21 ideas
20457 | Zeno assumes collecting an infinity of things makes an infinite thing [Rovelli] |
Full Idea: One possible answer is that Zeno is wrong because it is not true that by accumulating an infinite number of things one ends up with an infinite thing. | |
From: Carlo Rovelli (Reality is Not What it Seems [2014], 01) | |
A reaction: I do love it when deep and complex ideas are expressed with perfect simplicity. As long as the simple version is correct. |
20468 | Quantum mechanics deals with processes, rather than with things [Rovelli] |
Full Idea: Quantum mechanics teaches us not to think about the world in terms of 'things' which are in this or that state, but in terms of 'processes' instead. | |
From: Carlo Rovelli (Reality is Not What it Seems [2014], 04) |
20467 | Quantum mechanics describes the world entirely as events [Rovelli] |
Full Idea: The world of quantum mechanics is not a world of objects: it is a world of events. | |
From: Carlo Rovelli (Reality is Not What it Seems [2014], 04) | |
A reaction: I presume a philosopher is allowed to ask what an 'event' is. Since, as Rovelli tells it, time is eliminated from the picture, events seem to be unanalysable primitives. |
13195 | To explain a house we must describe its use, as well as its parts [Leibniz] |
Full Idea: A house would be badly explained if we were to describe only the arrangement of its parts, but not its use. | |
From: Gottfried Leibniz (On Body and Force, Against the Cartesians [1702], p.255) | |
A reaction: This must partly fall under pragmatics (i.e. what the enquirer is interested in). But function plays a genuine role in artefacts, and also in evolved biological organs. |
13193 | Active force is not just potential for action, since it involves a real effort or striving [Leibniz] |
Full Idea: Active force should not be thought of as the simple and common potential [potentia] or receptivity to action of the schools. Rather, active force involves an effort [conatus] or striving [tendentia] toward action. | |
From: Gottfried Leibniz (On Body and Force, Against the Cartesians [1702], p.252) | |
A reaction: This is why Leibniz is lured into making his active forces more and more animistic, till they end up like proto-minds (though never, remember, conscious and willing minds). |
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. |
20469 | There are probably no infinities, and 'infinite' names what we do not yet know [Rovelli] |
Full Idea: 'Infinite', ultimately, is the name that we give to what we do not yet know. Nature appears to be telling us that there is nothing truly infinite. | |
From: Carlo Rovelli (Reality is Not What it Seems [2014], 11) |
20461 | The basic ideas of fields and particles are merged in quantum mechanics [Rovelli] |
Full Idea: The notions of fields and particles, separated by Faraday and Maxwell, end up merging in quantum mechanics. | |
From: Carlo Rovelli (Reality is Not What it Seems [2014], 04) | |
A reaction: This sounds to me just like Anaximander's 'apeiron' - the unlimited [Rovelli agrees! p.168]. Anaximander predicted the wall which enquiry would hit, but we now have more detail. |
13194 | God's laws would be meaningless without internal powers for following them [Leibniz] |
Full Idea: To say that, in creation, God gave bodies a law for acting means nothing, unless, at the same time, he gave them something by means of which it could happen that the law is followed. | |
From: Gottfried Leibniz (On Body and Force, Against the Cartesians [1702], p.253) | |
A reaction: This is the beginning of the modern rebellion against the medieval view of laws as imposed from outside on passive matter. Unfortunately for Leibniz, once you have postulated active internal powers, the external laws become redundant. |
13196 | All qualities of bodies reduce to forces [Leibniz] |
Full Idea: All qualities of bodies .....are in the end reduced [revoco] to forces. | |
From: Gottfried Leibniz (On Body and Force, Against the Cartesians [1702], p.256) | |
A reaction: The dots conceal a long qualification, but he is essentially standing by this simple remark. If you substitute the word 'powers' for 'forces', I think that is just about right. |
13192 | Power is passive force, which is mass, and active force, which is entelechy or form [Leibniz] |
Full Idea: The dynamicon or power [potentia] in bodies is twofold, passive and active. Passive force [vis] constitutes matter or mass [massa], and active force constitutes entelechy or form. | |
From: Gottfried Leibniz (On Body and Force, Against the Cartesians [1702], p.252) | |
A reaction: This is explicitly equating the innate force understood in physics with Aristotelian form. The passive force is to explain the resistance of bodies. I like the equation of force with power. He says the entelechy is 'analogous' to a soul. |
20462 | Because it is quantised, a field behaves like a set of packets of energy [Rovelli] |
Full Idea: Since the energy of the electromagnetic field can take on only certain values, the field behaves like a set of packets of energy. | |
From: Carlo Rovelli (Reality is Not What it Seems [2014], 04) |
20463 | There are about fifteen particles fields, plus a few force fields [Rovelli] |
Full Idea: There are about fifteen fields, whose quanta are elementary particles (electrons, quarks, muons, neutrinos, Higgs, and little else), plus a few fields similar to the electromagnetic one, which describe forces at a nuclear scale, with quanta like photons. | |
From: Carlo Rovelli (Reality is Not What it Seems [2014], 04) | |
A reaction: According to Rovelli, this sentence describes the essence of physical reality. |
20464 | The world consists of quantum fields, with elementary events happening in spacetime [Rovelli] |
Full Idea: The world is not made up of fields and particles, but of a single type of entity: the quantum field. There are no longer particles which move in space with the passage of time, but quantum fields whose elementary events happen in spacetime. | |
From: Carlo Rovelli (Reality is Not What it Seems [2014], 04) | |
A reaction: If you are not a scientist, there is (I find) a strong tendency to read and digest stuff like this, and then forget it the next day, because it so far from our experience. Folk like me have to develop two parallel views of the nature of reality. |
20460 | Electrons are not waves, because their collisions are at a point, and not spread out [Rovelli] |
Full Idea: Schrödinger's wave is a bad image for an electron, because when a particle collides with something else, it is always at a point: it is never spread out in space like a wave. | |
From: Carlo Rovelli (Reality is Not What it Seems [2014], 04 note) | |
A reaction: And yet there is the diffusion in the two-slit experiment, which Thomas Young discovered for light. I must take Rovelli's word for this. |
20459 | Electrons only exist when they interact, and their being is their combination of quantum leaps [Rovelli] |
Full Idea: Electrons don't always exist. They exist when they interact. They materialize when they collide with something. The quantum leap from one orbit to another constitutes their way of being real. An electron is a combination of leaps between interactions. | |
From: Carlo Rovelli (Reality is Not What it Seems [2014], 04) | |
A reaction: If a philosopher with an Aristotelian interest in the nature of matter wants to grasp the modern view, the electron looks like the thing to focus on. You can feel Rovelli battling here to find formulations that might satisfy a philosopher. |
20466 | Quantum Theory describes events and possible interactions - not how things are [Rovelli] |
Full Idea: Quantum Theory does not describe things as they are: it describes how things occur and interact with each other. It doesn't describe where there is a particle but how it shows itself to others. The world of existence is reduced to possible interactions. | |
From: Carlo Rovelli (Reality is Not What it Seems [2014], 04) | |
A reaction: Fans of 'process philosophy' should like this, though he is not denying that there may be facts about how things are - it is just that this is not mentioned in the theory. There is not much point in philosophers yearning to know the reality. |
20465 | Nature has three aspects: granularity, indeterminacy, and relations [Rovelli] |
Full Idea: I think that quantum mechanics has revealed three aspects of the nature of things: granularity, indeterminacy, and the relational structure of the world. | |
From: Carlo Rovelli (Reality is Not What it Seems [2014], 04) |
20458 | The world is just particles plus fields; space is the gravitational field [Rovelli] |
Full Idea: The world is made up of particles + fields, and nothing else; there is no need to add space as an extra ingredient. Newton's space is the gravitational field. | |
From: Carlo Rovelli (Reality is Not What it Seems [2014], 03) | |
A reaction: I get the impression that particles are just bumps or waves in the fields [yes! Rovelli p.110], which would mean there are fields and nothing else. And no one seems to know what a field is. |
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. |
20470 | Only heat distinguishes past from future [Rovelli] |
Full Idea: It is always heat and only heat that distinguishes the past from the future. | |
From: Carlo Rovelli (Reality is Not What it Seems [2014], 12) | |
A reaction: I can remember the past but not the future - so can that fact be reduced to facts about heat? |