| 20646 | Helmholtz used 'energy' to mathematically link heat, light, electricity and magnetism [Helmholtz, by Watson] |
| Full Idea: Helmholtz provided the requisite mathematical formulation linking heat, light, electricity and magnetism, by treating these phenomena as different manifestations of 'energy'. | |
| From: report of Hermann von Helmholtz (On the Conservation of Force [1847]) by Peter Watson - Convergence 01 'Human' | |
| A reaction: I'm increasingly struck by the neglect by philosophers of nature of these amazing developments in 19th century physics, because they prefer the excitement of the latest nuclear physics. There is more philosophical interest in the earlier stages. |
| 20644 | Energy has progressed from a mere formula, to a principle pervading all nature [Kelvin] |
| Full Idea: The name 'energy', first used by Thomas Young, has come into use after it was raised from a mere formula of mathematical dynamics to become a principle pervading all nature, and guiding every field of science. | |
| From: Lord Kelvin (Wm Thomson) (works [1881]), quoted by Peter Watson - Convergence 01 'Principle' | |
| A reaction: [bit compressed] As far as I can see energy behaves exactly as if it were a substance, like water conserved in rainfalls, and yet it isn't a stuff, and seems to result from a process of abstraction. I take it to be one of the biggest mysteries in physics. |
| 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. |
| 12674 | Energy is the key multi-valued property, vital to scientific realism [Ellis] |
| Full Idea: Perhaps the most important of all multi-valued properties is energy itself. I think a scientific realist must believe that energy exists. | |
| From: Brian Ellis (The Metaphysics of Scientific Realism [2009], 2) | |
| A reaction: It's odd that the existence of the most basic thing in physics needs a credo from a certain sort of believer. I have been bothered by notion of 'energy' for fifty years, and am still none the wiser. I'm sure I could be scientific realist without it. |
| 15265 | 'Energy' is a quasi-substance invented as the bearer of change during interactions [Harré/Madden] |
| Full Idea: In the case of electron/positron/gamma ray annihilation scientists maintain the paradigm of rational explanation by inventing a quasi-substance as the bearer of continuity, and all three are seen in terms of 'energy'. | |
| From: Harré,R./Madden,E.H. (Causal Powers [1975], 6.III) | |
| A reaction: What a relief to see energy described as a 'quasi-substance'. I spent all of my physics studies bewildered by the nature of energy (especially when described as 'pure energy'). What does e=mc^2 mean if e is a quasi-substance? |
| 15280 | 'Kinetic energy' is used to explain the effects of moving things when they are stopped [Harré/Madden] |
| Full Idea: The 'store' of kinetic energy is used as a latency concept to explain the power of bringing about changes which is manifested by the moving thing when its motion is arrested. | |
| From: Harré,R./Madden,E.H. (Causal Powers [1975], 6.IV) | |
| A reaction: These ideas have been most illuminating in connecting for me the general idea of a 'power' to the rather dubious concept of 'energy' in physics. |
| 21183 | Thermodynamics introduced work and entropy, to understand steam engine efficiency [Hesketh] |
| Full Idea: The Laws of Thermodynamics introduced the concepts of entropy and work; put simply, how much useful energy you can really get out of a steam engine. | |
| From: Gavin Hesketh (The Particle Zoo [2016], 03) | |
| A reaction: The point of science by this stage was to introduce measurable and quantifiable concepts |