47 ideas
13838 | A decent modern definition should always imply a semantics [Hacking] |
13833 | 'Thinning' ('dilution') is the key difference between deduction (which allows it) and induction [Hacking] |
13834 | Gentzen's Cut Rule (or transitivity of deduction) is 'If A |- B and B |- C, then A |- C' [Hacking] |
13835 | Only Cut reduces complexity, so logic is constructive without it, and it can be dispensed with [Hacking] |
13845 | The various logics are abstractions made from terms like 'if...then' in English [Hacking] |
13840 | First-order logic is the strongest complete compact theory with Löwenheim-Skolem [Hacking] |
13844 | A limitation of first-order logic is that it cannot handle branching quantifiers [Hacking] |
13842 | Second-order completeness seems to need intensional entities and possible worlds [Hacking] |
13837 | With a pure notion of truth and consequence, the meanings of connectives are fixed syntactically [Hacking] |
13839 | Perhaps variables could be dispensed with, by arrows joining places in the scope of quantifiers [Hacking] |
13843 | If it is a logic, the Löwenheim-Skolem theorem holds for it [Hacking] |
17405 | If a theory can be fudged, so can observations [Scerri] |
17397 | The periodic system is the big counterexample to Kuhn's theory of revolutionary science [Scerri] |
17393 | Scientists eventually seek underlying explanations for every pattern [Scerri] |
17403 | The periodic table suggests accommodation to facts rates above prediction [Scerri] |
7357 | People who control others with fluent language often end up being hated [Kongzi (Confucius)] |
7358 | All men prefer outward appearance to true excellence [Kongzi (Confucius)] |
7362 | Humans are similar, but social conventions drive us apart (sages and idiots being the exceptions) [Kongzi (Confucius)] |
7360 | Do not do to others what you would not desire yourself [Kongzi (Confucius)] |
7359 | Excess and deficiency are equally at fault [Kongzi (Confucius)] |
7363 | The virtues of the best people are humility, maganimity, sincerity, diligence, and graciousness [Kongzi (Confucius)] |
7361 | Men of the highest calibre avoid political life completely [Kongzi (Confucius)] |
23393 | Confucianism assumes that all good developments have happened, and there is only one Way [Norden on Kongzi (Confucius)] |
17394 | Natural kinds are what are differentiated by nature, and not just by us [Scerri] |
17421 | If elements are natural kinds, might the groups of the periodic table also be natural kinds? [Scerri] |
17396 | The colour of gold is best explained by relativistic effects due to fast-moving inner-shell electrons [Scerri] |
17420 | The stability of nuclei can be estimated through their binding energy [Scerri] |
17411 | If all elements are multiples of one (of hydrogen), that suggests once again that matter is unified [Scerri] |
17407 | The electron is the main source of chemical properties [Scerri] |
17415 | A big chemistry idea is that covalent bonds are shared electrons, not transfer of electrons [Scerri] |
17409 | Does radioactivity show that only physics can explain chemistry? [Scerri] |
17392 | How can poisonous elements survive in the nutritious compound they compose? [Scerri] |
17391 | Periodicity and bonding are the two big ideas in chemistry [Scerri] |
17404 | Chemistry does not work from general principles, but by careful induction from large amounts of data [Scerri] |
17418 | It is now thought that all the elements have literally evolved from hydrogen [Scerri] |
17398 | 19th C views said elements survived abstractly in compounds, but also as 'material ingredients' [Scerri] |
17406 | Moseley, using X-rays, showed that atomic number ordered better than atomic weight [Scerri] |
17408 | Some suggested basing the new periodic table on isotopes, not elements [Scerri] |
17412 | Elements are placed in the table by the number of positive charges - the atomic number [Scerri] |
17413 | Elements in the table are grouped by having the same number of outer-shell electrons [Scerri] |
17416 | Orthodoxy says the periodic table is explained by quantum mechanics [Scerri] |
17414 | Pauli explained the electron shells, but not the lengths of the periods in the table [Scerri] |
17395 | Elements were ordered by equivalent weight; later by atomic weight; finally by atomic number [Scerri] |
17422 | The best classification needs the deepest and most general principles of the atoms [Scerri] |
17417 | To explain the table, quantum mechanics still needs to explain order of shell filling [Scerri] |
17419 | Since 99.96% of the universe is hydrogen and helium, the periodic table hardly matters [Scerri] |
17410 | Moseley showed the elements progress in units, and thereby clearly identified the gaps [Scerri] |