Questions questions im just wondering are modern day dating methods reliable i ask this because i was told there are different types of dating methods to test fossils etc for instance testing bones which using dating methods say 10 yrs ago are now classed unreliable i say this because i was told that historians dated human remains back to 20 million yrs i think and with a more modern technique it s now dated at only 5000 yrs i think so the question is can we trust todays modern dating methods or will they sometime in the near future be more accurate
are dating methods accurate??
by master chief 12 Replies latest jw friends
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AlanF
Some modern dating methods are fairly reliable and some are quite iffy. Radiocarbon (C14) dating, when used with care and corroborated by other means, is supposed to be accurate to better than 5% or so for dates under 10,000 years. The "other means" include tree-ring dating, and counting layers in peat bogs, lake bottom sediments and ice cores in Greenland and Antarctica. Thermoluminescence dating is not generally supposed to be as reliable as C14 dating. Potassium-argon dating is supposed to be reasonably good for dates of a million years old or more, but again much care needs to be taken to ensure that the basic assumptions about the method are met in a particular case. Other methods such as uranium-lead and thorium-lead have similar characteristics. Supposedly the most accurate radioactive dating technique is called the isochron method, which is too complicated to explain here.
For a good look at radioactive dating methods other than C14, see the 1993 book The Age of the Earth by Brent Dalrymple. For a good look at issues related to C14 and non-radioactive dating methods, see the website http://www.talkorigins.org .
Humans have never been dated back to 20 million years ago, at least, not by reputable scientists. The potassium-argon method has been used to date various humanoid fossils back to about 4 million years, and fossils of near-human species such as Homo erectus back to nearly 2 million years. Various fossils of so-called "archaic homo sapiens" go back to about 1 million years. But true humans -- meaning fossils displaying all of the features that scientists use to characterize living humans -- of the species Homo sapiens goes back only about 100,000 years. Homo neandertalensis goes back about 250,000 years.
Experience teaches scientists about the strengths and limitations of the various dating methods, so that today the methods are far more accurate than 50 years ago. No doubt in the future various dating methods will become more accurate.
AlanF
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Cygnus
: No doubt in the future various dating methods will become more accurate.
LOL
So you admit that such dating methods are just guesses.
Why not rather trust G-d's Word the Holy Bible when it authoritatively speaks of man coming into existence on the sixth day of creation? TRUE science does not conflict with the accurate historical records we can confidently confirm as the written word of YAHWEH G-d himself.
e'bdee e'bdee e'bdee
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JanH
From BITT to Cygnus to Troll. Some development you've done over the last years....
- Jan
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The believer is happy. The doubter is wise. -
Faithful2Jah
Yeah, what is it with Cygnus? Isn't he the same guy who used to post pieces of substance years ago at H2O? Now, it seems like all he posts are little pieces of worthless crap. I don't get it. What happened to him? Not that I am any great source of light. I've always been more of a reader than a poster. But Cygnus used to post quality stuff I enjoyed reading. Now it's all fluff and sarcasm.
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Amazing
I agree pretty much with AlanF. I can add though, that C14 Dating is good for up to almost 60,000 years ... but, beyond 50,000 it is more iffy. At 60,000 years about 99.9% of the C14 is gone. Generally, though C14 is better used for test samples below 50,000 years.
Also, some cite "comtamination" as a problem because they assume that any contamination will cause an object, specifically a non-metalic organic to appear older than it is. This is a false assumption made by novices, YEC's, and Fundys. Any contamination, such as C14, will cause the tested object to "always" appear younger than it really is.
Here is why: C14 decays at a given rate. There is no way that contamination will increase the decay rate, or somehow cause removal of an amount of C14. Once C14 is present in an organic, it stay there. When the organism dies, the C14 present starts to decay because C14 is no longer being replenished via air or nutrition.
If some C14 from a radioactive object comes in contact with the test sample such that is contaminates- a rare event - then there may be localized readings that will show less decay, and thus a younger life results. But, if the test sample is large enough, then the test points can be taken throughout the specimen, and result in a very accurate reading.
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Moxy
re c14 dating, the principal objection creationists use is not contamination, but rates of c14 creation in the past. they contend that c14 dating assumes the rates to be near constant when they are in fact wildly variable. this is a much better objection, simply because the answer is too complex to state concisely and leaves lots of wiggle room for doubters. just thinking thru the debate gives me such a headache. ive spent so much time on this topic....
mox
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Amazing
Hi Moxy: Citing contamination was mostly a WTS choice. I have heard Fundys make that claim too, and that is why I dealt with that one.
"re c14 dating, the principal objection creationists use is not contamination, but rates of c14 creation in the past. they contend that c14 dating assumes the rates to be near constant when they are in fact wildly variable."
They may make this claim, but it is not a good one. Part of the of C14 ratios in the atmosphere comes from the Fundy and YEC belief that the earth was covered by a water canopy prior to the flood of Noah. This is an absurd claim.The better claim is that there was a lot of above-ground nuclear testing between the mid 1940s through the 1960 when all such tests finally went under ground. However, the effects of any extra C14 can be factored in for such testing, and the data is accurate.
But, what everyone on the Fuindy and YEC side seems to miss is that our bodies maintain a constant ratio of C14 to C12. So, if there is extra C14 hanging around, our bodies pass this out. If there is less C14, our bodies do not pass this out in order to maintain the constant ratios of C14 to C12.
This phenomenon is true of other organics. Each has its own ratios, and this is why C14 dating is very accurate. C12 is stable and know for organics. C14 ratios are know for living organics. So, when the organic dies, then the C14 starts its decay because it is not replenished. Its ratios to C12 change ... and it is the accurate measure of this change that determines how long an organic has been dead.
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Moxy
But, what everyone on the Fuindy and YEC side seems to miss is that our bodies maintain a constant ratio of C14 to C12. So, if there is extra C14 hanging around, our bodies pass this out. If there is less C14, our bodies do not pass this out in order to maintain the constant ratios of C14 to C12.
come again? news to me. i think you might be thinking of the constant rates of intake. but the different rates of c14 production in the past do affect c14 dating, do need to be accounted for, and are.
mox
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Mindchild
The examples of dating methods mentioned by Alan are based on radioactivity. A further method relies upon looking at the direct evidence of radioactive decay in minerals by the by the trails of damage caused by radioactive decay. These are called fission tracks and they increase over time so you can tell the age of a mineral by looking at the density of its fission tracks and calibrating it by measuring the amounts of radioactive isotopes in the sample.
Another method is luminescence dating and is based on measuring the accumulation of “trapped” electrons in objects that have been subjected to natural radiation. A method that doesn’t depend upon radiation is Palomagnetism. It is based on the very slight magnetization in rocks that show both the direction and field intensity. It can be used for dating because we know the times when the magnetic field reverses itself. So, in some sedimentary rocks, we see alternating bands of magnetic orientation.
There are other methods in use besides these that use various approaches. One such method is to measure the trapped gases in materials to determine the atmospheric levels of different gases during time.
From what I remember, the outer limit of radio carbon dating was 70,000 years but really that is the end limit. For longer dating periods there is urainium/lead dating that is useful for billions of years. U238 has a half-life of 4.47 billion years and it gradually transforms itself into stable lead. When you examine the ratio of lead to U238 in a sample you can date it accordingly.
Just my two cents worth.
Skipper