I don’t know if it’s always true in the context he mentions - particle physics - but I’m pretty sure it is not always true in e.g. chemical physics. Both entrop

I don’t know if it’s always true in the context he mentions - particle physics - but I’m pretty sure it is not always true in e.g. chemical physics. Both entropy and enthalpy matter. The reaction of potassium vapor with bromine vapor is spontaneous even though the solid crystalline potassium bromide product has lower entropy than the gas phase reactants. In the comments on the article Milkshake also gives an example of an entropically driven spontaneous reaction: ammonium nitrate dissolving in water. You need enthalpic and entropic terms to predict if a reaction is thermodynamically spontaneous. And if you want to calculate if a thermodynamically spontaneous reaction will appreciably take place, you also need to understand the actual intermediates between A + B -> C, and find reaction barrier heights for all of them, and weight them appropriately. This is still very hard to do so information of this sort is mostly determined by experiment rather than calculation.