1. How do scientists find the age of planets (date samples) or planetary time ( relative age and absolute age)? We can then use radioactive age dating in order to date the ages of the surfaces There is a lot of evidence that this is true. . Once the half life of an isotope and its decay path are known, it is possible to use the. Radioactivity and radioactive decay are spontaneous processes. Students often struggle with this concept; therefore, it should be stressed that. 1 Isotopes; 2 Radioactive decay; 3 Statistics of radioactive decay; 4 Invariance of As we can see from this example, it is perfectly possible for different isotopes of the In the first place, it should be true in principle: it can be deduced from the.
The short half-life of carbon means it cannot be used to date fossils that are allegedly extremely old, e. The question should be whether or not carbon can be used to date any artifacts at all? The answer is not simple. There are a few categories of artifacts that can be dated using carbon; however, they cannot be more 50, years old.
Carbon cannot be used to date biological artifacts of organisms that did not get their carbon dioxide from the air. This rules out carbon dating for most aquatic organisms, because they often obtain at least some of their carbon from dissolved carbonate rock. The age of the carbon in the rock is different from that of the carbon in the air and makes carbon dating data for those organisms inaccurate under the assumptions normally used for carbon dating.
This restriction extends to animals that consume seafood in their diet. As stated previously, carbon dating cannot be used on artifacts over about 50, years old. These artifacts have gone through many carbon half-lives, and the amount of carbon remaining in them is miniscule and very difficult to detect. Carbon dating cannot be used on most fossils, not only because they are almost always allegedly too old, but also because they rarely contain the original carbon of the organism that has been fossilized.
Also, many fossils are contaminated with carbon from the environment during collection or preservation procedures. Scientists attempt to check the accuracy of carbon dating by comparing carbon dating data to data from other dating methods.
Other methods scientists use include counting rock layers and tree rings. When scientists first began to compare carbon dating data to data from tree rings, they found carbon dating provided "too-young" estimates of artifact age.
Scientists now realize that production of carbon has not been constant over the years, but has changed as the radiation from the sun has fluctuated. Nuclear tests, nuclear reactors and the use of nuclear weapons have also changed the composition of radioisotopes in the air over the last few decades.
This human nuclear activity will make precise dating of fossils from our lifetime very difficult due to contamination of the normal radioisotope composition of the earth with addition artificially produced radioactive atoms. The various confounding factors that can adversely affect the accuracy of carbon dating methods are evident in many of the other radioisotope dating methods. Although the half-life of some of them are more consistent with the evolutionary worldview of millions to billions of years, the assumptions used in radiometric dating put the results of all radiometric dating methods in doubt.
The following is an article on this subject.
These isotopes have longer half-lives and so are found in greater abundance in older fossils. Some of these other isotopes include: The assumptions are similar to the assumptions used in carbon dating.
The mathematical premise undergirding the use of these elements in radiometric dating contains the similar confounding factors that we find in carbon dating method. Most scientists today believe that life has existed on the earth for billions of years. This belief in long ages for the earth and the evolution of all life is based entirely on the hypothetical and non-empirical Theory of Evolution.
All dating methods that support this theory are embraced, while any evidence to the contrary, e. Prior to radiometric dating, evolution scientists used index fossils a. A paleontologist would take the discovered fossil to a geologist who would ask the paleontologist what other fossils searching for an index fossil were found near their discovery. If it sounds like circular reasoning, it is because this process in reality is based upon circular reasoning.
Henry Morris as follows: These long time periods are computed by measuring the ratio of daughter to parent substance in a rock, and inferring an age based on this ratio.
This age is computed under the assumption that the parent substance say, uranium gradually decays to the daughter substance say, leadso the higher the ratio of lead to uranium, the older the rock must be.
While there are many problems with such dating methods, such as parent or daughter substances entering or leaving the rock, e. Geologists assert that generally speaking, older dates are found deeper down in the geologic column, which they take as evidence that radiometric dating is giving true ages, since it is apparent that rocks that are deeper must be older.
But even if it is true that older radiometric dates are found lower down in the geologic column which is open to questionthis can potentially be explained by processes occurring in magma chambers which cause the lava erupting earlier to appear older than the lava erupting later. Lava erupting earlier would come from the top of the magma chamber, and lava erupting later would come from lower down.
A number of processes could cause the parent substance to be depleted at the top of the magma chamber, or the daughter product to be enriched, both of which would cause the lava erupting earlier to appear very old according to radiometric dating, and lava erupting later to appear younger. For the others, one can only use relative age dating such as counting craters in order to estimate the age of the surface and the history of the surface. The biggest assumption is that, to first order, the number of asteroids and comets hitting the Earth and the Moon was the same as for Mercury, Venus, and Mars.
There is a lot of evidence that this is true. The bottom line is that the more craters one sees, the older the surface is. Why is it important to establish the age of a planet?
This can be interpreted in two ways: Based on our study of meteorites and rocks from the Moon, as well as modeling the formation of planets, it is believed pretty much well-established that all of the objects in the Solar System formed very quickly about 4.
When we age date a planet, we are actually just dating the age of the surface, not the whole planet. We can get absolute ages only if we have rocks from that surface. For others, all we are doing is getting a relative age, using things like the formation of craters and other features on a surface.
By studying other planets, we are learning more about our own planet. The effects of impacts and how they might affect us here on Earth, global climate change Venus vs. Earth and what could happen to Earth in an extreme case, etc.
Carbon, Radiometric Dating - CSI
How do you technically define half-life? From Wikipedia, radioactive decay is the process in which an unstable atomic nucleus spontaneously loses energy by emitting ionizing particles and radiation.
This decay, or loss of energy, results in an atom element of one type, called the parent nuclide transforming to an atom of a different type another element or another isotope of the same elementnamed the daughter nuclide. It is impossible to predict when a given atom will decay, but given a large number of similar atoms, the decay rate on average is predictable.
This predictable decay is called the half-life of the parent atom, the time it takes for one half of all of the parent atoms to transform into the daughter. If carbon is so short-lived in comparison to potassium or uranium, why is it that in terms of the media, we mostly about carbon and rarely the others?