Is carbon dating appropriate for measuring the age of materials that are a few years old?
368441
No. Radiocarbon dating relys on Carbon 14 which has a half-life of 5730±40 years. Most answers for carbon dating give a range of 100-200 years over when a sample might be from.\n\nIn addition to the half-life, you also need to know something about where the carbon in the sample came from, because different sources have different starting amounts of C14. \n\nThis means that carbon dating something modern would tell you it was made in the last 100 years. You could probably get a better estimate of the age, just by looking at it.
411413
Usually it's an isotope of uranium or rubidium that's used to date something that is millions of years old.  These elements have much longer half-lives than C-14 and take much longer to decay.  Often more than one element is used to date an artifact for certainty.  In other words, the object will be dated using uranium, then with strontium, and the results checked against each other.\n\nRadiocarbon dating is not accurate for very recent artifacts and anything older than 60,000 years.  So, whatever this story is about living clam shells being misdated, it's not surprising nor does it disprove radiometric dating.  Variation in carbon levels make it difficult to accurately date a contemporary object.  Also, people sometimes state that all radiocarbon dating is wrong because of a few errors, this is misleading since it is very easy to contaminate objects with recent carbon and skew the results.
476885
Carbon-14: Archaeological dating\nAmericium-241: Smoke detectors\nCobalt-60: Food Irradiation\nPhosphorus-32: Biology study
569167
because the margin of error becaomes incredibly large. after a very long time, a very tiny percentage of c14 is is left with a very tiny mass. the extraction process is not perfect, so we might lose or gain a certain amount of error, and the measuremt itself is not perfect, so we get more error. after 50,000 years the expected amount of carbon 14 is on the order of the error or smaller, so it becomes basically meaningless.
779755
typically, using C14 dating.\n\nC14 is a natural isotope of regular Carbon (C12).\n\nCarbon is present in many molecules, and typically at least one, if not more, of the molecules typically found in most inks.\n\nC14's relative abundance in Carbon is just 1 part per trillion.  Its half-like is 5730 years (i.e. half of its nuclei will have decayed to non-radioactive N14.\n\nC14 is produced by neutrons induced by cosmic rays in the upper atmosphere of the Earth.  It ends up forming CO2, and thus enters the cycle of life.  So a living organism permanently restocks on C14.\n\nBut a dead organism stops restocking on C14 so the amount of C14 decays progressively, halving every 5730 years.\n\nSo by measuring the amount of radioactivity from C14 taken from one living tissue, scientists can fairly precisely determine when the organism was last alive.\n\nThe method is typically quite precise (say, +/- 30 years on 3'000 years, i.e. 1 percent).\n\nIt cannot be used very reliably for anything over about 60'000 years old though, because by then the radioactivity from C14 is so low, that it becomes indistinguishable from background radiation. (After 57'300 years, i.e. 10 periods, only 9.8% of the original radioactive C14 atoms will be left).\n\n\nHope this helps
1024575
Radiocarcon dating is used.\nRadiocarbon dating is a radiometric dating method that uses the naturally occurring isotope carbon-14 to determine the age of carbonaceous materials up to ca 60,000 years. Within archaeology it is considered an absolute dating technique. The technique was discovered by Willard Frank Libby and his colleagues in 1949 during his tenure as a professor at the University of Chicago. In 1960, Libby was awarded the Nobel Prize in chemistry for his method to use carbon-14 for age determination.\nCarbon has two stable, nonradioactive isotopes: carbon-12 (12C), and carbon-13 (13C). In addition, there are tiny amounts of the unstable isotope carbon-14 (14C) on Earth. Carbon-14 has a half-life of 5730 years and would have long ago vanished from Earth were it not for the unremitting cosmic ray impacts on nitrogen in the Earth's atmosphere, which forms more of the isotope. When cosmic rays enter the atmosphere, they undergo various transformations, including the production of neutrons. The resulting neutrons participate in the following reaction on one of the N atoms being knocked out of a Nitrogen (N2) molecule in the atmosphere:\n\n1n + 14N → 14C + 1p \n \nAtmospheric 14C, New Zealand[1] and Austria[2]. The New Zealand curve is representative for the Southern Hemisphere, the Austrian curve is representative for the Northern Hemisphere. Atmospheric nuclear weapon tests almost doubled the concentration of 14C in the Northern Hemisphere [3].The highest rate of carbon-14 production takes place at altitudes of 9 to 15 km (30,000 to 50,000 ft), and at high geomagnetic latitudes, but the carbon-14 spreads evenly throughout the atmosphere and reacts with oxygen to form carbon dioxide. Carbon dioxide also permeates the oceans, dissolving in the water. For approximate analysis it is assumed that the cosmic ray flux is constant over long periods of time; thus carbon-14 could be assumed to be continuously produced at a constant rate and therefore that the proportion of radioactive to non-radioactive carbon throughout the Earth's atmosphere and surface oceans is constant: ca. 1 part per trillion (600 billion atoms/mole). For more accurate work, the temporal variation of the cosmic ray flux can be compensated for with calibration curves. If these curves are used, their accuracy and shape will be the limiting factors in the determination of the radiocarbon age range of a given sample.\n\nPlants take up atmospheric carbon dioxide by photosynthesis, and are eaten by animals, so every living thing is constantly exchanging carbon-14 with its environment as long as it lives. Once it dies, however, this exchange stops, and the amount of carbon-14 gradually decreases through radioactive decay.\n\n14C → 14N + 0β \nBy emitting a β particle(Beta decay), carbon-14 is changed into stable (non-radioactive) nitrogen-14. This decay can be used to get a measure of how long ago a piece of once-living material died. However, aquatic plants obtain some of their carbon from dissolved carbonates which are likely to be very old, and thus deficient in the carbon-14 isotope, so the method is less reliable for such materials as well as for samples derived from animals with such plants in their food chain.
50952
like any physical parameter derived from measurement, results should be reported with a +/- experimental uncertainty.  unfortunately when these numbers are repeated in the media, rarely do they get repeated.  (and in fact, often scientists neglect to even publish them.  jerks.)\n\nanyway, a typical error bar for radiocarbon dating seems to be anywhere from 30-50 years.  so you can consider it accurate to within that margin of uncertainty.  however, depending on the data, sometimes this can increase to an error margin of several centuries!  (see 2nd link)
311743
Certain substances have a radioactive halflife.  That means it takes a certain amount of time for that substance to decay so far.  Carbon dating is the process of observing the decay of the carbon present in an object to determine its age.\n\nLike any scientific property, there is always error.  The equation and theory models very close to reality but never exactly.  And there are so many other things that could've assisted in the decay which result in incorrect data.\n\nWhich is why whenever you want to make a scientific claim about certain fossils containing carbon for example, you will take many samples from various objects within a certain layer of the soil, then take the average age of them all, giving a rough estimate of the age of that particular layer of soil.\n\nIs carbon dating perfect?  No.  No scientific method is without errors.  But if done intelligently it can give reliable statistics about the age of objects.\n\nMost of the people who are wholly against carbon dating point out errors and flaws with it that any reasonable scientist is fully aware of and they pretend that it's a profound problem which invalidates the whole process.  The majority of Carbon Dating critics are coming from the religious front, who oppose it because it disproves their beliefs.\n\nUltimately though, if done by a careful scientist with lots of samples, then averaged, carbon dating is generally reliable.
116378
Well I did some searching for Guanlong wucaii and I was not able to find anything about it on the internet. There is some chinese pottery named wucai that is from the Ming period, from about 1368-1642 CE. So I really have no idea what object it is you are referring to in your question. \n\nAnyway, carbon dating is not used dating objects as old as 190 million years. Carbon 14, a radioactive isotope of carbon, is not much good for dating things older than 60,000 years of age, because all the radioactive carbon will have decayed away if one looks at objects much older than that. However, there are dozens of radiometric dating techniques, some that are good for objects billions of years old (like potassium-argon dating, or uranium-lead dating).\n\nThere are many other techniques besides radioactive dating. One can count tree rings. One can count layers of ocean bottom mud. One can count rings of coral growth. One can look at the changes in the protein structure since a creature died (the handedness of the organic molecules changes with time). And there are many other techniques (see references). These methods can be cross-referenced against each other for checking and improving confidence, and reducing error bars.
264344
Geologists don't really know. And carbon dating has been proved to be inaccurate.\n   Just recently a geode was found.  A geologist looked at it and said it was 22 million years old, but when they x-rayed it they found a spark plug inside.  Guess what the spark plug was from 1961!!!!!  There are a lot of things being discovered in coal mines .     The coal layer is supposed to be 200 million years old but what are iron pots and brass bells and human bodies doing imbedded there.  They even found a concrete wall in one coal mine!!  Kind of makes you wonder about these things doesn't it?\n   The Bible says man has only been around about 6000 to 6500 years on the earth.
664010
carbon dating cannot be used for very old fossils. Radioactive dating is a better method used extensively by geologists. Carbon 14 is fairly reliable for fossils that are not too old.
68920
As one might expect NIST (the modern name for NBS) also helps with standards for radio carbon dating. The main two callibration methods are to the so-called "1890 wood" and the oxalic acid samples, as described below, although the ANU sugar standard is also used. \n\nThe original callibration materials used when the technique was developed was from wood found in an Egyptian tomb, and a sample of the Dead Sea Scrolls. \n\nI suspect you are asking this question because you do not believe radioactive dating, since it conflicts with  Bishop Usher's derived age of the earth. I might point out that counting rings of coral, like counting tree rings, shows that we have had continuous growth of some corals that go back tens of millions of years.
382215
The Earth is assumed to be about 4.6 billion years old, and unlike what everyone else said, it's not based solely on anything contained on Earth, including carbon dating. The oldest solid material found on Earth is about 4.1 billion years.\n\nThe guess -- and that's all it is, a guess -- is based on the rate of radiological decay of material on Earth and in meteorites found on Earth and around the solar system.\n\nIf you assume that the entire universe is formed from a common pool of matter (the essence of the Big Bang theory is that all material in the universe came from a single, supercondensed source that exploded); if you assume that therefore, all the matter in the universe has been equally distributed in all directions; if you assume that the rates of decay in all radiological material in the universe are consistent regardless of time, their position in the universe, etc.; then you can derive, by comparing the same kind of radiological material from celestial bodies that were not formed in our solar system, bodies that were part of our solar system when it formed, and that material now on Earth, the age that the Earth must be at the time it began to take solid form.\n\nThe paticular materials used to get that age is Lead-206 / Lead-207, which are the products of decay in Uranium-238.\n\nThis is further supported by temperature measurements of the universe and the evidence of background radiation from the timing of the Big Bang, which is assumed to have occurred about 15 billion years ago; given the rate of expansion of the universe visible to us, and the rate of change in both the speed of that expansion, the temperature of the universe and the density of space, we can verify the assumptions of the Earth's age to be within the estimation of a "young Earth" of 4.6 billion years old.\n\nAlso, to the person who said "The Bible": If you derive the history of the Earth from the Bible, as countless theological scholars have done through extensive research, it's about 6,000 years old; no scholarly Biblical research places the age of Earth at more than 10,000 years old.\n\nIf you want to believe that, in the face of overwhelming evidence to the contrary, that's fine. But you should at least agree with your evidence before citing it.
53656
Around 4.57 billion years old.
486649
The question is a little bit muddled, but I think I get the idea.\n\nThe atoms that are exposing the age of things are those atoms that are, or were, radioactive.  Any radioactive material decays.  It also decays at predictable, measurable rates that are distinctive to the element.  So you can date things that have radioactive elements (which most things do in some trace amount) or their decay elements within, based on how decayed they are.\n\nUranium-238 ultimately decays into lead.  You can date how long something containing uranium-238 has been in existence based on the ratio of Ur-238 to Pb.\n\nThis process operates at the same rate no matter what the temperature is.
1176345
the earth is about 4.5 billion years old
955424
Almost certainly copper, which can be found as the native metal, and in ores which are so easily smelted that they could have been discovered accidentally.  Wikipedia suggests 7500 BC, compared to 4000 BC for silver and gold, and noticeably later for iron.\n\nYou could get an argument from somebody about carbon, because charcoal was being used for painting and decorating caves at least 30,000 years ago, and it's not got a lot of impurities compared with pure carbon.