From invisible chaos to visible order
Kinetic theory is one of the boldest bridges physics has ever built: it connects macroscopic quantities (pressure, temperature) that we can touch with our hands to microscopic quantities (speed, collisions of billions of molecules) that we cannot see. But the power of this construction is twofold. On one hand it “explains” the macro starting from the micro: temperature is average kinetic energy. On the other hand it shows us that, within the limits of classical physics, the macro is robust against our ignorance of the micro: there is no need to know the position of every molecule to say “the pressure is atm”. This is the first lesson in statistical physics you will meet on your journey.
Collegamenti
Argomenti: Teoria cinetica dei gas Competenze: Interpretazione micro-macro
Esercizi collegati: Worked exercise — Helium in a braking truck · Problem — Escape temperature of hydrogen · Problem — Ranking of root-mean-square speeds