Mediocrity principle

"Mediocre" redirects here. For the album by Ximena Sariñana, see Mediocre (album).

The mediocrity principle is the notion in the philosophy of science that there is nothing special about humans or the Earth. It is a Copernican principle, used either as a heuristic about Earth's position or a philosophical statement about the place of humanity. In a broader context, the mediocrity principle states that whenever one observes a phenomenon, it is likely that the observed occurrence is only one out of many occurrences; if one witnesses an extraordinary event, it should be assumed that the event occurs more than once, given the proper circumstances.

The mediocrity principle as applied to humanity's and Earth's existence is further boosted by:

• Fossil evidence supported by genetics concluding that all humans have a common ancestor about 100,000 years ago and that they share a common ancestor with chimpanzees and bonobos about six million years ago. Therefore humans are part of the biosphere, not above it or unique to it.
• Humans share about 98% of their DNA with chimpanzees. Chimpanzees have actually undergone more genetic change than humans.
• The answering of Schrödinger's question What is Life? through the discovery of the double-helix structure of DNA and the reduction of life to organic chemistry, negating the vitalism of previous centuries.
• Edwin Hubble discovered that the universe is substantially larger than humans first thought and James Hutton discovered the Earth is a lot older. The Hubble Deep Field is a long exposure of thousands of galaxies, making it one of the best pictorial representations of the principle of mediocrity.

Earth is an unexceptional planet

The traditional formulation of the Copernican mediocrity principle is usually played out in the following way: Ancients of the Middle East and west once thought that the Earth was at the center of the universe, but Copernicus proposed that the Sun was at the center. In the 1930s, RJ Trumpler found that the solar system was not at the center of the Milky Way Galaxy (as Jacobus Kapteyn claimed), but 56% of the way out to the rim of the galaxy's core. In the mid-twentieth century, George Gamow (et al.) showed that although it appears that our Galaxy is at the center of an expanding universe (in accordance with Hubble's law), every point in space experiences the same phenomenon. And, at the end of the twentieth century, Geoff Marcy and colleagues discovered that extrasolar planets are quite common, putting to rest the idea that the Sun is unusual in having planets. In short, Copernican mediocrity is a series of astronomical findings that the Earth is a relatively ordinary planet orbiting a relatively ordinary star in a relatively ordinary galaxy which is one of countless others in a giant universe, possibly within an infinite multiverse. Nevertheless both George Gamow and Geoffrey Marcy have been accused of adopting unscientific methods in most of their core studies, letting those remain hypothetic up to date.

On the ordinariness of humanity

• Evolutionary psychology is discovering the limits to human rationality, biological psychology exposes the material nature of cognition and moral sense with fMRI scans, economic and political studies find regularities in the behaviors of large groups of humans.
• Francis Crick's "Astonishing Hypothesis" is that consciousness is simply the function of the brain.
• When the Human Genome Project released its findings in 2003, it was discovered that the human genome only has 24,000 genes. As recently as the 1990s, humans were considered so complex as to have about 300,000 genes.

As a philosophical statement

There is a stronger, philosophical version of the mediocrity principle. This associates the Renaissance with greater openness to radical ideas. The belief is that the Roman Catholic dogma of the day, with regards to the place of Earth in the cosmos, was that if God made man in God's image and that this were God's most perfect creation, then there was only one logical place to put this most perfect creation—at the center of the Universe. Therefore, Copernicus's suggestion that Earth was not the center of the entire Universe, implied the theological conclusion that man was not God's most perfect creation. Although this is a popular interpretation of history and of man's position in the cosmos, it is not historically accurate. Medieval theologians, most vividly illustrated in Dante's Divine Comedy, viewed the heavens as perfect, and Earth (and humans) as the dregs (rather than the pinnacle) of creation. Thus it seemed that Copernicus was actually promoting rather than demoting the Earth by removing it from the "basement", and the paradigm shift was of a very different character.

See also

• Anthropic principle - the only universe that we can observe is one that allows for our existence.
• Cosmic pluralism
• Deep ecology
• Defeatism
• Drake equation
• Fatalism
• Geocentric cosmology of Aristotle and Ptolemy
• Nihilism
• Plenitude principle
• Ptolemaic system
• The Rare Earth hypothesis is the antithesis of the Mediocrity principle
• Total Perspective Vortex
• Uniformity principle

References

Notations

• Gonzalez, Richards, The Privileged Planet: How Our Place in the Cosmos is Designed for Discovery 2004, Regnery Publishing, ISBN 0-89526-065-4
• Peter Ward and Donald Brownlee. Rare Earth: Why Complex Life is Uncommon in the Universe. Copernicus Books. January 2000. ISBN 0-387-98701-0

External links

• Goodwin, Gribbin, and Hendry's 1997 Hubble Parameter measurement relying on the mediocrity principle The authors call this the 'Principle of Terrestrial Mediocrity' even though the assumption they make is that the Milky Way Galaxy is typical (rather than Earth). This term was coined by Alexander Vilenkin (1995).