121 ideas
| 16604 | Philosophy consists of choosing between Plato, Aristotle and Democritus [Pasnau] |
| Full Idea: The history of philosophy consists in a series of choices between three primordial rivals: Plato, Aristotle and Democritus. | |
| From: Robert Pasnau (Metaphysical Themes 1274-1671 [2011], 05.1) | |
| A reaction: Pasnau's point is that the importance of Democritus is not usually appreciated. As far as I can see, Democritus may have been the greatest of all philosophers, but most of his works are lost. His fragments are the best fragments. |
| 16606 | Original philosophers invariably seek inspiration from past thinkers [Pasnau] |
| Full Idea: Philosophers almost never strike out on wholly new ground, without the historical inspiration of some figure or other. | |
| From: Robert Pasnau (Metaphysical Themes 1274-1671 [2011], 05.1) |
| 16586 | The commentaries of Averroes were the leading guide to Aristotle [Pasnau] |
| Full Idea: The commentaries of Averroes on virtually the whole Aristotelian corpus became by far the most important scholastic guide to the interpretation of Aristotle. | |
| From: Robert Pasnau (Metaphysical Themes 1274-1671 [2011], 03.1) |
| 16568 | Modernity begins in the late 12th century, with Averroes's commentaries on Aristotle [Pasnau] |
| Full Idea: I tend to think of modernity as coming in the late twelfth century, with Averroes's magisterial commentaries on Aristotle. | |
| From: Robert Pasnau (Metaphysical Themes 1274-1671 [2011], 1.1) | |
| A reaction: A rather quirky use of 'modernity', but this seems to be a huge landmark. Note that it comes from the Islamic Arab world, not from Europe. |
| 16653 | Once accidents were seen as real, 'Categories' became the major text for ontology [Pasnau] |
| Full Idea: Originally you count substances for ontology. Once there is the doctrine of real accidents (in the 14th cent) the list of ten categories begins to look like an inventory of the kinds of things there are, and 'Categories' looks like the fundamental text. | |
| From: Robert Pasnau (Metaphysical Themes 1274-1671 [2011], 12.1) | |
| A reaction: Prior to this development, 'Categories' was treated as a mere beginner's text, once the major corpus of Aristotle had been rediscovered in the 13th century. The result of this development is sortal essentialism, which I don't like. |
| 16704 | In 1347, the Church effectively stopped philosophy for the next 300 years [Pasnau] |
| Full Idea: The year 1347 is a great milestone in the history of philosophy, because then the route to modern philosophy was blocked by Church authorities, and effectively put on hold for almost 300 years. | |
| From: Robert Pasnau (Metaphysical Themes 1274-1671 [2011], 19.3) | |
| A reaction: It is interesting that it was 100 years after the Reformation before philosophy got going again, and then only thanks to one man. Islam stopped philosophy earlier. |
| 16605 | After c.1450 all of Plato was available. Before that, only the first half of 'Timaeus' was known [Pasnau] |
| Full Idea: From the mid-fifteenth century forward, for the first time, the whole Platonic corpus was available in Ficino's Latin translation. Before then, only the first half of the 'Timaeus' had widely circulated in Latin. | |
| From: Robert Pasnau (Metaphysical Themes 1274-1671 [2011], 05.1) |
| 16607 | Renaissance Platonism is peripheral [Pasnau] |
| Full Idea: The fabled phenomenon of Renaissance Platonism is peripheral. | |
| From: Robert Pasnau (Metaphysical Themes 1274-1671 [2011], 05.3) | |
| A reaction: The point is that only a few Italians pursued the Platonic line. Pasnau suggests Cartesian dualism as a possible influence from Plato. |
| 16715 | Plato only made an impact locally in 15th century Italy [Pasnau] |
| Full Idea: In certain limited circles in Italy, Plato made an impact in the fifteenth century, but his influence never came close to challenging Aristotle's. | |
| From: Robert Pasnau (Metaphysical Themes 1274-1671 [2011], 20.2) |
| 16610 | Philosophy could easily have died in 17th century, if it weren't for Descartes [Pasnau] |
| Full Idea: As scholasticism collapsed in the 17th century, it might easily have happened is that philosophy simply died. That this did not happen is due in large part to René Descartes. …It is remarkable that this brilliant man insisted on still doing philosophy. | |
| From: Robert Pasnau (Metaphysical Themes 1274-1671 [2011], 05.5) | |
| A reaction: The alternative view is, of course, that you just can't stop people from thinking philosophically (except by totalitarian education). Are there philosophers in North Korea, or among the Taliban? |
| 16781 | The 17th century is a metaphysical train wreck [Pasnau] |
| Full Idea: The seventeenth century is a metaphysical train wreck. | |
| From: Robert Pasnau (Metaphysical Themes 1274-1671 [2011], 26.6) | |
| A reaction: This is, roughly, because the corpuscularian philosophy lacked the resources to answer all the problems dealt with by substantial forms. |
| 16677 | Anti-Razor: if you can't account for a truth, keep positing things until you can [Pasnau] |
| Full Idea: The Anti-Razor says 'whenever an affirmative proposition is truly stated, if one thing does not suffice to account for its truth, then one must posit things, and if two do not suffice then three, and so on to infinity'. | |
| From: Robert Pasnau (Metaphysical Themes 1274-1671 [2011], 14.3) | |
| A reaction: This is quoted from an anonymous logic text of 1325. Apparently Ockham himself articulated the idea more than once. |
| 19482 | Current physics says matter and antimatter should have reduced to light at the big bang [New Sci.] |
| Full Idea: Our best theories of physics imply we shouldn't be here. The big bang ought to have produced equal amounts of matter and antimatter particles, which would have almost immediately annihilated each other, leaving nothing but light. | |
| From: New Scientist writers (New Scientist articles [2013], 2015.05.23) | |
| A reaction: This is not, of course, a rejection of physics, but a puzzle about the current standard model of physics. |
| 19483 | CP violation shows a decay imbalance in matter and antimatter, leading to matter's dominance [New Sci.] |
| Full Idea: The phenomenon of charge-parity (CP) violation says that under certain circumstances antiparticles decay at different rates from their matter counterpart. ...This might explain matter's dominance in the universe, but the effect is too small. | |
| From: New Scientist writers (New Scientist articles [2013], 2015.05.23) | |
| A reaction: Physicists are currently studying CP violations, hoping to explain why there is any matter in the universe. This will not, I presume, explain why matter and antimatter arrived in the first place. |
| 16598 | Priority was a major topic of dispute for scholastics [Pasnau] |
| Full Idea: For a scholastic author, hardly anything was so likely to precipitate a lengthy disputatio as talk of priority, in its various kinds. | |
| From: Robert Pasnau (Metaphysical Themes 1274-1671 [2011], 04.3) |
| 16727 | In mixtures, the four elements ceased to exist, replaced by a mixed body with a form [Pasnau] |
| Full Idea: The standard view was that in a mixture there is only the mixed body and its substantial form (gold). There are no further substantial forms of the elements, because the elements do not actually exist within the body. | |
| From: Robert Pasnau (Metaphysical Themes 1274-1671 [2011], 22.3) | |
| A reaction: This seems to me to be the key idea that was overthrown in the seventeenth century, so that corpuscular matter kept aspects of its ingredients, which science could then investigate. With the substantial form, investigation seemed impossible. |
| 16732 | 17th C qualities are either microphysical, or phenomenal, or powers [Pasnau] |
| Full Idea: The seventeenth century is often said to have bequeathed us three ways of thinking about sensible qualities: either in reductive microphysical terms, or as internal phenomenal states, or else as powers or dispositions. | |
| From: Robert Pasnau (Metaphysical Themes 1274-1671 [2011], 23.1) | |
| A reaction: Pasnau goes on to claim that no one in the 17th century believed the third one. I take it to be a very new, and totally wonderful and correct, view. |
| 16733 | 17th century authors only recognised categorical properties, never dispositions [Pasnau] |
| Full Idea: In the seventeenth century, my claim is that authors during the period recognise only categorical properties, and never dispositional properties. | |
| From: Robert Pasnau (Metaphysical Themes 1274-1671 [2011], 23.1) |
| 16662 | The biggest question for scholastics is whether properties are real, or modes of substances [Pasnau] |
| Full Idea: Among scholastics the primary agreement is that what primarily exist are substances. The primary disagreement concerns the nature of their changeable properties. Are they real accidents, or mere modes of substance? | |
| From: Robert Pasnau (Metaphysical Themes 1274-1671 [2011], 13.1) |
| 16767 | There is no centralised power, but we still need essence for a metaphysical understanding [Pasnau] |
| Full Idea: One could empirically reject a centralised power within a substance - and still think a genuine substance requires a form of some more abstract kind, not for a physical explanation, but for a full metaphysical understanding of how things are. | |
| From: Robert Pasnau (Metaphysical Themes 1274-1671 [2011], 25.2) | |
| A reaction: This divorce of the 'metaphysical' from the physical is a running theme in Pasnau, and he cites support from Leibniz. I'm not sure I understand 'metaphysical' understanding, if it is actually contrary to physics. I take it to be 'psychological'. |
| 16788 | Instead of adding Aristotelian forms to physical stuff, one could add dispositions [Pasnau] |
| Full Idea: Someone who wants to enrich a strict corpuscularian account with other metaphysical entities has alternatives other than Aristotelian hylomorphism. One can, for instance, introduce dispositions. | |
| From: Robert Pasnau (Metaphysical Themes 1274-1671 [2011], 28.2) | |
| A reaction: This slightly throws me, because I have been flirting with a dispositional account of hylomorphism. The implication is that the form is abstract and structural, where the disposition is real and physical. But dispositions can do the job of forms. |
| 16738 | Scholastics reject dispositions, because they are not actual, as forms require [Pasnau] |
| Full Idea: Scholastics reject anything like bare dispositions, on Aristotelian principles. Powers are forms, and forms actualise their subject, and are causally efficacious. Therefore no powers can be bare dispositions. | |
| From: Robert Pasnau (Metaphysical Themes 1274-1671 [2011], 23.5) | |
| A reaction: The point seems to be that a mere disposition is not actual, as a form is required to be. I would have thought that a power does not have to be operational to be actual. A live electric wire is a real phenomenon. It isn't waiting to be live. |
| 16649 | Scholastics say there is a genuine thing if it is 'separable' [Pasnau] |
| Full Idea: Among the scholastics (after Duns Scotus) it would be come to be taken for granted that the crucial test for being a genuine thing - a 'res' - is separability. | |
| From: Robert Pasnau (Metaphysical Themes 1274-1671 [2011], 11.2) | |
| A reaction: The idea of separability is implicit in Aristotle. In borderline cases, it seems that they are tempted to claim that things like accidental properties are separable, simply because they want them to be genuine things. A criterion for separability? |
| 16785 | If you reject essences, questions of individuation become extremely difficult [Pasnau] |
| Full Idea: Given the accepted linkage between a thing's essence and its identity, the rejection of essences makes a complete mess out of questions of individuation. | |
| From: Robert Pasnau (Metaphysical Themes 1274-1671 [2011], 27.6) | |
| A reaction: I note that he talks of a thing having 'identity', contra the view of identity as a two-place relation. I agree with this, but there is a chicken-egg problem. Do I perceive an identity and surmise an essence, or surmise an essence and deduce identity? |
| 16680 | Scholastics thought Quantity could be the principle of individuation [Pasnau] |
| Full Idea: Quantity was a leading scholastic contender for the principle of individuation. | |
| From: Robert Pasnau (Metaphysical Themes 1274-1671 [2011], 14.4) |
| 16628 | Corpuscularianism promised a decent account of substance [Pasnau] |
| Full Idea: One of the great attractions of corpuscularianism is that it promises to put our acquaintance with substances on a solid foundation. | |
| From: Robert Pasnau (Metaphysical Themes 1274-1671 [2011], 07.3) | |
| A reaction: This is why the seventeenth century did not abandon 'substance', even though they banished 'substantial form'. |
| 16617 | Corpuscularian critics of scholasticism say only substances exist [Pasnau] |
| Full Idea: Corpuscularian critics of scholasticism tend to think that only substances exist. | |
| From: Robert Pasnau (Metaphysical Themes 1274-1671 [2011], 06.2) | |
| A reaction: Pasnau treats this as an extreme 17th C reaction which was hopelessly inadequate as metaphysics. We have been struggling with the nature of 'properties' ever since, while losing our grip on the concept of a unified 'substance'. |
| 16741 | Scholastics wanted to treat Aristotelianism as physics, rather than as metaphysics [Pasnau] |
| Full Idea: There is a broad scholastic tendency to understand Aristotelianism not in abstract, metaphysical terms, but as a concrete, physical theory of the world. | |
| From: Robert Pasnau (Metaphysical Themes 1274-1671 [2011], 23.5) | |
| A reaction: This seems to give a good explanation of why Aristotelianism plummeted to oblivion in the 17th C. Pasnau obviously wants to revive it, by drawing a sharp line between metaphysics and science. I doubt the line. |
| 16777 | If crowds are things at all, they seem to be Substances, since they bear properties [Pasnau] |
| Full Idea: Crowds seem to be the bearers of properties, and if they are things at all, then there is no place for them other than in the category of Substance. | |
| From: Robert Pasnau (Metaphysical Themes 1274-1671 [2011], 26.1) | |
| A reaction: It is tempting to say, based on Aristotle, that a substance is whatever 1) bears properties, and 2) endures in spite of change, but a crowd is a nice problem case, because it looks too disunited to be a 'substance'. |
| 16615 | Scholastics use 'substantia' for thick concrete entities, and for thin metaphysical ones [Pasnau] |
| Full Idea: Scholastic texts are rife with different senses of 'substantia', using the term to refer, among other things, both to thick concrete entities and to thin metaphysical ones. | |
| From: Robert Pasnau (Metaphysical Themes 1274-1671 [2011], 06.1) | |
| A reaction: Pasnau introduces 'thin' and 'thick' substance for this reason. I may adopt this. Without distinctions between thin and thick concepts of things we can get very muddled. I like the word to label something which is an 'entity'. |
| 16775 | For corpuscularians, a substance is just its integral parts [Pasnau] |
| Full Idea: According to strict corpuscularianism the only real constituents of a substance are its integral parts. | |
| From: Robert Pasnau (Metaphysical Themes 1274-1671 [2011], 26.1) | |
| A reaction: An understandable reaction to the emptiness of Aristotelian substantial forms in science. It seems to leave out the structural principles that distinguish one arrangement of parts from another. See Koslicki on this. |
| 16769 | If clay survives destruction of the statue, the statue wasn't a substance, but a mere accident [Pasnau] |
| Full Idea: The unitarian view of substance says it cannot be divided. If the clay can survive the destruction of the statue, then that shows that the statue was not a substance at all, and that its shape (or whatever made it a statue) was merely a passing accident. | |
| From: Robert Pasnau (Metaphysical Themes 1274-1671 [2011], 25.3) | |
| A reaction: This seems to give the orthodox Aristotelian/Thomist reading, assuming that a substance only has one form, which unifies it. Since clay must have shape, and statues must have matter, I have never understood how there were two objects here. |
| 16602 | Corpuscularianism rejected not only form, but also the dependence of matter on form [Pasnau] |
| Full Idea: What marks the rise of the corpuscularian movement is not just the rejection of form, but the rejection of matter as dependent on form. | |
| From: Robert Pasnau (Metaphysical Themes 1274-1671 [2011], 04.5) | |
| A reaction: The point was that matter required form to have any kind of actual existence, but now matter can stand on its own. |
| 16612 | Hylomorphism may not be a rival to science, but an abstract account of unity and endurance [Pasnau] |
| Full Idea: Hylomorphism admits of an alternative formulation, as an explanatory schema at a different level of analysis, not competing with corpuscular-mechanistic theory, but accounting for abstract features of the world - notably unity and endurance of substances. | |
| From: Robert Pasnau (Metaphysical Themes 1274-1671 [2011], 06.1) | |
| A reaction: Pasnau is clearly sympathetic. As a view of why normal objects have unity and persist over time it is almost the only decent theory around. Hawley, for example, struggles to explain how 'stages' of a thing are linked. Classical mereology is silly. |
| 16613 | Hylomorphism declined because scholastics made it into a testable physical theory [Pasnau] |
| Full Idea: Scholastics lost their grip on hylomorphism as a metaphysical theory, conceiving of it as a concrete, physical hypothesis about causal forces. Once form and matter were made subject to empirical research, their days were inevitably numbered. | |
| From: Robert Pasnau (Metaphysical Themes 1274-1671 [2011], 06.1) | |
| A reaction: Pasnau seems to make a sharp distinction between science, and a separate realm he labels 'metaphysical'. You can't keep causation out of Aristotelian hylomorphism. The defence is that it is at a higher level of generality than science. |
| 16747 | Scholastics made forms substantial, in a way unintended by Aristotle [Pasnau] |
| Full Idea: The conception of form as somehow substantial took on new life among scholastic Aristotelians, and was developed in ways that Aristotle himself never suggested. | |
| From: Robert Pasnau (Metaphysical Themes 1274-1671 [2011], 24.1) | |
| A reaction: This is music to we modern neo-Aristotelians, because scholasticism was rightly dumped in the 17th C, but we can go back and start again from what The Philosopher actually said. |
| 16759 | Scholastics began to see substantial form more as Aristotle's 'efficient' cause [Pasnau] |
| Full Idea: The whole scholastic conception of substantial form came to have more and more in common with an Aristotelian efficient cause. | |
| From: Robert Pasnau (Metaphysical Themes 1274-1671 [2011], 24.2) | |
| A reaction: Aristotle, of course, identified the form with the 'formal cause [aitia]', which is the shape of the statue, rather than the efficient cause, which is the sculptor. |
| 16748 | Aquinas says a substance has one form; Scotists say it has many forms [Pasnau] |
| Full Idea: Aquinas subscribes to the unitarian doctrine that a single substance has just a single substantial form, but authors like Scotus subscribe to a plurality of substantial forms. | |
| From: Robert Pasnau (Metaphysical Themes 1274-1671 [2011], 24.1) | |
| A reaction: The Scotists seem to think that qualities themselve can have forms. I take it that Aristotle would have agreed with Aquinas. |
| 16671 | Scholastic Quantity either gives a body parts, or spreads them out in a unified way [Pasnau] |
| Full Idea: On one version of Quantity realism it is what makes a body have parts; on another version, it is what makes the body's parts be spread out in a continuous and unified way. | |
| From: Robert Pasnau (Metaphysical Themes 1274-1671 [2011], 14.1) |
| 16579 | There may be different types of substrate, or temporary substrates [Pasnau] |
| Full Idea: The substratum thesis says …perhaps there is a different subject for different kinds of changes, and perhaps what endures through one kind of change will be corrupted by another. | |
| From: Robert Pasnau (Metaphysical Themes 1274-1671 [2011], 02.5) |
| 16596 | A substratum can't be 'bare', because it has a job to do [Pasnau] |
| Full Idea: A completely bare substratum seems not just incoherent but also unable to carry out the function for which it is intended - to be a substratum. | |
| From: Robert Pasnau (Metaphysical Themes 1274-1671 [2011], 03.3) |
| 16584 | If a substrate gives causal support for change, quite a lot of the ingredients must endure [Pasnau] |
| Full Idea: When the substratum thesis is grounded on the idea that the ingredients must endure through the change, if they are to play a causal role, then it is natural to suppose that quite a lot of the ingredients must endure. | |
| From: Robert Pasnau (Metaphysical Themes 1274-1671 [2011], 02.5) | |
| A reaction: Aristotle sharply distinguishes alteration from substantial change, but as the substrate gets thinner, the boundary between those two would blur. |
| 16580 | A substrate may be 'prime matter', which endures through every change [Pasnau] |
| Full Idea: The 'conservation thesis' about substrates says that there is a single, most basic substrate that endures through every material change, something we call 'prime matter'. | |
| From: Robert Pasnau (Metaphysical Themes 1274-1671 [2011], 02.5) |
| 16749 | Aristotelians deny that all necessary properties are essential [Pasnau] |
| Full Idea: For an Aristotelian not all necessary properties are essential; the essential properties are those that define a thing as what it is. | |
| From: Robert Pasnau (Metaphysical Themes 1274-1671 [2011], 24.1) | |
| A reaction: I take it as basic that whatever is essential is in some way important, whereas necessities can be trivial. |
| 16694 | Typical successive things are time and motion [Pasnau] |
| Full Idea: The standard scholastic examples of 'entia successiva' are time and motion. | |
| From: Robert Pasnau (Metaphysical Themes 1274-1671 [2011], 18.1) | |
| A reaction: Aristotle's examples of a day and the Games seem clearer, as time and motion do not count so clearly as 'things'. |
| 16583 | Weak ex nihilo says it all comes from something; strong version says the old must partly endure [Pasnau] |
| Full Idea: The weak ex nihilo principle says that everything comes from something, and the strong ex nihilo principle says that in everything new, something of the old must endure | |
| From: Robert Pasnau (Metaphysical Themes 1274-1671 [2011], 02.5) |
| 19737 | A system can infer the structure of the world by making predictions about it [New Sci.] |
| Full Idea: If we can train a system for prediction, it can essentially infer the structure of the world it's looking at by doing this prediction. | |
| From: New Scientist writers (New Scientist articles [2013], 2015.12.12) | |
| A reaction: [AI expert] This seems to be powerful support for the centrality of mathematical laws of nature in achieving understanding of the world. We may downplay the 'mere' ability to predict, but this idea says that the rewards of prediction are very great. |
| 16783 | Essences must explain, so we can infer them causally from the accidents [Pasnau] |
| Full Idea: Without the explanatory role of essence, the underlying epistemic picture would be jeopardised, because there would no longer be any causal route by which we might get from accidents to essence. | |
| From: Robert Pasnau (Metaphysical Themes 1274-1671 [2011], 27.5) | |
| A reaction: There is a slight whiff of circularity here. It could be that we are psychologically desperate for essences, and so we invent bogus causal routes from the accidents to get at them. Can we know there are essences awaiting us, on independent grounds? |
| 19736 | Neural networks can extract the car-ness of a car, or the chair-ness of a chair [New Sci.] |
| Full Idea: Early neural nets were really good at recognising general categories, such as a car or a chair. Those networks are good at extracting the 'chair-ness' or the 'car-ness' of the object. | |
| From: New Scientist writers (New Scientist articles [2013], 2015.12.12) | |
| A reaction: [Interview with Yann LeCun, Facebook AI director] Fregean philosophers such as Geach think that extracting features is a ridiculous idea, but if even a machine can do it then I suspect that human beings can (and do) manage it too. |
| 16419 | No one has yet devised a rationality test [New Sci.] |
| Full Idea: The financial sector has been clamouring for a rationality test for years. | |
| From: New Scientist writers (New Scientist articles [2013], 2013.10.29) | |
| A reaction: Many aspects of intelligence tests do actually pick out what I would call rationality (which includes 'rational intuition', a new favourite of mine). But they are mixed in with rather mechanical geeky sort of tests. |
| 16417 | About a third of variation in human intelligence is environmental [New Sci.] |
| Full Idea: Possibly a third of the variation in our intelligence is down to the environment in which we grew up - nutrition and education, for example. | |
| From: New Scientist writers (New Scientist articles [2013], 2013.10.29) | |
| A reaction: This presumably leaves the other two-thirds to derive from genetics. I am a big believer in environment. Swapping babies between extremes of cultural environment would hugely affect intelligence, say I. |
| 16418 | People can be highly intelligent, yet very stupid [New Sci.] |
| Full Idea: You really can be highly intelligent, and at the same time very stupid. | |
| From: New Scientist writers (New Scientist articles [2013], 2013.10.29) | |
| A reaction: This is closely related to my observation (from a lifetime of study) that a talent for philosophy has a very limited correlation with standard notions of high intelligence. What matters is how conscious reasoning and intuition relate. Greek 'phronesis'. |
| 19484 | Psychologists measure personality along five dimensions [New Sci.] |
| Full Idea: Psychologists have long thought that measuring on a scale of just five personality dimensions - agreeableness, extroversion, neuroticism, conscientiousness and openness to new experiences - can capture all human variations in behaviour and attitude. | |
| From: New Scientist writers (New Scientist articles [2013], 2015.06.13) | |
| A reaction: Researchers are considering a sixth - called 'honesty-humility' - which is roughly how devious people are. The five mentioned here seem to be a well entrenched orthodoxy among professional psychologists. Is personality more superficial than character? |
| 16609 | Atomists say causation is mechanical collisions, and all true qualities are microscopic [Pasnau] |
| Full Idea: The atomist view is that causation is limited to collisions among corpuscles (which is 'mechanism'), and the only bodily qualities are those found at the microcorpuscular level; sensible qualities are in fact sensations. | |
| From: Robert Pasnau (Metaphysical Themes 1274-1671 [2011], 05.4) | |
| A reaction: [Part of a full summary of atomism by Pasnau] |
| 16603 | In the 17th C matter became body, and was then studied by science [Pasnau] |
| Full Idea: In the seventeenth century, matter becomes body, and body becomes the object of natural science. | |
| From: Robert Pasnau (Metaphysical Themes 1274-1671 [2011], 04.5) |
| 16592 | Atomism is the commonest version of corpuscularianism, but isn't required by it [Pasnau] |
| Full Idea: Atomism is the most common version of corpuscular prime matter, but it is not the only option. Indeed, atomism neither entails nor is entailed by the combination of corpuscularianism and the substratum thesis. | |
| From: Robert Pasnau (Metaphysical Themes 1274-1671 [2011], 03.2) | |
| A reaction: The point is that the corpuscles may be endlessly divisible (which Lewis called 'gunk'). |
| 16750 | If there are just arrangements of corpuscles, where are the boundaries between substances? [Pasnau] |
| Full Idea: If all there are corpuscles of various shapes and sizes, variously arranged, it is not easy to see how we might draw the boundary lines, at any given moment, between one substance and another. | |
| From: Robert Pasnau (Metaphysical Themes 1274-1671 [2011], 24.2) | |
| A reaction: We still have precisely that problem, and it leads to the nihilism about ordinary objects found in Unger, Van Inwagen and Merricks. I have so far found modern defences of ordinary objects unpersuasive. |
| 16722 | Scholastic causation is by changes in the primary qualities of hot, cold, wet, dry [Pasnau] |
| Full Idea: There is a scholastic theory of causation. Of Aristotle's Four Causes, the main one is the 'formal' cause, and that consists of changes in the primary, elemental qualities, which are hot, cold, wet and dry. | |
| From: Robert Pasnau (Metaphysical Themes 1274-1671 [2011], 21.2) | |
| A reaction: [my summary] It is probably right to call this 'scholastic' rather than 'Aristotelian', as I take Aristotelian essence to run deeper than this, and involve principles as well as qualities. |
| 16760 | Substantial forms were a step towards scientific essentialism [Pasnau] |
| Full Idea: Substantial forms might well be viewed as an early step in the development of scientific essentialism. | |
| From: Robert Pasnau (Metaphysical Themes 1274-1671 [2011], 24.4) | |
| A reaction: This is the scholastic view of substantial forms, which is much more physical and causal, rather than Aristotle's more abstract view. The rejection of substantial forms led to the 'Humean' view of laws of nature. |
| 21167 | Gravity is unusual, in that it always attracts and never repels [New Sci.] |
| Full Idea: Gravity is an odd sort of force, not least because it only ever works one way. Electromagnetism attracts and repels, but with gravity there are only positive masses always attract. | |
| From: New Scientist writers (Why the Universe Exists [2017], 05) | |
| A reaction: This leads to speculation about anti-gravity, but there is no current evidence for it. |
| 19950 | Entropy is the only time-asymmetric law, so time may be linked to entropy [New Sci.] |
| Full Idea: All our physical laws are time-symmetric, ...so things can run forwards or backwards. But entropy is an exception, saying that disorder increases over time. Many physicists therefore suspect that the flow of time is linked to entropy. | |
| From: New Scientist writers (New Scientist articles [2013], 2017.02.04) |
| 21176 | In the Big Bang general relativity fails, because gravity is too powerful [New Sci.] |
| Full Idea: At the origin of the universe gravity becomes so powerful that general relativity breaks down, giving infinity for every answer. | |
| From: New Scientist writers (Why the Universe Exists [2017], 09) |
| 21147 | Quantum electrodynamics incorporates special relativity and quantum mechanics [New Sci.] |
| Full Idea: The theory of electromagnetism that incorporates both special relativity and quantum mechanics is quantum electrodynamics (QED). It was developed by Dirac and others, and perfected in the 1940s. The field is a collection of quanta. | |
| From: New Scientist writers (Why the Universe Exists [2017], 02) | |
| A reaction: This builds on Maxwell's earlier classical theory. QED is said to be the best theory in all of physics. |
| 19478 | Light moves at a constant space-time speed, but its direction is in neither space nor time [New Sci.] |
| Full Idea: A light ray always moves at one unit of space per unit of time - a constant diagonal on the graph. ...But the direction that light rays travel in is neither space nor time, and is called 'null'. It is on the edge between space and time. | |
| From: New Scientist writers (New Scientist articles [2013], 2013.06.15) | |
| A reaction: Don't understand this, but it sounds fun. |
| 21155 | Photons have zero rest mass, so virtual photons have infinite range [New Sci.] |
| Full Idea: Photons, the field quanta of the electromagnetic force, have zero rest mass, so virtual photons can exist indefinitely and travel any distance, meaning the electromagnetic force has an infinite range. | |
| From: New Scientist writers (Why the Universe Exists [2017], 02) |
| 21161 | In the standard model all the fundamental force fields merge at extremely high energies [New Sci.] |
| Full Idea: The standard model says that the fields of all fundamental forces should merge at extremely high energies, meaning there is also a unified, high-energy field out there. | |
| From: New Scientist writers (Why the Universe Exists [2017], 03) | |
| A reaction: Not quite sure what 'out there' means. This idea is linked to the quest for dark energy. Is this unified phenomenon only found near the Big Bang? |
| 21146 | Electrons move fast, so are subject to special relativity [New Sci.] |
| Full Idea: Electrons in atoms move at high speeds, so they are subject to the special theory of relativity. | |
| From: New Scientist writers (Why the Universe Exists [2017], 02) | |
| A reaction: Presumably this implies a frame of reference, and defining velocities relative to other electrons. Plus time-dilation? |
| 19474 | Quantum states are measured by external time, of unknown origin [New Sci.] |
| Full Idea: When we measure the evolution of a quantum state, it is to the beat of an external timepiece of unknown provenance. | |
| From: New Scientist writers (New Scientist articles [2013], 2013.06.15) | |
| A reaction: It is best not to leap to philosophical conclusions when studying modern physics. Evidently time has a very different status in quantum mechanics and in relativity theory. |
| 19473 | The Schrödinger equation describes the evolution of an object's wave function in Hilbert space [New Sci.] |
| Full Idea: A quantum object's state is described by a wave function living in Hilbert space, encompassing all of its possible states. We see how the wave function evolves in time, moving from one state to another, using the Schrödinger equation. | |
| From: New Scientist writers (New Scientist articles [2013], 2013.06.15) | |
| A reaction: [These idea are basic explanations for non-scientific philosophers - please forgive anything that makes you wince] |
| 21148 | The strong force is repulsive at short distances, strong at medium, and fades at long [New Sci.] |
| Full Idea: Experiments show that the nuclear binding force does not follow the inverse square law, but is repulsive at the shortest distances, then attractive, then fades away rapidly as distance increases further. | |
| From: New Scientist writers (Why the Universe Exists [2017], 02) | |
| A reaction: So how does it know when to be strong? Magnetism doesn't vary according to distance, and light obeys the inverse square law, because everything is decided at the output. - See 21151 for an explanation. It interacts after departure. |
| 21151 | Gluons, the particles carrying the strong force, interact because of their colour charge [New Sci.] |
| Full Idea: In QCD the particles that carry the strong force are called gluons. ...Gluons carry their own colour charges, so they can interact with each other (unlike photons) via the strong nuclear force (which limits the range of the force). | |
| From: New Scientist writers (Why the Universe Exists [2017], 02) | |
| A reaction: So the force varies in strength with distance because the degree of separation among the spreading gluons varies? The force has one range, which is squashed when close, effective at medium, and loses touch with distance? |
| 21152 | The strong force binds quarks tight, and the nucleus more weakly [New Sci.] |
| Full Idea: The strong force holds quarks together within protons and neutrons, and residual effects of the strong force bind protons (whch repel one another) and neutrons together in nuclei. | |
| From: New Scientist writers (Why the Universe Exists [2017], 02) | |
| A reaction: So the force is much stronger between quarks (which can't escape), and only 'residual' in the nucleus, which must be why smashing nuclei open is fairly easy, but smashin protons open needs higher energies. |
| 21142 | Classifying hadrons revealed two symmetry patterns, produced by three basic elements [New Sci.] |
| Full Idea: Classifying hadrons according to charge, strangeness and spin revealed patterns of eight and ten particles (SU(3) symmetery). The mathematics then showed that these are built from a basic group of only three members. | |
| From: New Scientist writers (Why the Universe Exists [2017], 01) |
| 21143 | Quarks in threes can build hadrons with spin ˝ or with spin 3/2 [New Sci.] |
| Full Idea: Quarks in threes can build hadrons with spin ˝ (proton, duu; neutron, ddu; lambda, dus), or with spin 3/2 (omega-minus, sss). | |
| From: New Scientist writers (Why the Universe Exists [2017], 01) |
| 21150 | Three different colours of quark (as in the proton) can cancel out to give no colour [New Sci.] |
| Full Idea: Just as mixing three colours of light gives white, so the three colour charges of quarks can add up to give no colour. This is what happens in the proton, which always contains one blue-charge quark, one red and one green. | |
| From: New Scientist writers (Why the Universe Exists [2017], 02) |
| 21145 | The four fundamental forces (gravity, electromagnetism, weak and strong) are the effects of particles [New Sci.] |
| Full Idea: There are four fundamental forces: gravity, electromagnetism, and the weak and strong nuclear forces. Particle physics has so far failed to encompass the force of gravity. The forces that shape our world are themselves the effect of particles. | |
| From: New Scientist writers (Why the Universe Exists [2017], 02) | |
| A reaction: Philosophers must take note of the fact that forces are the effects of particles. Common sense pictures forces imposed on particles, like throwing a tennis ball, but the particles are actually the sources of force. The gravitino is speculative. |
| 21153 | The weak force explains beta decay, and the change of type by quarks and leptons [New Sci.] |
| Full Idea: The beta decay of the neutron (into a proton, an electron and an antineutrino) can be described in terms of the weak force, which is 10,000 times weaker than the strong force. It allows the quarks and leptons to change from one type to another. | |
| From: New Scientist writers (Why the Universe Exists [2017], 02) | |
| A reaction: This seems to make it the key source of radioactivity. Perhaps it should be called the Force of Change? |
| 21154 | Three particles enable the weak force: W+ and W- are charged, and Z° is not [New Sci.] |
| Full Idea: The quantum field theory of the weak force needs three carrier particles. The W+ and W- are electrically charged, and enable the weak force to change the charge of a particle. The Z° is uncharged, and mediates weak interactions with no charge change. | |
| From: New Scientist writers (Why the Universe Exists [2017], 02) |
| 21156 | The weak force particles are heavy, so the force has a short range [New Sci.] |
| Full Idea: The W and Z particles are heavy, and so cannot travel far from their parents. The weak force therefore has a very short range. | |
| From: New Scientist writers (Why the Universe Exists [2017], 02) |
| 21164 | Why do the charges of the very different proton and electron perfectly match up? [New Sci.] |
| Full Idea: Why do the proton and electron charges mirror each other so perfectly when they are such different particles? | |
| From: New Scientist writers (Why the Universe Exists [2017], 04) | |
| A reaction: We seem to have reached a common stage in science, where we have a wonderful descriptive model (the Standard Model), but we cannot explain why what is modelled is the way it is. |
| 21170 | The Standard Model cannot explain dark energy, survival of matter, gravity, or force strength [New Sci.] |
| Full Idea: The standard model cannot explain dark matter, or dark energy (which is causing expansion to accelerate). It cannot explain how matter survived annihilation with anti-matter in the Big Bang, or explain gravity. The strength of each force is unexplained. | |
| From: New Scientist writers (Why the Universe Exists [2017], 06) | |
| A reaction: [compressed] P.141 adds that the model has to be manipulated to keep the Higgs mass low enough. |
| 21140 | Spin is a built-in ration of angular momentum [New Sci.] |
| Full Idea: Spin is a built-in ration of angular momentum. | |
| From: New Scientist writers (Why the Universe Exists [2017], 01) | |
| A reaction: As an outsider all I can do is collect descriptions of such properties from the experts. The experts appear to be happy with the numbers inserted in the equations. |
| 21149 | Quarks have red, green or blue colour charge (akin to electric charge) [New Sci.] |
| Full Idea: Quarks have a property akin to electric charge, called their colour charge. It comes in three varieties, red, green and blue. | |
| From: New Scientist writers (Why the Universe Exists [2017], 02) |
| 21158 | Fermions, with spin ˝, are antisocial, and cannot share quantum states [New Sci.] |
| Full Idea: Particles with half-integer spin, such as electrons, protons or quarks (all spin ˝) have an asymmetry in their wavefunction that makes them antisocial. These particles (Fermions) cannot share a quantum state. | |
| From: New Scientist writers (Why the Universe Exists [2017], 02) | |
| A reaction: This is said to explain the complexity of matter, with carbon an especially good example. |
| 21165 | Spin is akin to rotation, and is easily measured in a magnetic field [New Sci.] |
| Full Idea: Spin is a quantum-mechanical property of a particle akin to rotation about its own axis. Particles of different spins respond to magnetic fields in different ways, so it is a relatively easy thing to measure. | |
| From: New Scientist writers (Why the Universe Exists [2017], 04) | |
| A reaction: I wish I knew what 'akin to' meant. Maybe particles are not rigid bodies, so they cannot spin in the way a top can? It must be an electro-magnetic property. Idea 21166 says spin has two possible directions. |
| 21157 | Particles are spread out, with wave-like properties, and higher energy shortens the wavelength [New Sci.] |
| Full Idea: Particles obeying the laws of quantum mechanics have wave-like properties - moving as a quantum wave-function, spread out in space, with wavelengths that get shorter as their energy increases. | |
| From: New Scientist writers (Why the Universe Exists [2017], 02) | |
| A reaction: Thus X-rays are dangerous, but long wave radio is not. De Broglie's equation. |
| 21163 | The mass of protons and neutrinos is mostly binding energy, not the quarks [New Sci.] |
| Full Idea: Most of a proton's or neutrino's mass is contained in the interaction energies of a 'sea' of quarks, antiquarks and gluons that bind them. ...You might feel solid, but in fact you're 99 per cent binding energy. | |
| From: New Scientist writers (Why the Universe Exists [2017], 04) | |
| A reaction: This is because energy is equivalent to mass (although gluons are said to have energy but no mass - puzzled by that). This is a fact which needs a bit of time to digest. Once you've grasped we are full of space, you still have understood it. |
| 21168 | Gravitional mass turns out to be the same as inertial mass [New Sci.] |
| Full Idea: There are two types of mass: gravitational mass quantifies how strongly an object feels gravity, while inertial mass quantifies an object's resistance to acceleration. There proven equality is at the heart of General Relativity. | |
| From: New Scientist writers (Why the Universe Exists [2017], 05) | |
| A reaction: It had never occurred to me that these two values might come apart. Doesn't their identical values demonstrate that they are in fact the same thing? Sounds like Hesperus/Phosphorus to me. The book calls it 'mysterious'. |
| 21138 | Neutrons are slightly heavier than protons, and decay into them by emitting an electron [New Sci.] |
| Full Idea: The proton (938.3 MeV) is lighter than the neutron (939.6 MeV) and does not decay, but the heavier neutron can change into a proton by emitting an electron. (If you gather a bucketful of neutrons, after ten minutes only half of them would be left). | |
| From: New Scientist writers (Why the Universe Exists [2017], 01) | |
| A reaction: Protons are more or less eternal, but some theories have them decaying after billions of years. Smashing protons together is a popular pastime for physicists. |
| 21144 | Top, bottom, charm and strange quarks quickly decay into up and down [New Sci.] |
| Full Idea: Quarks can change from one variety to another, and the top, bottom, charm and strange quarks all rapidly decay to the up and down quarks of everyday life. | |
| From: New Scientist writers (Why the Universe Exists [2017], 01) | |
| A reaction: Hence the universe is largely composed of up and down quarks and electrons. The other quarks seem to be more important in the early universe. |
| 21141 | Neutrinos were proposed as the missing energy in neutron beta decay [New Sci.] |
| Full Idea: When a neutron decays into a proton and an electron (one example of beta decay), the energy of the two particles adds up to less than the starting energy of the neutron. Pauli and Fermi concluded that a neutrino (an electron antineutrino) is emitted. | |
| From: New Scientist writers (Why the Universe Exists [2017], 01) | |
| A reaction: I'm wondering how much they could infer about the nature of the new particle (which was only confirmed 26 years later). |
| 21169 | Only neutrinos spin anticlockwise [New Sci.] |
| Full Idea: Neutrinos are the only particles that seem just to spin anticlockwise. | |
| From: New Scientist writers (Why the Universe Exists [2017], 06) | |
| A reaction: See 21166. Anti-neutrino spin is the opposite way. Which way up do you hold the neutrino when pronouncing that it is 'anticlockwise? |
| 21166 | Standard antineutrinos have opposite spin and opposite lepton number [New Sci.] |
| Full Idea: In the conventional standard model neutrinos have antiparticles - which spin in the opposite direction, and have the opposite lepton number. | |
| From: New Scientist writers (Why the Universe Exists [2017], 05) |
| 21171 | The symmetry of unified electromagnetic and weak forces was broken by the Higgs field [New Sci.] |
| Full Idea: In the very early hot universe the electromagnetic and weak nuclear forces were one. The early emergence of the Higgs field led to electroweak symmetry breaking. The W and Z bosons grew fat, and the photon raced away mass-free. | |
| From: New Scientist writers (Why the Universe Exists [2017], 07) |
| 19954 | It is impossible for find a model of actuality among the innumerable models in string theory [New Sci.] |
| Full Idea: String theory has more than 10-to-the-500th solutions, each describing a different sort of universe, so it is nigh-on impossible to find the one solution that corresponds to our geometrically flat, expanding space-time full of particles. | |
| From: New Scientist writers (New Scientist articles [2013], 2015.11.07) |
| 21178 | String theory is now part of 11-dimensional M-Theory, involving p-branes [New Sci.] |
| Full Idea: String theory has now been incorporated into Ed Witten's M-Theory, which is a mathematical framework that lives in 11-dimensional space-time, involving higher-dimensional objects called p-branes, of which strings are a special case. | |
| From: New Scientist writers (Why the Universe Exists [2017], 09) |
| 21175 | String theory might be tested by colliding strings to make bigger 'stringballs' [New Sci.] |
| Full Idea: A future accelerator might create 'stringballs', when two strings slam into one another and, rather than combining to form a stretched string, make a tangled ball. Finding them would prove string theory. | |
| From: New Scientist writers (Why the Universe Exists [2017], 08) | |
| A reaction: This is the only possible test for string theory which I have seen suggested. How do you 'slam strings together'? |
| 21177 | String theory offers a quantum theory of gravity, by describing the graviton [New Sci.] |
| Full Idea: String theory works as a quantum theory of gravity because string vibrations can describe gravitons, the hypothetical carriers of the gravitational force. | |
| From: New Scientist writers (Why the Universe Exists [2017], 09) | |
| A reaction: Presumably the main aim of a quantum theory of gravity is to include gravitons within particle theory. This idea has to be a main attraction of string theory. Compare Idea 21166. |
| 19953 | In string theory space-time has a grainy indivisible substructure [New Sci.] |
| Full Idea: String theory suggests that space-time has a grainy substructure - you can't keep chopping it indefinitely into smaller and smaller pieces. | |
| From: New Scientist writers (New Scientist articles [2013], 2015.11.07) | |
| A reaction: Presumably the proposal is that strings are the true 'atoms'. |
| 19476 | String theory needs at least 10 space-time dimensions [New Sci.] |
| Full Idea: String theory needs at least 10 space-time dimensions to be mathematically consistent. | |
| From: New Scientist writers (New Scientist articles [2013], 2013.06.15) | |
| A reaction: Apparently because of 'Ads/CFT', it may be possible to swap this situation for a more tractable 4-dimensional version. |
| 21179 | Supersymmetric string theory can be expressed using loop quantum gravity [New Sci.] |
| Full Idea: String theory, together with its supersymmetric particles, has recently been rewritten in the space-time described by loop quantum gravity (which says that space-time ust be made from finite chunks). | |
| From: New Scientist writers (Why the Universe Exists [2017], 09) |
| 21159 | Supersymmetry has extra heavy bosons and heavy fermions [New Sci.] |
| Full Idea: Supersymmetry posits heavy boson partners for all fermions, and heavy fermions for all bosons. | |
| From: New Scientist writers (Why the Universe Exists [2017], 02) | |
| A reaction: The main Fermions are electron, proton and quark. Do extra bosons imply extra forces? Peter Higgs favours supersymmetry. |
| 21162 | Only supersymmetry offers to incorporate gravity into the scheme [New Sci.] |
| Full Idea: Peter Higgs says he is a fan of supersymmetry, largely because it seems to be the only route by which gravity can be brought into the scheme. | |
| From: New Scientist writers (Why the Universe Exists [2017], 03) | |
| A reaction: Peter Higgs proposed the Higgs boson (now discovered). This seems a very good reason to favour supersymmetry. A grand unified theory that left out gravity doesn't seem to be unified quite grandly enough. |
| 21173 | Supersymmetry says particles and superpartners were unities, but then split [New Sci.] |
| Full Idea: The key to supersymmetry is that in the high-energy soup of the early universe, particles and their superpartners were indistinguishable. Each pair existed as single massless entities. With expansion and cooling this supersymmetry broke down. | |
| From: New Scientist writers (Why the Universe Exists [2017], 08) |
| 21172 | The evidence for supersymmetry keeps failing to appear [New Sci.] |
| Full Idea: The old front-runner theory, supersymmetry, has fallen from grace as the Large Hadron Collider keeps failing to find it. | |
| From: New Scientist writers (Why the Universe Exists [2017], 07) |
| 19947 | Hilbert Space is an abstraction representing all possible states of a quantum system [New Sci.] |
| Full Idea: The elements of the abstract mathematical entity called Hilbert Space represent all the possible states of a quantum system | |
| From: New Scientist writers (New Scientist articles [2013], 1017.02.04) |
| 21160 | The Higgs field means even low energy space is not empty [New Sci.] |
| Full Idea: The point about the Higgs field is that even the lowest-energy state of space is not empty. | |
| From: New Scientist writers (Why the Universe Exists [2017], 02) | |
| A reaction: So where is the Higgs field located? Even if there is no utterly empty space, the concept of location implies a concept of space more basic than the fields (about 16, I gather) which occupy it. You can't describe movement without a concept of location. |
| 19948 | Einstein's merging of time with space has left us confused about the nature of time [New Sci.] |
| Full Idea: Our hunt for the most basic ingredients of reality has left us muddled about the status of time. One culprit for this was Einstein, whose theory of general relativity merged time with space. | |
| From: New Scientist writers (New Scientist articles [2013], 2017.02.04) |
| 19475 | Relativity makes time and space jointly basic; quantum theory splits them, and prioritises time [New Sci.] |
| Full Idea: Relativity says space and time are on the same footing - together they are the fabric of reality. Quantum mechanics, on the other hand, treats time and space differently, with time occasionally seeming more fundamental. | |
| From: New Scientist writers (New Scientist articles [2013], 2013.06.15) | |
| A reaction: Interesting. When talking about time, people glibly cite relativistic space-time to tell you that time is just another dimension. Now I can reply 'Aaah, but what about time in quantum mechanics? Eh? Eh?'. Excellent. |
| 19955 | Space-time may be a geometrical manifestation of quantum entanglement [New Sci.] |
| Full Idea: A promising theory (based on the 'Maldacena duality' - that string equations for gravity are the same as quantum equations for surface area) is that space-time is really just geometrical manifestations of quantum entanglement. | |
| From: New Scientist writers (New Scientist articles [2013], 2015.11.07) | |
| A reaction: This is a speculation which might unite the incompatible quantum and general relativity theories. |
| 19949 | Quantum theory relies on a clock outside the system - but where is it located? [New Sci.] |
| Full Idea: After general relativity, quantum mechanics reinstated our familiar notion of time. The buzzing of the quantum world plays out according to the authoritative tick of a clock outside the described system, ...but where is this clock doing its ticking? | |
| From: New Scientist writers (New Scientist articles [2013], 2017.02.04) |
| 19951 | Entropy is puzzling, so we may need to build new laws which include time directionality [New Sci.] |
| Full Idea: Smolin observes that if entropy increases, the early universe must have been highly ordered, which we cannot explain. Maybe we need to build time directionality into the laws, instead of making time depend on entropy. | |
| From: New Scientist writers (New Scientist articles [2013], 2017.02.04) | |
| A reaction: [compressed] |
| 16581 | Scholastic authors agree that matter was created by God, out of nothing [Pasnau] |
| Full Idea: Authors from 1274 to 1671 unanimously endorse the Christian doctrine that matter was created by God, before which time there was no material world at all. | |
| From: Robert Pasnau (Metaphysical Themes 1274-1671 [2011], 02.5) |
| 19477 | General relativity predicts black holes, as former massive stars, and as galaxy centres [New Sci.] |
| Full Idea: Black holes are predicted by general relativity, and are thought to exist where massive stars once lived, as well as at the heart of every galaxy. | |
| From: New Scientist writers (New Scientist articles [2013], 2013.06.15) | |
| A reaction: Since black holes now seem to be a certainty, that is one hell of an impressive prediction. |
| 19952 | Black holes have entropy, but general relativity says they are unstructured, and lack entropy [New Sci.] |
| Full Idea: Black holes have a temperature, and hence entropy. ...But if a black hole are just an extreme scrunching of smooth space-time, it should have no substructure, and thus no entropy. This is probably the most obvious incompleteness of general relativity. | |
| From: New Scientist writers (New Scientist articles [2013], 2015.11.07) |
| 16420 | 84.5 percent of the universe is made of dark matter [New Sci.] |
| Full Idea: Dark matter makes up 84.5 percent of the universe's matter. | |
| From: New Scientist writers (New Scientist articles [2013], 2013.10.29) |
| 21174 | Dark matter must have mass, to produce gravity, and no electric charge, to not reflect light [New Sci.] |
| Full Idea: Whatever dark matter is made of, it must have mass to feel and generate gravity; but no electric charge, so it does not interact with light. The leading candidate has been the weakly interacting massive particle (WIMP), much heavier than a proton. | |
| From: New Scientist writers (Why the Universe Exists [2017], 08) | |
| A reaction: Note that it must 'generate' gravity. The idea of a law of gravity which is externally imposed on matter is long dead. Heavy WIMPs have not yet been detected. |
| 17604 | We are halfway to synthesising any molecule we want [New Sci.] |
| Full Idea: Ei-ichi Negishi (Nobel chemist of 2010) says 'the ultimate goal is to be able to synthesise any molecule we want. We are probably about halfway there'. | |
| From: New Scientist writers (New Scientist articles [2013], 2010.10.16) |
| 17603 | Chemistry just needs the periodic table, and protons, electrons and neutrinos [New Sci.] |
| Full Idea: Ei-ichi Negishi (Nobel chemist of 2010) says 'I work with the periodic table in front of me at all times, and approach all challenges in terms of three particles, positively charged protons, negatively charged electrons, and neutral neutrinos'. | |
| From: New Scientist writers (New Scientist articles [2013], 2010.10.16) |
| 16642 | Transubstantion says accidents of bread and wine don't inhere in the substance [Pasnau] |
| Full Idea: Transubstantiation maintains that the accidents of the bread and wine endure after consecration without inhering in the substance. | |
| From: Robert Pasnau (Metaphysical Themes 1274-1671 [2011], 10.3) | |
| A reaction: It's a big puzzle to outsiders why softness and nice taste should have theological significance. If it is the body and blood of Christ, presumably a miracle has occurred, so normal theories don't apply. It is the key difficulty for scholastic metaphysics. |
| 1513 | The Egyptians were the first to say the soul is immortal and reincarnated [Herodotus] |
| Full Idea: The Egyptians were the first to claim that the soul of a human being is immortal, and that each time the body dies the soul enters another creature just as it is being born. | |
| From: Herodotus (The Histories [c.435 BCE], 2.123.2) |