Earth | |
---|---|
Symbol | |
Orbital characteristics | |
Primary | Sun |
Order from primary | 3 |
Perihelion | 147,090,000 km (0.983 AU)[1] |
Aphelion | 152,100,000 km (1.017 AU)[1] |
Semi-major axis | 149,597,886.5 km (1.00000011 AU)[1] |
Titius-Bode prediction | 1.0 AU |
Orbital eccentricity | 0.01671022[1] |
Sidereal year | 365.256366 da[1] |
Synodic year | 365.256366 da |
Avg. orbital speed | 29.783 km/s[1] |
Inclination | 0° to the ecliptic |
Rotational characteristics | |
Sidereal day | 23.9345 h[1] |
Solar day | 24 h[1] |
Rotational speed | 465.11 m/s |
Axial tilt | 23.439281° |
Physical characteristics | |
Mass | 5.9736 * 1024 kg[1] |
Density | 5,515.3 kg/m³[1] |
Mean radius | 6371 km[1][2] |
Equatorial radius | 6378.135 km[1] |
Polar radius | 6356.750 km[1] |
Surface gravity | 9.780327 m/s² |
Escape speed | 11.186 km/s |
Surface area | 510,065,600 km² |
Land area | 148,939,100 km² |
Water area | 361,126,400 km² |
Minimum temperature | 185 K |
Mean temperature | 287 K |
Maximum temperature | 331 K |
Number of moons | 1 |
Composition | Rock |
Albedo | 0.37[1] |
Magnetosphere | |
Magnetic flux density | 0.3076 G[1] |
Magnetic dipole moment at present | 7.98 * 1022 N-m/T[3] |
Magnetic dipole moment at creation | 1.41 * 1024 N-m/T[4] |
Decay time | 2049 a[4] |
Half life | 1420 a[3] |
The Earth is the third planet in the Solar System. It is the largest of the terrestrial planets[5] and is the only known planet which has life as we know it. The surface of the planet is approximately two-thirds covered in water. The atmosphere is roughly 78% nitrogen, 21% oxygen and 0.9% argon with the remaining 0.1% being made of water vapor, carbon dioxide, and other elements. Some Biblical scholars have calculated that the earth is around 6000 years old, using the genealogical information provided in Genesis. Some biblically illiterate scientists, however, disagree with this method of calculation, falsely predicting it to be 4.5 billion years old.[6] (See also: Age of the Earth).
Within the Solar System, Earth is the third planet from the Sun. It is approximately 8,000 miles (13,000 km) in diameter; its equatorial circumference (measured around the equator) is 24,901 miles (40,075 kilometers), and the polar circumference is slightly less at 24,809 miles (40,008 km).[7] The reason its metric circumference is so close to the "round number" of 40,000 is that the kilometer was defined (by the French) as 1/10,000th the distance from the Equator to the North Pole.
Its surface area is approximately 4·π (4000 mi)2 = 200 million square miles (510 million km2). It has been said that Earth should really be called "water", as the larger part of it—about 70%—is covered by water. In fact, the Pacific and Indian oceans alone cover about half of the Earth's surface.
The Earth orbits at an average distance of about 93 million miles (150 million km) from the Sun in an almost circular orbit. The plane of this orbit, or ecliptic, is the common reference plane for the inclinations of the orbits of all planets and dwarf planets in the Solar System, though in fact Earth's orbit is inclined 7.25° to the plane of the Sun's equator. It takes light (and other forms of electromagnetic radiation) approximately 500 seconds to travel from the Sun to the Earth, i.e. the distance can also be stated as "500 light-seconds." The distance to nearby stars is made by measuring the stellar parallax between observations when the earth is at opposite ends of its orbit, so the Earth's orbit itself is a measuring stick for astronomical distances, and is known as the astronomical unit (A. U.) It is worth noting that if the Earth were slightly closer to the Sun, it would be too hot for life while if Earth were slightly further away from the Sun, water would freeze and life as we know it would be impossible.
People disagree about when and how the Earth was created. The three most popular ideas are:
Clashes between adherents of these ideas have gone on since time immemorial (see origins debate), though the last theory has only matured in the last 200 years.
Young Earth creationists believe, on the basis of the biblical account in Genesis and biblical geochronologies, that the entire Earth, including animal, plant, and human life, was formed in six days, around 4000 B.C. Mainstream scientific journals, committed to a naturalistic worldview, contend this view.[8][9][10][11]
Most scientists believe that the Earth formed by natural processes instead of having been created by a supernatural entity. However, as one scientist noted, “... most every prediction by theorists about planetary formation has been wrong.” [12]
Earth is surrounded by a magnetic field powerful enough to prevent most of the Sun's radiation from reaching the Earth and harming the life on it. This field has been decaying at a known exponential rate, as decades of recordkeeping reveal. In 1984, Dr. Russell Humphreys developed a model for the creation of magnetic fields[4] that suggests that the Earth was at first made entirely of water,[13] much of which God transmuted into other elements after He made the Earth, probably on the third day of Creation. Humphreys's predicted magnetic decay time for the Earth agrees well with published data and thus constitutes further evidence for a young Earth.
Some people dispute the shape of the Earth, arguing that the Bible describes the Earth as flat (presumably square, given that it is described as having "four corners" (Revelations 7:1) ) rather than spherical. However, no credible organization has ever expressed support for this theory.[14] Some have disputed the idea that the Earth rotates around the Sun.[15]
In Revelations 7:1 it is stated: "And after these things I saw four angels standing on the four corners of the earth". A sphere has no corners. The four corners are also mentioned in Isaiah 11:12. This is often accepted to be a figure of speech.
It is also stated:
"Then was the iron, the clay, the brass, the silver, and the gold, broken to pieces together, and became like the chaff of the summer threshing floors; and the wind carried them away, that no place was found for them: and the stone that smote the image became a great mountain, and filled the whole earth." (Daniel 2:35)
AND
"Thus were the visions of mine head in my bed; I saw, and behold a tree in the midst of the earth, and the height thereof was great. The tree grew, and was strong, and the height thereof reached unto heaven, and the sight thereof to the end of all the earth:" (Daniel 4:10-11)
AND
"Behold, [Jesus] cometh with clouds; and every eye shall see him" (Revelations 1:7)
AND
"Once again, the devil took him to a very high mountain, and showed him all the kingdoms of the world [cosmos] in their glory." (Matthew 4:8). Apologist JP Holding's suggests this may have been a vision.[16]
According to Creation Ministries International, most young earth creationists use a hermeneutic "best described as the historical-grammatical method in which historical narrative (such as the book of Genesis) is interpreted as literal history, prophecy is interpreted as prophecy, poetry is interpreted as poetry, etc."[17] Creation Ministries International further states that "Historical-grammatical exegesis involves a systematic approach to analyzing in detail the historical situation, events and circumstances surrounding the text, and the semantics and syntactical relationships of the words which comprise the text."[18]
Bible scholars have estimated the age of the earth based on the Creation account in Genesis and the genealogical accounts in Numbers and other books of the Pentateuch. One famous estimate was published in 1650 by James Ussher Archbishop of Armagh in a book called Annals of the World, in which he estimated the Creation to have occurred on 23 October 4004 B.C. Other Biblical scholars maintain that there are possible gaps in the genealogies, often using the ideas of the 19th century Calvinist theologian Benjamin Warfield on the issue.[19] However, James Barr, regius professor of Hebrew at Oxford University, wrote in 1984 the following: "… probably, so far as I know, there is no professor of Hebrew or Old Testament at any world-class university who does not believe that the writer(s) of Genesis 1–11 intended to convey to their readers the ideas that: … the figures contained in the Genesis genealogies provided by simple addition a chronology from the beginning of the world up to later stages in the biblical story.’" [20] Furthermore, it should be noted that Barr himself rejects supernatural Christianity, and so is not a priori biased in favor of creationism.[21]
Many Christians believe that the Earth is the perfect distance away from the Sun and take this to be evidence of God's existence.[22] Secular scientists, however, reject this reasoning using the anthropic principle.[23]
Many mainstream Christian denominations believe the story of Genesis is not meant to be read literally, and believe that the age of the Earth is on the order of millions or billions of years, not thousands of years.[24]
Uniformitarian scientists believe that the earth is beyond 4 billion years old.[25] They also refute that the Earth is only 6,000 years old by quoting older human societies dated by their dating method as older than that.[26]
Estimates by uniformitarian geologists of the age of the Earth and the beginning of life give about 4.55 billion years and 3.5 billion years ago respectively. These estimates are primarily based on radioactive dating of meteorites and fossil specimens. Most scientists today conclude that the Earth formed by natural processes, specifically by the accumulation of debris orbiting the sun billions of years in the past.[27]
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