Mediocrity principle

Mediocrity principle

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The mediocrity principle is the notion in philosophy of science
Philosophy of science
The philosophy of science is concerned with the assumptions, foundations, methods and implications of science. It is also concerned with the use and merit of science and sometimes overlaps metaphysics and epistemology by exploring whether scientific results are actually a study of truth...

 that there is nothing very unusual about the evolution of our solar system, the Earth, any one nation, or humans. It is a heuristic
Heuristic refers to experience-based techniques for problem solving, learning, and discovery. Heuristic methods are used to speed up the process of finding a satisfactory solution, where an exhaustive search is impractical...

 in the vein of the Copernican principle
Copernican principle
In physical cosmology, the Copernican principle, named after Nicolaus Copernicus, states that the Earth is not in a central, specially favored position. More recently, the principle has been generalized to the relativistic concept that humans are not privileged observers of the universe...

, and is sometimes used as a philosophical statement about the place of humanity. The idea is to assume mediocrity, rather than starting with the assumption that a phenomenon is special or has somehow violated the laws of the universe.

The Copernican principle

The mediocrity, as the Copernican principle, states that life
Life is a characteristic that distinguishes objects that have signaling and self-sustaining processes from those that do not, either because such functions have ceased , or else because they lack such functions and are classified as inanimate...

 on Earth
Earth is the third planet from the Sun, and the densest and fifth-largest of the eight planets in the Solar System. It is also the largest of the Solar System's four terrestrial planets...

 depends on just a few basic molecules, the elements
Chemical element
A chemical element is a pure chemical substance consisting of one type of atom distinguished by its atomic number, which is the number of protons in its nucleus. Familiar examples of elements include carbon, oxygen, aluminum, iron, copper, gold, mercury, and lead.As of November 2011, 118 elements...

 that make up these molecules are (to a greater or lesser extent) common to all stars, and the laws of science
Science is a systematic enterprise that builds and organizes knowledge in the form of testable explanations and predictions about the universe...

 we know apply to the entire universe
The Universe is commonly defined as the totality of everything that exists, including all matter and energy, the planets, stars, galaxies, and the contents of intergalactic space. Definitions and usage vary and similar terms include the cosmos, the world and nature...

 (and there is no reason to assume that they do not). Given sufficient time
Time is a part of the measuring system used to sequence events, to compare the durations of events and the intervals between them, and to quantify rates of change such as the motions of objects....

, it seems reasonable to expect that life
Life is a characteristic that distinguishes objects that have signaling and self-sustaining processes from those that do not, either because such functions have ceased , or else because they lack such functions and are classified as inanimate...

 would originate somewhere, and has probably originated elsewhere in the cosmos
In the general sense, a cosmos is an orderly or harmonious system. It originates from the Greek term κόσμος , meaning "order" or "ornament" and is antithetical to the concept of chaos. Today, the word is generally used as a synonym of the word Universe . The word cosmos originates from the same root...

This idea is bolstered by Edwin Hubble
Edwin Hubble
Edwin Powell Hubble was an American astronomer who profoundly changed the understanding of the universe by confirming the existence of galaxies other than the Milky Way - our own galaxy...

's discovery that the universe is substantially larger than humans first thought. The Hubble Deep Field
Hubble Deep Field
The Hubble Deep Field is an image of a small region in the constellation Ursa Major, constructed from a series of observations by the Hubble Space Telescope. It covers an area 2.5 arcminutes across, two parts in a million of the whole sky, which is equivalent in angular size to a 65 mm tennis...

 is a long exposure of thousands of galaxies, making it one of the best pictorial representations of the principle of mediocrity.

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
Robert Julius Trumpler
Robert Julius Trumpler was a Swiss-American astronomer....

 found that the solar system was not at the center of the Milky Way Galaxy (as Jacobus Kapteyn
Jacobus Kapteyn
Jacobus Cornelius Kapteyn, was a Dutch astronomer, best known for his extensive studies of the Milky Way and as the first discoverer of evidence for galactic rotation....

 claimed), but 56% of the way out to the rim from the galaxy's core
Galactic Center
The Galactic Center is the rotational center of the Milky Way galaxy. It is located at a distance of 8.33±0.35 kpc from the Earth in the direction of the constellations Sagittarius, Ophiuchus, and Scorpius where the Milky Way appears brightest...

. In the mid-twentieth century, George Gamow
George Gamow
George Gamow , born Georgiy Antonovich Gamov , was a Russian-born theoretical physicist and cosmologist. He discovered alpha decay via quantum tunneling and worked on radioactive decay of the atomic nucleus, star formation, stellar nucleosynthesis, Big Bang nucleosynthesis, cosmic microwave...

 (et al.) demonstrated that although it appears that our Galaxy is at the center of an expanding universe (in accordance with Hubble's law
Hubble's law
Hubble's law is the name for the astronomical observation in physical cosmology that: all objects observed in deep space are found to have a doppler shift observable relative velocity to Earth, and to each other; and that this doppler-shift-measured velocity, of various galaxies receding from...

), every point in space could be experiencing the same phenomenon. And, at the end of the twentieth century, Geoff Marcy
Geoffrey Marcy
Geoffrey W. Marcy is an American astronomer, who is currently Professor of Astronomy at the University of California, Berkeley, famous for discovering more extrasolar planets than anyone else, 70 out of the first 100 to be discovered, along with R...

 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
Astronomy is a natural science that deals with the study of celestial objects and phenomena that originate outside the atmosphere of Earth...

 findings that the Earth
Earth is the third planet from the Sun, and the densest and fifth-largest of the eight planets in the Solar System. It is also the largest of the Solar System's four terrestrial planets...

 is a relatively ordinary planet orbiting a relatively ordinary star in a relatively ordinary galaxy
A galaxy is a massive, gravitationally bound system that consists of stars and stellar remnants, an interstellar medium of gas and dust, and an important but poorly understood component tentatively dubbed dark matter. The word galaxy is derived from the Greek galaxias , literally "milky", a...

 which is one of countless others in a giant universe, possibly within an infinite multiverse
Multiverse (science)
The multiverse is the hypothetical set of multiple possible universes that together comprise everything that exists and can exist: the entirety of space, time, matter, and energy as well as the physical laws and constants that describe them...


Other uses of the heuristic

The mediocrity principle as applied to humanity is supported by much of the evidence of common descent. Such evidence (from fossils, genetics, morphology, etc.) suggests that all humans have a common ancestor about 100,000 years ago, and that they share a common ancestor with chimpanzees and bonobo
The bonobo , Pan paniscus, previously called the pygmy chimpanzee and less often, the dwarf or gracile chimpanzee, is a great ape and one of the two species making up the genus Pan. The other species in genus Pan is Pan troglodytes, or the common chimpanzee...

s about six million years ago. By some measures, Humans share about 98% of their DNA
Deoxyribonucleic acid is a nucleic acid that contains the genetic instructions used in the development and functioning of all known living organisms . The DNA segments that carry this genetic information are called genes, but other DNA sequences have structural purposes, or are involved in...

 with chimpanzees. When the Human Genome Project
Human Genome Project
The Human Genome Project is an international scientific research project with a primary goal of determining the sequence of chemical base pairs which make up DNA, and of identifying and mapping the approximately 20,000–25,000 genes of the human genome from both a physical and functional...

 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
Gênes is the name of a département of the First French Empire in present Italy, named after the city of Genoa. It was formed in 1805, when Napoleon Bonaparte occupied the Republic of Genoa. Its capital was Genoa, and it was divided in the arrondissements of Genoa, Bobbio, Novi Ligure, Tortona and...

. Chimpanzees have actually undergone more genetic change than humans.

Abiogenesis or biopoesis is the study of how biological life arises from inorganic matter through natural processes, and the method by which life on Earth arose...

 is likewise pursuing an answer to Schrödinger's question "What is Life?
What is Life? (Schrödinger)
What Is Life? is a 1944 non-fiction science book written for the lay reader by physicist Erwin Schrödinger. The book was based on a course of public lectures delivered by Schrödinger in February 1943, under the auspices of the Dublin Institute for Advanced Studies at Trinity College, Dublin...

", and rather than supporting some form of vitalism
Vitalism, as defined by the Merriam-Webster dictionary, is#a doctrine that the functions of a living organism are due to a vital principle distinct from biochemical reactions...

, evidence is breaking down the barriers between life and nonlife. Francis Crick
Francis Crick
Francis Harry Compton Crick OM FRS was an English molecular biologist, biophysicist, and neuroscientist, and most noted for being one of two co-discoverers of the structure of the DNA molecule in 1953, together with James D. Watson...

's "Astonishing Hypothesis
The Astonishing Hypothesis
The Astonishing Hypothesisis a 1994 book by scientist Francis Crick about consciousness. Crick, one of the co-discoverers of the molecular structure of DNA in 1953, later became a theorist for neurobiology and the study of the brain...

" is that consciousness
Consciousness is a term that refers to the relationship between the mind and the world with which it interacts. It has been defined as: subjectivity, awareness, the ability to experience or to feel, wakefulness, having a sense of selfhood, and the executive control system of the mind...

 is simply the function of the brain. This possibility is also related to research into the Neuroscience of free will
Neuroscience of free will
Neuroscience of free will refers to recent neuroscientific investigations shedding light on the question of free will, which is a philosophical and scientific question as to whether, and in what sense, rational agents exercise control over their actions or decisions. As it has become possible to...

. PZ Myers
PZ Myers
Paul Zachary "PZ" Myers is an American biology professor at the University of Minnesota Morris and the author of the Pharyngula science blog. He is currently an associate professor of biology at UMM, works with zebrafish in the field of evolutionary developmental biology , and also cultivates an...

 believes the mediocrity principle can be taken further. He believes that careful use of the heuristic reminds individuals not to hold their own country, nor their own preferences, in too unique or special a regard. Other sciences are humbling humankind similarly, whether it is Evolutionary psychology
Evolutionary psychology
Evolutionary psychology is an approach in the social and natural sciences that examines psychological traits such as memory, perception, and language from a modern evolutionary perspective. It seeks to identify which human psychological traits are evolved adaptations, that is, the functional...

 discovering the limits to human rationality, biological psychology exposing the material nature of cognition and moral sense with neuroimaging
Neuroimaging includes the use of various techniques to either directly or indirectly image the structure, function/pharmacology of the brain...

, or economic and political studies finding regularities in the behaviors of large groups of humans.

David Deutsch
David Deutsch
David Elieser Deutsch, FRS is an Israeli-British physicist at the University of Oxford. He is a non-stipendiary Visiting Professor in the Department of Atomic and Laser Physics at the Centre for Quantum Computation in the Clarendon Laboratory of the University of Oxford...

 argues that the mediocrity principle is not actually correct from a physical point of view, either in reference to our part of the universe or to our species. Deutsch refers to Stephen Hawking
Stephen Hawking
Stephen William Hawking, CH, CBE, FRS, FRSA is an English theoretical physicist and cosmologist, whose scientific books and public appearances have made him an academic celebrity...

's quote that "The human race is just a chemical scum on a moderate-sized planet, orbiting around a very average star in the outer suburb of one among a hundred billion galaxies.", noting that our neighborhood in the universe is not typical (80% of the universe's mass is dark matter
Dark matter
In astronomy and cosmology, dark matter is matter that neither emits nor scatters light or other electromagnetic radiation, and so cannot be directly detected via optical or radio astronomy...

) and that a concentration of mass such as our solar system is an "isolated, uncommon phenomenon". He also argues with Richard Dawkins
Richard Dawkins
Clinton Richard Dawkins, FRS, FRSL , known as Richard Dawkins, is a British ethologist, evolutionary biologist and author...

' opinion that humans, as result of natural evolution, are limited to the capabilities of our species — Deutsch responds that even though evolution did not give humans the ability to detect neutrino
A neutrino is an electrically neutral, weakly interacting elementary subatomic particle with a half-integer spin, chirality and a disputed but small non-zero mass. It is able to pass through ordinary matter almost unaffected...

s, scientists can currently detect them, significantly expanding their capabilities beyond what is available as result of evolution.

See also

  • Anthropic principle
    Anthropic principle
    In astrophysics and cosmology, the anthropic principle is the philosophical argument that observations of the physical Universe must be compatible with the conscious life that observes it. Some proponents of the argument reason that it explains why the Universe has the age and the fundamental...

     - the only universe that we can observe is one that allows for our existence.
  • Copernican principle
    Copernican principle
    In physical cosmology, the Copernican principle, named after Nicolaus Copernicus, states that the Earth is not in a central, specially favored position. More recently, the principle has been generalized to the relativistic concept that humans are not privileged observers of the universe...

  • Cosmic pluralism
    Cosmic pluralism
    Cosmic pluralism, the plurality of worlds, or simply pluralism, describes the belief in numerous other worlds which harbour extraterrestrial life. The debate over pluralism began as early as the time of Thales Cosmic pluralism, the plurality of worlds, or simply pluralism, describes the belief in...

  • Cosmological principle
    Cosmological Principle
    In modern physical cosmology, the cosmological principle is the working assumption that observers on Earth do not occupy an unusual or privileged location within the universe as a whole, judged as observers of the physical phenomena produced by uniform and universal laws of physics...

     - viewed on a sufficiently large scale, the properties of the Universe are the same for all observers
  • Deep ecology
    Deep ecology
    Deep ecology is a contemporary ecological philosophy that recognizes an inherent worth of all living beings, regardless of their instrumental utility to human needs. The philosophy emphasizes the interdependence of organisms within ecosystems and that of ecosystems with each other within the...

  • Drake equation
    Drake equation
    The Drake equation is an equation used to estimate the number of detectable extraterrestrial civilizations in the Milky Way galaxy. It is used in the fields of exobiology and the Search for ExtraTerrestrial Intelligence...

  • Geocentric cosmology of Aristotle
    Aristotle was a Greek philosopher and polymath, a student of Plato and teacher of Alexander the Great. His writings cover many subjects, including physics, metaphysics, poetry, theater, music, logic, rhetoric, linguistics, politics, government, ethics, biology, and zoology...

     and Ptolemy
    Claudius Ptolemy , was a Roman citizen of Egypt who wrote in Greek. He was a mathematician, astronomer, geographer, astrologer, and poet of a single epigram in the Greek Anthology. He lived in Egypt under Roman rule, and is believed to have been born in the town of Ptolemais Hermiou in the...

  • Neocatastrophism
    Neocatastrophism is the theory that life-exterminating events such as gamma-ray bursts have acted as a galactic regulation mechanism in the Milky Way upon the emergence of complex life in its habitable zone...

  • Plenitude principle
    Plenitude principle
    The plenitude principle or principle of plenitude asserts that everything that can happen will happen.The historian of ideas Arthur Lovejoy was the first to discuss this philosophically important Principle explicitly, it back to Aristotle, who said that no possibilities which remain eternally...

  • Ptolemaic system
  • The Rare Earth hypothesis
    Rare Earth hypothesis
    In planetary astronomy and astrobiology, the Rare Earth hypothesis argues that the emergence of complex multicellular life on Earth required an improbable combination of astrophysical and geological events and circumstances...

     is the antithesis
    Antithesis is a counter-proposition and denotes a direct contrast to the original proposition...

     of the Mediocrity principle
  • Uniformitarianism
    In the philosophy of naturalism, the uniformitarianism assumption is that the same natural laws and processes that operate in the universe now, have always operated in the universe in the past and apply everywhere in the universe. It has included the gradualistic concept that "the present is the...

  • Cosmicism
    Cosmicism is the literary philosophy developed and used by the American writer H. P. Lovecraft in his weird fiction. Lovecraft was a writer of philosophically intense horror stories that involve occult phenomena like astral possession and alien miscegenation, and the themes of his fiction over time...

  • Exceptionalism
    Exceptionalism is the perception that a country, society, institution, movement, or time period is "exceptional" in some way and thus does not need to conform to normal rules or general principles...

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
    Alexander Vilenkin
    Alexander Vilenkin is Professor of Physics and Director of the Institute of Cosmology at Tufts University. A theoretical physicist who has been working in the field of cosmology for 25 years, Vilenkin has written over 150 papers and is responsible for introducing the ideas of eternal inflation and...