am drawn to the two extreme views, and suspicious of compromise. |
| 7958 | Properties are sets of exactly resembling property-particulars [Macdonald,C] |
| Full Idea: Trope Nominalism says properties are classes or sets of exactly similar or resembling tropes, where tropes are what we might called 'property-tokens' or 'particularized properties'. | |
| From: Cynthia Macdonald (Varieties of Things [2005], Ch.6) | |
| A reaction: We still seem to have the problem of 'resembling' here, and we certainly have the perennial problem of why any given particular should be placed in any particular set. See Idea 7959. |
| 7972 | Tropes are abstract particulars, not concrete particulars, so the theory is not nominalist [Macdonald,C] |
| Full Idea: Trope 'Nominalism' is not a version of nominalism, because tropes are abstract particulars, rather than concrete particulars. Of course, a trope account of the relations between particulars and their properties has ramifications for concrete particulars. | |
| From: Cynthia Macdonald (Varieties of Things [2005], Ch.6 n16) | |
| A reaction: Cf. Idea 7971. At this point the boundary between nominalist and realist theories seems to blur. Possibly that is bad news for tropes. Not many dilemmas can be solved by simply blurring the boundary. |
| 7959 | How do a group of resembling tropes all resemble one another in the same way? [Macdonald,C] |
| Full Idea: The problem is how a group of resembling tropes can be of the same type, that is, that they can resemble one another in the same way. This problem is not settled simply by positing tropes. | |
| From: Cynthia Macdonald (Varieties of Things [2005], Ch.6) | |
| A reaction: There seems to be a fundamental fact that there is no resemblance unless the respect of resemblance is specified. Two identical objects could still said to be different because of their locations. Is resemblance natural or conventional? Consider atoms. |
| 7960 | Trope Nominalism is the only nominalism to introduce new entities, inviting Ockham's Razor [Macdonald,C] |
| Full Idea: Of all the nominalist solutions, Trope Nominalism is the only one that tries to solve the problem at issue by introducing entities; all the others try to get by with concrete particulars and sets of them. This might invite Ockham's Razor. | |
| From: Cynthia Macdonald (Varieties of Things [2005], Ch.6) | |
| A reaction: We could reply that tropes are necessities. The issue seems to be a key one, which is whether our fundamental onotology should include properties (in some form or other). I am inclined to exclude them (Ideas 3322, 3906, 4029). |
| 17534 | A 'probability wave' is a quantitative version of Aristotle's potential, a mid-way type of reality [Heisenberg] |
| Full Idea: The 1924 idea of the 'probability wave' meant a tendency for something. It was a quantitative version of the old concept of 'potentia' in Aristotelian philosophy ...a strange kind of physical reality just in the middle between possibility and reality. | |
| From: Werner Heisenberg (Physics and Philosophy [1958], 02) | |
| A reaction: [compressed] As far as I can see, he is talking about a disposition or power, which is exactly between a mere theoretical possibility and an actuality. See the Mumford/Lill Anjum proposal for a third modal value, between possible and necessary. |
| 7951 | Numerical sameness is explained by theories of identity, but what explains qualitative identity? [Macdonald,C] |
| Full Idea: We can distinguish between numerical identity and qualitative identity. Numerical sameness is explained by a theory of identity, but what explains qualitative sameness? | |
| From: Cynthia Macdonald (Varieties of Things [2005], Ch.6) | |
| A reaction: The distinction is between type and token identity. Tokens are particulars, and types are sets, so her question comes down to the one of what entitles something to be a member of a set? Nothing, if sets are totally conventional, but they aren't. |
| 7964 | How can universals connect instances, if they are nothing like them? [Macdonald,C] |
| Full Idea: The 'one over many' problem is to explain how universals can unify their instances if they are wholly other than them. | |
| From: Cynthia Macdonald (Varieties of Things [2005], Ch.6) | |
| A reaction: If universals are self-predicating (beauty is beautiful) then they have a massive amount in common, despite one being general. You then have the regress problem of explaining the beauty of the beautiful. Baffling regress, or baffling participation. |
| 7971 | Real Nominalism is only committed to concrete particulars, word-tokens, and (possibly) sets [Macdonald,C] |
| Full Idea: All real forms of Nominalism should hold that the only objects relevant to the explanation of generality are concrete particulars, words (i.e. word-tokens, not word-types), and perhaps sets. | |
| From: Cynthia Macdonald (Varieties of Things [2005], Ch.6 n16) | |
| A reaction: The addition of sets seems controversial (see Idea 7970). The context is her rejection of the use of tropes in nominalist theories. I would doubt whether a theory still counted as nominalist if it admitted sets (e.g. Quine). |
| 7955 | Resemblance Nominalism cannot explain either new resemblances, or absence of resemblances [Macdonald,C] |
| Full Idea: Resemblance Nominalism cannot explain the fact that we know when and in what way new objects resemble old ones, and that we know when and in what ways new objects do not resemble old ones. | |
| From: Cynthia Macdonald (Varieties of Things [2005], Ch.6) | |
| A reaction: It is not clear what sort of theory would be needed to 'explain' such a thing. Unless there is an explanation of resemblance waiting in the wings (beyond asserting that resemblance is a universal), then this is not a strong objection. |
| 7961 | A 'thing' cannot be in two places at once, and two things cannot be in the same place at once [Macdonald,C] |
| Full Idea: The so-called 'laws of thinghood' govern particulars, saying that one thing cannot be wholly present at different places at the same time, and two things cannot occupy the same place at the same time. | |
| From: Cynthia Macdonald (Varieties of Things [2005], Ch.6) | |
| A reaction: Is this an empirical observation, or a tautology? Or might it even be a priori synthetic? What happens when two water drops or clouds merge? Or an amoeba fissions? In what sense is an image in two places at once? Se also Idea 2351. |
| 7926 | We 'individuate' kinds of object, and 'identify' particular specimens [Macdonald,C] |
| Full Idea: We can usefully refer to 'individuation conditions', to distinguish objects of that kind from objects not of that kind, and to 'identity conditions', to distinguish objects within that kind from one another. | |
| From: Cynthia Macdonald (Varieties of Things [2005], Ch.2) | |
| A reaction: So we individuate types or sets, and identify tokens or particulars. Sounds good. Should be in every philosopher's toolkit, and on every introductory philosophy course. |
| 7936 | Unlike bundles of properties, substances have an intrinsic unity [Macdonald,C] |
| Full Idea: Substances have a kind of unity that mere collocations of properties do not have, namely an instrinsic unity. So substances cannot be collocations - bundles - of properties. | |
| From: Cynthia Macdonald (Varieties of Things [2005], Ch.3) | |
| A reaction: A team is a unity. Compare a similar thought, Idea 1395, about personal identity. How can something which is a pure unity have more than one property? What distinguishes substances? Why can't a substance have a certain property? |
| 17553 | We can retain the idea of 'substance', as indestructible mass or energy [Heisenberg] |
| Full Idea: One could consider mass and energy as two different forms of the same 'substance' and thereby keep the idea of substance as indestructible. | |
| From: Werner Heisenberg (Physics and Philosophy [1958], 07) |
| 7930 | The bundle theory of substance implies the identity of indiscernibles [Macdonald,C] |
| Full Idea: The bundle theory of substance requires unconditional commitment to the truth of the Principle of the Identity of Indiscernibles: that things that are alike with respect to all of their properties are identical. | |
| From: Cynthia Macdonald (Varieties of Things [2005], Ch.3) | |
| A reaction: Since the identity of indiscernibles is very dubious (see Ideas 1365, 4476, 5746, 7928), this is bad news for the bundle theory. I suspect that all of these problems arise because no one seems to have a clear concept of a property. |
| 7932 | A phenomenalist cannot distinguish substance from attribute, so must accept the bundle view [Macdonald,C] |
| Full Idea: Commitment to the view that only what can be an object of possible sensory experience can exist eliminates the possibility of distinguishing between substance and attribute, leaving only one alternative, namely the bundle view. | |
| From: Cynthia Macdonald (Varieties of Things [2005], Ch.3) | |
| A reaction: Phenomenalism strikes me as a paradigm case of confusing ontology with epistemology. Presumably physicists (even empiricist ones) are committed to the 'interior' of quarks and electrons, but no one expects to experience them. |
| 7937 | When we ascribe a property to a substance, the bundle theory will make that a tautology [Macdonald,C] |
| Full Idea: The bundle theory makes all true statements ascribing properties to substances uninformative, by making them logical truths. The property of being a feline animal is literally a constituent of a cat. | |
| From: Cynthia Macdonald (Varieties of Things [2005], Ch.3) | |
| A reaction: The solution would seem to a distinction between accidental and essential properties. Compare 'that plane is red' with 'that plane has wings'. 'Of course it does - it's a plane'. We might still survive without a plane-substance. |
| 7939 | Substances persist through change, but the bundle theory says they can't [Macdonald,C] |
| Full Idea: Substances are capable of persisting through change, where this involves change in properties; but the bundle theory has the consequence that substances cannot survive change. | |
| From: Cynthia Macdonald (Varieties of Things [2005], Ch.3) | |
| A reaction: Her example is an apple remaining an apple when it turns brown. It doesn't look, though, as if there is a precise moment when the apple-substance ceases. The end of an apple seems to be more a matter of a loss of crucial properties. |
| 7940 | A substance might be a sequence of bundles, rather than a single bundle [Macdonald,C] |
| Full Idea: Maybe a substance is not itself a bundle of properties, but a sum or sequence of bundles of properties, a bundle of bundles of properties (which 'perdures' rather than 'endures'). | |
| From: Cynthia Macdonald (Varieties of Things [2005], Ch.3) | |
| A reaction: There remains the problem of deciding when the bundle has drifted too far away from the original to perdure correctly. A caterpillar can turn into a butterfly (which is pretty bizarre!), but not into a cathedral. Why? She says this idea denies change. |
| 7948 | A statue and its matter have different persistence conditions, so they are not identical [Macdonald,C] |
| Full Idea: Because a statue and the lump of matter that constitute it have different persistence conditions, they are not identical. | |
| From: Cynthia Macdonald (Varieties of Things [2005], Ch.4) | |
| A reaction: Maybe being a statue is a relational property? All the relational properties of a thing will have different persistence conditions. Suppose I see a face in a bowl of sugar, and you don't? |
| 17544 | Basic particles have a mathematical form, which is more important than their substance [Heisenberg] |
| Full Idea: The smallest parts of matter are not the fundamental Beings, as in the philosophy of Democritus, but are mathematical forms. Here it is quite evident that the form is more important than the substance of which it is the form. | |
| From: Werner Heisenberg (Physics and Philosophy [1958], 04) | |
| A reaction: Heisenberg is quite consciously endorsing hylomorphism here, with a Pythagorean twist to it. |
| 7929 | A substance is either a bundle of properties, or a bare substratum, or an essence [Macdonald,C] |
| Full Idea: The three main theories of substance are the bundle theory (Leibniz, Berkeley, Hume, Ayer), the bare substratum theory (Locke and Bergmann), and the essentialist theory. | |
| From: Cynthia Macdonald (Varieties of Things [2005], Ch.3) | |
| A reaction: Macdonald defends the essentialist theory. The essentialist view immediately appeals to me. Properties must be OF something, and the something must have the power to produce properties. So there. |
| 7941 | Each substance contains a non-property, which is its substratum or bare particular [Macdonald,C] |
| Full Idea: A rival to the bundle theory says that, for each substance, there is a constituent of it that is not a property but is both essential and unique to it, this constituent being referred to as a 'bare particular' or 'substratum'. | |
| From: Cynthia Macdonald (Varieties of Things [2005], Ch.3) | |
| A reaction: This doesn't sound promising. It is unclear what existence devoid of all properties could be like. How could it 'have' its properties if it was devoid of features (it seems to need property-hooks)? It is an ontological black hole. How do you prove it? |
| 7942 | The substratum theory explains the unity of substances, and their survival through change [Macdonald,C] |
| Full Idea: If there is a substratum or bare particular within a substance, this gives an explanation of the unity of substances, and it is something which can survive intact when a substance changes. | |
| From: Cynthia Macdonald (Varieties of Things [2005], Ch.3) | |
| A reaction: [v. compressed wording] Many problems here. The one that strikes me is that when things change they sometimes lose their unity and identity, and that seems to be decided entirely from observation of properties, not from assessing the substratum. |
| 7943 | A substratum has the quality of being bare, and they are useless because indiscernible [Macdonald,C] |
| Full Idea: There seems to be no way of identifying a substratum as the bearer of qualities without qualifiying it as bare (having the property of being bare?), ..and they cannot be used to individuate things, because they are necessarily indiscernible. | |
| From: Cynthia Macdonald (Varieties of Things [2005], Ch.3) | |
| A reaction: The defence would probably be a priori, claiming an axiomatic necessity for substrata in our thinking about the world, along with a denial that bareness is a property (any more than not being a contemporary of Napoleon is a property). |
| 7927 | At different times Leibniz articulated three different versions of his so-called Law [Macdonald,C] |
| Full Idea: There are three distinct versions of Leibniz's Law, all traced to remarks made by Leibniz: the Identity of Indiscernibles (same properties, same thing), the Indiscernibility of Identicals (same thing, same properties), and the Substitution Principle. | |
| From: Cynthia Macdonald (Varieties of Things [2005], Ch.2) | |
| A reaction: The best view seems to be to treat the second one as Leibniz's Law (and uncontroversially true), and the first one as being an interesting but dubious claim. |
| 7928 | The Identity of Indiscernibles is false, because it is not necessarily true [Macdonald,C] |
| Full Idea: One common argument to the conclusion that the Principle of the Identity of Indiscernibles is false is that it is not necessarily true. | |
| From: Cynthia Macdonald (Varieties of Things [2005], Ch.2 n32) | |
| A reaction: This sounds like a good argument. If you test the Principle with an example ('this butler is the murderer') then total identity does not seem to necessitate identity, though it strongly implies it (the butler may have a twin etc). |
| 17550 | We give a mathematical account of a system of natural connections in order to clarify them [Heisenberg] |
| Full Idea: When we represent a group of connections by a closed and coherent set of concepts, axioms, definitions and laws which in turn is represented by a mathematical scheme we have isolated and idealised them with the purpose of clarification. | |
| From: Werner Heisenberg (Physics and Philosophy [1958], 06) | |
| A reaction: Attacks on the regularity theory of laws, and the notion that explanation is by laws, tend to downplay this point - that obtaining clarity and precision is a sort of explanation, even if it fails to go deeper. |
| 7947 | In continuity, what matters is not just the beginning and end states, but the process itself [Macdonald,C] |
| Full Idea: What matters to continuity is not just the beginning and end states of the process by which a thing persists, perhaps through change, but the process itself. | |
| From: Cynthia Macdonald (Varieties of Things [2005], Ch.4) | |
| A reaction: This strikes me as being a really important insight. Compare Idea 4931. If this is the key to understanding mind and personal identity, it means that the concept of a 'process' must be a central issue in ontology. How do you individuate a process? |
| 13304 | Learned men gain more in one day than others do in a lifetime [Posidonius] |
| Full Idea: In a single day there lies open to men of learning more than there ever does to the unenlightened in the longest of lifetimes. | |
| From: Posidonius (fragments/reports [c.95 BCE]), quoted by Seneca the Younger - Letters from a Stoic 078 | |
| A reaction: These remarks endorsing the infinite superiority of the educated to the uneducated seem to have been popular in late antiquity. It tends to be the religions which discourage great learning, especially in their emphasis on a single book. |
| 17549 | Seven theories in science: mechanics, heat, electricity, quantum, particles, relativity, life [Heisenberg, by PG] |
| Full Idea: Science has seven closed systems of concepts and axioms: Newtonian mechanics; the theory of heat; electricity and magnetism; quantum theory; the theory of elementary particles; general relativity; and the theory of organic life. | |
| From: report of Werner Heisenberg (Physics and Philosophy [1958], 06) by PG - Db (ideas) | |
| A reaction: [my summary of pp.86-88 and 92] It is interesting to have spelled out that there are number of 'closed' theories, which are only loosely connected to one another. New discoveries launch whole new theories, instead of being subsumed. |
| 17540 | Energy is that which moves, and is the substance from which everything is made [Heisenberg] |
| Full Idea: Energy is the substance from which all elementary particles, all atoms and therefore all things are made, and energy is that which moves. | |
| From: Werner Heisenberg (Physics and Philosophy [1958], 04) | |
| A reaction: I'm not sure what energy is, but I like this because it says that nature is fundamentally active. Nothing makes sense without that basic assumption (on which Leibniz continually insists). |
| 17541 | Energy is an unchanging substance, having many forms, and causing all change [Heisenberg] |
| Full Idea: Energy is a substance, since its total amount does not change. ...Energy can be changed into motion, into heat, into light and into tension. Energy may be called the fundamental cause for all change in the world. | |
| From: Werner Heisenberg (Physics and Philosophy [1958], 04) | |
| A reaction: Grandiose stuff. I remain unconvinced that Heisenberg (clever fellow, I'm told) has any idea of what he is talking about. |
| 17548 | Maxwell introduced real fields, which transferred forces from point to point [Heisenberg] |
| Full Idea: In the theory of fields of force one came back to the older idea, that action is transferred from one point to a neighbouring point. ...With Maxwell the fields of force seemed to have acquired the same degree of reality as the body's of Newton's theory. | |
| From: Werner Heisenberg (Physics and Philosophy [1958], 06) |
| 17533 | Radiation interference needs waves, but radiation photoelectric effects needs particles [Heisenberg] |
| Full Idea: How could it be that the same radiation that produces interference patterns, and therefore must consist of waves, also produces the photoelectric effect, and therefore must consist of moving particles. | |
| From: Werner Heisenberg (Physics and Philosophy [1958], 02) |
| 17537 | Position is complementary to velocity or momentum, so the whole system is indeterminate [Heisenberg] |
| Full Idea: The knowledge of the position of a particle is complementary to the knowledge of its velocity or momentum. If we know one with high accuracy we cannot know the other with high accuracy; still we must know both for determining the behaviour of the system. | |
| From: Werner Heisenberg (Physics and Philosophy [1958], 03) | |
| A reaction: This is the famous Uncertainty Principle, expressed in plain language by the man himself. At this point we lost our grip on the prospects of determining the behaviour of natural systems. |
| 17551 | It was formerly assumed that electromagnetic waves could not be a reality in themselves [Heisenberg] |
| Full Idea: The idea that electromagnetic waves could be a reality in themselves, independent of any bodies, did at that time not occur to the physicists. | |
| From: Werner Heisenberg (Physics and Philosophy [1958], 07) | |
| A reaction: 'At that time' is when they thought the waves must travel through something, called the 'ether'. |
| 17532 | An atom's stability after collisions needs explaining (which Newton's mechanics can't do) [Heisenberg] |
| Full Idea: The first new model of the atom could not explain the most characteristic features of the atom, its enormous stability. No planetary system following the laws of Newton's mechanics would ever go back to its original configuration after a collision. | |
| From: Werner Heisenberg (Physics and Philosophy [1958], 02) |
| 17543 | So-called 'empty' space is the carrier of geometry and kinematics [Heisenberg] |
| Full Idea: From our modern point of view we would say that the empty space between the atoms was not nothing; it was the carrier of geometry and kinematics. | |
| From: Werner Heisenberg (Physics and Philosophy [1958], 04) | |
| A reaction: I'm not sure what the 'carrier of geometry and kinematics' means, but it is interesting that he doesn't mention 'fields' (unless they carry the kinematics?) |
| 20820 | Time is an interval of motion, or the measure of speed [Posidonius, by Stobaeus] |
| Full Idea: Posidonius defined time thus: it is an interval of motion, or the measure of speed and slowness. | |
| From: report of Posidonius (fragments/reports [c.95 BCE]) by John Stobaeus - Anthology 1.08.42 | |
| A reaction: Hm. Can we define motion or speed without alluding to time? Looks like we have to define them as a conjoined pair, which means we cannot fully understand either of them. |
| 17552 | In relativity the length of the 'present moment' is relative to distance from the observer [Heisenberg] |
| Full Idea: In classical theory we assume past and future are separated by an infinitely short time interval called the present moment. In relativity it is different: future and past are separated by a finite time interval dependent on the distance from the observer. | |
| From: Werner Heisenberg (Physics and Philosophy [1958], 07) | |
| A reaction: Not sure I understand this, but it is a revelation to realise that not only is time made relative to observers, but the length of the 'present moment' also becomes relative. The infinitesimal present moment has always bothered me. |