Spherical cow

Comic of a spherical cow as illustrated by a 1996 meeting of the American Astronomical Association, in reference to astronomy modeling

The spherical cow is a humorous metaphor for highly simplified scientific models of complex phenomena. Originating in theoretical physics, the metaphor refers to some scientific tendencies to develop toy models that reduce a problem to the simplest form imaginable, making calculations more feasible, even if the simplification hinders the model's application to reality.

History

The phrase comes from a joke that spoofs the simplifying assumptions sometimes used in theoretical physics.

John Harte, who received his Ph.D. from the University of Wisconsin in 1965, reported that he first heard the joke as a graduate student. One of the earliest published references is in a 1970 article by Arthur O. Williams Jr. of Brown University, who described it as "a professional joke that circulated among scientists a few years ago".

The story is told in many variants, including a joke about a physicist who said he could predict the winner of any race provided it involved spherical horses moving through a vacuum. A 1973 letter to the editor in the journal ''Science'' describes the "famous story" about a physicist whose solution to a poultry farm's egg-production problems began with "Postulate a spherical chicken".

Cultural references

The concept is familiar enough that the phrase is sometimes used as shorthand for the entire issue of proper modeling. For example, ''Consider a Spherical Cow'' is a 1985 book about problem solving using simplified models. A 2015 paper on the systemic errors introduced by simplifying assumptions about spherical symmetries in galactic dark-matter haloes was titled "Milking the spherical cow – on aspherical dynamics in spherical coordinates".

References to the joke appear even outside the field of scientific modeling. "Spherical Cow" was chosen as the code name for the Fedora 18 Linux distribution. In the sitcom ''The Big Bang Theory'', a joke is told by Dr. Leonard Hofstadter with the punchline mentioning "spherical chickens in a vacuum", in " The Cooper-Hofstadter Polarization" episode. In the space gravity simulator educational video game ''Universe Sandbox'', a spherical cow was added as a user-placeable object in March 2023.

See also

* Assume a can opener, a joke about invalid assumptions in economics
* Amorphous globosus, a rare and fatal birth defect in cattle, producing a ball of underdeveloped tissue
* Fermi problem, efforts to produce very broad estimates
* ''Homo economicus'', a hypothetical rational person
* Naïve physics, also called folk physics
* Schwarzschild metric, an exact solution of the Einstein field equations assuming a uniform spherical symmetric nonrotating uncharged mass in a vacuum

References

{{reflist, 30em

External links

NASA:Exploration of the Universe Division – Supernova models as spherical cows


related history from Space Telescope Institute

Humour in science
In-jokes
Metaphors referring to cattle
Scientific modelling
Theoretical physics