33 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. |
22180 | Multiple realisability is said to make reduction impossible [Okasha] |
Full Idea: Philosophers have often invoked multiple realisability to explain why psychology cannot be reduced to physics or chemistry, but in principle the explanation works for any higher-level science. | |
From: Samir Okasha (Philosophy of Science: Very Short Intro (2nd ed) [2016], 3) | |
A reaction: He gives the example of a 'cell' in biology, which can be implemented in all sorts of ways. Presumably that can be reduced to many sorts of physics, but not just to one sort. The high level contains patterns that vanish at the low level. |
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. |
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. |
21515 | Incoherence may be more important for enquiry than coherence [Olsson] |
Full Idea: While coherence may lack the positive role many have assigned to it, ...incoherence plays an important negative role in our enquiries. | |
From: Erik J. Olsson (Against Coherence [2005], 10.1) | |
A reaction: [He cites Peirce as the main source for this idea] We can hardly by deeply impressed by incoherence if we have no sense of coherence. Incoherence is just one of many markers for theory failure. Missing the target, bad concepts... |
21514 | Coherence is the capacity to answer objections [Olsson] |
Full Idea: According to Lehrer, coherence should be understood in terms of the capacity to answer objections. | |
From: Erik J. Olsson (Against Coherence [2005], 9) | |
A reaction: [Keith Lehrer 1990] We can connect this with the Greek requirement of being able to give an account [logos], which is the hallmark of understanding. I take coherence to be the best method of achieving understanding. Any understanding meets Lehrer's test. |
21496 | Mere agreement of testimonies is not enough to make truth very likely [Olsson] |
Full Idea: Far from guaranteeing a high likelihood of truth by itself, testimonial agreement can apparently do so only if the circumstances are favourable as regards independence, prior probability, and individual credibility. | |
From: Erik J. Olsson (Against Coherence [2005], 1) | |
A reaction: This is Olson's main thesis. His targets are C.I.Lewis and Bonjour, who hoped that a mere consensus of evidence would increase verisimilitude. I don't see a problem for coherence in general, since his favourable circumstances are part of it. |
21499 | Coherence is only needed if the information sources are not fully reliable [Olsson] |
Full Idea: An enquirer who is fortunate enough to have at his or her disposal fully reliable information sources has no use for coherence, the need for which arises only in the context of less than fully reliable informations sources. | |
From: Erik J. Olsson (Against Coherence [2005], 2.6.2) | |
A reaction: I take this to be entirely false. How do you assess reliability? 'I've seen it with my own eyes'. Why trust your eyes? In what visibility conditions do you begin to doubt your eyes? Why do rational people mistrust their intuitions? |
21502 | A purely coherent theory cannot be true of the world without some contact with the world [Olsson] |
Full Idea: The Input Objection says a pure coherence theory would seem to allow that a system of beliefs be justified in spite of being utterly out of contact with the world it purports to describe, so long as it is, to a sufficient extent, coherent. | |
From: Erik J. Olsson (Against Coherence [2005], 4.1) | |
A reaction: Olson seems impressed by this objection, but I don't see how a system could be coherently about the world if it had no known contact with the world. Olson seems to ignore meta-coherence, which evaluates the status of the system being studied. |
21512 | Extending a system makes it less probable, so extending coherence can't make it more probable [Olsson] |
Full Idea: Any non-trivial extension of a belief system is less probable than the original system, but there are extensions that are more coherent than the original system. Hence more coherence does not imply a higher probability. | |
From: Erik J. Olsson (Against Coherence [2005], 6.4) | |
A reaction: [Olson cites Klein and Warfield 1994; compressed] The example rightly says the extension could have high internal coherence, but not whether the extension is coherent with the system being extended. |
22172 | Not all sciences are experimental; astronomy relies on careful observation [Okasha] |
Full Idea: Not all sciences are experimental - astronomers obviously cannot do experiments on the heavens, but have to content themselves with careful observation instead. | |
From: Samir Okasha (Philosophy of Science: Very Short Intro (2nd ed) [2016], 1) | |
A reaction: Biology too. Psychology tries hard to be experimental, but I doubt whether the main theories emerge from experiments. |
22177 | Randomised Control Trials have a treatment and a control group, chosen at random [Okasha] |
Full Idea: In the Randomised Controlled Trial for a new drug, patients are divided at random into a treatment group who receive the drug, and a control group who do not. Randomisation is important to eliminate confounding factors. | |
From: Samir Okasha (Philosophy of Science: Very Short Intro (2nd ed) [2016], 2) | |
A reaction: [compressed] Devised in the 1930s, and a major breakthrough in methodology for that kind of trial. Psychologists use the method all the time. Some theorists say it is the only reliable method. |
22174 | The discoverers of Neptune didn't change their theory because of an anomaly [Okasha] |
Full Idea: Adams and Leverrier began with Newton's theory of gravity, which made an incorrect prediction about the orbit of Uranus. They explained away the conflicting observations by postulating a new planet, Neptune. | |
From: Samir Okasha (Philosophy of Science: Very Short Intro (2nd ed) [2016], 1) | |
A reaction: The falsificationists can say that the anomalous observation did not falsify the theory, because they didn't know quite what they were observing. It was not in fact an anomaly for Newtonian theory at all. |
22175 | Science mostly aims at confirming theories, rather than falsifying them [Okasha] |
Full Idea: The goal of science is not solely to refute theories, but also to determine which theories are true (or probably true). When a scientist collects data …they are trying to show that their own theory is true. | |
From: Samir Okasha (Philosophy of Science: Very Short Intro (2nd ed) [2016], 2) | |
A reaction: This is the aim of 'accommodation' to a wide set of data, rather than prediction or refutation. |
22182 | Theories with unobservables are underdetermined by the evidence [Okasha] |
Full Idea: According to anti-realists, scientific theories which posit unobservable entities are underdetermined by the empirical data - there will always be a number of competing theories which can account for the data equally well. | |
From: Samir Okasha (Philosophy of Science: Very Short Intro (2nd ed) [2016], 4) | |
A reaction: The fancy version is Putnam's model theoretic argument, explored by Tim Button. The reply, apparently, is that there are other criteria for theory choice, apart from the data. And we don't have to actually observe everything in a theory. |
22185 | Two things can't be incompatible if they are incommensurable [Okasha] |
Full Idea: If two things are incommensurable they cannot be incompatible. | |
From: Samir Okasha (Philosophy of Science: Very Short Intro (2nd ed) [2016], 5) | |
A reaction: Kuhn had claimed that two rival theories are incompatible, which forces the paradigm shift. He can't stop the slide off into total relativism. The point is there cannot be a conflict if there cannot even be a comparison. |
22176 | Induction is inferences from examined to unexamined instances of a given kind [Okasha] |
Full Idea: Some philosophers use 'inductive' to just mean not deductive, …but we reserve it for inferences from examined to unexamined instances of a given kind. | |
From: Samir Okasha (Philosophy of Science: Very Short Intro (2nd ed) [2016], 2) | |
A reaction: The instances must at least be comparable. Must you know the kind before you start? Surely you can examine a sequence of things, trying to decide whether or not they are of one kind? Is checking the uniformity of a kind induction? |
22178 | If the rules only concern changes of belief, and not the starting point, absurd views can look ratiional [Okasha] |
Full Idea: If the only objective constraints concern how we should change our credences, but what our initial credences should be is entirely subjective, then individuals with very bizarre opinions about the world will count as perfectly rational. | |
From: Samir Okasha (Philosophy of Science: Very Short Intro (2nd ed) [2016], 2) | |
A reaction: The important rationality has to be the assessement of a diverse batch of evidence, for which there can never be any rules or mathematics. |
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. |
22173 | Galileo refuted the Aristotelian theory that heavier objects fall faster [Okasha] |
Full Idea: Galileo's most enduring contribution lay in mechanics, where he refuted the Aristotelian theory that heavier bodies fall faster than lighter. | |
From: Samir Okasha (Philosophy of Science: Very Short Intro (2nd ed) [2016], 2) | |
A reaction: This must the first idea in the theory of mechanics, allowing mathematical treatment and accurate comparisons. |
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. |