96 ideas
17713 | After 1903, Husserl avoids metaphysical commitments [Mares] |
18781 | Inconsistency doesn't prevent us reasoning about some system [Mares] |
18789 | Intuitionist logic looks best as natural deduction [Mares] |
18790 | Intuitionism as natural deduction has no rule for negation [Mares] |
18787 | Three-valued logic is useful for a theory of presupposition [Mares] |
18793 | Material implication (and classical logic) considers nothing but truth values for implications [Mares] |
18784 | In classical logic the connectives can be related elegantly, as in De Morgan's laws [Mares] |
18780 | Standard disjunction and negation force us to accept the principle of bivalence [Mares] |
18786 | Excluded middle standardly implies bivalence; attacks use non-contradiction, De M 3, or double negation [Mares] |
18782 | The connectives are studied either through model theory or through proof theory [Mares] |
18783 | Many-valued logics lack a natural deduction system [Mares] |
18792 | Situation semantics for logics: not possible worlds, but information in situations [Mares] |
18785 | Consistency is semantic, but non-contradiction is syntactic [Mares] |
17715 | The truth of the axioms doesn't matter for pure mathematics, but it does for applied [Mares] |
17716 | Mathematics is relations between properties we abstract from experience [Mares] |
18788 | For intuitionists there are not numbers and sets, but processes of counting and collecting [Mares] |
19482 | Current physics says matter and antimatter should have reduced to light at the big bang [New Sci.] |
19483 | CP violation shows a decay imbalance in matter and antimatter, leading to matter's dominance [New Sci.] |
17703 | Light in straight lines is contingent a priori; stipulated as straight, because they happen to be so [Mares] |
17714 | Aristotelians dislike the idea of a priori judgements from pure reason [Mares] |
17705 | Empiricists say rationalists mistake imaginative powers for modal insights [Mares] |
17700 | The most popular view is that coherent beliefs explain one another [Mares] |
19737 | A system can infer the structure of the world by making predictions about it [New Sci.] |
17704 | Operationalism defines concepts by our ways of measuring them [Mares] |
19736 | Neural networks can extract the car-ness of a car, or the chair-ness of a chair [New Sci.] |
16419 | No one has yet devised a rationality test [New Sci.] |
16418 | People can be highly intelligent, yet very stupid [New Sci.] |
16417 | About a third of variation in human intelligence is environmental [New Sci.] |
19484 | Psychologists measure personality along five dimensions [New Sci.] |
17710 | Aristotelian justification uses concepts abstracted from experience [Mares] |
17706 | The essence of a concept is either its definition or its conceptual relations? [Mares] |
18791 | In 'situation semantics' our main concepts are abstracted from situations [Mares] |
17701 | Possible worlds semantics has a nice compositional account of modal statements [Mares] |
17702 | Unstructured propositions are sets of possible worlds; structured ones have components [Mares] |
5845 | Niceratus learnt the whole of Homer by heart, as a guide to goodness [Xenophon] |
5833 | Education is the greatest of human goods [Xenophon] |
21167 | Gravity is unusual, in that it always attracts and never repels [New Sci.] |
19950 | Entropy is the only time-asymmetric law, so time may be linked to entropy [New Sci.] |
21176 | In the Big Bang general relativity fails, because gravity is too powerful [New Sci.] |
21147 | Quantum electrodynamics incorporates special relativity and quantum mechanics [New Sci.] |
19478 | Light moves at a constant space-time speed, but its direction is in neither space nor time [New Sci.] |
21155 | Photons have zero rest mass, so virtual photons have infinite range [New Sci.] |
21161 | In the standard model all the fundamental force fields merge at extremely high energies [New Sci.] |
21146 | Electrons move fast, so are subject to special relativity [New Sci.] |
19474 | Quantum states are measured by external time, of unknown origin [New Sci.] |
19473 | The Schrödinger equation describes the evolution of an object's wave function in Hilbert space [New Sci.] |
21148 | The strong force is repulsive at short distances, strong at medium, and fades at long [New Sci.] |
21152 | The strong force binds quarks tight, and the nucleus more weakly [New Sci.] |
21151 | Gluons, the particles carrying the strong force, interact because of their colour charge [New Sci.] |
21150 | Three different colours of quark (as in the proton) can cancel out to give no colour [New Sci.] |
21143 | Quarks in threes can build hadrons with spin ½ or with spin 3/2 [New Sci.] |
21142 | Classifying hadrons revealed two symmetry patterns, produced by three basic elements [New Sci.] |
21145 | The four fundamental forces (gravity, electromagnetism, weak and strong) are the effects of particles [New Sci.] |
21153 | The weak force explains beta decay, and the change of type by quarks and leptons [New Sci.] |
21156 | The weak force particles are heavy, so the force has a short range [New Sci.] |
21164 | Why do the charges of the very different proton and electron perfectly match up? [New Sci.] |
21170 | The Standard Model cannot explain dark energy, survival of matter, gravity, or force strength [New Sci.] |
21154 | Three particles enable the weak force: W+ and W- are charged, and Z° is not [New Sci.] |
21140 | Spin is a built-in ration of angular momentum [New Sci.] |
21158 | Fermions, with spin ½, are antisocial, and cannot share quantum states [New Sci.] |
21165 | Spin is akin to rotation, and is easily measured in a magnetic field [New Sci.] |
21149 | Quarks have red, green or blue colour charge (akin to electric charge) [New Sci.] |
21157 | Particles are spread out, with wave-like properties, and higher energy shortens the wavelength [New Sci.] |
21163 | The mass of protons and neutrinos is mostly binding energy, not the quarks [New Sci.] |
21168 | Gravitional mass turns out to be the same as inertial mass [New Sci.] |
21144 | Top, bottom, charm and strange quarks quickly decay into up and down [New Sci.] |
21138 | Neutrons are slightly heavier than protons, and decay into them by emitting an electron [New Sci.] |
21141 | Neutrinos were proposed as the missing energy in neutron beta decay [New Sci.] |
21169 | Only neutrinos spin anticlockwise [New Sci.] |
21166 | Standard antineutrinos have opposite spin and opposite lepton number [New Sci.] |
21171 | The symmetry of unified electromagnetic and weak forces was broken by the Higgs field [New Sci.] |
19953 | In string theory space-time has a grainy indivisible substructure [New Sci.] |
19954 | It is impossible for find a model of actuality among the innumerable models in string theory [New Sci.] |
19476 | String theory needs at least 10 space-time dimensions [New Sci.] |
21175 | String theory might be tested by colliding strings to make bigger 'stringballs' [New Sci.] |
21177 | String theory offers a quantum theory of gravity, by describing the graviton [New Sci.] |
21178 | String theory is now part of 11-dimensional M-Theory, involving p-branes [New Sci.] |
21179 | Supersymmetric string theory can be expressed using loop quantum gravity [New Sci.] |
21159 | Supersymmetry has extra heavy bosons and heavy fermions [New Sci.] |
21162 | Only supersymmetry offers to incorporate gravity into the scheme [New Sci.] |
21172 | The evidence for supersymmetry keeps failing to appear [New Sci.] |
21173 | Supersymmetry says particles and superpartners were unities, but then split [New Sci.] |
19947 | Hilbert Space is an abstraction representing all possible states of a quantum system [New Sci.] |
17708 | Maybe space has points, but processes always need regions with a size [Mares] |
21160 | The Higgs field means even low energy space is not empty [New Sci.] |
19955 | Space-time may be a geometrical manifestation of quantum entanglement [New Sci.] |
19948 | Einstein's merging of time with space has left us confused about the nature of time [New Sci.] |
19475 | Relativity makes time and space jointly basic; quantum theory splits them, and prioritises time [New Sci.] |
19949 | Quantum theory relies on a clock outside the system - but where is it located? [New Sci.] |
19951 | Entropy is puzzling, so we may need to build new laws which include time directionality [New Sci.] |
19477 | General relativity predicts black holes, as former massive stars, and as galaxy centres [New Sci.] |
19952 | Black holes have entropy, but general relativity says they are unstructured, and lack entropy [New Sci.] |
21174 | Dark matter must have mass, to produce gravity, and no electric charge, to not reflect light [New Sci.] |
16420 | 84.5 percent of the universe is made of dark matter [New Sci.] |
17604 | We are halfway to synthesising any molecule we want [New Sci.] |
17603 | Chemistry just needs the periodic table, and protons, electrons and neutrinos [New Sci.] |