Asymptor: Third Law of Thermodynamics
Thermodynamics & Statistical Physics arc, page 51 of 193. Back to The Pixelated Physics Universe
Who they are
Asymptor has one line, and says it often: “Zero kelvin: always one more step.”
Asymptor is a character of the Thermodynamics & Statistical Physics arc: drawn in pixels, ruled by one piece of real physics, and never allowed to break it.
The physics
Unattainability form of the third law: absolute zero cannot be reached in a finite number of steps (finite time and resources).
$$ \begin{gathered} \lim_{T \to 0} \Delta S = 0 \end{gathered} $$
| Symbol | Meaning | SI unit |
|---|---|---|
| $\Delta S$ | entropy change of an isothermal process | J/K |
| $T$ | temperature | K |
Sources
- W. Nernst, Sitzungsber. Preuss. Akad. Wiss. 1912, 134
- L. Masanes & J. Oppenheim, Nat. Commun. 8, 14538 (2017)
Crossovers
Asymptor meets Molassa (Doppler Cooling Limit). Molassa can cool atoms to microkelvins and below. Asymptor reminds her that no number of finite steps reaches absolute zero itself. Every cooling stage helps, and none of them finishes the job.
Asymptor meets Degreeda (Equipartition Theorem). Degreeda gives ½k_BT to every active quadratic degree of freedom. Asymptor lowers the temperature until quantum level spacing freezes those modes out, one by one. Equipartition is a high-temperature rule.
Asymptor meets Cryoselle (Dilution Fridge Qubit). Cryoselle runs her dilution fridge at 20 mK and calls it quiet, since hf/k_BT is about 12 for her qubit. Asymptor reminds her that colder is always possible and zero never is.
Wear the lore
Concept keywords: Third Law of Thermodynamics, Asymptor, Thermodynamics & Statistical Physics, physics lore, Pixelated Physics