Radiative imbalance with the sky → Chemical fuel

Matrix context

D = disequilibrium row · C = coupling family column. A cell reads the state of the atlas for that pair.

D.12 × C.20 · Radiative imbalance with the sky × Photothermalfamily: PhotothermalD.12 × C.33 · Radiative imbalance with the sky × Thermodiffusivefamily: ThermodiffusiveD.12 × C.30 · Radiative imbalance with the sky × Biologicalfamily: Biological

Typed bounds on this route

Every limit the atlas holds for this route, as constraint records: reached through bounded_by claims on the route's own entities. Hard bounds (an upper bound or a formula) decide the thermodynamic-bound check above; benchmarks, constitutive relations and resource limits are listed and never decisive. No prose limit exists anywhere (pass 42).

• Radiative cooling power bound · resource-bound · listed, never decisive
  net cooling power ≲ 100–150 W/m² under a clear sky
• Carnot limit · formula-bound · hard, applies to this route
  η ≤ 1 − T_c/T_h for any heat engine between reservoirs at T_h and T_c
• Onsager–Casimir reciprocity · constitutive-relation · listed, never decisive
  L_ij(B) = ε_i ε_j L_ji(−B): the cross-coefficients of coupled linear transport are equal up to the time-reversal parities ε of the variables and reversal of the magnetic field; L_ij = L_ji is the zero-field, even-parity case

Steps

1. 01
   Radiative imbalance with the sky —drives→ Radiative sky coolingreplicatedclaim record

   radiative → thermal

   • an emitter with high emissivity in the 8–13 µm window and high solar reflectance
   • a clear sky; humidity and cloud close the window

   refs [1] [2] [3]
2. 02
   Radiative sky cooling —produces→ Temperature gradientreplicatedclaim record

   thermal → thermal

   • the cooled surface sits a few kelvin below ambient air

   refs [1] [4] [3]
3. 03
   Temperature gradient —drives→ Soret effectestablishedclaim record

   thermal → chemical · loss to thermal

   • a liquid mixture or solution under a steady temperature gradient

   liquid · temperature gradient required

   refs [5] [6]
4. 04
   Soret effect —produces→ Concentration gradientestablishedclaim record

   chemical → chemical

   refs [6]
5. 05
   Concentration gradient —drives→ Chemiosmosisestablishedclaim record

   chemical → chemical · loss to thermal

   • a proton gradient across a membrane containing ATP synthase

   aqueous medium required · selective membrane required · room temperature

   refs [7] [8]
6. 06
   Chemiosmosis —converts into→ Chemical fuelestablishedclaim record

   chemical → chemical · loss to thermal

   • ATP synthesised from ADP and phosphate

   refs [7] [8]

Evidence for the complete composition · 0

No source on record for this exact composition. The sources below support the individual steps, not the route as a whole.

Evidence for the constituent relations · 8

1. [1]
   A. P. Raman et al.. Passive radiative cooling below ambient air temperature under direct sunlight (2014)

   Nature 515, 540–544 · doi:10.1038/nature13883 · crossref ✓ 2026-09-19 · record
2. [2]
   Y. Zhai et al.. Scalable-manufactured randomized glass-polymer hybrid metamaterial for daytime radiative cooling (2017)

   Science 355, 1062–1066 · doi:10.1126/science.aai7899 · crossref ✓ 2026-09-19 · record
3. [3]
   J.-l. Kou et al.. Daytime radiative cooling using near-black infrared emitters (2017)

   ACS Photonics 4, 626–630 · doi:10.1021/acsphotonics.6b00991 · crossref ✓ 2026-09-19 · record
4. [4]
   A. P. Raman, W. Li, S. Fan. Generating light from darkness (2019)

   Joule 3, 2679–2686 · doi:10.1016/j.joule.2019.08.009 · crossref ✓ 2026-09-19 · record
5. [5]
   C. Soret. Sur l'état d'équilibre que prend au point de vue de sa concentration une dissolution saline primitivement homogène dont deux parties sont portées à des températures différentes (1879)

   Archives des Sciences Physiques et Naturelles 2, 48–61 · paper, no DOI · record
6. [6]
   S. R. de Groot, P. Mazur. Non-Equilibrium Thermodynamics (1962)

   North-Holland · book, no DOI · record
7. [7]
   P. Mitchell. Coupling of phosphorylation to electron and hydrogen transfer by a chemi-osmotic type of mechanism (1961)

   Nature 191, 144–148 · doi:10.1038/191144a0 · crossref ✓ 2026-09-19 · record
8. [8]
   D. G. Nicholls, S. J. Ferguson. Bioenergetics (4th ed.) (2013)

   Academic Press · doi:10.1016/C2010-0-64902-9 · crossref ✓ 2026-09-19 · record