31 ideas
10301 | The axiom of choice is controversial, but it could be replaced [Shapiro] |
10588 | First-order logic is Complete, and Compact, with the Löwenheim-Skolem Theorems [Shapiro] |
10298 | Some say that second-order logic is mathematics, not logic [Shapiro] |
10299 | If the aim of logic is to codify inferences, second-order logic is useless [Shapiro] |
10300 | Logical consequence can be defined in terms of the logical terminology [Shapiro] |
10290 | Second-order variables also range over properties, sets, relations or functions [Shapiro] |
10590 | Up Löwenheim-Skolem: if natural numbers satisfy wffs, then an infinite domain satisfies them [Shapiro] |
10296 | The Löwenheim-Skolem Theorems fail for second-order languages with standard semantics [Shapiro] |
10297 | The Löwenheim-Skolem theorem seems to be a defect of first-order logic [Shapiro] |
10292 | Downward Löwenheim-Skolem: if there's an infinite model, there is a countable model [Shapiro] |
10294 | Second-order logic has the expressive power for mathematics, but an unworkable model theory [Shapiro] |
17536 | If it can't be expressed mathematically, it can't occur in nature? [Heisenberg] |
17545 | Quantum theory shows that exact science does not need dogmatic realism [Heisenberg] |
17538 | Quantum theory does not introduce minds into atomic events [Heisenberg] |
10591 | Logicians use 'property' and 'set' interchangeably, with little hanging on it [Shapiro] |
17534 | A 'probability wave' is a quantitative version of Aristotle's potential, a mid-way type of reality [Heisenberg] |
17553 | We can retain the idea of 'substance', as indestructible mass or energy [Heisenberg] |
17544 | Basic particles have a mathematical form, which is more important than their substance [Heisenberg] |
17550 | We give a mathematical account of a system of natural connections in order to clarify them [Heisenberg] |
1748 | Archelaus was the first person to say that the universe is boundless [Archelaus, by Diog. Laertius] |
17549 | Seven theories in science: mechanics, heat, electricity, quantum, particles, relativity, life [Heisenberg, by PG] |
17540 | Energy is that which moves, and is the substance from which everything is made [Heisenberg] |
17541 | Energy is an unchanging substance, having many forms, and causing all change [Heisenberg] |
17548 | Maxwell introduced real fields, which transferred forces from point to point [Heisenberg] |
17533 | Radiation interference needs waves, but radiation photoelectric effects needs particles [Heisenberg] |
17532 | An atom's stability after collisions needs explaining (which Newton's mechanics can't do) [Heisenberg] |
17537 | Position is complementary to velocity or momentum, so the whole system is indeterminate [Heisenberg] |
17551 | It was formerly assumed that electromagnetic waves could not be a reality in themselves [Heisenberg] |
17543 | So-called 'empty' space is the carrier of geometry and kinematics [Heisenberg] |
17552 | In relativity the length of the 'present moment' is relative to distance from the observer [Heisenberg] |
5989 | Archelaus said life began in a primeval slime [Archelaus, by Schofield] |