Mediocrity principle

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The assumptions of mediocrity principle is the notion in philosophy of science that there is nothing special about humans or the Earth. It is a Copernican principle, used either as an heuristic about Earth's position or a philosophical statement about the place of humanity. In a broader context, the mediocrity principle states that:

(1) life on Earth depends on just a few basic molecules;
(2) the elements that make up these molecules are (to a greater or lesser extent) common to all stars, and
(3) the laws of science we know apply to the entire universe (and there is no reason to assume that they do not),
(Conclusion) then – given sufficient time – life must have originated elsewhere in the cosmos. ^[1]

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^[2].
• 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. 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

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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 could be experiencing 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.

For criticism of this view, see Rare Earth hypothesis.

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, and 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.

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

Footnotes

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).