more on this theme | more from this thinker
Full Idea
One suggestion is that any two different substance, however alike, exhibit a positive entropy change on mixing. So absence of entropy change on isothermal mixing provides a criterion of sameness of kind.
Clarification
'isothermal' means at the same temperature
Gist of Idea
Maybe two kinds are the same if there is no change of entropy on isothermal mixing
Source
Robin F. Hendry (Chemistry [2008], 'Micro')
Book Ref
'Routledge Companion to Philosophy of Science', ed/tr. Psillos,S/Curd,M [Routledge 2010], p.522
A Reaction
[He cites Paul Needham 2000] This sounds nice, because at a more amateur level we can say that stuff is the same if mixing two samples of it produces no difference. I call it the Upanishads Test.
Related Idea
Idea 8153 By knowing one piece of clay or gold, you know all of clay or gold [Anon (Upan)]
| 17476 | Elements survive chemical change, and are tracked to explain direction and properties [Hendry] |
| 17477 | Defining elements by atomic number allowed atoms of an element to have different masses [Hendry] |
| 17480 | Generally it is nuclear charge (not nuclear mass) which determines behaviour [Hendry] |
| 17481 | Nuclear charge (plus laws) explains electron structure and spectrum, but not vice versa [Hendry] |
| 17478 | Maybe two kinds are the same if there is no change of entropy on isothermal mixing [Hendry] |
| 17484 | Maybe the nature of water is macroscopic, and not in the microstructure [Hendry] |
| 17479 | The nature of an element must survive chemical change, so it is the nucleus, not the electrons [Hendry] |
| 17485 | Maybe water is the smallest part of it that still counts as water (which is H2O molecules) [Hendry] |
| 17482 | Compounds can differ with the same collection of atoms, so structure matters too [Hendry] |
| 17483 | Water continuously changes, with new groupings of molecules [Hendry] |
| 17486 | Supervenience is simply modally robust property co-variance [Hendry] |