MemberlistThe Library Index  FAQFAQ   SearchSearch   RegisterRegister   ProfileProfile   Log in to check your private messagesLog in to check your private messages   Log inLog in 
Beaker People (Pre-History)
Reply to topic Goto page Previous  1, 2, 3 ... 22, 23, 24
View previous topic :: View next topic  
Ishmael


In: Toronto
View user's profile
Reply with quote

Mick Harper wrote:
And it does it so completely that it is interesting in an AE sort of way just why they either haven't done it or declined to publicise the results if they have done it.

Well my sources tell me that the really ancient old trees only grow in North America, where they are of limited historical applicability.
Send private message
Komorikid


In: Gold Coast, Australia
View user's profile
Reply with quote

Well my sources tell me that the really ancient old trees only grow in North America, where they are of limited historical applicability.

Your sources are correct: the oldest known tree was cut down in the 1960's at the ripe old age of 4900 years old. But please qualify - of limited historical applicability.
Send private message
Ishmael


In: Toronto
View user's profile
Reply with quote

Komorikid wrote:
Your sources are correct the oldest know tree was cut down in the 1960s at the ripe old age of 4900 years old. But please qualify - of limited historical applicability.

Because 4900-year old North American trees were not used in the manufacture of Mesopotamian furnishings.
Send private message
Komorikid


In: Gold Coast, Australia
View user's profile
Reply with quote

Because 4900-year old North American trees were not used in the manufacture of Mesopotamian furnishings
.
No they can't, but they can be used to provide a continuous 4900 year chronology; well within the time frame we are discussing.
Send private message
DPCrisp


In: Bedfordshire
View user's profile
Reply with quote

No they can't, but they can be used to provide a continuous 4900 year chronology; well within the time frame we are discussing.

Now it is you who is missing the point, KomoriDude. The question isn't whether an accurate chronology is possible, but whether we have one. Even a perfectly accurate 10,000 year chronology of North American events doesn't help us with the majority of ancient history unless we can line up New World and Old World events. Which we can't.

We can work backwards pretty reliably and say Tokugawa became shogun in the year that Elizabeth I died and maybe a totem pole can be found that was felled around the same time. But what would a pueblo dated to 234 BC tell us about European events of 234 BC?

The utility of dendrochronology is a matter of luck: for which periods and places can we assemble continuous records... and for which species... and can gaps be bridged with data from other species... and do we even have artefacts of any significance made of suitable wood...?

Even a 10,000 year old English oak would be of limited value, if you think about it. Pretty good for radiocarbon calibration though.
Send private message
Mick Harper
Site Admin

In: London
View user's profile
Reply with quote

Everyone is missing the Applied Epistemological point.

If it is accepted that tree rings are completely objective, that is one tree ring equals one year, then we have an objective method for testing carbon dating. What we do is take a 4,900 year old tree (ie one that has 4,900 rings) and carbon date a sliver from every (say) five hundredth ring. If the carbon date marries up to the ring date absolutely then we know that carbon dating is literally, ie chemically, rigorous.

If on the other hand the dates do not match up then we have to re-callibrate. Since we do not know the causal factor that requires the re-callibration we would have to do the same thing with a stastistical sample of trees. If the result is consistent then we have an objective validation of carbon dating plus recallibration.

It presumably doesn't matter where the tree samples are taken from since whatever the factor is that slows down or speeds up carbon decay it presumably affects everywhere on earth (indeed the entire universe) but just to make sure it is not a local factor, Old World samples (so far as they go back) would need to be included in the sample.
Send private message
Ishmael


In: Toronto
View user's profile
Reply with quote

This sounds rational. We should do some additional reading on Radio-Carbon dating to find out if this critique truly has the merit it appears to possess.
Send private message
DPCrisp


In: Bedfordshire
View user's profile
Reply with quote

(As I said) It is my understanding that that is is precisely how tree rings were/are used to calibrate carbon dating.

There's something odd about saying the rate of decay (the half-life) is constant, not influenced by environmetal factors, while the proportions of C14 and C12 in the environment can be affected by cosmic rays (anything else?). Nevertheless, accurate calibration must account for any variations in both.
Send private message
Ishmael


In: Toronto
View user's profile
Reply with quote

I'll have more to share on this subject shortly. A specific critique we can rebut or take into account.
Send private message
Tilo Rebar


In: Sussex
View user's profile
Reply with quote

Some physicists are coming around to the idea that the decay rates for radio-nucleotides are not constant. Article here...

More evidence that radioactive decay is not constant
http://www.examiner.com/article/more-evidence-that-radioactive-decay-is-not-constant

"...But it might force a re-examination of radiometric dating of once-living things using the carbon-14 method. Those dates might be considerably wide of the mark on account of an unknown number of solar flares between the death of the organism being sampled and the present day. More to the point, the notion that radioactive day rates are variable is a direct blow to the heart of the conventional case for an old earth, because it forces a re-examination of every premise that uses radiometric dating as its basis."

This is another good reason to always question the results of radiometric dating until the science is fully settled.
Send private message
Pulp History


In: Wales
View user's profile
Reply with quote

Is the science EVER settled? Surely if we accept that it is we stop going back and testing the original hypothesis.... hence a house of cards is assembled.
_________________
Question everything!
Send private message
Tilo Rebar


In: Sussex
View user's profile
Reply with quote

Pulp History wrote:
Is the science EVER settled?


It will only be settled once we start to understand the fundamental physical processes which lie behind the observed effects.

All the strange paradoxes, which plague many areas of theoretical science, are an indication that our basic understanding of how things work is flawed.

Empirical mathematical models based on faulty assumptions are bound to lead all areas of knowledge in the wrong direction. The issues surrounding carbon dating methodology is a good example of the damage this can do.
Send private message
Boreades


In: finity and beyond
View user's profile
Reply with quote

Mick Harper wrote:
Everyone is missing the Applied Epistemological point.

If it is accepted that tree rings are completely objective, that is one tree ring equals one year, then we have an objective method for testing carbon dating. What we do is take a 4,900 year old tree (ie one that has 4,900 rings) and carbon date a sliver from every (say) five hundredth ring. If the carbon date marries up to the ring date absolutely then we know that carbon dating is literally, ie chemically, rigorous.

If on the other hand the dates do not match up then we have to re-callibrate. Since we do not know the causal factor that requires the re-callibration we would have to do the same thing with a stastistical sample of trees. If the result is consistent then we have an objective validation of carbon dating plus recallibration.

It presumably doesn't matter where the tree samples are taken from since whatever the factor is that slows down or speeds up carbon decay it presumably affects everywhere on earth (indeed the entire universe) but just to make sure it is not a local factor, Old World samples (so far as they go back) would need to be included in the sample.


Has anyone found a statistical sample of 4900 year-old trees?
Send private message
Mick Harper
Site Admin

In: London
View user's profile
Reply with quote

There are examples of coppices in Britain that are (said to be) 2,000 years old (ie a clump of trees is cut down every 10 to 20 years and regrows and this process has lasted without hiatus for 2000 years) but I don't quite see how you dendrochronologise this.
Send private message
Boreades


In: finity and beyond
View user's profile
Reply with quote

DPCrisp wrote:

But look at this map of the "Beaker People"

http://www.comp-archaeology.org/BenzGramschEtAl1988MapCordedWareCAWEB


I would if I could, but that link now offers me Weight Loss and Penis Extension products. Some mistake surely?
Send private message
Display posts from previous:   
Reply to topic Goto page Previous  1, 2, 3 ... 22, 23, 24

Jump to:  
Page 24 of 24

MemberlistThe Library Index  FAQFAQ   SearchSearch   RegisterRegister   ProfileProfile   Log in to check your private messagesLog in to check your private messages   Log inLog in 


Powered by phpBB © 2001, 2005 phpBB Group