54 ideas
| 19066 | Philosophy aims to understand the world, through ordinary experience and science [Dummett] |
| 19067 | A successful proof requires recognition of truth at every step [Dummett] |
| 19060 | Truth-tables are dubious in some cases, and may be a bad way to explain connective meaning [Dummett] |
| 11066 | Deduction is justified by the semantics of its metalanguage [Dummett, by Hanna] |
| 19058 | Syntactic consequence is positive, for validity; semantic version is negative, with counterexamples [Dummett] |
| 19063 | Beth trees show semantics for intuitionistic logic, in terms of how truth has been established [Dummett] |
| 19059 | In standard views you could replace 'true' and 'false' with mere 0 and 1 [Dummett] |
| 19062 | Classical two-valued semantics implies that meaning is grasped through truth-conditions [Dummett] |
| 19065 | Soundness and completeness proofs test the theory of meaning, rather than the logic theory [Dummett] |
| 8840 | There are five possible responses to the problem of infinite regress in justification [Cleve] |
| 8841 | Modern foundationalists say basic beliefs are fallible, and coherence is relevant [Cleve] |
| 19061 | An explanation is often a deduction, but that may well beg the question [Dummett] |
| 19064 | Holism is not a theory of meaning; it is the denial that a theory of meaning is possible [Dummett] |
| 21167 | Gravity is unusual, in that it always attracts and never repels [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.] |
| 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.] |
| 21148 | The strong force is repulsive at short distances, strong at medium, and fades at long [New Sci.] |
| 21151 | Gluons, the particles carrying the strong force, interact because of their colour charge [New Sci.] |
| 21152 | The strong force binds quarks tight, and the nucleus more weakly [New Sci.] |
| 21143 | Quarks in threes can build hadrons with spin ½ or with spin 3/2 [New Sci.] |
| 21150 | Three different colours of quark (as in the proton) can cancel out to give no colour [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.] |
| 21154 | Three particles enable the weak force: W+ and W- are charged, and Z° is not [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.] |
| 21140 | Spin is a built-in ration of angular momentum [New Sci.] |
| 21149 | Quarks have red, green or blue colour charge (akin to electric charge) [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.] |
| 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.] |
| 21138 | Neutrons are slightly heavier than protons, and decay into them by emitting an electron [New Sci.] |
| 21144 | Top, bottom, charm and strange quarks quickly decay into up and down [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.] |
| 21178 | String theory is now part of 11-dimensional M-Theory, involving p-branes [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.] |
| 21179 | Supersymmetric string theory can be expressed using loop quantum gravity [New Sci.] |
| 21162 | Only supersymmetry offers to incorporate gravity into the scheme [New Sci.] |
| 21173 | Supersymmetry says particles and superpartners were unities, but then split [New Sci.] |
| 21159 | Supersymmetry has extra heavy bosons and heavy fermions [New Sci.] |
| 21172 | The evidence for supersymmetry keeps failing to appear [New Sci.] |
| 21160 | The Higgs field means even low energy space is not empty [New Sci.] |
| 21174 | Dark matter must have mass, to produce gravity, and no electric charge, to not reflect light [New Sci.] |