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Physics and Archaeology
Guinnessy writes: "In 1960 Willard Frank Libby won a Nobel Prize for his work on radiocarbon dating, a technique that truly revolutionize archaeology. Now Physics Today magazine has an article describing how new methods are yielding more accurate dates for our prehistoric ancestors, profoundly affecting our understanding of the past. Neat stuff."
be useful in determining exactly when "Quirky Engeneers" went the way of the dinasour? ;)
If I can't see it in Lynx I'm not interested.
Boy, if we have more accurate techniques, the Scientific Creationism community is going to have to come up with new excuses to explain away why things test older than they claim the Earth to be...
Before the radio-carbon dating and the physics of glow curves and AMS testing and all the other modern techniques were available, archaeologists were digging in the dirt looking for "old-stuff" to examine. It's a natural human behaviour, a curiousity to know where we came from.
So what did people use in the old days? Their eyes and their brains. Observations and an understanding of basic anatomy, history and geology are tools that you can take anywhere, don't require an expensive lab, and never need new batteries.
Today's technology may be nailing down more accurate dating, but human experience out in the field is still you're best place to start in an archaeological dig. While the two should compliment each other, the people who rely on machines to do all the work for them don't really understand what it means to be an archaeologist.
Indiana Jones and the Lost Particle
I didn't really see a lot of new information in the article, but it did mention some radio-dating techniques I had heard of.
What's left to consider are the reprocussions from this kind of discovery. It's important to remember that all of human social sciences... language, philosiphy, psychology... all of them will benifit dramatically from knowing not only the exact time of origin of the human species, but early human's movement patterns.
One of the problems about human history that this kind of dating will help solve is the origin of human language. When did humans learn to speak? What languages descended from which? Why do many 'fairy tales' appear in more than one culture? Was there a single human 'parent' language that was responsible for this?
This kind of 'early' human history dating will help us probe out these kind of conundrums.
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Nope, not me, I must be someone else...
We developed archaeology without any carbon dating. We had to use anthropological methods tofigure out what the meaning of a bunch of stuff in a dig was, and where it came from.
Carbon dating is a wonderful technology - it dates stuff within a range of a century or so. It enables us to confirm hypothesis made by other methods.
A more rigid and absolute dating technology would probably enable archaeologists to fill in many of the gaps in current knowledge.
I worry about too much reliance on an absolute technology, though. Even if you take a bore of soil and can tell the exact day when each item fell into it, you still learn nothing about trade routes, cultures, mythologies, ancient lifestyles, etc.
This is where anthropology, an inexact science, must take the lead.
Goat sex free since 2001
One thing this article fails to mention is that when these dating techniques are used, they often give wildly varying results for a single sample often with a spread of 2 orders of magnitude!!! Another interesting point is that all the radioactive dating methods are based on critical assumptions about our earth which in some cases (Carbon-14 in the atmosphere) have been proven wrong. I'm _not_ a creationist - I believe that if anything the creation story is meant to be an allegory of some sort. So I don't pay much attention to creationist rants. I have read several good books which address these issues, particularly as the related to evolution and archaeology. On is: Shattering the Myths of Darwinism (thats a review of it). It discusses in scientific detail what is wrong with the radioactive dating methods both theoretically and in their application. I highly recommend the book even though I am not truly qualified to assess its arguments (IANAS(cientist)).
Helping with organizational effectiveness is our job.
From hypertextbook.com
potassium-argon dating
Potassium-argon dating is used to determine the age of igneous rocks based on the ratio of an unstable isotope of potassium to that of argon. Potassium is a comon element found in many minerals. The isotopic distribution of potassium on the earth is approximately 93% 39K and 7% 41K. Since these values are only approximate, the total percent abundance of these two isotopes is not 100%, but 99.9883%. The remaining 0.0117% is 40K -- an unstable isotope with a half life of 1.26 x 10^9 years. 40K has three decay modes: beta decay, positron emission, and electron capture.
1.26*10^9 = 1.26 BILLION. On a logarithmic basis, the article is much closer than you.
Our lab here at Purdue, PRIME Lab, is a great example of this, retooling an older tandem accelerator lab for a new use as funding for nuclear physics began to dry up, and other similar facilities around the country closed. We've even got one of the accelerators with the highest energies of any AMS facility in the US by reusing the facility in this way.
First paragraph in the article... and already they've lost my (suspension of dis)belief....
a cadia.asx
==> Traditional archaeology has not been a field that suffers science easily. Only gradually have archaeologists accepted physics as a tool for archaeological research. Perhaps as a result, the physicists who work in archaeology, their methods, and their theories, are neither well known nor numerous. Archaeometry, as the wider field of scientific archaeology is known, has no Heisenbergs or Einsteins, uncertainty principles or relativity theories. The only physical discovery to truly revolutionize archaeology has been radiocarbon dating.
Physicists have developped ground-based RADAR technology and Echo-location technologies which are having a profound impact on the archaeological world.
Take a look at: http://www.exn.ca/inc/demo.asp?Video=exn20011009-
(Windows media player format, sorry.)
These RADAR/SONAR devices have drastically reduced the time it takes to locate archaeological sites, and yet they don't even mention it until the end of the article. After having clearly stated that "The only physical discovery to truly revolutionize archaeology has been radiocarbon dating."
If you believe everything you read, you'd better not read. - Japanese proverb
<40Ar test>
Question 1:
How old ARe you? 40? _______
</40Ar test>
I swear your honor, she said she was 18...
RC
I heard someone say that the biggest technological contribution to archaeology in the last 50 years was the zip-lok bag.
One thing the article didn't really go into that I found interesting is how carbon 14 dating was found to be inaccurate. It had been assumed that C-14 decayed at a constant rate. However, a guy named Schulman studying the Bristlecone Pine trees in the White Mountains of California discovered that C-14 dates didn't match the tree ring dates. Subsequently, tree rings between living and dead bristlecones have been used to construct accurate dating back 9000 years, and it has been determined that C-14 rates do change. Read more about it on the Inyo National Forest page.
variations in things like the speed of light over time
;)
Well, I'd be willing to say that the lights turn on now-a-days much faster than they did 100 years ago.. does this affect isotope dating?
--
Relax, it's a joke. Have a good friday!
the bible tells me that there is just no way that stuff could be that old.
hee hee.
silly bible.
There are some odd things afoot now, in the Villa Straylight.
is that you can tell easily item one is just a s old as item two. But unless you have a way to date one of the items some other way, all you can tell is that the items are the same age, but not how old they are.
When you are talking about artifacts millions of years old, there is no "proof" of the age of any item.
Some scientists put together a theory of how carbon acts over millions of years (and obviously because of the timeframe involved have no empiracle evidence about the behavior of carbon over millions of years) Then they date things relative to the theory.
Note I am not saying carbon dating is wrong, but it certainly hasn't been proven.
What you're saying here is that historically, we have used a deductive approach, generating theories and the confirming them with our technology.
I worry about too much reliance on an absolute technology, though. Even if you take a bore of soil and can tell the exact day when each item fell into it, you still learn nothing about trade routes, cultures, mythologies, ancient lifestyles, etc.
This only becomes a worry if you are still working on the inductive approach. When you have accurate enough data in large enough quantities, you can use a deductive approach to generate your theories from the data itself. In the presences of such data, this can be very effective. You can take that soil, find when every item fell into it, and use that to guess at trade routes, rather than guessing at trade routes and then using the bore to see if you were right.
Just because we developed archaeology without carbon dating and then used carbon dating to verify the theories of previous archaeological work doesn't mean that's the best way to do it. Just because it's a different approach doesn't mean it's any worse then then "anthropological" approach. The best results will surely come of combining anthropology and technology (and, more than likely, deduction and induction), but the order in which they are applied may shift. Times change, technologies change, and sometimes we have to change our ways of thinking in order to keep on doing better.
Just a thought.
-Puk
C-14 dating only has "reasonable" error ranges for items dated at 5000 years or less (around 1 century). If you use C-14 to date something older, say, 10000 years (or 10,000,000 years), the percentage of error margin gets significantly larger. The man who designed carbon dating (his name escapes me) explained this in his thesis which won him the Nobel Prize.
-Ted
PS: What cites? You know where to find them
Yes, this is kinda silly and kinda offtopic, but I can't be bothered to do some proper searching on the subject.
When were the oldest pyramids in Egypt built - really?
I saw a special on Discovery a year ago, and they said that carbon dating was estimating the pyramids to be (IIRC) between 4 and 11 thousand years old. Not too accurate, is it? Can someone explain, why there is so much doubt when estimating the age of pyramids, when they could set the age of the Egyptian pharaoh's tomb to 5730 years? And have any of these new techniques set some more accurate dates?
-Kraft
Live and let live
Willard Libby designed C-14 Dating. Apparently the error range is not 5000 years but 60000 years as referenced here.
-Ted
This link should give you information on the pyramids. I believe they dated the pyramids because of how they were aligned to the night sky when they were created (since the sky slowly shifts over time).
-Ted
Timeo idiotikOS et dona ferentes
Sorry, I wasn't trying to list all of the possible variations on the "how did we get here" theme :-) I actually *was* a theistic evolutionist up until a fairly short time ago, and as such know exactly where you're coming from. One great thing about the Bible, is that it is almost infinetly malleable. If I am proven wrong, (and I very well might be) and someone has indisputable *proof* of evolution, then I will quite happily go back to being a theistic evolutionist. While trying to explain to some people why my faith is unshakeable, even though it is scientifically unprovable (which, btw, isn't strictly true), I generally bring up the following example. They have a theory of an all-powerful force that affects the universe, that you can't see/smell/touch. Scientists can't prove by direct observation that they exist. They call this force a "blackhole". :-) (And yes, I know it's not a direct correlation. that's why it's called an analogy, stupid!).
3) Agnostics that find the debate amusing and feed the trolls on both sides, happy to spout off whatever keeps the thread growing.
4) Proponents of the 'Intelligent Design' theory, who roughly propose that God (or someone) was the initial force or energy behind the 'Big-Bang' some 15 or so billion years ago and guided the outcome including the details of life on this planet.
Bleh!