## Philosophy Lexicon of Arguments | |||

Author | Item | Excerpt | Meta data |
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Books on Amazon |
I 159 Definition Propensitiy/Popper/Fraassen: Thesis: according to this, probability is itself a physical quantity, the strength or intensity of the real chance of an occurrence or event that cannot be reduced by reference to actual classes of actual occurrences. --- I 165 Probability/Fraassen: a) epistemic: e.g. 1.75% of the recruits of 44 have survived. - 2. Jones is recruit 44 - 1 and 2 are objective. - But the probability is subjective for me, because I have no further information about Jones. - N.B.: the information that I sum up has not the word "probability" in itself. - Information: that Jones belongs to a certain class. Thus, statistical mechanics has nothing to do with ignorance either. --- I 166 f Objective Probability/Fraassen. For example, information about the time a system spends in a state is objective information. To call a probability function a measure for something is neither subjective nor objective. - It can also be a measure of ignorance. - objective and subjective (epistemic) probability cannot always be kept apart in practice. --- I 167 Statistics/probability/infinite/Fraassen: because subregions can be subdivided into even smaller parts ((s) why? - because they end up as points) one needs infinite classes. -> Kolmogoroff axioms (countable additivity). - to map probability onto real numbers. - still extrapolation of finite proportions. --- I 169 Probability/Quantum mechanics/Fraassen: Problem: Meaningless: half-life of a single atom. - Also for odd numbers of atoms (due to the decay of a half atom). - Solution: subjective probability. I have no further information on this atom. - Problem: objectively accurate ½, subjective: about 1/2 - Problem: there is no relation between exact and approximate! - Solution: in quantum mechanics there is no classic probability. --- I 170 Mixture/Quantum mechanics: Contrary to pure state: - analog in statistical mechanics: Difference between micro- and macro-state. - Ignorance: to say that the system is in one of e.g. three pure states. - (Ignorance interpretation) - Problem: mixed state: can be decomposed in more than one way. --- I 174 Probability/Double Slit/Quantum mechanics/Fraassem: must not be equated with the proportions, to find the electron in a certain place. --- I 177 Infinite/Probability-Theory/Quantum Mechanics/Fraassen: Problem: there are so many pure states and maximal observables as there are real numbers - Probability-Theory: Theorem: if each of a class of mutually exclusive events has a probability > 0, there are only countable many - Problem: then modality comes into play; the probabilities are about what would be the case if ... --- I 178 Epistemic probability/subjective/Fraassen: can be left to the epistemology. - Objective probability: is a philosophical problem. - What does a probabilistic theory say? - To what are we bound to with this? --- I 179 Probability Space: 1.K: sample space, event-R, 2.F: family of events, 3.P: Probability measure. - Significance: Problem when too fine-grained. - Definition field: family of subsets of K, completed under the operations average, union, complement formation. - Probability Space: if Field = Borel-Field (Sigma-Field): completed under countable infinitely many unions. - + + Propensity, strict frequency. |
Fr I B. van Fraassen The Scientific Image Oxford 1980 |

> Counter arguments against **Fraassen**

> Counter arguments in relation to **Probability**

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Ed. Martin Schulz, access date 2017-05-26