Carnot's Ideal

Plate 11 speaks for itself: “Between boiling and freezing water, even perfection leaks 73%.”

The Physics

No heat engine between two reservoirs can beat the reversible Carnot engine, whose efficiency depends only on the two absolute temperatures.

η_max = 1 − T_c / T_h

• η_max: maximum efficiency, dimensionless
• T_h: hot reservoir temperature, K
• T_c: cold reservoir temperature, K

T_h = 373.15 K, T_c = 273.15 K: 26.8%, so 73.2% of the heat must be rejected.

Sources

• S. Carnot, Réflexions sur la puissance motrice du feu (Paris, 1824).

On the poster

Plate 011, “Carnot's Ideal”: the pixel-art plate with its slogan “Between boiling and freezing water, even perfection leaks 73%.”, the key equation and the facts panel shown above. Pixelated Physics. Physics. Personified.