116 ideas
13310 | Wisdom does not lie in books, and unread people can also become wise [Seneca] |
Full Idea: What grounds could I possibly have for supposing that a person who has no acquaintance with books will never be a wise man? For wisdom does not lie in books. | |
From: Seneca the Younger (Letters from a Stoic [c.60], 088) | |
A reaction: A useful warning to the likes of me, who may have retreated from the hurly-burly of the agora (see Callicles in Plato's 'Gorgias'), under the illusion that detachment is needed for wisdom. Maybe involvement is needed for wisdom. |
13560 | A wise man is not subservient to anything [Seneca] |
Full Idea: I do not call any man wise who is subservient to anything. | |
From: Seneca the Younger (On the Happy Life [c.60], §11) | |
A reaction: At the very least, a wise man should be subservient to a wiser man. |
13295 | Wise people escape necessity by willing it [Seneca] |
Full Idea: There is nothing a wise man does reluctantly; he escapes necessity because he wills what necessity is going to force on him. | |
From: Seneca the Younger (Letters from a Stoic [c.60], 054) | |
A reaction: He is discussing death in this letter. The difficulty here is sliding into fatalism. For instance, if you are informed that you have cancer, it is tempting to become 'wise' and will your own death, but lots of people fight it, and win. |
13317 | Philosophy aims at happiness [Seneca] |
Full Idea: Philosophy takes as her aim the state of happiness. | |
From: Seneca the Younger (Letters from a Stoic [c.60], 090) | |
A reaction: A startlingly forthright view. It seems to neglect what I take to be the main aim of philosophy, which is to achieve understanding. I presume true happiness would follow from that. Seneca must now explain why soporific pleasure is wrong. |
13293 | What philosophy offers humanity is guidance [Seneca] |
Full Idea: Shall I tell you what philosophy holds out for humanity? Counsel. | |
From: Seneca the Younger (Letters from a Stoic [c.60], 048) | |
A reaction: See Quine for a flat modern denial of this claim (Idea 9764). There is a modern tendency to see ethics and political thought operating at a meta- or metameta- level. I take the main ethical theories to be very illuminating of real life. |
13309 | That something is a necessary condition of something else doesn't mean it caused it [Seneca] |
Full Idea: There's no reason for you to assume that, X being something without which Y could never have come about, Y came about as a result of the assistance of X. | |
From: Seneca the Younger (Letters from a Stoic [c.60], 088) | |
A reaction: This thought originates with Carneades, reported by Cicero. This is a clear message to the likes of Mackie, who are in danger of thinking that giving the preconditions of something is sufficient to give its causes. |
13313 | Even philosophers have got bogged down in analysing tiny bits of language [Seneca] |
Full Idea: Even the philosophers have descended to the level of drawing distinctions between the uses of different syllables and discussing the proper meanings of prepositions and conjunctions. | |
From: Seneca the Younger (Letters from a Stoic [c.60], 088) | |
A reaction: How wonderfully prescient! The vast industry of modern philosophy of language exactly fits Seneca's description. I don't quite share his contempt, of course, and I think Seneca would have a bit of sympathy with modern analysis (just a bit!). |
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. |
3061 | Anaxarchus said that he was not even sure that he knew nothing [Anaxarchus, by Diog. Laertius] |
Full Idea: Anaxarchus said that he was not even sure that he knew nothing. | |
From: report of Anaxarchus (fragments/reports [c.340 BCE]) by Diogenes Laertius - Lives of Eminent Philosophers 09.10.1 |
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. |
13297 | To the four causes Plato adds a fifth, the idea which guided the event [Seneca] |
Full Idea: To the four Aristotelian causes Plato adds a fifth in the model - what he himself calls the 'idea' - this being what the sculptor had constantly before his eyes as he executed the intended work. | |
From: Seneca the Younger (Letters from a Stoic [c.60], 065) | |
A reaction: A very interesting interpretation. I take the four 'causes' to be primarily the four 'explanations', and it exactly fits how we should understand Plato, as offer a crucial underlying explanation. The statue is Aristotle's example. |
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. |
13307 | If everything can be measured, try measuring the size of a man's soul [Seneca] |
Full Idea: Nothing's outside your scope when it comes to measurement. Well, if you're such an expert, measure a man's soul; tell me how large or how small that is. | |
From: Seneca the Younger (Letters from a Stoic [c.60], 088) | |
A reaction: This is Descartes's non-spatial argument, which I take to be one of the four main props to his mind-body dualism. As always, it is expressed with beautiful concision by Seneca. |
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? |
21399 | Referring to a person, and speaking about him, are very different [Seneca] |
Full Idea: It makes a very great difference whether you refer to the person directly, or speak about him. | |
From: Seneca the Younger (Letters from a Stoic [c.60], 117.13), quoted by A.A. Long - Hellenistic Philosophy 4.3.2 | |
A reaction: We seem to think that the distinctiveness of reference was first spotted by Frege. Not so. |
13558 | The supreme good is harmony of spirit [Seneca] |
Full Idea: The highest good is harmony of spirit. | |
From: Seneca the Younger (On the Happy Life [c.60], §08) | |
A reaction: This idea is straight from Plato's Republic. |
13325 | Trouble in life comes from copying other people, which is following convention instead of reason [Seneca] |
Full Idea: One of the causes of the troubles that beset us is the way our lives are guided by the example of others; instead of being set to rights by reason we're seduced by convention. | |
From: Seneca the Younger (Letters from a Stoic [c.60], 123) | |
A reaction: An interesting practical spin and critique of the standard metaethical idea that morality is just convention. If you think morality is convention, presumably your moral duty is to imitate your neighbours. Nice deconstruction. |
22239 | Humans acquired the concept of virtue from an analogy with bodily health and strength [Seneca, by Allen] |
Full Idea: Seneca held that human beings owe the original acquisition of the concept of virtue to an analogy with bodily health and strength | |
From: report of Seneca the Younger (Letters from a Stoic [c.60], 120.5) by James Allen - Soul's Virtue and the Health of the Body p.76 | |
A reaction: This is an unusual view, even for a stoic, but shows how close the concepts of health and virtue were. Notice that it is strength as well as health. Plato just emphasises mental and physical harmony. |
13294 | We know death, which is like before birth; ceasing to be and never beginning are the same [Seneca] |
Full Idea: I already know what death is like - it will be the same after me as it was before me. ..Only an utter idiot would think a lamp was worse off when it was put out than before it was lit. ..What does it matter whether you cease to be or never begin? | |
From: Seneca the Younger (Letters from a Stoic [c.60], 054) | |
A reaction: These sentiments are, interestingly, derived from the epicureans, rather than from the stoic tradition, but to us they probably look close together, where they looked like opponents at the time. |
13299 | Living is nothing wonderful; what matters is to die well [Seneca] |
Full Idea: There's nothing so very great about living - all your slaves and all the animals do it. What is, however, a great thing is to die in a manner which is honourable, enlightened and courageous. | |
From: Seneca the Younger (Letters from a Stoic [c.60], 077) | |
A reaction: You get the feeling that Seneca actually thought suicide was better than a natural death. Did he actually seek his own death? It is an odd interpretation of his own stoic injunction to 'live according to nature'. |
13300 | It is as silly to lament ceasing to be as to lament not having lived in the remote past [Seneca] |
Full Idea: Wouldn't you think a man a prize fool if he burst into tears because he didn't live a thousand years ago? A man is such a fool for shedding tears because he isn't going to be alive a thousand years from now. | |
From: Seneca the Younger (Letters from a Stoic [c.60], 077) | |
A reaction: These thoughts are traditional, dating back to Epicurus, but Seneca is exceptionally going at finding new variations and examples to reinforce the basic thought. |
13321 | Is anything sweeter than valuing yourself more when you find you are loved? [Seneca] |
Full Idea: Can anything be sweeter than to find that you are so dear to your wife that this makes you dearer to yourself? | |
From: Seneca the Younger (Letters from a Stoic [c.60], 104) | |
A reaction: Another lovely penetrating remark from Seneca. I suppose a symptom of low self-esteem might be 'why does she love someone as worthless as me?', but that would be unusual. |
13292 | Selfishness does not produce happiness; to live for yourself, live for others [Seneca] |
Full Idea: No one can lead a happy life if he thinks only of himself and turns everything to his own purposes. You should live for the other person if you wish to live for yourself. | |
From: Seneca the Younger (Letters from a Stoic [c.60], 048) | |
A reaction: It is important to see this as a key aspect of the ancient aspiration to virtue. The end result is not far from Christianity. It is simplistic to see the quest for virtue as a crass self-obsessed quest for self-improvement. We are social. |
13550 | To be always happy is to lack knowledge of one half of nature [Seneca] |
Full Idea: To be always happy and to pass through life without any mental distress is to lack knowledge of one half of nature. | |
From: Seneca the Younger (On Providence [c.60], §4) | |
A reaction: These kind of paradoxes plague virtue theory, and any theory which aims at an ideal. Heaven, for example, seems to have no problems to solve, which spells boredom. The fascination of corrupt people is their superior knowledge of the world. |
13303 | A man is as unhappy as he has convinced himself he is [Seneca] |
Full Idea: A man is as unhappy as he has convinced himself he is. | |
From: Seneca the Younger (Letters from a Stoic [c.60], 078) | |
A reaction: Seneca is a very penetrating thinker about ordinary life - an aspect of philosophy which is nowadays totally neglected by the most eminent philosophers. |
13302 | Life is like a play - it is the quality that matters, not the length [Seneca] |
Full Idea: As it is with a play, so it is with life - what matters is not how long the acting lasts, but how good it is. | |
From: Seneca the Younger (Letters from a Stoic [c.60], 077) | |
A reaction: A very nice epigram, culminating the wonderful Letter 77 on the subject of death. A play needs to be a decent length if it is to exhibit its qualities. It would be heartbreaking if all of Shakespeare's plays were just 20-minute sketches. |
13301 | We are scared of death - except when we are immersed in pleasure! [Seneca] |
Full Idea: You are scared of death - but how heedless of it you are while you are dealing with a dish of choice mushrooms! | |
From: Seneca the Younger (Letters from a Stoic [c.60], 077) | |
A reaction: A beautifully simple observation, from the greatest philosopher of death. Maybe hospices should concentrate on sex, drugs and rock and roll. |
13323 | The whole point of pleasure-seeking is novelty, and abandoning established ways [Seneca] |
Full Idea: The whole object of luxurious living is the delight it takes in irregular ways and in not merely departing from the correct course but going to the farthest point away from it, and in eventually even taking a stand diametrically opposed to it. | |
From: Seneca the Younger (Letters from a Stoic [c.60], 122) | |
A reaction: A rather conservative and puritanical remark, but worthy of contemplation even for committed hedonists. It is just a sad facts that most pleasures diminish with familiarity. Small children make delightful remarks. Imagine if they repeated them. |
13318 | Nature doesn't give us virtue; we must unremittingly pursue it, as a training and an art [Seneca] |
Full Idea: Nature does not give a man virtue; the process of becoming a good man is an art. ...Virtue only comes to a character which has been thoroughly schooled and trained and brought to a pitch of perfection by unremitting practice. | |
From: Seneca the Younger (Letters from a Stoic [c.60], 090) | |
A reaction: This is an important gloss from a leading stoic on the slogan of 'live according to nature'. One might say that the natural life must be 'tracked' (as Philip Larkin says we track happiness). The natural life is, above all, the rational life, for stoics. |
13324 | Living contrary to nature is like rowing against the stream [Seneca] |
Full Idea: For those who follow nature everything is easy and straightforward, whereas for those who fight against her life is just like rowing against the stream. | |
From: Seneca the Younger (Letters from a Stoic [c.60], 102) | |
A reaction: A classic statement of the well-known stoic slogan, but expressed with Seneca's characteristic elegance. There is always a slight hidden of dubious fatalism in the slogan. 'Rage, rage, against the dying of the light!' - Dylan Thomas. |
13559 | I seek virtue, because it is its own reward [Seneca] |
Full Idea: You ask what I seek from virtue? Virtue herself. For she has nothing better, she is herself her own reward. | |
From: Seneca the Younger (On the Happy Life [c.60], §09) | |
A reaction: Presumably this is the source of the popular saying that 'virtue is its own reward'. The trouble is that this doesn't seem a very persuasive thing to say to a sceptic who doubts whether being virtuous is worth the trouble. |
13554 | True greatness is never allowing events to disturb you [Seneca] |
Full Idea: There is no more reliable proof of greatness than to be in a state where nothing can happen to make you disturbed. | |
From: Seneca the Younger (On Anger (Book 3) [c.60], §06) | |
A reaction: He specifically opposes Aristotle's view that there are times when anger is appropriate, and failure to be very angry indeed is a failure of character. |
13305 | Character is ruined by not looking back over our pasts, since the future rests on the past [Seneca] |
Full Idea: What really ruins our characters is the fact that none of us looks back over his life. We think a little about what we are going to do, and fail to think about what we have done, yet plans for the future depend on the past. | |
From: Seneca the Younger (Letters from a Stoic [c.60], 083) | |
A reaction: One always assumes that writings about the wisdom of daily life will be one mass of clichés, but Seneca proves otherwise. With a pang I realise that I may be too guilty of not thinking about the past. I've even been proud of it. |
13561 | Virtue is always moderate, so excess need not be feared [Seneca] |
Full Idea: In the case of virtue excess should not be feared, since in virtue resides moderation. | |
From: Seneca the Younger (On the Happy Life [c.60], §13) | |
A reaction: This seems to imply that all of the virtues are unified in the one achievement of the virtuous state. It leaves the notion of 'virtue' a bit thin in content, though. |
13556 | Every night I critically review how I have behaved during the day [Seneca] |
Full Idea: When the lamp has been removed from my sight, and my wife, no stranger now to my habit, has fallen silent, I examine the whole of my day and retrace my actions and words; I hide nothing from myself. | |
From: Seneca the Younger (On Anger (Book 3) [c.60], §36) |
13562 | It is shameful to not even recognise your own slaves [Seneca] |
Full Idea: Why, to your shame, are you so careless that you do not know your handful of slaves by sight? | |
From: Seneca the Younger (On the Happy Life [c.60], §17) |
13552 | Anger is an extreme vice, threatening sanity, and gripping whole states [Seneca] |
Full Idea: Other vices drive the mind on, anger hurls it headlong; ..other vices revolt from good sense, this one from sanity; ...other vices seize individuals, this is the one passion that sometimes takes hold of an entire state. | |
From: Seneca the Younger (On Anger (Book 3) [c.60], §01) | |
A reaction: He particularly dislikes anger because it is the vice that leads to violence. |
13553 | Anger is a vice which afflicts good men as well as bad [Seneca] |
Full Idea: Other vile passions affect only the worst sort of men, but anger creeps up even on enlightened me who are otherwise sane. | |
From: Seneca the Younger (On Anger (Book 3) [c.60], §04) | |
A reaction: A very interesting observation for anyone who is trying to analyse the key issues in virtue theory. |
13312 | Excessive curiosity is a form of intemperance [Seneca] |
Full Idea: To want to know more than is sufficient is a form of intemperance. | |
From: Seneca the Younger (Letters from a Stoic [c.60], 088) | |
A reaction: This comes as a bit of a surprise, given the high value that philosophers place on knowledge. I'm reminded of Auberon Waugh's criticism of the Scots as a 'wildly over-educated people'. I think the problem is what you could have been doing instead. |
13308 | It's no good winning lots of fights, if you are then conquered by your own temper [Seneca] |
Full Idea: What's the use of overcoming opponent after opponent in the wrestling or boxing rings if you can be overcome by your temper? | |
From: Seneca the Younger (Letters from a Stoic [c.60], 088) | |
A reaction: He has such a nice way of presenting what might be traditional and commonplace ideas. If you see life as a battle, then you should think very carefully about who the opponents are - because they may be hiding within. |
13549 | Nothing bad can happen to a good man [Seneca] |
Full Idea: Nothing bad can happen to a good man. | |
From: Seneca the Younger (On Providence [c.60], §2) | |
A reaction: This is a pithy summary of a well know ancient attitude - one that is rejected by Aristotle, but defended by Socrates. It depends what you mean by 'bad' - but that is a rather modern response. |
13563 | Why does your wife wear in her ears the income of a wealthy house? [Seneca] |
Full Idea: Why does your wife wear in her ears the income of a wealthy house? | |
From: Seneca the Younger (On the Happy Life [c.60], §17) |
13565 | If wealth was a good, it would make men good [Seneca] |
Full Idea: Wealth is not a good; for it it was, it would make men good. | |
From: Seneca the Younger (On the Happy Life [c.60], §24) | |
A reaction: An immediately attractive argument, but should we assume that anything which is good will enhance our personal goodness? If goodness is a habit, then continual pursuit of wealth is the test case to examine. Seneca is right! |
13564 | There is far more scope for virtue if you are wealthy; poverty only allows endurance [Seneca] |
Full Idea: What doubt can there be that the wise man has greater scope for displaying his powers if he is rich than if he is poor, since in the case of poverty only one kind of virtue exists - refusal to be bowed down and crushed. | |
From: Seneca the Younger (On the Happy Life [c.60], §22) | |
A reaction: It is against this view that I see Jesus proposing poverty as central to virtue. But then he has the surprising view (to Seneca) that humility is a virtue. What Nietzsche calls the slaves' inversion of values. |
13315 | To govern used to mean to serve, not to rule; rulers did not test their powers over those who bestowed it [Seneca] |
Full Idea: In the Golden Age, to govern was to serve, not to rule. No one used to try out the extent of his power over those to whom he owed that power in the first place. | |
From: Seneca the Younger (Letters from a Stoic [c.60], 090) | |
A reaction: I spent my professional career trying to persuade people that management should be a subjection to the managed. Wake up! The second half of this idea is the interesting bit - the temptation to just 'try out' your powers gets to them all. |
13557 | Unfortunately the majority do not tend to favour what is best [Seneca] |
Full Idea: Human concerns are not so happily arranged that the majority favours the better things. | |
From: Seneca the Younger (On the Happy Life [c.60], §02) | |
A reaction: On the whole Seneca is unimpressed by democracy, as people are rushed into decisions by the crowd, and live to regret them. |
13290 | One joy of learning is making teaching possible [Seneca] |
Full Idea: Part of my joy in learning is that it puts me in a position to teach. | |
From: Seneca the Younger (Letters from a Stoic [c.60], 006) | |
A reaction: This doesn't quite distinguish between bad learning and good learning, but I take a commitment to wanting to teach what you know as an essential part of wanting to know. |
13322 | Both teachers and pupils should aim at one thing - the improvement of the pupil [Seneca] |
Full Idea: A person teaching and a person learning should have the same end in view: the improvement of the latter. | |
From: Seneca the Younger (Letters from a Stoic [c.60], 108) | |
A reaction: [He cites a philospher called Attalus for this remark] This is worthy to be up in the hall of every educational institution in the world, and especially in the staff rooms. |
13298 | Suicide may be appropriate even when it is not urgent, if there are few reasons against it [Seneca] |
Full Idea: There are many occasions on which a man should leave life not only bravely but for reasons which are not as pressing as they might be - the reasons which restrain us being not so pressing either. | |
From: Seneca the Younger (Letters from a Stoic [c.60], 077) | |
A reaction: This is an interesting and startling claim from the great champion of suicide, who nobly and memorably committed suicide himself. But we all dread a loved one miscalculating Seneca's dialectic, and dying when living would have been better. |
13320 | Sometimes we have a duty not to commit suicide, for those we love [Seneca] |
Full Idea: There are times when, however pressing one's reasons to the contrary, one's dying breath must be held back as it is passing one's lips, even if this is torture, simply out of consideration for one's dear ones. | |
From: Seneca the Younger (Letters from a Stoic [c.60], 104) | |
A reaction: This is, of course, a highly significant counterbalance to his normal acceptance of suicide. I wish anyone who is planning suicide would heed it. They have no idea how much suffering will usually result from their action. |
13319 | If we control our own death, no one has power over us [Seneca] |
Full Idea: No one has power over us when death is in our own power. | |
From: Seneca the Younger (Letters from a Stoic [c.60], 091) | |
A reaction: A classic slogan for the stoic view of suicide, an idea that crops up in Shakespeare's 'Julius Caesar'. He doesn't seem to have understood that they can take away your shoelaces. |
13548 | The ocean changes in volume in proportion to the attraction of the moon [Seneca] |
Full Idea: The waves increase by degrees, approaching to the hour and day proportionately larger or smaller in volume as they are attracted by the star we call the moon, whose power controls the ocean's surge. | |
From: Seneca the Younger (On Providence [c.60], §1) | |
A reaction: ....just in case anyone thought that Isaac Newton had invented gravity. |
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. |
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. |
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? |
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) |
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 ½ or with spin 3/2 [New Sci.] |
Full Idea: Quarks in threes can build hadrons with spin ½ (proton, duu; neutron, ddu; lambda, dus), or with spin 3/2 (omega-minus, sss). | |
From: New Scientist writers (Why the Universe Exists [2017], 01) |
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) |
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? |
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. |
21158 | Fermions, with spin ½, are antisocial, and cannot share quantum states [New Sci.] |
Full Idea: Particles with half-integer spin, such as electrons, protons or quarks (all spin ½) 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. |
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) |
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. |
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) |
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'. |
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. |
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. |
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) |
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) |
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) |
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. |
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) |
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) |
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. |
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. |
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. |
13311 | Does time exist on its own? Did anything precede it? Did it pre-exist the cosmos? [Seneca] |
Full Idea: Look how many questions there are on time. Does it have an existence of its own? Does anything exist prior to time, independently of it? Did it begin with the universe, or did it exist even before then? | |
From: Seneca the Younger (Letters from a Stoic [c.60], 088) | |
A reaction: I'm not sure that the questions have shifted or become any clearer after two thousand years, despite Einstein and co. Note that discussions of time were not initiated by Augustine. |
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] |
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) |