In thermodynamics, unitless thermodynamics is the use of thermodynamic formula or variables, stripped of SI units, but instead used with new units, no units, or some other situationally-based choice of units.
Individuals in this obscure and very questionable group include: American electrical engineer Claude Shannon (1948), who infamously choose to measure entropy in bits, Nikos Salingaros (1997), Australian environmental chemist Ivan Kennedy (2001), and Israeli physical chemist Arieh Ben-Naim (2007-2010) who argues that the entire SI unit system should be reformulated, e.g. with a new version of absolute temperature a new Planck's constant among other outlandish ideas, all in the name of replacing the joules per kelvin per mol units of entropy with units of bits.
Kennedy's version of "biothermodynamics", which he claims it to be, is the prime example of unitless thermodynamics, wherein he introduces the concept of 'action', which he defines as a unitless thermodynamic property related to entropy, resulting from impulses of energy on matter producing force, based on the sole principle of the conservation of momentum, and uses this a unifying concept to make a so-called unified theory. [1]
References
1. Kennedy, Ivan R. (2001). Action in Ecosystems: Biothermodynamics for Sustainability (ch. 4: Action Thermodynamics, pgs. 65-98). Research Studies Press.
