Earth

File:Artw 17.jpg

View of the Earth as seen by the Apollo 17 crew traveling toward the moon. This translunar coast photograph extends from the Mediterranean Sea area to the Antarctica south polar ice cap. This is the first time the Apollo trajectory made it possible to photograph the south polar ice cap. Note the heavy cloud cover in the Southern Hemisphere. Almost the entire coastline of Africa is clearly visible. The Arabian Peninsula can be seen at the northeastern edge of Africa. The large island off the coast of Africa is the Malagasy Republic. The Asian mainland is on the horizon toward the northeast.

Description

The Earth is the third planet from the Sun. It is approximately 8,000 miles (13,000 km) in diameter, which means that 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).[1] 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. 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 (just as Venus is) while if Earth were slightly further away from the Sun, water would freeze and life would be impossible.

Evolutionary view

Estimates by geologists of the age of the Earth give about 4.55 billion years. This estimate is primarily based on radioactive dating of meteorites. The extreme majority of scientists conclude that the Earth formed by natural processes, specifically by the accumulation of debris orbiting the sun billions of years in the past. Indeed, astronomers have detected dust lanes around other stars that indicate planet formation is a common and ongoing process.

Young Earth Creationist view

Young Earth creationists believe, as Biblical chronology suggests, that the Earth was created around 6,000 years ago. Mainstream scientific journals do not publish these views, because they are ideologically opposed to them.

Some Biblical literalists also dispute the idea that the Earth Rotates around the sun. Biblical passages used to support this view include:

• "He has fixed the earth firm, immovable." (1 Chronicles 16:30)
• "Thou hast fixed the earth immovable and firm ..." (Psalm 93:1)
• "Thou didst fix the earth on its foundation so that it never can be shaken." (Psalm 104:5)
• "...who made the earth and fashioned it, and himself fixed it fast..." (Isaiah 45:18)

Most creationists reject that these passages are teaching that the Earth is fixed in space with all else revolving around it.

Christianity and the Earth

Uniformitarian scientists believe that the earth is beyond 4 billion years old. 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.

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. 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.’" Furthermore, it should be noted that Barr himself rejects supernatural Christianity, and so is not a priori biased in favor of creationism.

Many Christians believe that the Earth is the perfect distance away from the Sun and take this to be evidence of God's existence. Secular scientists, however, reject this reasoning using the anthropic principle.