cGh physics

cGh physics refers to the mainstream attempts in physics to unify relativity, gravitation and quantum mechanics, in particular following the ideas of Matvei Petrovich Bronstein and George Gamow. The letters are the standard symbols for the speed of light (c), the gravitational constant (G), and Planck's constant (h).

If one considers these three universal constants as the basis for a 3-D coordinate system and one envisions a cube, then this pedagogic construction provides a framework referred to as the "cGh cube" or "physics cube". This cube can used for organizing major subjects within physics as occupying each of the eight corners.^[1][2] The eight corners of the cGh physics cube are:

• Classical mechanics (_,_,_)
• Special relativity (c,_,_), Gravitation (_,G,_), Quantum mechanics (_,_,h)
• General relativity (c,G,_), Quantum field theory (c,_,h), Non-relativistic quantum theory with gravity (_,G,h)
• Theory of everything, or relativistic quantum gravity (c,G,h)

Diagram showing where quantum gravity sits in the a near-cube hierarchy of physics theories. Note that electromagnetism and quantum field theory in curved spacetime are added in as an extra and distinct items.

Other cGh subjects include Planck units, Hawking radiation and black hole thermodynamics.

While there are several other physical constants, these three are given special consideration, because they can be used to define all Planck units and thus all physical quantities.^[3] The three constants are therefore used sometimes as a framework for philosophical study and as one of pedagogical patterns.^[4]

In popular culture

• George Gamow chose "C. G. H." as the initials of his fictitious character, Mr C. G. H. Tompkins.

References

1. Gorelik, Gennady (1992-01-01). "Studies in the history of general relativity: First Steps of Quantum Gravity and the Planck Values". Einstein Studies (Birkhäuser Boston) 3 (1): 364–379. Retrieved 2009-05-01.
2. The Physics Cube, C.J. Wainwright
3. Duff, Michael; Lev B. Okun; Gabriele Veneziano (2002). "Trialogue on the number of fundamental constants". Journal of High Energy Physics (3). arXiv:physics/0110060. Bibcode:2002JHEP...03..023D. doi:10.1088/1126-6708/2002/03/023.
4. Okun, Lev (1991-01-01). "The fundamental constants of physics". Soviet Physics Uspekhi (Sov. Phys. Usp.) 34 (9): 818–826. Bibcode:1991SvPhU..34..818O. doi:10.1070/PU1991v034n09ABEH002475. PACS 06.20.Jr.