23 ideas
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. |
16045 | General facts supervene on particular facts, but cannot be inferred from them [Russell, by Bennett,K] |
Full Idea: Russell noted that you cannot arrive at general facts by inference from numerous particular facts, ..but general facts logically supervene on particular ones. So the general facts supervene, but are not entailed. | |
From: report of Bertrand Russell (On Relations of Universals and Particulars [1911]) by Karen Bennett - Supervenience §3.2 | |
A reaction: The belief that the general facts supervene on the particular ones then seems to be more a matter of faith than of fact. Or maybe it is analytic, depending on what we understand by 'general'. Universal, or generalised? |
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. |
14327 | Trope theorists cannot explain how tropes resemble each other [Russell, by Mumford] |
Full Idea: The trope theorist cannot explain how a number of tropes resemble each other. | |
From: report of Bertrand Russell (On Relations of Universals and Particulars [1911]) by Stephen Mumford - Dispositions 07.6 | |
A reaction: [My 13,000th Idea: 31/10/11] Every theory is left with something it cannot explain. Is it likely that we could come up with an explanation of resemblance? It seems like a combination of identity in the physics, and identity in the brain mechanisms. |
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. |
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) |
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. |
19553 | Commitment to 'I have a hand' only makes sense in a context where it has been doubted [Hawthorne] |
Full Idea: If I utter 'I know I have a hand' then I can only be reckoned a cooperative conversant by my interlocutors on the assumption that there was a real question as to whether I have a hand. | |
From: John Hawthorne (The Case for Closure [2005], 2) | |
A reaction: This seems to point to the contextualist approach to global scepticism, which concerns whether we are setting the bar high or low for 'knowledge'. |
19551 | How can we know the heavyweight implications of normal knowledge? Must we distort 'knowledge'? [Hawthorne] |
Full Idea: Those who deny skepticism but accept closure will have to explain how we know the various 'heavyweight' skeptical hypotheses to be false. Do we then twist the concept of knowledge to fit the twin desiderata of closue and anti-skepticism? | |
From: John Hawthorne (The Case for Closure [2005], Intro) | |
A reaction: [He is giving Dretske's view; Dretske says we do twist knowledge] Thus if I remember yesterday, that has the heavyweight implication that the past is real. Hawthorne nicely summarises why closure produces a philosophical problem. |
19552 | We wouldn't know the logical implications of our knowledge if small risks added up to big risks [Hawthorne] |
Full Idea: Maybe one cannot know the logical consequences of the proposition that one knows, on account of the fact that small risks add up to big risks. | |
From: John Hawthorne (The Case for Closure [2005], 1) | |
A reaction: The idea of closure is that the new knowledge has the certainty of logic, and each step is accepted. An array of receding propositions can lose reliability, but that shouldn't apply to logic implications. Assuming monotonic logic, of course. |
19554 | Denying closure is denying we know P when we know P and Q, which is absurd in simple cases [Hawthorne] |
Full Idea: How could we know that P and Q but not be in a position to know that P (as deniers of closure must say)? If my glass is full of wine, we know 'g is full of wine, and not full of non-wine'. How can we deny that we know it is not full of non-wine? | |
From: John Hawthorne (The Case for Closure [2005], 2) | |
A reaction: Hawthorne merely raises this doubt. Dretske is concerned with heavyweight implications, but how do you accept lightweight implications like this one, and then suddenly reject them when they become too heavy? [see p.49] |
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. |
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) |
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) |
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'. |
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?) |
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. |