I have made other posts on this subject on the Symposium before.....but I believe this one to be a better explanation of "Earth's Age According To Bible And Science"...... to see links to the other posts see click on Spoiler: bottom of page.

Earth's Age According To Bible And Science.....(the link to this excellant article-bottom of page)

Introduction

The age of the earth has been a topic of debate among Christians over the last two centuries. Several Christian ministries promote the idea that the earth is less than 10,000 years old, which they say comes from the Bible. In reality, the Bible makes no claim as to the age of the earth, although it does establish a minimum age. This page examines some of the history of the controversy—what the Bible actually says and does not say—and the scientific evidence surrounding the age of the earth.
Age of the earth according to the Bible

The following is a summary of the biblical evidence presented on this website regarding the age of the earth. For more detailed explanations of each topic, please click on the associated link.

History of the age of the earth

As indicated earlier, the Bible does not fix the age of the earth, contrary to the claims of Answers in Genesis. Historically, their claim comes from the work of James Ussher, Bishop in the Church of Ireland, from 1625 to 1656. Archbishop Ussher took the genealogies of Genesis, assuming they were complete, and calculated all the years to arrive at a date for the creation of the earth on Sunday, October 23, 4004 B.C. Of course, even assuming the method was valid, such an exact date is not possible from the genealogies of the Bible (Ussher assumed all the years the patriarchs lived were exactly 365.25 days long and that they all died the day before their next birthday). There are a number of other assumptions implicit in the calculation. The first, and foremost, assumption is that the genealogies of Genesis are complete, from father to son throughout the entire course of human existence. The second assumption is that the Genesis creation "days" were exactly 24-hours in length. It turns out that both assumptions are false.

Incomplete genealogies

Although Archbishop Ussher assumed the Genesis genealogies were complete, it is clear from the rest of the Bible that those genealogies were telescoped (some names were left out for the sake of brevity), which is common in biblical genealogies but rare in modern genealogies. Similarly, the key genealogical terms (such as "son" and "father") have much broader meanings in Hebrew than their corresponding English words. The Hebrew word translated "son" can also have the meaning of "grandson," "great grandson," "descendant," etc. Likewise, the Hebrew word translated "father" can mean "grandfather," "great grandfather," "ancestor," etc. An accurate understanding of biblical genealogies is difficult, yet it is important for the understanding of Scripture. Having a proper understanding of biblical genealogies is a prerequisite to attempting to address the Genesis genealogies. By cross referencing the biblical genealogies with other events dated in the Bible, one can find instances where numerous genealogies were telescoped, resulting in the exclusion of numerous generations of individuals. When examining individual genealogies, one can find examples where individuals are excluded or added to the lists found in Genesis. The fact that the genealogies of the Bible are given symmetrically (where the numbers of generations in each group are identical) lends credence to the argument that they are representative of generations found throughout human history. More information about the biblical genealogies can be found in our article, The Genesis Genealogies: Are They Complete?

Length of creation days

Most people who read English translations of the Bible assume that the English words have the same meaning as the original languages in which the Bible was written (Hebrew and Aramaic for the Old Testament, and Greek for the New Testament). In fact, the original biblical languages contained many fewer words than modern English, which means that the words in those languages had more different meanings. In the Genesis 1 creation account, each "day" ends as "evening and morning 'n' day," where "n" is the day's number. Although many Christians claim this makes the days exactly 24-hours in length, the Hebrew word translated "day" in English actually has three literal translations; the daylight portion of a 24-hour day, a 24-hour day, and a long, unspecified period of time (as in "day of the dinosaurs"). The Hebrew word translated "evening" also means "sunset," "night" or "ending of the day." The Hebrew word translated "morning" also means "sunrise," "coming of light," "beginning of the day," or "dawning," with possible metaphoric usage. Our English expression: "The dawning of an age" serves to illustrate this point. The intended meaning of the word should be determined from the context. More information and examples can be found in our article Biblical Evidence for Long Creation Days.

24-hour days?

Although some Christians claim the days of creation are exactly 24-hours in length, it is apparent from the literal reading of the Genesis 1 text that this is not so. Two days stand out, in particular. On the third day, God created the plants. The particulars are important, so let's look at what Genesis 1 says:

Then God said, "Let the earth sprout vegetation, plants yielding seed, and fruit trees bearing fruit after their kind, with seed in them, on the earth"; and it was so. And the earth brought forth vegetation, plants yielding seed after their kind, and trees bearing fruit, with seed in them, after their kind; and God saw that it was good. (Genesis 1:11-12)

The interesting part of the account is that God did not create the plants in the manner we might assume He did. Instead of creating a world filled with full-grown plants, God actually created seeds and planted those. We understand this from the word "sprout," which refers to God allowing the earth to produce plants through germination (sprouting). The Hebrew word dasha tells us that God used processes identical to what we see on the earth today. Plants spouted, grew to maturity, and produced seeds. Several kinds of plants are described. The Hebrew word deshe refers primarily to grasses; the word eseb refers primarily to herbs and the words 'peri ets refer' to fruit trees. Some Christians claim that God could have sped up the process so that it all this sprouting and growing happened within a period of 24-hours. However, the text clearly states that the land produced the vegetation and trees. Conjecture about what God could have done to speed up the process have no biblical support and directly contradict what the text actually says. Since fruit trees take several years to mature and produce fruit, the third "day" must have been at least several years long.

The sixth day was also a very busy "day." On the sixth day, God created the nephesh (soulish) animals, including the wild animals (carnivores), cattle (herbivores) and "creeping things" (rodents?) (Genesis 1:25). Then God created Adam, the first man (Genesis 1:27, 2:7). He placed the man into a special garden that He had planted (Genesis 2:. Again, God was playing farmer by planting the garden and letting it grow (Genesis 2:9). Adam was placed into the garden "to work it and take care of it" (Genesis 2:15). We don't know how long Adam worked the garden before God gave him another assignment. However, it wouldn't have been much "work" if Adam was there for less than 24 hours. Next, God had Adam give names to "all the beasts of the field and all the birds of the air" (Genesis 2:19). The process would have required Adam naming tens of thousands of species (minimum). Even naming one animal every ten seconds would have taken Adam several days, at minimum. Then God put Adam to sleep and created Eve from part of Adam's side (Genesis 2:22-23). Adam's response to Eve's creation is also telling, since upon seeing Eve for the first time, Adam said "at last." This is not exactly the response one would have expected from a man who had waited for less than one day (or else Adam was the most impatient man in the history of humanity). So, we must conclude that the sixth day was much longer than 24 hours, and probably took at least several years, based on Adam's response. For more information, see our article Genesis 1: The Literal Interpretation of the Creation Account.

The seventh day

Besides the biblical evidence that at least some of the Genesis "days" are long periods of time, Genesis 2:4 refers to all 6 days of creation as one day:

This is the account of the heavens and the earth when they were created, in the day that the Lord God made earth and heaven. (Genesis 2:4)

In addition, the seventh day of Genesis is not closed:

Then God blessed the seventh day and sanctified it, because in it He rested from all His work which God had created and made. (Genesis 2:3)

In all other days the text says, "there is the evening and the morning, the n day." In the book of Hebrews, the author tells us to labor to enter into God's seventh day of rest.

"For He has thus said somewhere concerning the seventh day, And God rested on the seventh day from all His works"... Let us therefore be diligent to enter that rest, lest anyone fall through following the same example of disobedience. (Hebrews 4:4-11)

By any calculation, God's seventh day of rest from creating has been at least 6,000 years long, since it continues to today. God's seventh day of rest from creating will end when He creates the new heavens and new earth.

Age of humanity

Other than incomplete genealogies, there are other measures of the age of humanity found in the Bible. First, the Bible says that the Lord made a covenant and commanded his law to 1,000 generations:

Remember His covenant forever, The word which He commanded to a thousand generations, (1 Chronicles 16:15)
He has remembered His covenant forever, The word which He commanded to a thousand generations, (Psalm 105:
but showing love to a thousand generations of those who love me and keep my commandments. (Exodus 20:6)
but showing love to a thousand generations of those who love me and keep my commandments. (Deuteronomy 5:10)
Know therefore that the LORD your God is God; he is the faithful God, keeping his covenant of love to a thousand generations of those who love him and keep his commands. (Deuteronomy 7:9)

Unless those generations are only 6 years long, these verses indicate that humanity has been around much longer than 6,000 years. In most instances, a biblical generation is ~40 years long, meaning that human beings have been around for at least 40,000 years.

Another, less accurate way to look at the age of humanity is to compare an early biblical event with earth's natural history. One example is the person Peleg, of whom it is said "for in his days the earth was divided..." (Genesis 10:25) This dividing of the earth was likely a result of the removal of land bridges at the end of the last interglacial period, about 12,000 years ago. During this time, seal levels rose several hundred feet as continental ice sheets melted and flowed into the oceans. Assuming the biblical genealogies were complete, we could calculate that Peleg lived ~4,000 years ago. However, since the dividing of the earth really occurred 12,000 years ago, one can determine that the genealogies represent only one third of the actual generations (12,000 ÷ 4,000). This would place the beginning of humanity at ~24,000 years ago, assuming the missing genealogies are missing at the same rate throughout human history. Since it would seem likely that more of the earlier genealogies are missing, the estimate is likely low, probably being more in line with the biblical 40,000 years.

From a scientific standpoint, I would place the creation of Adam as the first modern human (Homo sapiens sapiens), corresponding with the explosion of sophisticated tool making, art, and religious worship in Europe, about 50,000 years ago. I do not believe that Adam was a Neanderthal, Homo erectus, or other hominid species found in the fossil record, but a fully modern, spiritual human being.

Summary of biblical evidence

Contrary to the calculation of Archbishop Ussher, it seems that the biblical genealogies are telescoped, representing only a small percentage of the actual human generations. Therefore, the time that humanity has existed on earth is in the tens of thousands of years rather than thousands of years. However, humanity was the very last of God's creations, on the sixth days. The days of creation can be shown to be longer than ordinary calendar days, with at least two of the days being years long or longer. So, although the Bible may give us an approximate date for the creation of human beings, we can only guess at how long the other creation "days" are. However, God has given us another "book" that testifies to His power and creative ability—none other than the creation itself. The Bible explicitly tells us that God's creation is a reliable witness for the truth about God's power and righteousness. The Bible also says that one can see the truth about God from His creation, so that unbelievers are "without excuse" in denying God's "eternal power and divine nature." So, the Bible says that we can learn about God from His creation. Let's do that!

Age of the earth according to science

The age of the earth can be measured by numerous different techniques, most of which provide just a minimum age. The absolute age of the earth has been most accurately measured through radioactive decay of its rocks. Because of plate tectonics (which recycles the earth's crust) and the late heavy bombardment, none of the original rock formations appear on the surface of the earth at this time. So, the oldest known rock formations have been dated to 4.0-4.2 billion years old. However, tiny zircons, some of the hardest minerals on earth, have survived these catastrophic events and have been reliably dated to 4.4 billion years old. Rocks returned from the Apollo moon missions, along with meteorites derived from Mars have been dated at 4.5 billion years old. Meteorites from the solar system that have landed on the earth have been dated to 4.56 billion years old, which establishes the date at which the solar system and all its worlds were created.

Radioactive decay

There are over 100 elements in the periodic table (right). The properties of each element are determined by the number of protons and neutrons in each element's atoms. The atomic number (which defines each element) is a function of the number of protons (positively charged), which is exactly balanced by the number of electrons (negatively charged). The number of neutrons (each consisting of a proton and electron, being charge-neutral) within each atom is usually about the same as the number of protons, although some elements can exist in different forms (called isotopes) based upon different numbers of neutrons. A fundamental physical law, called the weak nuclear force, determines the stability of atoms that contain differing numbers of neutrons. Some isotopes are somewhat or very unstable and decay in a predictable way and at a predictable rate. Depending upon the isotope, this decay can occur in several different ways. One form of radioactive decay consists of a neutron decaying into a proton and electron, which is ejected from the nucleus. The atom's atomic number increases by one, so it becomes one element higher on the periodic table, although its mass remains about the same. In other forms of radioactive decay, a proton combines with an electron to form a neutron, resulting in its atomic number decreasing by one. Still another form of radioactive decay results in the emission of an alpha particle (two neutrons and two protons), which lowers the atomic number by 2 and mass by 4. Both the original amount of an element and its decay product(s) can be measured to determine the age of the sample.

Isotopes and the age of the earth

The important thing about radioactive decay is that is provides us with clocks that allow us to determine the ages of various materials on the earth. The stability of a particular isotope determines its "half-life," the amount of time required for half of the atoms to decay. Half-lives of isotopes vary from billions of years (or longer) to fractions of a second. The existence of certain isotopes on the earth give us a minimum age for the earth. It is significant that there are over 150 unstable isotopes, although the vast majority of those do not exist naturally on the planet. It turns out that every isotope (other than those which are products of other radioactive decay or are formed today) with a half-life less than 80 million years do not exist. One could make the claim that maybe God didn't want to create isotopes with "short" half-lives (other than carbon-14). However, the most compelling answer is that all those isotopes with short half-lives have completely decayed over the earth's 4.5 billion year history. An earth that was only tens of thousands of years old would be expected to contain isotopes with half lives less than thousands of years long. However, there are none, with the exception of carbon-14, which is formed continually in the earths atmosphere, through the bombardment of atmospheric nitrogen-14 with cosmic rays. Some young earth creationists have attempted to get around the radioisotope problem by claiming that the half-lives of radioactive elements were shorter in the past. However, since the half-lives of radioisotopes vary over many orders of magnitude, this would require that God would have had to have changed pre-fall or pre-flood physics to adjust the decay rates of individual isotopes more or less compared to others. Needless to say, creationists who propose such special pleading have never produced any kind of coherent scientific model for how this contrived idea might have been accomplished. In addition, the Bible tells us that the physics of the universe are constant and "fixed," suggesting that such special pleading is incongruent with biblical theology.

Dating of meteorites

Because of the earth's aggressive tectonic activity, it was anticipated that dating of the earth's rocks would yield a minimum, but probably "young" date for the earth. As stated previously, the oldest rock formations are just over 4.2 billion years old, while the earth's oldest minerals are 4.4 billion years old. Since the moon has no measureable tectonics, its oldest rocks date from 4.5 billion years ago. With the assumption that all the solar system bodies were formed at the same time, scientists have dated meteorites to determine the age of the solar system. Using different isochron methods, the dates for all these meteorites fall in the same range—from 4.5-4.6 billion years ago.

Other dating techniques

Radioactivity is not the only means of measuring the age of the earth, although it does give us the most accurate measure. However, other techniques allow us to calculate a minimum age for the earth, one such is 'Dolomite formation'..... Replacement of calcium carbonate particles in lime sediment or lime rock gives strong evidence of vast amounts of time required. Rate is as slow as 200 million years/mm.

Conclusion

The Bible establishes a minimum date for the creation of human beings on the sixth "day" of ~50,000 years ago. However, because the Bible clearly indicates the length of the previous five creation "days," are longer than ordinary solar days, we must look to God's creation to establish an accurate date for the length of the days and the age of the earth. The age of the earth is most accurately established by examining the age of its rocks, along with the age of rocks from the moon and meteorites, which were formed around the same time. All these measurements indicate that the earth is just over 4.5 billion years old. Measurement of the ages of some of earth's features establish a minimum age for those features that is in the hundred of thousands to millions of years. Since most of the measurement merely involve the counting of annual layers, they are unlikely to be grossly inaccurate. Therefore, the young earth paradigm that the earth is merely 6,000 years old is falsified by both the Bible and science. The vast ages of the earth does not diminish the power and glory of God, but establishes that God thought that preparing the earth for human habitation was billions of years of preparation. Since God is not subject to the temporal dimension of this universe, it all happened instantly for Him.


How Old is the Earth According to the Bible and Science? by Rich Deem
http://www.godandscience.org/youngearth/age_of_the_earth.html#.UE8psoWovs0

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