Renaissance Now, let’s look at some specific examples. One type of atom that does not normally react is Neon. See the picture to the left. It already has the correct number of electrons in it’s outside electron layer so Neon does not react. Neon, along with Helium and Argon are known as non-reacting gasses because they do not need to react to be stable. Other types of atoms such as Hydrogen, Carbon, and Oxygen do not have the correct number of electrons to be stable by itself.
The Radiometric Dating Game Radiometric dating methods estimate the age of rocks using calculations based on the decay rates of radioactive elements such as uranium, strontium, and potassium. On the surface, radiometric dating methods appear to give powerful support to the statement that life has existed on the earth for hundreds of millions, even billions, of years. We are told that these methods are accurate to a few percent, and that there are many different methods.
We are told that of all the radiometric dates that are measured, only a few percent are anomalous. This gives us the impression that all but a small percentage of the dates computed by radiometric methods agree with the assumed ages of the rocks in which they are found, and that all of these various methods almost always give ages that agree with each other to within a few percentage points. Since there doesn’t seem to be any systematic error that could cause so many methods to agree with each other so often, it seems that there is no other rational conclusion than to accept these dates as accurate.
Note: the half-life durations listed in the text sections of this tutorial are rounded off for uranium and potassium
The approximate hardness of these materials is listed next to the minerals of the Mohs scale in Table 3. Because there is a general link between hardness and chemical composition , these generalizations can be made: Because hardness is a highly diagnostic property in mineral identification, most determinative tables use relative hardness as a sorting parameter. Tenacity Several mineral properties that depend on the cohesive force between atoms and ions in mineral structures are grouped under tenacity.
Thus a mineral with a specific gravity of 2 weighs twice as much as the same volume of water. Since it is a ratio, specific gravity has no units.
Isotopes of calcium
Radiocarbon dating (also referred to as carbon dating or carbon dating) is a method for determining the age of an object containing organic material by using the properties of radiocarbon, a radioactive isotope of carbon.
Moon Dust and the Age of the Solar System Answers in Genesis , the leading young-earth creationist ministry, disowns cosmic dust arguments. The most amazing thing about the cosmic dust argument is that it is still being used! It has coasted along on obsolete evidence, and nothing but obsolete evidence, for the last 25 years!! It nicely illustrates how creationists borrow from each other and never do any outside reading.
The obsolescence of this argument has been brought out in numerous debates and published in countless books, journals, and newsletters. It can be discovered by anyone who exercises his or her library card.
How Good Are Those Young-Earth Arguments?
The Hou Hanshu states: They resemble the people of the Middle Kingdom and that is why this kingdom is called Da Qin. They say they originally came from China, but left it. Graf , pp. For the most part, such mythological elements are so strikingly evident that they represent only a minimal problem. According to the Hou-Han shu, the Roman Empire was so named precisely because its people and civilization were comparable to those of China.
Dating Methods using Radioactive Isotopes. Oliver Seely Radiocarbon method. There is another often used dating technique for samples considerably older than 60, years. It is called potassium-argon dating and is based upon the detected ratio of 40 Ar to 40 K in a given sample.
Updated 8 January c Introduction In a related article on geologic ages Ages , we presented a chart with the various geologic eras and their ages. In a separate article Radiometric dating , we sketched in some technical detail how these dates are calculated using radiometric dating techniques. As we pointed out in these two articles, radiometric dates are based on known rates of radioactivity, a phenomenon that is rooted in fundamental laws of physics and follows simple mathematical formulas.
Dating schemes based on rates of radioactivity have been refined and scrutinized for several decades. The latest high-tech equipment permits reliable results to be obtained even with microscopic samples. Radiometric dating is self-checking, because the data after certain preliminary calculations are made are fitted to a straight line an “isochron” by means of standard linear regression methods of statistics.
The slope of the line determines the date, and the closeness of fit is a measure of the statistical reliability of the resulting date. Technical details on how these dates are calculated are given in Radiometric dating. Here is one example of an isochron, based on measurements of basaltic meteorites in this case the resulting date is 4.
1. Rate of Decay
USGS Paleontology glossary Acritarch microscopic organic structure from any of a number of organisms; common during the Proterozoic. Adaptive radiation, evolutionary radiation the rapid expansion and diversification of a group of organisms as they fill unoccupied ecological niches , evolving into new species. Age of Mammals term found in popular books on evolutionary systematics for the Cenozoic era, beginning with the Paleocene Epoch when following the K—T end Cretaceous mass extinction , mammals underwent a huge evolutionary radiation and thus replaced reptiles as the dominant life on Earth.
The Age of Mammals has in turn been replaced by the Anthropocene or Age of Man, Holocene when humans dominate every conceivable environment and most other life forms apart from weedy species are suffering a mass extinction Yes, I know humans are also mammals, so technically speaking this is still the Age of Mammals, but I tend to think of the Age of Mammals as a period of flourishing biodiversity.
MAK Age of Reptiles term found in popular books on evolutionary systematics for the Permian through to Cretaceous periods but obviously originating with Victorian discoveries of “antediluvian monsters” , when reptiles first mammal-like reptiles , then archosaurs and marine reptiles were the dominant life on Earth.
Radiometric dating or radioactive dating is a technique used to date materials such as rocks or carbon, in which trace radioactive impurities were selectively incorporated when they were formed. The method compares the abundance of a naturally occurring radioactive isotope within the material to the abundance of its decay products, which form.
Gentry by [Last Updated: It can be an especially difficult challenge when the Creationist author has professional credentials and has published in mainstream scientific journals. One such individual is Robert Gentry, who holds a Master’s degree in Physics and an honorary doctorate from the fundamentalist Columbia Union College. For over thirteen years he held a research associate’s position at the Oak Ridge National Laboratory where he was part of a team which investigated ways to immobilize nuclear waste.
Gentry has spent most of his professional life studying the nature of very small discoloration features in mica and other minerals, and concluded that they are proof of a young Earth. About the Rocks Geologists classify rocks into three main categories – sedimentary, igneous, and metamorphic – based on the way in which they form. Sedimentary rocks are secondary in formation, being the product of precursor rocks of any type. Igneous rocks form from molten material, and are further subdivided into two main categories, the volcanic rocks which form from lava extruded at or near the surface; and plutonic rocks which form from magma, deep within the crust.
Both types of igneous rocks comprise a mixture of different minerals. As igneous rocks cool, mineral crystals form following a specific sequence.
Accuracy of Fossils and Dating Methods
Love-hungry teenagers and archaeologists agree: But while the difficulties of single life may be intractable, the challenge of determining the age of prehistoric artifacts and fossils is greatly aided by measuring certain radioactive isotopes. Until this century, relative dating was the only technique for identifying the age of a truly ancient object. By examining the object’s relation to layers of deposits in the area, and by comparing the object to others found at the site, archaeologists can estimate when the object arrived at the site.
Mineralogy As a discipline, mineralogy has had close historical ties with geology. Minerals as basic constituents of rocks and ore deposits are obviously an integral aspect of geology. The problems and techniques of mineralogy, however, are distinct in many respects from those of the rest of geology, with the result that mineralogy has grown to be a large, complex discipline in itself.
Nepheline greasy light gray , sodalite blue , cancrinite yellow , feldspar white , and ferromagnesian minerals black in an alkalic syenite from Litchfield, Maine, U. About 3, distinct mineral species are recognized, but relatively few are important in the kinds of rocks that are abundant in the outer part of the Earth. Thus a few minerals such as the feldspars, quartz, and mica are the essential ingredients in granite and its near relatives. Limestones , which are widely distributed on all continents, consist largely of only two minerals, calcite and dolomite.
Many rocks have a more complex mineralogy, and in some the mineral particles are so minute that they can be identified only through specialized techniques. It is possible to identify an individual mineral in a specimen by examining and testing its physical properties. Determining the hardness of a mineral is the most practical way of identifying it.
This can be done by using the Mohs scale of hardness, which lists 10 common minerals in their relative order of hardness: Harder minerals scratch softer ones, so that an unknown mineral can be readily positioned between minerals on the scale.
Nuclear forensics international technical working group
Consider also the most popular explanation offered for the photo right , that a concretion formed around an s-era hammer as minerals precipitated out of the surrounding limestone. From Adam until Real Science Radio , in only generations! Another paper, in the American Journal of Physical Anthropology Eugenie Scott ‘s own field on High mitochondrial mutation rates , shows that one mitochondrial DNA mutation occurs every other generation, which, as creationists point out , indicates that mtEve would have lived about generations ago.
That’s not so old! As our List of Not So Old Things this web page reveals, by a kneejerk reaction evolutionary scientists assign ages of tens or hundreds of thousands of years or at least just long enough to contradict Moses’ chronology in Genesis.
• radiometric dating (which uses the concept of radioactive • used to determine the age of rocks and fossils • uses the concept of isotopes • uses the concept of half-life • This method is a useful technique for dating fossils and archaeological specimens from to 50, years old • .
Some pieces of this meteorite have proven to be “unstable” – rusting in collections. Read the newspaper account below describing the Braunau fall of On the 14th July last, a remarkable aerolite fell at Braunau, in Bohemia. Two fragments were found, one weighing fifteen, the other twenty-one kilogrammes. The aerolite appeared to proceed, as is very often the case, from a small black cloud.
The smaller fragment fell upon a house, pierce the roof, struck the beam which caused it to deviate slightly from its course, passed through a ceiling composed of white clay and straw, and entered a room where several persons were assembled, but, fortunately, no one was hurt A fragment has been analyzed by M.
Isotopes of uranium
INFL Guideline for alpha spectrometry Alpha Spectrometry is used for isotopic composition measurement of radioactive elements that decay by the emission of an alpha particle. These include many of the actinide elements thorium, uranium, neptunium, plutonium, americium and curium and some of the heavy elements e.
The concentration of an isotope can be determined by using an isotope dilution technique i. Separation and purification of the element of interest is required prior to analysis. The chemical processes are well developed and the equipment components for analysis are fairly inexpensive.
Dating Methods using Radioactive Isotopes Oliver Seely Radiocarbon method The age of ancient artifacts which contain carbon can be determined by a method known as radiocarbon dating. This method is sometimes called C or carbon dating. Carbon is formed in the upper atmosphere by the bombardment of nitrogen by cosmic rays. Cosmic rays are protons, particles and some heavier ions.
Other particles, including neutrons, are produced by subsequent collisions. The collision of a neutron with the nucleus of a N isotope produces C , as follows: This form of carbon is radioactive. That is, it decays spontaneously to nitrogen 14 by a path involving the emission of a high energy electron a beta particle: But it decays very slowly, taking years for half of a sample of carbon to be converted back to nitrogen
Isotopes of rubidium
Various specimens of Tyrannosaurus rex with a human for scale. Size comparison of selected giant theropod dinosaurs, with Tyrannosaurus in purple. Tyrannosaurus rex was one of the largest land carnivores of all time; the largest complete specimen, FMNH PR ” Sue ” , measured The forelimbs were long thought to bear only two digits, but there is an unpublished report of a third, vestigial digit in one specimen. The tail was heavy and long, sometimes containing over forty vertebrae, in order to balance the massive head and torso.
To compensate for the immense bulk of the animal, many bones throughout the skeleton were hollow, reducing its weight without significant loss of strength.
Uses of radioactive isotopes These materials have a variety of uses and a selection of these are listed below. (a) dating geological specimens, using uranium, rubidium or bismuth;.
Radiometric dating In , shortly after the discovery of radioactivity , the American chemist Bertram Boltwood suggested that lead is one of the disintegration products of uranium, in which case the older a uranium-bearing mineral the greater should be its proportional part of lead. Analyzing specimens whose relative geologic ages were known, Boltwood found that the ratio of lead to uranium did indeed increase with age. After estimating the rate of this radioactive change, he calculated that the absolute ages of his specimens ranged from million to 2.
Though his figures were too high by about 20 percent, their order of magnitude was enough to dispose of the short scale of geologic time proposed by Lord Kelvin. Versions of the modern mass spectrometer were invented in the early s and s, and during World War II the device was improved substantially to help in the development of the atomic bomb. Soon after the war, Harold C. Wasserburg applied the mass spectrometer to the study of geochronology. This device separates the different isotopes of the same element and can measure the variations in these isotopic abundances to within one part in 10, By determining the amount of the parent and daughter isotopes present in a sample and by knowing their rate of radioactive decay each radioisotope has its own decay constant , the isotopic age of the sample can be calculated.