27 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. |
| 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) |
| 12756 | Substance is a force for acting and being acted upon [Leibniz] |
| Full Idea: The very substance in things consists of a force for acting and being acted upon. | |
| From: Gottfried Leibniz (On Nature Itself (De Ipsa Natura) [1698], §08) | |
| A reaction: Garber places this text just before the spiritual notion of monads took a grip on Leibniz. He seems to have thought that only some non-physical entity, with appetite and perception, could generate force. Wrong. |
| 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. |
| 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. |
| 12755 | Final causes can help with explanations in physics [Leibniz] |
| Full Idea: Final causes not only advance virtue and piety in ethics and natural theology, but also help us to find and lay bare hidden truths in physics itself. | |
| From: Gottfried Leibniz (On Nature Itself (De Ipsa Natura) [1698], §04) | |
| A reaction: This rearguard action against the attack on teleology is certainly aimed at Spinoza. The notion of purpose still seems to have a role to play in evolutionary biology, but probably not in physics. |
| 12760 | Something rather like souls (though not intelligent) could be found everywhere [Leibniz] |
| Full Idea: Nor is there any reason why souls or things analogous to souls should not be everywhere, even if dominant and consequently intelligent souls, like human souls, cannot be everywhere. | |
| From: Gottfried Leibniz (On Nature Itself (De Ipsa Natura) [1698], §12) | |
| A reaction: He is always flirting with panpsychism, though he doesn't seem to offer any account of how these little baby souls can be built up to create one intelligent soul, the latter being indivisible. 'Souls' are very different from things 'analous to souls'! |
| 1748 | Archelaus was the first person to say that the universe is boundless [Archelaus, by Diog. Laertius] |
| Full Idea: Archelaus was the first person to say that the universe is boundless. | |
| From: report of Archelaus (fragments/reports [c.450 BCE]) by Diogenes Laertius - Lives of Eminent Philosophers 02.Ar.3 |
| 12759 | There are atoms of substance, but no atoms of bulk or extension [Leibniz] |
| Full Idea: Although there are atoms of substance, namely monads, which lack parts, there are no atoms of bulk [moles], that is, atoms of the least possible extension, nor are there any ultimate elements, since a continuum cannot be composed out of points. | |
| From: Gottfried Leibniz (On Nature Itself (De Ipsa Natura) [1698], §11) | |
| A reaction: Leibniz has a constant battle for the rest of his career to explain what these 'atoms of substance' are, since they have location but no extension, they are self-sufficient yet generate force, and are non-physical but interact with matter. |
| 12718 | Secondary matter is active and complete; primary matter is passive and incomplete [Leibniz] |
| Full Idea: I understand matter as either secondary or primary. Secondary matter is, indeed, a complete substance, but it is not merely passive; primary matter is merely passive, but it is not a complete substance. So we must add a soul or form... | |
| From: Gottfried Leibniz (On Nature Itself (De Ipsa Natura) [1698], §12), quoted by Daniel Garber - Leibniz:Body,Substance,Monad 4 | |
| A reaction: It sounds as if primary matter is redundant, but Garber suggests that secondary matter is just the combination of primary matter with form. |
| 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. |
| 11854 | If there is some trace of God in things, that would explain their natural force [Leibniz] |
| Full Idea: If the law of God does indeed leave some vestige of him expressed in things...then it must be granted that there is a certain efficacy residing in things, a form or force such as we usually designate by the name of nature, from which the phenomena follow. | |
| From: Gottfried Leibniz (On Nature Itself (De Ipsa Natura) [1698], §06) | |
| A reaction: I wouldn't rate this as a very promising theory of powers, but it seems to me important that Leibniz recognises the innate power in things as needing explanation. If you remove divine power, you are left with unexplained intrinsic powers. |
| 12758 | It is plausible to think substances contain the same immanent force seen in our free will [Leibniz] |
| Full Idea: If we attribute an inherent force to our mind, a force acting immanently, then nothing forbids us to suppose that the same force would be found in other souls or forms, or, if you prefer, in the nature of substances. | |
| From: Gottfried Leibniz (On Nature Itself (De Ipsa Natura) [1698], §10) | |
| A reaction: This is the kind of bizarre idea that you are driven to, once you start thinking that God must have a will outside nature, and then that we have the same thing. Why shouldn't such a thing pop up all over the place? Only Leibniz spots the slippery slope. |
| 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. |
| 5989 | Archelaus said life began in a primeval slime [Archelaus, by Schofield] |
| Full Idea: Archelaus wrote that life on Earth began in a primeval slime. | |
| From: report of Archelaus (fragments/reports [c.450 BCE]) by Malcolm Schofield - Archelaus | |
| A reaction: This sounds like a fairly clearcut assertion of the production of life by evolution. Darwin's contribution was to propose the mechanism for achieving it. We should honour the name of Archelaus for this idea. |
| 19408 | To say that nature or the one universal substance is God is a pernicious doctrine [Leibniz] |
| Full Idea: To say that nature itself or the substance of all things is God is a pernicious doctrine, recently introduced into the world or renewed by a subtle or profane author. | |
| From: Gottfried Leibniz (On Nature Itself (De Ipsa Natura) [1698], 8) | |
| A reaction: The dastardly profane author is, of course, Spinoza, whom Leibniz had met in 1676. The doctrine may be pernicious to religious orthodoxy, but to me it is rather baffling, since in my understanding nature and God have almost nothing in common. |