Sunday, May 4, 2008

Nature


Nature, in the broadest sense, is equivalent to the natural world, physical universe, material world or material universe. "Nature" refers to the phenomena of the physical world, and also to life in general. Manufactured objects and human interaction are not considered part of nature unless qualified in ways such as "human nature" or "the whole of nature". Nature is generally distinguished from the supernatural. It ranges in scale from the subatomic to the galactic.

The word nature is derived from the Latin word natura, or "the course of things, natural character."[1] Natura was a Latin translation of the Greek word physis (φύσις), which originally related to the intrinsic characteristics that plants, animals, and other features of the world develop of their own accord.[2] This is shown in the first written use of the word φύσις, in connection with a plant.[3] The concept of nature as a whole, the physical universe, is one of several expansions of the original notion; it began with certain core applications of the word φύσις by pre-Socratic philosophers, and has steadily gained currency ever since. This usage was confirmed during the advent of modern scientific method in the last several centuries.[4][5]

Within the various uses of the word today, "nature" may refer to the general realm of various types of living plants and animals, and in some cases to the processes associated with inanimate objects – the way that particular types of things exist and change of their own accord, such as the weather and geology of the Earth, and the matter and energy of which all these things are composed. It is often taken to mean the "natural environment" or wilderness – wild animals, rocks, forest, beaches, and in general those things that have not been substantially altered by human intervention, or which persist despite human intervention. This more traditional concept of natural things which can still be found today implies a distinction between the natural and the artificial, with the latter being understood as that which has been brought into being by a human or human-like consciousness or mind.


Painting by Song Dynasty artist Fan Kuan (c. 970–1020).

Beauty in nature has long been a common theme in life and in art, and books emphasizing beauty in nature fill large sections of libraries and bookstores. That nature has been depicted and celebrated by so much art, photography, poetry and other literature shows the strength with which many people associate nature and beauty. Why this association exists, and what the association consists of, is studied by the branch of philosophy called aesthetics. Beyond certain basic characteristics that many philosophers agree about to explain what is seen as beautiful, the opinions are virtually endless.[67]

Looked at through the lens of the visual arts, nature and wildness have been important subjects in various epochs of world history. An early tradition of landscape art began in China during the Tang Dynasty (618-907). The tradition of representing nature as it is became one of the aims of Chinese painting and was a significant influence in Asian art. Artists learned to depict mountains and rivers "from the perspective of nature as a whole and on the basis of their understanding of the laws of nature … as if seen through the eyes of a bird." In the 13th century, the Song Dynasty artist Shi Erji listed "scenes lacking any places made inaccessible by nature," as one of the 12 things to avoid in painting.[68]

In the Western world the idea of wilderness having intrinsic value emerged in the 1800s, especially in the works of the Romantic movement. British artists John Constable and JMW Turner turned their attention to capturing the beauty of the natural world in their paintings. Before that, paintings had been primarily of religious scenes or of human beings. William Wordsworth’s poetry described the wonder of the natural world, which had formerly been viewed as a threatening place. Increasingly the valuing of nature became an aspect of Western culture.[69] This artistic movement also coincided with the Transcendentalist movement in the Western world.

Many scientists, who study nature in more specific and organized ways, also share the conviction that nature is beautiful; the French mathematician, Jules Henri Poincaré (1854-1912) said:

The scientist does not study nature because it is useful; he studies it because he delights in it, and he delights in it because it is beautiful.
If nature were not beautiful, it would not be worth knowing, and if nature were not worth knowing, life would not be worth living. Of course I do not here speak of that beauty which strikes the senses, the beauty of qualities and of appearance; not that I undervalue such beauty, far from it, but it has nothing to do with science; I mean that profounder beauty which comes from the harmonious order of the parts and which a pure intelligence can grasp.[70]

A common classical idea of beautiful art involves the word mimesis, the imitation of nature. Also in the realm of ideas about beauty in nature is that the perfect is implied through symmetry, equal division, and other perfect mathematical forms and notions

Beauty in nature


Beauty in nature

Salmon fry hatching.  The root of the Latin   "natura" {"nature") is "natus," from "nasci" ("to be born").

Salmon fry hatching. The root of the Latin "natura" {"nature") is "natus," from "nasci" ("to be born").[66]

Painting by Song Dynasty artist Fan Kuan (c. 970–1020).

Painting by Song Dynasty artist Fan Kuan (c. 970–1020).

Beauty in nature has long been a common theme in life and in art, and books emphasizing beauty in nature fill large sections of libraries and bookstores. That nature has been depicted and celebrated by so much art, photography, poetry and other literature shows the strength with which many people associate nature and beauty. Why this association exists, and what the association consists of, is studied by the branch of philosophy called aesthetics. Beyond certain basic characteristics that many philosophers agree about to explain what is seen as beautiful, the opinions are virtually endless.[67]

Looked at through the lens of the visual arts, nature and wildness have been important subjects in various epochs of world history. An early tradition of landscape art began in China during the Tang Dynasty (618-907). The tradition of representing nature as it is became one of the aims of Chinese painting and was a significant influence in Asian art. Artists learned to depict mountains and rivers "from the perspective of nature as a whole and on the basis of their understanding of the laws of nature … as if seen through the eyes of a bird." In the 13th century, the Song Dynasty artist Shi Erji listed "scenes lacking any places made inaccessible by nature," as one of the 12 things to avoid in painting.[68]

In the Western world the idea of wilderness having intrinsic value emerged in the 1800s, especially in the works of the Romantic movement. British artists John Constable and JMW Turner turned their attention to capturing the beauty of the natural world in their paintings. Before that, paintings had been primarily of religious scenes or of human beings. William Wordsworth’s poetry described the wonder of the natural world, which had formerly been viewed as a threatening place. Increasingly the valuing of nature became an aspect of Western culture.[69] This artistic movement also coincided with the Transcendentalist movement in the Western world.

Many scientists, who study nature in more specific and organized ways, also share the conviction that nature is beautiful; the French mathematician, Jules Henri Poincaré (1854-1912) said:

The scientist does not study nature because it is useful; he studies it because he delights in it, and he delights in it because it is beautiful.
If nature were not beautiful, it would not be worth knowing, and if nature were not worth knowing, life would not be worth living. Of course I do not here speak of that beauty which strikes the senses, the beauty of qualities and of appearance; not that I undervalue such beauty, far from it, but it has nothing to do with science; I mean that profounder beauty which comes from the harmonious order of the parts and which a pure intelligence can grasp.[70]

A common classical idea of beautiful art involves the word mimesis, the imitation of nature. Also in the realm of ideas about beauty in nature is that the perfect is implied through symmetry, equal division, and other perfect mathematical forms and notions.

Matter and energy


Matter and energy

Main articles: Matter and Energy

The first few hydrogen atom electron orbitals shown as cross-sections with color-coded probability density

Some fields of science see nature as matter in motion, obeying certain laws of nature which science seeks to understand. For this reason the most fundamental science is generally understood to be "physics"—the name for which is still recognizable as meaning that it is the study of nature.

Matter is commonly defined as the substance of which physical objects are composed. It constitutes the observable universe. According to the theory of special relativity, there is no unchangeable distinction between matter and energy, because matter can be converted to energy (see annihilation), and vice versa (see matter creation). The visible components of the universe are now believed to compose only 4 percent of the total mass. The remainder is believed to consist of 23 percent cold dark matter and 73 percent dark energy.[71] The exact nature of these components is still unknown and is currently under intensive investigation by physicists.

The behavior of matter and energy throughout the observable universe appears to follow well-defined physical laws. These laws have been employed to produce cosmological models that successfully explain the structure and the evolution of the universe we can observe. The mathematical expressions of the laws of physics employ a set of twenty physical constants[72] that appear to be static across the observable universe.[73] The values of these constants have been carefully measured, but the reason for their specific values remains a mystery.

Matter and energy


Matter and energy

Main articles: Matter and Energy

The first few hydrogen atom electron orbitals shown as cross-sections with color-coded probability density

Some fields of science see nature as matter in motion, obeying certain laws of nature which science seeks to understand. For this reason the most fundamental science is generally understood to be "physics"—the name for which is still recognizable as meaning that it is the study of nature

Matter is commonly defined as the substance of which physical objects are composed. It constitutes the observable universe. According to the theory of special relativity, there is no unchangeable distinction between matter and energy, because matter can be converted to energy (see annihilation), and vice versa (see matter creation). The visible components of the universe are now believed to compose only 4 percent of the total mass. The remainder is believed to consist of 23 percent cold dark matter and 73 percent dark energy.[71] The exact nature of these components is still unknown and is currently under intensive investigation by physicists.

The behavior of matter and energy throughout the observable universe appears to follow well-defined physical laws. These laws have been employed to produce cosmological models that successfully explain the structure and the evolution of the universe we can observe. The mathematical expressions of the laws of physics employ a set of twenty physical constants[72] that appear to be static across the observable universe.[73] The values of these constants have been carefully measured, but the reason for their specific values remains a mystery.

Nature beyond Earth



Outer space, also simply called space, refers to the relatively empty regions of the universe outside the atmospheres of celestial bodies. Outer space is used to distinguish it from airspace (and terrestrial locations). There is no discrete boundary between the Earth's atmosphere and space, as the atmosphere gradually attenuates with increasing altitude. Outer space within the solar system is called interplanetary space, which passes over into interstellar space at what is known as the heliopause.

Outer space is certainly spacious, but it is far from empty. Outer space is sparsely filled with several dozen types of organic molecules discovered to date by microwave spectroscopy, blackbody radiation left over from the big bang and the origin of the universe, and cosmic rays, which include ionized atomic nuclei and various subatomic particles. There is also some gas, plasma and dust, and small meteors. Additionally, there are signs of human life in outer space today, such as material left over from previous manned and unmanned launches which are a potential hazard to spacecraft. Some of this debris re-enters the atmosphere periodically.

Although the planet Earth is currently the only known body within the solar system to support life, current evidence suggests that in the distant past the planet Mars possessed bodies of liquid water on the surface.[74] For a brief period in Mars' history, it may have also been capable of forming life. At present though, most of the water remaining on Mars is frozen. If life exists at all on Mars, it is most likely to be located underground where liquid water can still exist.[75]

Conditions on the other terrestrial planets, Mercury and Venus, appears to be too harsh to support life as we know it. But it has been conjectured that Europa, the fourth-largest moon of Jupiter, may possess a sub-surface ocean of liquid water and could potentially host life.[76]

Recently, the team of Stéphane Udry have discovered a new planet named Gliese 581 c, which is an extrasolar planet orbiting the red dwarf star Gliese 581. Gliese 581 c appears to lay in the habitable zone of space surrounding the star, and therefore could possibly host life as we know it.

[edit] Nature beyond Earth

NGC 4414, a typical spiral galaxy in the constellation Coma Berenices, is about 56,000 light years in diameter and approximately 60 million light years distant.

NGC 4414, a typical spiral galaxy in the constellation Coma Berenices, is about 56,000 light years in diameter and approximately 60 million light years distant.

The deepest visible-light image of the universe, the Hubble Ultra Deep Field, contains an estimated 10,000 galaxies in a patch of sky just one-tenth the diameter of the full moon. Image Credit: NASA, ESA, S. Beckwith (STScI) and the HUDF team.

The deepest visible-light image of the universe, the Hubble Ultra Deep Field, contains an estimated 10,000 galaxies in a patch of sky just one-tenth the diameter of the full moon. Image Credit: NASA, ESA, S. Beckwith (STScI) and the HUDF team.

Main articles: Outer space and Universe

nateure world life



Outer space, also simply called space, refers to the relatively empty regions of the universe outside the atmospheres of celestial bodies. Outer space is used to distinguish it from airspace (and terrestrial locations). There is no discrete boundary between the Earth's atmosphere and space, as the atmosphere gradually attenuates with increasing altitude. Outer space within the solar system is called interplanetary space, which passes over into interstellar space at what is known as the heliopause.

Outer space is certainly spacious, but it is far from empty. Outer space is sparsely filled with several dozen types of organic molecules discovered to date by microwave spectroscopy, blackbody radiation left over from the big bang and the origin of the universe, and cosmic rays, which include ionized atomic nuclei and various subatomic particles. There is also some gas, plasma and dust, and small meteors. Additionally, there are signs of human life in outer space today, such as material left over from previous manned and unmanned launches which are a potential hazard to spacecraft. Some of this debris re-enters the atmosphere periodically.

Although the planet Earth is currently the only known body within the solar system to support life, current evidence suggests that in the distant past the planet Mars possessed bodies of liquid water on the surface.[74] For a brief period in Mars' history, it may have also been capable of forming life. At present though, most of the water remaining on Mars is frozen. If life exists at all on Mars, it is most likely to be located underground where liquid water can still exist.[75]

Conditions on the other terrestrial planets, Mercury and Venus, appears to be too harsh to support life as we know it. But it has been conjectured that Europa, the fourth-largest moon of Jupiter, may possess a sub-surface ocean of liquid water and could potentially host life.[76]

Recently, the team of Stéphane Udry have discovered a new planet named Gliese 581 c, which is an extrasolar planet orbiting the red dwarf star Gliese 581. Gliese 581 c appears to lay in the habitable zone of space surrounding the star, and therefore could possibly host life as we know it.