In science, θ∆ics, also: θΔ or θΔcs, is the Greek letter shorthand notation for the newly-formed science of 'thermo-dynamics' (see: ΘΔ = ThermoDynamics) used in the 1870s correspondences between James Maxwell, William Thomson, and Peter Tait.
The following shows the θΔ icon that has been at the bottom of every Hmolpedia article, from 2007-2020:
The Theta symbol "θ" is code for heat, the sun, or "sun god". The Delta symbol "Δ" is code for either fire, change, or transformation, famously depicted in the shape of the construction of the Egyptian pyramids. 
The following are related quotes:
- “Only perhaps Kirchhoff ignored Hamilton first and Clausius followed him unwittingly not being a constant reader of the RIA transactions and knowing nothing of H except (lately) his Princip, which he and other try to degrade into the 2nd law of θ∆ as if any pure dynamical statement would submit to such indignity.”
- — James Maxwell (1876), “Letter to Peter Tait”, Oct 3
1. Thims, Libb. (2020). Human Chemical Thermodynamics — Chemical Thermodynamics Applied to the Humanities: Meaning, Morality, Purpose; Sociology, Economics, Ecology; History, Philosophy, Government, Anthropology, Politics, Business, Jurisprudence; Religion, Relationships, Warfare, and Love (pdf). Publisher.
- θ∆ics – Hmolpedia 2020.