How accurate is carbon dating or is it just a guess
@thedailyclick (3017)
January 16, 2010 2:47pm CST
It often bemuses me when you hear that an old bone suddenly dug up is over a million years old thanks to carbon dating tests carried out. Now what bemuses me is that carbon dating works on measuring the decay in the radioactive carbon-14 because science states that carbon-14 decays at a constant rate. But how can they prove this when it's impossible to know what effects climate change and other natural events have on the rate of decay because simply these situations cannot be replicated in a scientific surrounding to prove conclusively that carbon-14 does decays at a constant rate no matter what. So therefore by using this measurement as a test of how old something is can only be at most an educated guess, yet so much faith is placed upon the results of carbon dating. It's not like they can dig up an old bone with a date on it to calibrate how effective their carbon dating is.
So does anyone else find carbon dating to be nothing more that a best guess using scientific calculations but not as conclusive as we are lead to believe?
3 people like this
9 responses
@balasri (26537)
• India
17 Jan 10
To make the carbon dating accurate there should be some fundamental assumptions which have to be true. We must assume to know that the rate at which carbon-14 decays into nitrogen-14 hasn't somehow changed throughout the unobservable past. We must also assume to know what the ratio of carbon-12 to carbon-14 was in the environment in which our specimen lived during its lifetime. And finally, we must assume that there hasn't been any contamination in the specimen which we are attempting to date. Scientists have made progress in the second assumption but with certain uncertainties. It needs further research to fine tune and increase confidence in carbon dating method.
1 person likes this
@Torunn (8607)
• Norway
16 Jan 10
I don't think it's any worse than many other things that scientists measure, when measuring things in real life you have to take a lot of things into account that you can't simulate in a lab environment. For some time periodes, dates found with carbon dating have been checked with dates found with other methods so the scientists have a time line. Of course it is important to remember that that time line will be only be accurate for a certain geographical area if they have been checked against for example tree rings.
Of course, the problem isn't just whether the rate of decay is constant or not. Things like C13/C12 fractionation (hate spelling that word!), variation in past C14 production rate etc will also influence the age you find. Some of these things have been checked against carbon found in ice cores, but how big the problem will be of course depends on what you want to check. I think I read somewhere once that they carbon dated things found on Iceland to check whether the dates the sagas give for the first settlements were correct. As the sagas give very accurate dates, you'd want to check them against something that have +/- a year accuracy, and then maybe you get +/-50 years. Then you might try to find another method to check that particular date :-)
Then of course there's the man made changes, the atom bombs didn't make carbon dating any easier :-/
Radio carbon dating is more accurate than some other things though, I think for example counting of populations of wild animals or fish would be less accurate.
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@thedailyclick (3017)
•
17 Jan 10
Torunn, many thanks for your response and joining in the discussions it's really interesting the research and variables you mentioned along with bringing up Radio Carbon Dating. I would agree that at the moment radio carbon dating is probably the best that science has to offer when it comes to estimating dates. But for me it's the fact that there are so many variables which cannot be taken into account which always causes me to question the reliability of these results and as such by saying something is millions of years old actually carries any true weight because it can never be reliably proven. In doing so we are basically saying for examples that dinosaurs roamed the world so many millions of years ago when in fact the figures could be so far out because those changes which have happened in the intervening years cannot be reproduced.
@Torunn (8607)
• Norway
17 Jan 10
Carbon dating isn't necesseraly the best, but it is one of the easier and possibly also cheaper methods. Which is why we here about it all the time.
And you wouldn't use carbon for dating dinosaur bones, not unless you had to. The half-time of carbon-14 is somewhere around 5500 I think, so what they do for things that are millions of years old is to find another way to date it. If possible of course. One thing they can do is date the layers in which the bones are found, if it fossils found in stone. The good thing with that is layers of stone that has been under several other layers of stone, most likely since they were made, aren't very likely to have been influenced by climate changes, volcanic eruptions etc in the same way as things closer to or on the surface of the earth.
@PeacefulWmn9 (10420)
• United States
16 Jan 10
I have always wondered precisely the same thing. Going billions of years back with carbon dating? Now, really, how do they know that is accurate? How could science truly proove it? I think they cannot. Just because it might work going X amount of years backward, still, you get into the thousands millions billions?
They cannot proove that.
@thedailyclick (3017)
•
17 Jan 10
The strange things is that I believe the calculations scientists use are very good, except they have to assume things which have happened in the past which are impossible to take into account which inturn makes me always think when they say something is millions of years old that it is an unprovable calculated estimate and nothing more.
@megamatt (14292)
• United States
16 Jan 10
The calculations have some basis of fact, I suppose. However, I doubt that anyone could get it accurate right on the nose. There has to be some variables that everyone is not accounting for, that might throw any calculation off. No method is without its flaws. It would be hard to prove them wrong however, but it would be just as hard to prove them right.
@thedailyclick (3017)
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17 Jan 10
Hi megamatt, many thanks for joining in and making the very important point that these scientific calculations can either be proven or disproven, which makes me wonder wny so much weight is put on these findings as being fact.
@codeofuniverse (558)
• India
17 Jan 10
carbon dating technique is just to guess , what may happened at some times in the history of science.. the problem in the technique is that no metal or gas or form remain pure in the couse of time there are lot variations and processes with al atoms.. some variations may be due to magnetic or electrial effects.. so it is very dificult to find out..correct findings..there are some different methods like pb..lead dating to find out life or age of extraterrestial objects.., planets .or stars..but all are just guess
@bryce22 (69)
• Poland
16 Jan 10
Scientist would not state a fact if they cannot prove it.A number of test and experiments is what they did to support their research.So why not believe with them?.At least you are also a scientist.There's no 100 percent accuracy so when your in doubt you should be wise enough to say that you contradicts.
@thedailyclick (3017)
•
17 Jan 10
@bryce22 - You ask why not believe them, well quite simply it's impossible for scienec to completely take into variables such as the change in atmosphere over supposedly millions of years in a scientific test and so the results of these carbon dating tests will always be based on unproven assumptions.
@PeacefulWmn9 - another good point about science evolving. I do wonder if in say 50 years time someone comes up with some sort of testing which says the world is in fact not millions of years old rather than say the extreme of just thousands whether those scientists will ever allow it to come to light because it will throw everything which has been taken as fact into disarray, lol.
@PeacefulWmn9 (10420)
• United States
16 Jan 10
Scientists themselves proove and disproove their own theories on a regular basis, or disprove today what was considered fact 50 years ago. It evolves like anything else.
1 person likes this
@poingly (605)
• United States
17 Jan 10
Using Newton's laws (like the law of gravity), we can predict how all sorts of things move in the universe from a race car on the ground to planets and stars. We were able to discover far off planets like Neptune to calculate deviations in the orbits of planets based on some mysterious force using these equations. However, then that jerk Einstein came along and proved that darn law of gravity wrong.
Well, our coffee tables don't go flying into the sky just because Newton was wrong. Einstein tweaked Newton's math to formulate a better equation, but even he theorized his equations would fall apart near a black hole. We still teach Newton's theories in class because they are simple and work for most things.
Another way to think about it is figuring out the area of a circle, which is PI*r².
We could estimate PI as 3.14, which would be pretty close.
We could estimate PI as 3.14159265358975323, which would be closer.
We could calculate PI out to millions of digits, but it would be impossible to get it exact.
Carbon-dating is like cutting off PI after a good number of decimal places, you don't QUITE get the area of the circle, but it's close.
@scarlet_woman (23463)
• United States
17 Jan 10
it's fairly accurate within a couple thousand plus or minus..
so if you take it as an estimate,it's a pretty good benchmark.
one of the problems they have occasionally is when something has been through a fire-like the shroud of turin.that can mess with the carbon date.
@poingly (605)
• United States
17 Jan 10
Oh, as far as accuracy goes, just to let you know. If you were born after 1950, they could take your tooth and use carbon dating to figure out the year you were born (give or take a year or two). For something around 2000 year old, that give or take goes up to about 50 years. At 6000 years old, the give or take goes to 150 years or so. At 30,000 years old, that give or take is like 2000 years. Unpredictable C14 levels could push these margins a little wider.
@sanjeevsingh (392)
• India
17 Jan 10
Well carbon dating till now is the best method for estimating the age of fossils. It gives the best possible estimation ..
