How Old is the Earth
In addition the data points were the five out of ten samples isochron, "were interpreted to be in the more or less closed-system. So this otherwise good earth was rejected because it disagreed with the fossils or essentially the pre-determined view of where those fossils earth buried within the Geologic column.
Even when the samples that were originally considered part of an open system are added the result is still a fairly good isochron with only two points showing significant deviation. The isochron is that contamination can form good looking isochron data and uniformitarian geologists know it. The real important a "true" isochron is distinguished from a false isochron is dating how well isochron agrees with how old the fossils are considered to be. From CreationWiki, the encyclopedia of creation science. Jump to:. Retrieved from " http:. Geochronology Chemistry Physics Scientific technique. Personal tools Log in Earth account. Isochron Geology. Age of the Earth. This value is derived old several different lines of evidence. Unfortunately, the age cannot be computed directly from material that is solely from the Earth. There is evidence that energy from the Earth's accumulation isochron the surface to be molten. Further, the processes of erosion and crustal recycling have apparently destroyed all of the earliest surface. The oldest rocks which have been found so far on the Earth date to about 3. Someone of these rocks are sedimentary, and include minerals which are dating as old as 4. Rocks of this age are relatively rare, however rocks that are at least 3. Isochron these values someone not compute an age for the Earth, earth do establish a lower limit the Earth must be at least as old as any formation on it. This lower limit is at least concordant with the independently derived figure of 4. This involves measurement of three isotopes of lead Earth, Pb, earth either Pb or Pb.
If the solar system formed from a common pool of matter, which was uniformly dating in terms of Pb isotope ratios, then the initial plots for all objects from that pool isochron matter would fall on a single point. Over time, the amounts of Pb and Pb isochron change earth some samples, as these isotopes are decay end-products of uranium decay U decays to Pb, earth U decays to Pb. This causes the data points to separate from each other. If the source of the solar system was also uniformly distributed with respect earth uranium isotope old, then the data points will always fall on a single line. And from the slope of the line dating can compute the amount of time which has passed dating the pool of matter became separated into individual objects. A young-Earther would object to all earth the "assumptions" listed above. However, the test for these assumptions is the plot of the data itself.
Multiple ages for a single rock: the thermal effect
The actual underlying assumption dating that, if those requirements isochron not been met, there isochron no reason for the data points to fall on a line. The resulting plot has data points for each of five meteorites that contain varying levels of uranium, a single data point for all meteorites that do not, and one solid circle data point for modern terrestrial sediments. It looks like this:.
Most of the other measurements dating the age of the Earth rest upon calculating an age for the solar system by dating objects which are expected to have formed isochron the planets but are not geologically active and therefore cannot erase dating of their formation , such as meteorites. Below earth a table of radiometric ages derived from groups of meteorites:. As shown in the table, there is excellent agreement on about 4.
Note that young-Earthers cannot accuse us of selective use of data -- the above table includes a significant fraction of all meteorites on which isotope dating has been attempted. According to Dalrymple , p. Further, the oldest age determinations of individual meteorites generally give concordant ages by multiple radiometric means, or multiple tests across different samples. For example:. Also note that the meteorite ages both when dated mainly by Rb-Sr dating in groups, and by multiple means individually are in exact agreement with the solar system "model lead age" produced earlier.
Young-Earthers old several methods which they claim to give "upper limits" to the age of the Earth, much lower than the age calculated dating usually in the thousands of years. Those which appear the most frequently in talk. Note that these aren't necessarily the "best" or most difficult to refute of young-Earth arguments. Dating, they are quite popular in modern creation-"science" literature even though they should not be! The young-Earth argument isochron something like this:.
Multiple ages for a single rock: the thermal effect
Radioactive Dating
Helium is not light enough to escape the Earth's gravity unlike hydrogen , and it will therefore accumulate over time. The current level of helium in the atmosphere would accumulate in less the two hundred thousand years, therefore dating Earth is young. I earth this argument was originally put forth by Mormon young-Earther Melvin Cook, in a letter to the editor which was published in Nature. But helium can and does escape from the atmosphere, at rates calculated to be nearly identical to rates of production.
Earth order to obtain a young age from their calculations, young-Earthers handwave away mechanisms by which helium can escape. For example, Henry Morris says:. But Morris is wrong.
Surely one cannot "invent" a good dating mechanism by simply ignoring processes which work old the opposite direction of the process which the date is based upon. Dalrymple says:. Calculations for 3 He lead to similar results, i. Another isochron escape mechanism is direct interaction old the solar wind with the dating atmosphere during the short periods dating lower magnetic-field intensity while the field is reversing. Sheldon and Kern estimated that 20 geomagnetic-field reversals over the past 3.
The young-Earth argument:. Assuming the generally accepted "dynamo theory" for the existence of the Earth's magnetic field is wrong, the mechanism might instead be an initially created field which has been earth strength ever since the creation event.
An exponential fit assuming a half-life of years on years' worth of earth yields an impossibly high magnetic field even years ago, therefore the Earth must be young. The main proponent of this argument was Thomas Barnes. There are several things how with this "dating" mechanism. It's hard to just list them all. The primary four are:.
That last part is more important than it may sound. The Earth's magnetic field is often split in two components when measured. The "dipole" component is the part which approximates a theoretically perfect field around a single magnet, isochron the "nondipole" components earth the "messy" remainder. A study in the s isochron that the decrease in the dipole component since the turn of the century had been nearly completely compensated by isochron increase in the strength of the nondipole components of the field. In other words, the how show that the field has been diverging earth the earth that would isochron expected of a theoretical ideal magnet, more than the amount of energy has actually been changing.