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Life

Specialty Definition: Life

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Specialty Definition: Afterlife

(From Wikipedia, the free Encyclopedia)

This article is about life after death. For the Japanese movie, see After life.

The afterlife (also known as life after death) is the notion of something, typically spiritual and experiential, that happens to human beings when they die.

There is no widely agreed-upon scientific evidence for life after death, though some would point to studies of near-death experiences as such evidence. In any case, some -- particularly atheists and agnostics of a scientific, rational, or rationalistic mindset -- hold that we entirely cease to exist. For those who do believe in an afterlife, there are various notions about it. Probably the most common notion (common to Judaism, Christianity, and Islam) is that human souls go on for eternity to a place of happiness or torment, such as heaven, hell, or purgatory or limbo. Others, notably Hindus, believe we reincarnate, whether as humans or as animals. Some Neopagans believe in personal reincarnation, whereas some believe that the energy of one's soul reintegrates with a continuum of such energy which is recycled into other living things as they are born.

The study of views of the afterlife is a part of Eschatology, which deals with the soul, the resurrection of the dead, the messianic era, and the end of the world.

Many religions hold that after death people get reward or punishment based on their deeds or faith. The Christian Bible, for example, contains the words of Jesus: "The measure you give will be the measure you get." (from the Sermon on the Mount?). For many, believe in an afterlife is a consolation in connection with death of a beloved one or the prospect of one's own death. On the other hand, fear of hell etc. may make death worse.

In view of the eternity of afterlife, some consider regular life as relatively unimportant, except for determining whether or not afterlife follows, and/or what kind. It is just a provisional situation, and the metaphor of a tent as provisional housing facility is used:

Quote from the bible, Corinthians-2, 5:1: For we know that if our earthly house of this tabernacle were dissolved, we have a building of God, a house not made with hands, eternal in the heavens.

Others, including some Universalists, believe in universalism which holds that all will be rewarded regardless of what they have done or believed.

The question whether or not there is life after death is closely related to the mind-body problem, and like that problem is one of the classic problems of so-called rational psychology and hence of one (now largely outdated) notion of the scope of metaphysics.

The belief in the existence of ghosts and other undead is a reflection of the belief in an afterlife.

See also Eschatology, predestination, Immortality, Salvation, Soul, Out-of-body experience, Reincarnation.

External Links

• Truth Journal: The Case for Life After Death
• Soul-searching doctors find life after death
• Frederic Myers - Proof of Life After Death

  Source: adapted by the editor from Wikipedia, the free encyclopedia under a copyleft GNU Free Documentation License (GFDL) from the article "Afterlife."

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Biology

(From Wikipedia, the free Encyclopedia)

simple:Life science

Biology is the science of life. It is concerned with the characteristics and behaviors of organisms, how species and individuals come into being, and what interactions they have with each other and their environments.

Overview of biology

Biology encompasses a broad spectrum of academic fields that are often viewed as independent disciplines. Together, they study life over a wide range of scales:

• at the atomic and molecular scale, through molecular biology, biochemistry
• at the cellular scale, through cell biology
• at the multicellular scales, through physiology, anatomy, and histology
• at the level of the development or ontogeny of an individual organism, through developmental biology
• at the level of heredity between parent and offspring through genetics
• at the level of group behavior through ethology
• at the level of an entire population, through population genetics
• on the multi-species scale of lineages, through systematics
• at the level of interdependent populations and their habitats through ecology and evolutionary biology
• and speculatively through Xenobiology at the level of life beyond the Earth.

Fields of study in biology

Aerobiology -- Anatomy -- Astrobiology -- Biochemistry -- Bionics -- Biogeography -- Bioinformatics -- Biophysics-- Biotechnology -- Botany -- Cell biology -- Chorology -- Cladistics -- Crustaceology -- Cryptozoology -- Cytology -- Developmental biology -- Disease (Genetic diseases, Infectious diseases) -- Ecology (Theoretical ecology, Symbiology, Autecology, Synecology) -- Ethology -- Entomology -- Evolution (Evolutionary biology) -- Evolutionary developmental biology ("Evo-devo" or Evolution of Development) -- Freshwater biology -- Genetics (Population genetics, Quantitative genetics, Genomics, Proteomics) -- Herpetology -- Histology -- Ichthyology -- Immunology -- Infectious diseases -- Pathology -- Epidemiology -- Limnology -- Malacology -- Mammalogy -- Marine biology -- Microbiology (Bacteriology) -- Molecular Biology -- Morphology -- Mycology / Lichenology --- Myrmecology --- Neuroscience (Neuroanatomy, Neurophysiology, Systems neuroscience, Biological psychology, Psychiatry, Psychopharmacology, Behavioral science, Neuroethology, Psychophysics, Computational neuroscience, Cognitive science)-- Oncology (the study of cancer) -- Ontogeny -- Ornithology -- Paleontology (Palaeobotany, Palaezoology)-- Parasitology -- Phycology (Algology) -- Phylogeny (Phylogenetics, Phylogeography) -- Physiology -- Phytopathology -- Structural biology -- Taxonomy -- Toxicology (the study of poisons and pollution) -- Virology -- Xenobiology -- Zoology

Related disciplines

Medicine -- Physical anthropology

People and history

Famous biologists -- History of biology -- Nobel prize in physiology or medicine -- Timeline of biology and organic chemistry

What are our priorities for writing in this area? To help develop a list of the most basic topics in biology, please see Wikipedia:biology basic topics.

Evolution and biology

One of the central, organizing concepts in biology is that all life has descended from a common origin through a process of evolution. Charles Darwin articulated the concept of evolution that remains central to this day, which he did by proposing natural selection as a mechanism. Genetic drift was embraced as an additional mechanism in the so-called modern synthesis. The evolutionary history of a species--which tells the characteristics of the various species from which it descended--together with its genealogical relationship to every other species is called its phylogeny. Widely varied approaches to biology generate information about phylogeny. These include the comparisons of DNA sequences conducted within molecular biology or genomics, and comparisons of fossils or other records of ancient organisms in paleontology. Biologists organize and analyze evolutionary relationships through various methods, including phylogenetics, phenetics, and cladistics. Major events in the evolution of life, as biologists currently understand them, are summarized on this evolutionary timeline.

Classification of life

The classification of living things is called systematics, or taxonomy, and should reflect the evolutionary trees (phylogenetic trees) of the different organisms. Taxonomy piles up organisms in groups called taxa, while systematics seeks their relationships. The dominant system is called Linnaean taxonomy, which includes ranks and binomial nomenclature. How organisms are named is governed by international agreements such as the International Code of Botanical Nomenclature (ICBN), the International Code of Zoological Nomenclature (ICZN), and the International Code of Nomenclature of Bacteria (ICNB). A fourth Draft BioCode was published in 1997 in an attempt to standardize naming in the three areas, but it does not appear to have yet been formally adopted. The International Code of Virus Classification and Nomenclature (ICVCN) remains outside the BioCode.

Traditionally, living things were divided into five kingdoms:

Monera -- Protista -- Fungi -- Plantae -- Animalia

However, this five-kingdom system is now considered by many to be outdated. More modern alternatives generally begin with the three-domain system:

Archaea -- Eubacteria -- Eukaryota

These domains reflect whether cells have nuclei or not as well as differences in cell exteriors.

There is also a series of intracellular "parasites" that are progressively less alive in terms of being metabolically active:

Viruses -- Viroids -- Prions

History of the word "biology"

The word "biology" in its modern sense seems to have been introduced independently by Gottfried Reinhold Treviranus (Biologie oder Philosophie der lebenden Natur, 1802) and by Jean-Baptiste Lamarck (Hydrogéologie, 1802). The word itself is sometimes said to have been coined in 1800 by Karl Friedrich Burdach, but it appears in the title of Volume 3 of Michael Christoph Hanov's Philosophiae naturalis sive physicae dogmaticae: Geologia, biologia, phytologia generalis et dendrologia, published in 1766.

External links and resources

Links

• Kimball's Biology Pages, http://users.rcn.com/jkimball.ma.ultranet/BiologyPages : An online searchable textbook.
• The Tree of Life, http://tolweb.org/tree/phylogeny.html : A multi-authored, distributed Internet project containing information about phylogeny and biodiversity.
• The Journal of Biology, http://www.jbiol.com : A small, but free, research journal
• The Public Library of Science: Biology, http://biology.plosjournals.org : A newer, but more ambitious free research journal.
• BioCode, http://www.rom.on.ca/biodiversity/biocode/biocode1997.html : A proposal for organism naming

Further reading

• Lynn Margulis: Five Kingdoms: An Illustrated Guide to the Phyla of Life on Earth, 3rd ed., St. Martin's Press, 1997, paperback, ISBN 0805072527 (There are numerous other editions)
• Neil Campbell, Biology: Concepts & Connections (4th edition), Benjamin-Cummings Publishing Company, 2002, hardcover, 781 pages, ISBN 080536627X A college-level textbook.

  Source: adapted by the editor from Wikipedia, the free encyclopedia under a copyleft GNU Free Documentation License (GFDL) from the article "Biology."

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Conway's Game of Life

(From Wikipedia, the free Encyclopedia)

The Game of Life is a cellular automaton devised by the British mathematician John Horton Conway in 1970. It is the best-known example of a cellular automaton.

It made its first public appearance in the October 1970 issue of Scientific American, in Martin Gardner's "Mathematical Games" column. From a theoretical point of view, it is interesting because it has the power of a Universal Turing Machine: that is, anything that can be computed algorithmically can be computed within Conway's Game of Life.

Ever since its publication, it has attracted much interest because of the surprising ways the patterns can evolve. Soon after publication the R-pentomino and glider patterns were discovered, which led to a wave of people studying the game. This was helped by the fact that Life was described right when a new generation of inexpensive minicomputers were being released into the market, meaning that the game could be run for hours on these machines which were otherwise unused at night. For many afficianados Life was simply a programming challenge, a fun way to waste CPU cycles. For many others, however, Life developed a cult following through the 1970s and into the mid-1980s.

Description

The "game" is actually a zero-player game, meaning that its evolution is determined by its initial state, needing no input from human players. It runs on a grid of squares ("cells") which stretches to infinity in all directions. Each cell has eight "neighbours", which are the cells adjacent to it, including diagonally. Each cell can be in one of two states: it is either "alive" or "dead". (The terms "on" and "off" are also used.) The state of the grid evolves in discrete time steps. The states of all of the cells at one time are taken into account to calculate the states of the cells one time step later. All of the cells are then updated simultaneously.

The transitions depend only on the number of live neighbours:

• A dead cell with exactly 3 live neighbours becomes alive (or is "born").
• A live cell with 2 or 3 live neighbours stays alive; otherwise it dies (from "loneliness" or "overcrowding").

Examples of patterns

There are all sorts of different patterns that occur in the Game of Life, including static patterns ("still lifes"), repeating patterns ("oscillators" - a superset of still lifes), and patterns that translate themselves across the board ("spaceships"). The simplest examples of these three classes are shown below, with live cells shown in black, and dead cells shown in white.

Block	Boat	Blinker	Toad	Glider	LWSS

The "block" and "boat" are still lifes, the "blinker" and "toad" are oscillators, and the "glider" and "lightweight spaceship" ("LWSS") are spaceships.

Patterns called "Methuselahs" can evolve for long periods before repeating. A "diehard" is a pattern that eventually disappears after 130 generations, or steps. An "acorn" takes 5206 generations to generate 13 gliders then stabilises as many oscillators.

Diehard	Acorn

In the game's original appearance in "Mathematical Games", Conway offered a cash prize for any patterns that grew indefinitely. The first of these was found by Bill Gosper in November 1970. They include "guns", which shoot out gliders or other spaceships; "puffers", which move along leaving behind a trail of debris; and "rakes", which do both. He also discovered a pattern with a quadratic growth rate, called a "breeder", which works by leaving behind a trail of guns. Since then, various complicated constructions have been made, including glider logic gates, an adder, a prime number generator, and a unit cell which emulates the Game of Life at a much larger scale and slower pace.

The first glider gun found is still the smallest one known:

Gosper Glider Gun

Simpler patterns were later found that also have infinite growth. All three of the following patterns have infinite growth. The first has only 10 live cells (which has been proven to be minimal). The second fits in a 5 x 5 square. The third is only 1 cell high:

It is possible for gliders to interact with other objects in interesting ways. For example, if two gliders are shot at a block in just the right way, the block will move closer to the source of the gliders. If three gliders are shot in just the right way, the block will move further away. This "sliding block memory" can be used to simulate a counter. It is possible to construct logic gates AND, OR and NOT using gliders. It is possible to build a pattern which acts like a finite state machine connected to two counters. This has the same computational power as a Universal Turing Machine (see counter for the proof), so the Game of Life is as powerful as any computer with unlimited memory: it is Turing complete. Furthermore, a pattern can contain a collection of guns that combine to construct new objects, including copies of the original pattern. A "universal constructor" can be built which contains a Turing complete computer, and which can build many types of complex objects, including more copies of itself.

Variations on Life

Since life's original inception, new rules have been developed. The standard Game of Life, in which a cell is "born" if it has exactly 3 neighbors, stays alive if it has 2 or 3 alive neighbors, and dies otherwise, is symbolized as "23/3". The first number, or list of numbers, is what is required for a cell to continue. The second set is the requirement for birth. Hence "16/6" means "a cell is born if there are 6 neighbours, and lives on if there are either 1 or 6 neighbours". HighLife is therefore 23/36, because 6 neighbors, in addition to the original game's 23/3 rule, causes a birth. HighLife is most well known for its replicators. Additional variations on life exist, although the vast majority of these universes are either too chaotic or desolate.

• 5678/35678 (chaotic) diamonds castrophes
• /2 (exploding) phoenix, minimal
• /234 (exploding) phoenix, lacey patterns
• 12345/3 (exploding) maze-like designs
• 125/36 (chaotic) Life-like 2x2 block rule
• 1357/1357 (exploding) everything is a replicator
• 1358/357 (chaotic) a balanced amoeba rule
• 23/3 (chaotic) "Conway's Life" (default)
• 23/36 (chaotic) "HighLife" (has replicator)
• 235678/3678 (stable) ink blot, quick drying
• 235678/378 (exploding) coagulations in chaos
• 238/357 (chaotic) broken life
• 245/368 (stable) death plus puffers and ships
• 34/34 (exploding) "34 Life"
• 34678/3678 (exploding) "Day Night"
• 45678/3 (exploding) slow coral growth
• 5/346 (stable) "Long life"

Source: Life32

External links

• Life Lexicon
• Conway's Game of Life applet software home page
• "Eric Weisstein's Treasure Trove of the Life C.A." - a site by Dr. Eric Weisstein containing many descriptions and animations of Life patterns

Conway's Game of Life should not be confused with the board game "The Game of Life", for which see Hasbro's Game of Life.

Source: adapted by the editor from Wikipedia, the free encyclopedia under a copyleft GNU Free Documentation License (GFDL) from the article "Conway's Game of Life."

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Extraterrestrial life

(From Wikipedia, the free Encyclopedia)

Extraterrestrial life is life beyond planet Earth (other than humans travelling in space, and living organisms they bring along or send).

There are many questions about extraterrestrial life, including:

• Does it exist?
• Where?
• What kind?
• Could there be non-carbon based life forms, e.g. life forms based on other elements like silicon (see carbon chauvinism)?
• How does life differ depending on the type of structure (unicellular life, multicellular, intelligent, advanced technological)?
• What range of conditions are required for the evolution of life?

The scientific study of extraterrestrial life is called xenobiology (or exobiology or astrobiology).

Scientists are searching for extraterrestrial life in two very different ways. Firstly, they are searching for evidence of unicellular life within the solar system: searching Mars and meteors which have fallen to Earth, and a proposed mission to Europa, one of Jupiter's moons with a liquid water layer under its surface, which may contain life.

There is some evidence for the existence of microbial life on Mars. An experiment on the Viking Mars lander reported gas emissions from heated Martian soil that some argue are consistent with the presence of microbes, though the lack of corroborating evidence from other experiments on the Viking indicates that a non-biological reaction is a more likely hypothesis. Indepedently, in 1996 structures resembling bacteria were discovered in a meteorite known to be formed of rock ejected from Mars. Again, this evidence is vigorously disputed.

Secondly, it is theorised that any technological society will be transmitting information: man-made electromagnetic radiation is already detectable within an eighty light-year radius of Earth, and is constantly spreading. SETI, the Search for Extraterrestrial Intelligence, takes the data gathered by the world's largest radiotelescopes and analyses it for artificial patterns using supercomputers and one of the largest distributed computing projects in the world, SETI@home.

Some scientists believe that some UFOs are the spacecraft of intelligent extraterrestrials; however since these scientists are currently very much in the minority, work such as SETI continues in the hopes that a signal will be detected.

Astronomers also search for extrasolar planets that would be conducive to life. Current radiodetection methods have been inadequate for such a search, as the resolution afforded by recent technology is inadequate for detailed study of extrasolar planetary objects. Future telescopes should be able to image planets around nearby stars, which may reveal the presence of life (either directly or through spectrography revealing, for instance, the presence of free oxygen in a planet's atmosphere).

Panspermia holds that (extraterrestrial) life is prevalent through space in a form analogous to spores.

Extraterrestrial life forms, especially intelligent ones, are often referred to as aliens.

See also: Panspermia, Exoplanet, Fermi paradox, Drake equation, UFO

Fiction: see E.T. the Extra-Terrestrial

Source: adapted by the editor from Wikipedia, the free encyclopedia under a copyleft GNU Free Documentation License (GFDL) from the article "Extraterrestrial life."

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Hasbro's Game of Life

(From Wikipedia, the free Encyclopedia)

The Game of Life is a board game designed by Reuben Klamer and originally published by Milton Bradley (a subsidiary of Hasbro) in 1960 to celebrate Milton Bradley's centennial.

Between 2 and 10 players each get a plastic car in which they can collect their "family" throughout the game. Each turn consists of spinning a wheel with the numbers 1 to 10 on it. As you go through the game you collect cards with life events on them (e.g. give birth to a baby girl, take out a $10,000 mortgage, etc.). The game board also has small mountains and other similar pieces, so the board does not appear flat. The player with the most money at the end of the game wins.

The game was endorsed by Art Linkletter in the 1960s and was updated in 1992 to reward players for "good" behavior, such as recycling trash. It is now part of the permanent collection of the Smithsonian's National Museum of American History.

It should not be confused with the cellular automaton devised by mathematician John Conway, for which see Conway's Game of Life.

Source: adapted by the editor from Wikipedia, the free encyclopedia under a copyleft GNU Free Documentation License (GFDL) from the article "Hasbro's Game of Life."

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Life

(From Wikipedia, the free Encyclopedia)

simple:Life

Alternate meanings: Conway's Game of Life, Hasbro's Game of Life, personal life, Life magazine, Life imprisonment

Life is a primarily biological concept with no simple definition.

Attempts to define the concept of life

The conventional definition

An entity is usually considered to be alive if it exhibits the following phenomena at least once during its existence:

• Growth
• Metabolism, consuming, transforming and storing energy; growing by absorbing and reorganizing mass; excreting waste
• Motion, either moving itself, or having internal motion
• Reproduction, the ability to create roughly exact copies of itself
• Stimulus response, the ability to measure properties of its surrounding environment, and act on certain conditions

Controversially, according to this definition,

• fire is alive. (This could be remedied by adding the requirement of locality, where there is an obvious feature that delineates the spatial extension of the living being (such as a cell membrane).)
• a mule is not alive. (It cannot reproduce and produce a mule.)
• virii are not alive. (They cannot grow or evince behavior.)

Other definitions

Other definitions include:

• Lynn Margulis's definition of life as an autopoietic (self-producing), water based, lipid-protein bound, carbon metabolic, nucleic acid replicated, protein readout system
• "a system of inferior negative feedbacks subordinated to a superior positive feedback" (J. theor Biol. 2001)
• "functional organization for sustaining self and kind, involving active use of energy and information replication (respectively)" (Human Knowledge: Foundations and Limits, which classifies about twenty-five categories of replicating or self-sustaining phenomena)
• Tom Kinch's definition of life as a highly organized auto-cannibalizing system naturally emerging from conditions common on planetary bodies, and consisting of a population of replicators capable of mutation, around each set of which a homeostatic metabolizing organism, which actively helps reproduce and/or protect the replicator(s), has evolved
• Stuart Kauffman's definition of life as an autonomous agent or autonomous agents capable of reproducing itself or themselves, and of completing at least one thermodynamic work cycle

Descent with modification: a "useful" characteristic

A useful characteristic upon which to base a definition of life is that of descent with modification: the ability of a life form to produce offspring that are like it, but that also have the possibility of random variations. This characteristic alone is sufficient to allow evolution, assuming the variations in the offspring allow for differential survivability. The study of this form of heritability is called genetics, and in all known life forms, with the exception of prions, the genetic material is primarily DNA, or the related molecule, RNA. Another exception might be the software code of certain forms of virii and programs created through genetic programming, but whether computer programs can be alive even by this definition is still a matter of some contention.

Exceptions to the common definiton

Note that many individual organisms are incapable of reproduction and yet are still generally considered to be "alive;" see mules and ants for examples. However, these exceptions can be accounted for by applying the definition of life on the level of entire species or of individual genes. (For example, see kin selection for information about one way by which non-reproducing individuals can still enhance the spread of their genes and the survival of their species.)

Virii reproduce, flames grow, some software programs mutate and evolve, future software programs will probably evince (even high-order) behavior, machines move, and proto-life, consisting of metabolizing cells without reproduction apparatus, can have existed. Still, some would not call these entities alive. Generally, all six characteristics are required for a population to be considered alive.

The possibility of extraterrestrial life

As of 2003, Earth is the only planet in the universe known by humans to support life. The question of whether life exists elsewhere in the universe remains an open question, although the probability that Earth is the only location in the universe, or even the galaxy, that harbors life, is extremely low. There have been a number of false alarms of life elsewhere in the universe, but none of these apparent discoveries have so far survived scientific scrutiny.

Currently, the closest that scientists have come to finding extraterrestrial life is fossil evidence of possible bacterial life on Mars. There also may be simple life forms on Jupiter's moons.

Other facts

All life on Earth is based on the chemistry of carbon compounds. Some assert that this must be the case for all possible forms of life throughout the universe; others describe this position as 'carbon chauvinism'.

The most successful animal of the earth, in terms of biomass, is the Antarctic krill, Euphausia superba, with a biomass of probably over 500 million tonnes.

Lifespan is the length of life in each species. Death is the termination of life in a living system, or in part thereof. Some people think that life was created by God or gods.

Related articles

• Meaning of life
• Vitalism
• Materialism
• Artificial life
• Value of life
• Afterlife

Reference

• Kauffman, Stuart. The Adjacent Possible: A Talk with Stuart Kauffman. Retrieved Nov. 30, 2003 from [http://www.edge.org/3rd_culture/kauffman03/kauffman_index.html]" class="external">[1]

External link

• "The Adjacent Possible: A Talk with Stuart Kauffman"

  Source: adapted by the editor from Wikipedia, the free encyclopedia under a copyleft GNU Free Documentation License (GFDL) from the article "Life."

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Life magazine

(From Wikipedia, the free Encyclopedia)

Life is a photojournalism magazine, founded by Henry Luce in 1936 (first issue dated November 23). Originally published weekly, Life became a monthly magazine in 1971 and ceased monthly publication in 2000. It is now published frequently as a special graphic paperback book, referred to by Life as a "megazine".

Life is now owned by AOL Time Warner. Life publication's mission was "to see life; see the world". Life has presented some of the lasting iconic images of the world's notable events. Archival issues of Life are a source of photographic history.

List of LIFE magazine's 10 most important events of the last millennium

LIFE magazine tried to rank the top 10 events of the millennium:

1. Bookprint (Johann Gutenberg, 1455)
2. Discovery of New World (Christopher Columbus, 1492)
3. A new major religion (Martin Luther, 1527)
4. Steam engine starts industrial revolution (James Watt, 1769)
5. Earth revolves around sun (Galileo Galilei, 1610)
6. Germ theory of disease (Louis Pasteur, 1864; Robert Koch,1876)
7. Gunpowder weapons (China, 1100)
8. Declaration of independence (US, 1776)
9. Adolf Hitler comes to power (1933)
10. Compass goes to sea (China, 1117)

This list has been critisized for being too focused on Western achievements. For example, the Chinese also invented a variant of book print long before Gutenberg, and until the mid 18th century the bulk of the world's printed material was Chinese.

List of LIFE magazine's 100 most important people of the last millennium

The list above stands in odd contrast to another, even more critisized list of the US-magazine which unexpectedly placed Edison (a US inventor) first in the "100 Most Important People in the Last 1000 Years". Predictably, this has been dubbed overblown patriotism, since even during Edison's lifetime there were non-US inventors whose inventions (combustion engine, car, electricity-making machines, etc) had greater impact than Edison's. The top 100 list was further ridiculed for mixing truly outstanding heroes of mankind, such as Newton and Einstein and Luther and da Vinci, with numerous Americans largely unknown outside the US:

1. Thomas Edison
2. Christopher Columbus
3. Martin Luther
4. Galileo Galilei
5. Leonardo Da Vinci
6. Isaac Newton
7. Ferdinand Magellan
8. Louis Pasteur
9. Charles Darwin
10. Thomas Jefferson
11. William Shakespeare
12. Napoleon Bonaparte
13. Adolf Hitler
14. Zheng He
15. Henry Ford
16. Sigmund Freud
17. Richard Arkwright
18. Karl Marx
19. Nicolaus Copernicus
20. Orville and Wilbur Wright
21. Albert Einstein
22. Mohandas Gandhi
23. Kublai Khan
24. James Madison
25. Simon Bolivar
26. Mary Wollstonecraft
27. Guglielmo Marconi
28. Mao Zedong
29. Vladimir Lenin
30. Martin Luther King Jr
31. Alexander Graham Bell
32. Rene Descartes
33. Ludwig Van Beethoven
34. Thomas Aquinas
35. Abraham Lincoln
36. Michelangelo
37. Vasco Da Gama
38. Suleyman the Magnificent
39. Samuel F. B. Morse
40. John Calvin
41. Florence Nightingale
42. Hernan Cortes
43. Joseph Lister
44. Ibn Battuta
45. Zhu Xi
46. Gregor Mendel
47. John Locke
48. Akbar
49. Marco Polo
50. Dante Alighieri
51. John D. Rockefeller
52. Jean Jacques Rousseau
53. Niels Bohr
54. Joan of Arc
55. Frederick Douglass
56. Louis XIV of France
57. Nikola Tesla
58. Immanuel Kant
59. Fan Kuan
60. Otto von Bismarck
61. William the Conqueror
62. Guido of Arezzo
63. John Harrison
64. Pope Innocent III
65. Hiram Maxim
66. Jane Addams
67. Cao Xueqin
68. Matteo Ricci
69. Louis Armstrong
70. Michael Faraday
71. Ibn Sina
72. Simone de Beauvoir
73. Jalal al-Din Muhammad Rumi
74. Adam Smith
75. Marie Curie
76. Andrea Palladio
77. Peter the Great
78. Pablo Picasso
79. Louis Jacques Mande Daguerre
80. Antoine Laurent Lavoisier
81. Phineas Taylor Barnum
82. Edwin Hubble
83. Susan B. Anthony
84. Raphael
85. Helen Keller
86. Hokusai
87. Theodor Herzl
88. Elizabeth I of England
89. Claudio Monteverdi
90. Walt Disney
91. Nelson Mandela
92. Roger Bannister
93. Leo Tolstoy
94. John Von Neumann
95. Santiago Ramon y Cajal
96. Jacques Cousteau
97. Catherine de Medici
98. Ibn Khaldun
99. Kwame Nkrumah
100. Carolus Linnaeus

External links

• Life
• Life's Millennium list I
• Life's Millennium list II

  Source: adapted by the editor from Wikipedia, the free encyclopedia under a copyleft GNU Free Documentation License (GFDL) from the article "Life magazine."

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Organism

(From Wikipedia, the free Encyclopedia)

An organism is a living being.

The origin of life and the relationships between its major lineages are controversial. Two main grades may be distinguished, the prokaryotes and eukaryotes. The prokaryotes are generally considered to represent two separate domains, called the Bacteria and Archaea, which are not closer to one another than to the eukaryotes. The gap between prokaryote and eukaryotes is widely considered as a major missing link in evolutionary history. Two eukaryotic organelles, namely mitochondria and chloroplasts, are generally considered to be derived from endosymbiotic bacteria.

The phrase complex organism describes any organism with more than one cell.

Characteristics common to many organisms include:

• Movement
• Feeding
• Respiration
• Growth
• Reproduction
• Sensitivity to stimuli

These are not universal, however. Many organisms are incapable of independent movement, and do not respond directly to their environment. Bacteria may not conduct respiration, using alternate chemical pathways instead. And many organisms are incapable of reproduction.

Biological Organization

• Atoms
  • Molecule
    • Macromolecule
      • Organelle
        • Cell
          • Tissue
            • Organ
              • Organ System
                • Organsism

Environmental Organization

• Population
  • Comunity
    • Ecosystem
      • Biosphere

Classification

The following articles are entry points for information about the classification of organisms:

• Scientific classification
• Binomial nomenclature
• species
• subspecies

Viruses

Viruses are not typically considered to be organisms because they are not capable of independent reproduction or metabolism. This is problematic, though, since some parasites and endosymbionts are incapable of independent life either. Although viruses do have enzymes and molecules characteristic of living organisms, they are incapable of surviving outside a host cell and most of their metabolic processes require a host and its 'genetic machinery'. The origin of such parasites is uncertain, but it appears most likely that they are derived from their hosts.

Life span

One of the basic parameters of organism is its life span. Some animals live as short as one day, while some plants can live thousands of years. Aging is important when determining life span of most organisms, bacterium, a virus or even a prion.

See also

Biology

microorganism

External links

• NCBI Taxonomy entry: root (rich)
• NCBI Taxonomy resources (rich)
• Species 2000 Indexing the world's known species. Species 2000 has the objective of enumerating all known species of plants, animals, fungi and microbes on Earth as the baseline dataset for studies of global biodiversity. It will also provide a simple access point enabling users to link from here to other data systems for all groups of organisms, using direct species-links.
• The Tree of Life. Its basic goals are:
  • to provide a uniform and linked framework in which to publish electronically information about the evolutionary history and characteristics of all groups of organisms
  • to present a modern scientific view of the evolutionary tree that units all organisms on Earth
  • to aid education about and appreciation of biological diversity
  • to provide (eventually) a life-wide database and searching system about characteristics of organisms
  • to provide a means to find taxon-specific information on the Internet, both taxonomic and otherwise
• Green Plant Phylogeny, Research Coordination Group, "DEEP GREEN", Understanding the Diversity of Plants. A five-year effort to reconstruct the evolutionary relationships among all green plants has resulted in the most complete "tree of life" of any group of living things on the planet, including animals.
• BBC News, August 4, 1999: The mother of all plants. Scientists have discovered that every plant species alive on land today shares a single common ancestor, at least 450 million years old.
• 7 August, 2000, Fantastic fungus find Citat: "...Researchers in the US have found what is probably the largest living organism on Earth....Scientists say it covers 890 hectares (2,200 acres) of land - an area equivalent to about 1,220 football pitches. The fungus is called Armillaria ostoyae, but is more popularly known as the honey mushroom. This particular specimen is calculated to be about 2,400 years old, although it could be two to three times this age...."
• BBCNews: 27 September, 2000, When slime is not so thick Citat: "...It means that some of the lowliest creatures in the plant and animal kingdoms, such as slime and amoeba, may not be as primitive as once thought...."
• BBCNews, 4 December, 2002, Life 'began on the ocean floor'
  • SpaceRef.com, July 29, 1997: Scientists Discover Methane Ice Worms On Gulf Of Mexico Sea Floor
    • The Eberly College of Science: Methane Ice Worms discovered on Gulf of Mexico Sea Floor download Publication quality photos
  • Artikel, 2000: Methane Ice Worms: Hesiocaeca methanicola. Colonizing Fossil Fuel Reserves
  • SpaceRef.com, May 04, 2001: Redefining "Life as We Know it" Hesiocaeca methanicola In 1997, Charles Fisher, professor of biology at Penn State, discovered this remarkable creature living on mounds of methane ice under half a mile of ocean on the floor of the Gulf of Mexico.
• BBCNews, 18 December, 2002, 'Space bugs' grown in lab Citat: "...Bacillus simplex and Staphylococcus pasteuri...Engyodontium album...The strains cultured by Dr Wainwright seemed to be resistant to the effects of UV - one quality required for survival in space...."
• BBCNews, 19 June, 2003, Ancient organism challenges cell evolution Citat: "..."It appears that this organelle has been conserved in evolution from prokaryotes to eukaryotes, since it is present in both,"..."
• Saint Anselm College: Survey of representatives of the major Kingdoms Citat: "...Number of kingdomss has not been resolved...Bacteria present a problem with their diversity...Protista present a problem with their diversity...", Interactive Syllabus for General Biology - BI 04, Saint Anselm College, Summer 2003
• Jacob Feldman: Stramenopila

  Source: adapted by the editor from Wikipedia, the free encyclopedia under a copyleft GNU Free Documentation License (GFDL) from the article "Organism."

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Personal life

(From Wikipedia, the free Encyclopedia)

This article concentrates on life as a concept in popular culture and sociology. For other senses of "life" (such as life in the biological sense), see life.

Life or personal life or human existence refers to the pleasant or alarming idea that each individual human runs a personal private career during their lifespan, based on the principles of free will. We find this notion very commonly in modern existence, and a swathe of service industries stands ready to help the hapless run their "lives" through counselling or even through life coaching.

A "life" as a whole may seem "good" or "bad". It (or part of it) may find literary reflection in a biography, an autobiography or a memoir. Some outstanding lives merit hagiography or a vita.

The career from birth to death need not appear as a uniform "daily life". Thus people speak of their "intellectual lives", their "workinging lives", their "family lives" and (particularly) their "sex lives". The religiously inclined may have "spiritual lives" or "religious lives" intertwined with their everyday activities; they may also expect an afterlife (for some the most important thing). In the interim, those who can afford to do so may adopt a lifestyle or assess their quality of life.

Continual doubts, however, may assail the would-be life-conductor. Acquaintances will encourage such to "get a life" -- in the sense of promoting fuller participation in human (especially socially approved) activities. Coercive state or corporate agencies will encourage alleged "individuals" to submerge themselves in collective wholes: mass movements or teams. For so widespread a concept, personal life may seem precarious.

Compare Physical quality of life index

Source: adapted by the editor from Wikipedia, the free encyclopedia under a copyleft GNU Free Documentation License (GFDL) from the article "Personal life."

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Abbreviations & Acronyms: Life

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Synonyms within Context: Life

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Modern Usage: Life

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Commercial Usage: Life

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Image Slideshow: Life

Photos: Life More pictures...

Illustrations: Life More pictures...

Computer Images: Life More pictures...

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Photo Album: Life

Thumbnail	Description & Credit	Thumbnail	Description & Credit
	The human immunodeficiency virus (HIV-I) enters the T-lymphocyte where the virus loses its outer envelop, releasing its RNA and its reverse transcriptase. The reverse transcriptase builds a complimentary DNA strand from the viral RNA template. The DNA helix is inserted into the host genome. When this is transcribed by the infected cell, the new viral RNA and proteins are produced to form new viruses that then bud from the cell membrane, thus completing the life cycle of the virus. See artwork: GR-32. Credit: Trudy Nicholson (artist).		Vials of serum hold information about nutrition, health, disease patterns and life styles. Credit: CDC.
	Salmonella typhosus, also known as Eberthella typhi and Bacillus typhosus, is the cause of Typhoid fever. This life threatening disease is characterized by fever, headache, malaise, anorexia, splenomegaly, and a relative bradycardia. Credit: CDC.		Advanced Life Support System. Credit: NASA.
	Life Cycle of Stars. Credit: NASA.		Ham Tries Out His Life Support System. Credit: NASA.
	In the beginning of the 1946 holiday film classic "It's a Wonderful Life," angelic figures ... Credit: NASA.		This oddly shaped object is an aging, Sun-like star near the end of its life. The Hubble ... Credit: NASA.
	Life imitating art in the Indian Ocean - celestial navigation Very similar to Winslow Homer print of navigators on Georges Bank Navigating on the PIONEER. Credit: Coast & Geodetic Survey Historical Image Collection.		Whistler's Anacapa Island engraving from a William B. McMurtrie sketch The seagulls were added to give life to an otherwise sterile landscape. Credit: Coast & Geodetic Survey Historical Image Collection.
Source: pictures compiled by the editor from various references; see picture credits.

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Digital Photo Gallery: Life
 

"Accelerated life" by Ozgur Atmaca Commentary: "Istanbul / beyoglu A.V. : F4.0 S.S. : 8.0" E.V. :+1.3 ."	"College Life" by Tom Spitznas Commentary: "Another shot of a college campus."
Source: photographs selected by the editor, with permission from the photographers.

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Sounds Captioned with "Life".

Play	Caption
	Vapid; empty; no life forms; lifeless; uninhabited; vast; space.
Source: compiled by the editor from various references; see credits.

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Familiar Quotations: Life

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Historic Usage: Life

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Use in Literature: Life