22 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. |
| 11984 | Asserting a possible property is to say it would have had the property if that world had been actual [Plantinga] |
| Full Idea: To say than x has a property in a possible world is simply to say that x would have had the property if that world had been actual. | |
| From: Alvin Plantinga (Transworld Identity or worldbound Individuals? [1973], I) | |
| A reaction: Plantinga tries to defuse all the problems with identity across possible worlds, by hanging on to subjunctive verbs and modal modifiers. The point, though, was to explain these, or at least to try to give their logical form. |
| 11980 | A possible world is a maximal possible state of affairs [Plantinga] |
| Full Idea: A possible world is just a maximal possible state of affairs. | |
| From: Alvin Plantinga (Transworld Identity or worldbound Individuals? [1973], I) | |
| A reaction: The key point here is that Plantinga includes the word 'possible' in his definition. Possibility defines the worlds, and so worlds cannot be used on their own to define possibility. |
| 11982 | If possible Socrates differs from actual Socrates, the Indiscernibility of Identicals says they are different [Plantinga] |
| Full Idea: If the Socrates of the actual world has snubnosedness but Socrates-in-W does not, this is surely inconsistent with the Indiscernibility of Identicals, a principle than which none sounder can be conceived. | |
| From: Alvin Plantinga (Transworld Identity or worldbound Individuals? [1973], I) | |
| A reaction: However, we allow Socrates to differ over time while remaining the same Socrates, so some similar approach should apply here. In both cases we need some notion of what is essential to Socrates. But what unites aged 3 with aged 70? |
| 11983 | It doesn't matter that we can't identify the possible Socrates; we can't identify adults from baby photos [Plantinga] |
| Full Idea: We may say it makes no sense to say that Socrates exists at a world, if there is in principle no way of identifying him. ...But this is confused. To suppose Agnew was a precocious baby, we needn't be able to pick him from a gallery of babies. | |
| From: Alvin Plantinga (Transworld Identity or worldbound Individuals? [1973], I) | |
| A reaction: This seems a good point, and yet we have a space-time line joining adult Agnew with baby Agnew, and no such causal link is available between persons in different possible worlds. What would be the criterion in each case? |
| 11985 | If individuals can only exist in one world, then they can never lack any of their properties [Plantinga] |
| Full Idea: The Theory of Worldbound Individuals contends that no object exists in more than one possible world; this implies the outrageous view that - taking properties in the broadest sense - no object could have lacked any property that it in fact has. | |
| From: Alvin Plantinga (Transworld Identity or worldbound Individuals? [1973], II) | |
| A reaction: Leibniz is the best known exponent of this 'outrageous view', though Plantinga shows that Lewis may be seen in the same light, since only counterparts are found in possible worlds, not the real thing. The Theory does seem wrong. |
| 11986 | The counterparts of Socrates have self-identity, but only the actual Socrates has identity-with-Socrates [Plantinga] |
| Full Idea: While Socrates has no counterparts that lack self-identity, he does have counterparts that lack identity-with-Socrates. He alone has that - the property, that is, of being identical with the object that in fact instantiates Socrateity. | |
| From: Alvin Plantinga (Transworld Identity or worldbound Individuals? [1973], II) | |
| A reaction: I am never persuaded by arguments which rest on such dubious pseudo-properties. Whether or not a counterpart of Socrates has any sort of identity with Socrates cannot be prejudged, as it would beg the question. |
| 11987 | Counterpart Theory absurdly says I would be someone else if things went differently [Plantinga] |
| Full Idea: It makes no sense to say I could have been someone else, yet Counterpart Theory implies not merely that I could have been distinct from myself, but that I would have been distinct from myself had things gone differently in even the most miniscule detail. | |
| From: Alvin Plantinga (Transworld Identity or worldbound Individuals? [1973], II) | |
| A reaction: A counterpart doesn't appear to be 'me being distinct from myself'. We have to combine counterparts over possible worlds with perdurance over time. I am a 'worm' of time-slices. Anything not in that worm is not strictly me. |
| 468 | Musical performance can reveal a range of virtues [Damon of Ath.] |
| Full Idea: In singing and playing the lyre, a boy will be likely to reveal not only courage and moderation, but also justice. | |
| From: Damon (fragments/reports [c.460 BCE], B4), quoted by (who?) - where? |
| 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. |
| 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. |
| 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. |
| 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. |
| 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. |
| 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? |