How radiometric dating works and why it's wrong

[ThaiDuykhang]

Well done! Thai has proved that gap theorists don't exist!



And of course, the examples are substantiated with verifiable references to primary source documents, are they? The principal source of the age of the earth doesn't come from moon rocks (as far as I know) but from isochron dating of meteorite fragments.

Do you think after the miserable failure to date moon rocks they will not use the method that dated earth's age? Do they need to tell you that "4.6b is chosen because of it matches the age of earth" if they use a reliable method and get a correct result?

 

[gluadys]

For such understanding of science I can even expect a TE to refute you.No one ever tries to date that 4000 year old tree. Where's the caliberation?I have shown you the "anual layer" of ice core isn't anual. you've read it?Robert the Pilegrim has done the search for you in that Sirius thread. and came up with a poor result. go and read it.
Let every new member come and see which side is swearing and insulting.

Why do you keep talking about "that 4000 year old tree"? Do you think dendrochronology is based on data from just one tree?

And it doesn't sound as if you even know what calibration is.

I read Robert's references on Sirius. It didn't sound like a poor result to me.

 

[ThaiDuykhang]

Why do you keep talking about "that 4000 year old tree"? Do you think dendrochronology is based on data from just one tree?

And it doesn't sound as if you even know what calibration is.

I read Robert's references on Sirius. It didn't sound like a poor result to me.

Someone from your side keep talking about that 4000 year old tree. I don't know what calibration is? After so many calibration, the carbon dating stop giving out laughable result?Robert's claim is good? You don't even understand Chinese. Do you need a little language course on Chinese? I'll be glad to be your teacher. for free! It's full of elementary problems in that article.

 

[gluadys]

Someone from your side keep talking about that 4000 year old tree. I don't know what calibration is? After so many calibration, the carbon dating stop giving out laughable result?Robert's claim is good? You don't even understand Chinese. Do you need a little language course on Chinese? I'll be glad to be your teacher. for free! It's full of elementary problems in that article.

I have never heard anyone from "my side" talk about a single 4,000 year old tree. I don't know where you are getting that from.

If you understand what calibration is, let's see you explain what it means.

No, I don't speak Chinese. So I won't comment on whether the translation was good or bad.

 

[ThaiDuykhang]

I have never heard anyone from "my side" talk about a single 4,000 year old tree. I don't know where you are getting that from.

If you understand what calibration is, let's see you explain what it means.

No, I don't speak Chinese. So I won't comment on whether the translation was good or bad.

I'll not find where your side mentioned that tree since your post is obvious an attempt to drag the thread offtopic.
Calibration is bogus. if it's serious they should calibrate 23000 years to 0 year first.Now you can explain the process.I can speak Chinese and I can tell you robert's article is rubbish.

 

[ThaiDuykhang]

To those who say a decay of 1000 years is undetectable, in 1000 years about 11.4% of C14 will decay.

 

[Deamiter]

if no decay is present, it will give an age of zero. a typing mistake I guess?
Does the handbook of carbon metric dating says failure to detect enough decay for procedure means the age is 0? do you think dating professionals are that ignorant or is this a creationist conspiracy?

Well... we're talking about two different things. Technicians DETECT radioactive decay by detecting the number of alpha and beta particles produced. So if they detect NO decay, then there is NO radioactive media in the sample. In reality, there is ALWAYS some radiation detected -- from cosmic rays if nothing else. And there is always some C14 decay -- they can tell the difference due to the energy of the particles released. But if they DETECT no decay, or in the real world -- decay that's very near background noise, then the date has a huge error because it's impossible to tell it from the background noise.

If they detect LOTS of radiation, that means that little radioactive decay HAS happened.

If I can't observe it hasn't moved, I'll say it hasn't moved instead of saying it has moved greatly. you're trying inject logical confusion here. but not into me.
400 year old may be dated 200 year old or 600 year old. as they both are not within your range of application. but you don't date them as 20000 years which is within the working range of carbon dating.
Put it simply, the water level goes down 0.5mm and it's not very easy to observe. you can say it goes down 0.2mm or 1mm, both are ok. but you don't say it goes down 10mm which is highly observable.

If a carbon dating can't be used to date thing less than 1000 years. it can't distinguish 1000 years of change anywhere. be it 1000-2000 years or 10000-11000 years. however the accuracy claimed by dating professionals are stunning: 60 years for example. if you can't observe a 1mm drop of water level at the beginning, you also can't observe a drop 1mm when the tank is only half full.

I did a little more searching, and it seems I was wrong about C14 dating not being used for very recent artifacts. The dating can indeed used up to 1950 when the C14 levels become so erratic (increasing sharply with each nuclear test) that there is no equilibrium for plants to come TO. The reason it's NOT used is primarily that it's easier and simpler to date things based on surrounding artifacts. And certainly there's a limited use for dating -- when dating a wooden boat, for example, you're not getting the date the boat was USED, you're getting the date of when that part of the wood GREW. I've seen this factor cited in a number of articles on historical finds -- they can and DO date artifacts, but just because it's possible to find out when the artifact DIED (stopped taking in atmospheric carbon) doesn't mean it's possible to find when it was USED.

About the water thing, you're quite wrong about the accuracy. The water will pour through the hole slower and slower as it gets to the bottom, but radiation is even more tricky than that. Because of half-lives, the AMOUNT of C14 NEVER gets to zero. It decays exponentially TO zero, but as it gets lower and lower, it's harder and harder to distinguish C14 from other background radiation. It's the background radiation that provides the limiting factor, not the amount of Carbon 14. So while labs can provide dates to within 5 years in the last 1000, when you get up over 25,000, the error becomes 50 years.

Some labs round to the nearest 10 years (or 50 years when over 25,000) and some don't. Some labs report ages over a certain point as "background" and others will simply give the measured age. It's up to the researcher to know and take into account the particular lab's standards when analyzing the data.

 

[Deamiter]

The age of 4000 of that tree is measured by counting tree rings. not by carbon dating.
No one has yet proved within 4000 years C14 level doesn't change.

Actually that's not true. Yes, the age was measured by counting tree rings. And when they tested each ring, they found that the C14 level was almost constant at each ring. Of course, older rings had less and less C14 LEFT, but the AMOUNT left was exactly as predicted by radioactive decay. In essence, since we KNOW the tree is 4000 years old, we can measure the C14 levels at each ring and use a simple equation to calculate the amount that WAS there when the ring was formed.

Why do I say "ALMOST constant?" Simply because it's not precisely constant. As I have said before, the amount of C14 in the atmosphere has been precisely calibrated (using these tree rings and ice cores all over the earth) to account for effects like the sun's 11 year cycle and climate change. The actual variation is only within 5% in the last few millenia though.

It doesn't matter you make mistakes. everyone has made some. however while there're less C14 in water. there're also less C12 in water. Even if C12 enters water much more readily than C14, Don't you think they have measured the amout of C14 in water first before measuring the amount of C14 in fish and seals? Why do they put out blunder after blunder when the solution according to you is quite simple?

Of COURSE they measured the amount of C14 in the water before measuring the amount of C14 in fish and seals. That's why they know it's not accurate.

And you're right, C14 and C12 ENTER the water from the atmosphere at the same rate. The problem is that there is a LOT of water in the ocean that's very far away from the atmosphere. In that water, the C14 has mostly decayed (to background levels) so something that lives in THAT water would give much older ages than something that lives near the surface.

The reason it can't be used ANYWHERE in the ocean is that there is some constant circulation of the ocean water. There are places where deep-ocean water is drawn up to the surface, and there are places where it's more stagnant. Unfortunately, sea creatures don't just stay in one of those areas for their entire lives (and neither does the ocean currents stay exactly the same year after year). It's not that there is NO C14 in the ocean, it's just that the ocean is not homogeneous. There is no CONSISTANT C14 level the way there is in the atmosphere.

First this is answered in passages above. Second, there's no reason for unable to detect enough decay other than the sample is too young. and technicians are not ignorant. when they fail to detect enough decay, they'll tell you it's less than 1000 years old. they get the answer of 20000 years because they have detected enough decay and believe the sample is old enough to date.

As in my last post, I WAS very wrong about recent dating. I knew it wasn't used often but I had forgotten why. Quite simply, there are easier (less costly in both time AND money) ways to date artifacts. And though things ARE dated, the dates given aren't accurate to when the artifact was USED (or buried) but to when the artifact DIED.

Well, when you get too close to a tower and hear a strong signal, you'll believe you're quite near the tower (corresponding to <1000 years) instead of very far from the tower (corresponding to 20000 years)

When you're too far from the tower. you say "hey I must be mre than 10km(corresponding to 50000 years) away from the tower" instead of "I'm 23.5km (corresponding to old age resulted from carbon dating) away from a tower"

Exactly right -- that's exactly how carbon dating works. When something is too old, they'll say, "it's indistinguishable from background" and when it's too young (after nuclear testing screwed up the equilibrium) they'll say "there's no baseline to test it against."

Please show me the record of C14 level before 1950. tree rings only indicate the oldest tree is 4000 years old and no one has yet dated it. if you date a tree died 1 year ago -2000~4000 years old and have already known it's chopped down 1 year ago, you'll put the number 1 year on the report. I've said previously the range of result is so wild that they just put the number fittest to them. see the moon rock example.

Trees that are grown in the same area will nearly always exibit the same ring pattern from year to year. This a well known fact. Of course there are some isolated exceptions -- like the trees that grow multiple rings per year, but it's a particular TYPE of tree that only exibits that behavior in a particular TYPE of environment. Further, the multiple rings are readily obvious to scientists who do this sort of research.

So one can rather easily fit tree rings in a live tree with those from a dead tree, and fit THOSE with that of an older dead tree etc... The sequence has been shown unbroken for at LEAST 8000 years, though you're right that the oldest LIVING tree was 4000 years old.

in the 5.5 feet per year of ice. numberous "anual" layers have been found. I forget the exact number but the thickness of an "anual" layer in greenland is no different than an "anual" layer in Iceland. if you use it to date planes buried there in ww2, you'll think they're hundreds of years old.

Wait a second, why are we talking about greenland and iceland? Ice cores are from the north and south POLES where the thickness of the annual layers is a couple of millimeters (after being compressed)! How you get 5.5 feet when the annual PRECIPITATION is under 3 centimeters is quite beyond me!

You've quite wonderfully shown that counting annual layers is insane in places that get a whole lot of snowfall. Of course, it's still done (though not in places with THAT much precipitation to my knowledge). The summer daily layers crystallize quite differently than the winter layers due to differing temperatures.

However, again, accurate dating is done in the arctic and antarctic where the annual precipitation is tiny. As I've said before, worldwide events -- even those in recent history like the Mt. St. Hellens eruption have been recorded in the annual layers. These events are used to verify the accuracy of the ice-core data.

an "anual" layer is formed because of a shift of temperature. for example within a day or something like that.
the "summer" layer in ice core corresponds to the warmer part of the day and the "winter" layer in ice core corresponds to the colder part of the day.

I just explained this (sorry to split up your quote). Once again, a daily layer only makes sense when you're getting snow daily (or even weekly). In the desert of the North Pole, no matter WHAT the temperature when it snows, the ice formed will crystalize differently based on the average temperature over MONTHS, not hours.

I don't know how to caliberate sun's cycle with ice core. will you please explain it in detail?

Quite simple really. The sun's cycle corresponds to a variation in radiation (from sunspot activity). There is a corresponding change in the amount of radioactive elements in the ice cores. It corresponds to recently measured activity levels, and the radioactive fluctuation extends well past the point where the annual layers are compressed so much as to be indistinguishable.

In short, even though it's not a VISIBLE layer, it's very detectable.

Tree rings only tell how old the tree was when it died. it can't tell how long the tree has been dead. so you can't use trees rings to detect the date valcanos. will you please show me the source of this claim? it's just too wild

This is a very simple and very common technique... I STRONGLY suggest you look it up yourself (google has dozens of results) because I feel that if you're not understanding something so simple, I must be missing a vital point that I take for granted but which you've never heard of.

Of course tree rings only tell how old the tree was when it died. But there are a few ways that tree rings can be calibrated.

First of all, as I said before, tree rings can be compared to each other to generate an unbroken history to present. The similarity is so obvious that you wouldn't argue with it if you saw the effect in person -- sometime if you have a chance, cut down two trees in the same forest (even a hundred miles from each other). Then compare their rings and you'll be able to tell exactly where they overlap. If you're feeling adventurous, compare the rings of a freshly-cut tree to that of an old stump. Again, you'll see exactly where they overlap.

Second, you can get to within a few years by counting rings to where there are a number of rings very close together. Trees near a volcano will be damaged by the eruption and will grow very little for a few years after the eruption. There will even be missing rings in many cases where the tree didn't grow at all for a few years. By comparing trees that were affected to nearby trees outside of the influence of the volcano, you can tell how many rings are missing and get a precise year (and often even a season) of the eruption.

This has been done for very recent events like Mt. St. Helens in 1980. It's been done for older eruptions in the 1800s and 1700s. The method is undeniably accurate -- and you can easily verify it yourself by cutting down a tree or two. I did it at my grandparent's house where they heat their house with a wood-burning stove. It's really rather cool how the rings overlap so obviously and show where there were droughts, cold years, even floods!

 

[Deamiter]

I'll not find where your side mentioned that tree since your post is obvious an attempt to drag the thread offtopic.
Calibration is bogus. if it's serious they should calibrate 23000 years to 0 year first.Now you can explain the process.I can speak Chinese and I can tell you robert's article is rubbish.

You'll not find it because YOU mentioned it first yesterday in post 31. We were saying that tree dating is accurate to about 9000 years (by comparing tree rings of multiple trees). You said the oldest living tree is 4000 years old.

They've calibrated 1950 to year zero. All ages given are in years BEFORE 1950.

Again, because of the exponential nature of radioactive decay, there's no point at which it HITS zero. It just gets lower and lower until it's indistinguishable from background radiation.

About the 1000 years old, it's not USED because archaeologists generally have a better idea of when something happened within that 1000 years than dating can produce. It's not that the dating is inaccurate in that range -- it's just that archaeologists want to know when a civilization existed or when a boat sailed -- knowing when the tool was made or when the trees for the boat were cut down adds DECADES of error to finding out WHEN an event (like a battle or the life of a king) happened.

I must apologize for a third time for saying that technicians CAN'T date something that died 1000 years ago. I do welcome the correction.

 

[Robert the Pilegrim]

I've also studied nuclear science.

What are your primary sources of education/information about nuclear science and radiocarbon dating?

I'm still waiting to hear your primary sources of education/information about General Relativity and what you think an inertial reference frame is.

 

[ThaiDuykhang]

Well... we're talking about two different things. Technicians DETECT radioactive decay by detecting the number of alpha and beta particles produced. So if they detect NO decay, then there is NO radioactive media in the sample. In reality, there is ALWAYS some radiation detected -- from cosmic rays if nothing else. And there is always some C14 decay -- they can tell the difference due to the energy of the particles released. But if they DETECT no decay, or in the real world -- decay that's very near background noise, then the date has a huge error because it's impossible to tell it from the background noise.

If they detect LOTS of radiation, that means that little radioactive decay HAS happened.

OK, we're having different things in mind.

I did a little more searching, and it seems I was wrong about C14 dating not being used for very recent artifacts. The dating can indeed used up to 1950 when the C14 levels become so erratic (increasing sharply with each nuclear test) that there is no equilibrium for plants to come TO. The reason it's NOT used is primarily that it's easier and simpler to date things based on surrounding artifacts. And certainly there's a limited use for dating -- when dating a wooden boat, for example, you're not getting the date the boat was USED, you're getting the date of when that part of the wood GREW. I've seen this factor cited in a number of articles on historical finds -- they can and DO date artifacts, but just because it's possible to find out when the artifact DIED (stopped taking in atmospheric carbon) doesn't mean it's possible to find when it was USED.

I searched the net and it indeed said carbon dating shouldn't be used on thing less than 1000 years. it fails to give the reason. I guess the result is so OBVIOUSLY wild that no one would trust it any longer. if you date something and get a result no one can falsify and prove it's much easier to get away with it. I guess you can't explain it either. if you date something 0 years old and get an error of 20000 years, you date something supposedly 3000 years old, the error should be the same as it still passes the time of 1000-0 years. the accumulated error should be no lower than dating something 0 years.

About the water thing, you're quite wrong about the accuracy. The water will pour through the hole slower and slower as it gets to the bottom, but radiation is even more tricky than that. Because of half-lives, the AMOUNT of C14 NEVER gets to zero. It decays exponentially TO zero, but as it gets lower and lower, it's harder and harder to distinguish C14 from other background radiation. It's the background radiation that provides the limiting factor, not the amount of Carbon 14. So while labs can provide dates to within 5 years in the last 1000, when you get up over 25,000, the error becomes 50 years.

you're not replying to my post. If you can't distinguish something 0-1000 years, that's an error margin of 100% at best(dating something 1000 years as 0 year) unlimited error at worst(when dating something 0 years as 20000 years). talking about the error margin, under your assumption, you have to carry it to any year you date. when you date something 25000 years it maybe anywhere from 0 to 50000 years using the best assumption(100% error). if you use the worst error margin the result is totally meaningless. You shouldn't oppose me. my assumption in that post is actually better than the situation you proposed for carbon dating supporters. I assume if the minimum observable drop in water level is 1mm, it's still the required amount when the water tank is half full. It's favors your side much more than the fixed-proportion assumption. using that assumption. In your assumption. if you measure a water level drop of 2mm as 2+-1mm. the uncertainty is +-50%. carry this to 200mm and the result should be 200+-100mm. under my assumption it should be 200+-1mm. I hope you can understand it now.

Some labs round to the nearest 10 years (or 50 years when over 25,000) and some don't. Some labs report ages over a certain point as "background" and others will simply give the measured age. It's up to the researcher to know and take into account the particular lab's standards when analyzing the data.

What's meaning of 10 years when they date things of 0 year as 20000 years?

 

[ThaiDuykhang]

Actually that's not true. Yes, the age was measured by counting tree rings. And when they tested each ring, they found that the C14 level was almost constant at each ring. Of course, older rings had less and less C14 LEFT, but the AMOUNT left was exactly as predicted by radioactive decay. In essence, since we KNOW the tree is 4000 years old, we can measure the C14 levels at each ring and use a simple equation to calculate the amount that WAS there when the ring was formed.

You're wrong. no one calibrate carbon dating this way (or it can't be calibrated)
1) taken the outer most layer for example, that should give them a clear idea of how something 0 year old look like, but they still date 0 year old as 20000 year old.
2) There's no record of calibration this way. if possible, will you please find an account of calibration on the net?
3) since they can't measure anything within 1000 years with any usable result, it means they simply can't measure the amount of C14 within 1000 years. anything old than that also have to pass the phase of 0-1000 years, so there's no reason they can measure that either. Calibration with a 4000 year old tree is meaningless if they can't measure the amount of C14 in the last 1000 years.

Why do I say "ALMOST constant?" Simply because it's not precisely constant. As I have said before, the amount of C14 in the atmosphere has been precisely calibrated (using these tree rings and ice cores all over the earth) to account for effects like the sun's 11 year cycle and climate change. The actual variation is only within 5% in the last few millenia though.

I've shown you ice core's don't have anual rings. daily rings maybe, but not anual. what would be result when you calibrate to the wrong standard? I don't think they can calibrate it with anything.

Of COURSE they measured the amount of C14 in the water before measuring the amount of C14 in fish and seals. That's why they know it's not accurate.

And you're right, C14 and C12 ENTER the water from the atmosphere at the same rate. The problem is that there is a LOT of water in the ocean that's very far away from the atmosphere. In that water, the C14 has mostly decayed (to background levels) so something that lives in THAT water would give much older ages than something that lives near the surface.

The reason it can't be used ANYWHERE in the ocean is that there is some constant circulation of the ocean water. There are places where deep-ocean water is drawn up to the surface, and there are places where it's more stagnant. Unfortunately, sea creatures don't just stay in one of those areas for their entire lives (and neither does the ocean currents stay exactly the same year after year). It's not that there is NO C14 in the ocean, it's just that the ocean is not homogeneous. There is no CONSISTANT C14 level the way there is in the atmosphere.

It's the ratio of C14/C12 that is important, not the absolute amount of C14. so even the sea has less absolute amount of C14 or the absolute amount of C14 varies with place. the ratio stays the same every where.(anyone want to shoot at this?) so it doesn't affect the validity of Carbon dating. (784:1 in atmophere) To give you an idea of why only the relative mount of C14 to C12 is important. let's suppose 2 dinosaurs die at the same time. one large and one small, the large one sure has more C14 within its body that the small one. however the C14/C12 ratio is the same. the aim of carbon dating is to date them as having the same age. so it can't use absolute amount of C14. another example, you send a bone to be dated. professionals don't ask you: What's the weight of the animal where you get this bone? it's not important. only the relative amount matters.

As in my last post, I WAS very wrong about recent dating. I knew it wasn't used often but I had forgotten why. Quite simply, there are easier (less costly in both time AND money) ways to date artifacts. And though things ARE dated, the dates given aren't accurate to when the artifact was USED (or buried) but to when the artifact DIED.

I forget when we talked about artifacts. so you can forget about it without feeling sorry.
We've talked a lot about newly killed seals, newly killed snails, human remains though.

Exactly right -- that's exactly how carbon dating works. When something is too old, they'll say, "it's indistinguishable from background" and when it's too young (after nuclear testing screwed up the equilibrium) they'll say "there's no baseline to test it against."

OK, when dating something 0 years old, they tell you it's 20000 years instead of the correct answer of less than 1000 years old. so I guess they can't measure anything up to 20000 years? and that's more than 3 half lives of C14.

Trees that are grown in the same area will nearly always exibit the same ring pattern from year to year. This a well known fact. Of course there are some isolated exceptions -- like the trees that grow multiple rings per year, but it's a particular TYPE of tree that only exibits that behavior in a particular TYPE of environment. Further, the multiple rings are readily obvious to scientists who do this sort of research.

So one can rather easily fit tree rings in a live tree with those from a dead tree, and fit THOSE with that of an older dead tree etc... The sequence has been shown unbroken for at LEAST 8000 years, though you're right that the oldest LIVING tree was 4000 years old.

1. How do you know there're 8000 years(or more) of earth's history? One has to assume the earth is very very old. it's circular reasoning.
2. Tree pattern are generally repetitive. especially climate is relatively stable.
3. How do you know a dead tree is older than another dead tree? Carbon dating can't even show relative age. when they date a snail 20000 years old, they certainly have dated a lot of thing supposedly less than 20000 years old.

btw that 4000 year old tree is the longest-lived tree ever found by counting tree rings.

Wait a second, why are we talking about greenland and iceland? Ice cores are from the north and south POLES where the thickness of the annual layers is a couple of millimeters (after being compressed)! How you get 5.5 feet when the annual PRECIPITATION is under 3 centimeters is quite beyond me!

You've quite wonderfully shown that counting annual layers is insane in places that get a whole lot of snowfall. Of course, it's still done (though not in places with THAT much precipitation to my knowledge). The summer daily layers crystallize quite differently than the winter layers due to differing temperatures.

However, again, accurate dating is done in the arctic and antarctic where the annual precipitation is tiny. As I've said before, worldwide events -- even those in recent history like the Mt. St. Hellens eruption have been recorded in the annual layers. These events are used to verify the accuracy of the ice-core data.

I just explained this (sorry to split up your quote). Once again, a daily layer only makes sense when you're getting snow daily (or even weekly). In the desert of the North Pole, no matter WHAT the temperature when it snows, the ice formed will crystalize differently based on the average temperature over MONTHS, not hours.

Quite simple really. The sun's cycle corresponds to a variation in radiation (from sunspot activity). There is a corresponding change in the amount of radioactive elements in the ice cores. It corresponds to recently measured activity levels, and the radioactive fluctuation extends well past the point where the annual layers are compressed so much as to be indistinguishable.

In short, even though it's not a VISIBLE layer, it's very detectable.

We're talking about Greenland, because the "anual" layers there is also a few millimeters deep. I didn't mention this previously because I can't remember the exact figure. you're right a layer can't be 5'5" feet deep. so if you assume counter ice core layers is accurate then why so many layers are deposited in one year? (if you don't think this is enough I'll look for the exact figure right)

also ice core professionals believe counting ice core layer in greenland isn't insane. have a look at this:
http://en.wikipedia.org/wiki/Greenland

Between 1989 and 1993, U.S. and European climate researchers drilled into the summit of Greenland's ice sheet, obtaining a pair of two-mile (3.2 km) long ice cores. Analysis of the layering and chemical composition of the cores has provided a revolutionary new record of climate change in the Northern Hemisphere going back about 100,000 years and illustrated that the world's weather and temperature have often shifted rapidly from one seemingly stable state to another, with worldwide consequences.

The 2 most important site for drilling ice core is greenland and antarctica
http://en.wikipedia.org/wiki/Ice_core#Ice_core_sites

We're talking about ice cores not snow cores, so snowfall is relatively unimportant. I can't remember clearly. but I have an impression the snowfall in greenland isn't very heavy. in fact in northern greenland there're not enough snow to form an ice cap.

This is a very simple and very common technique... I STRONGLY suggest you look it up yourself (google has dozens of results) because I feel that if you're not understanding something so simple, I must be missing a vital point that I take for granted but which you've never heard of.

Of course tree rings only tell how old the tree was when it died. But there are a few ways that tree rings can be calibrated.

First of all, as I said before, tree rings can be compared to each other to generate an unbroken history to present. The similarity is so obvious that you wouldn't argue with it if you saw the effect in person -- sometime if you have a chance, cut down two trees in the same forest (even a hundred miles from each other). Then compare their rings and you'll be able to tell exactly where they overlap. If you're feeling adventurous, compare the rings of a freshly-cut tree to that of an old stump. Again, you'll see exactly where they overlap.

Second, you can get to within a few years by counting rings to where there are a number of rings very close together. Trees near a volcano will be damaged by the eruption and will grow very little for a few years after the eruption. There will even be missing rings in many cases where the tree didn't grow at all for a few years. By comparing trees that were affected to nearby trees outside of the influence of the volcano, you can tell how many rings are missing and get a precise year (and often even a season) of the eruption.

This has been done for very recent events like Mt. St. Helens in 1980. It's been done for older eruptions in the 1800s and 1700s. The method is undeniably accurate -- and you can easily verify it yourself by cutting down a tree or two. I did it at my grandparent's house where they heat their house with a wood-burning stove. It's really rather cool how the rings overlap so obviously and show where there were droughts, cold years, even floods!

Already refuted above
Look at these pictures.
http://web.utk.edu/~grissino/images/llc%20ring2.jpg
http://web.utk.edu/~grissino/images/ashland_hemlock2.jpg
from this site: http://web.utk.edu/~grissino/
what do you find? many rings look similar, right? given a particular ring, you can places it on many different places. it's quite arbitary, I can build them in a way to show the earth is older than 6000 years.

 

[ThaiDuykhang]

You'll not find it because YOU mentioned it first yesterday in post 31. We were saying that tree dating is accurate to about 9000 years (by comparing tree rings of multiple trees). You said the oldest living tree is 4000 years old.

They've calibrated 1950 to year zero. All ages given are in years BEFORE 1950.

Again, because of the exponential nature of radioactive decay, there's no point at which it HITS zero. It just gets lower and lower until it's indistinguishable from background radiation.

About the 1000 years old, it's not USED because archaeologists generally have a better idea of when something happened within that 1000 years than dating can produce. It's not that the dating is inaccurate in that range -- it's just that archaeologists want to know when a civilization existed or when a boat sailed -- knowing when the tool was made or when the trees for the boat were cut down adds DECADES of error to finding out WHEN an event (like a battle or the life of a king) happened.

I must apologize for a third time for saying that technicians CAN'T date something that died 1000 years ago. I do welcome the correction.

So it's still TEs force me to mention that 4000 year old tree. OK this should make things clear.

You don't need to apologize. I've searched the web to show the minimum age carbon dating can date is 1000 years. it's not used because the result it gives is obviously meaningless, like confusing a newly snail with something 20000 years old. this shows within 20000 years it's still meaningless. suppose I give you something dated 20000 years. do you know it's age? perhaps not.

 

[shernren]

I searched the net and it indeed said carbon dating shouldn't be used on thing less than 1000 years.

What's the URL?

so even the sea has less absolute amount of C14 or the absolute amount of C14 varies with place. the ratio stays the same every where.

This is simply not true. If a particular mass of ocean water is not brought to the surface, its total amount of C-14 decreases while its total amount of C-12 remains constant. C-12/C-14 equilibrium ratio between biomass and water in the environment goes up.

We're talking about Greenland, because the "anual" layers there is also a few millimeters deep.

Quote your source for this. The Wikipedia quote you supplied said that 3.2km of core corresponded to 100,000 years. Elementary division shows that an "annual layer" in Greenland must therefore be 32mm after compression, not "a few millimeters".

 

[ThaiDuykhang]

What's the URL?

http://www.seed.slb.com/qa2/FAQView.cfm?ID=431

This is simply not true. If a particular mass of ocean water is not brought to the surface, its total amount of C-14 decreases while its total amount of C-12 remains constant. C-12/C-14 equilibrium ratio between biomass and water in the environment goes up.

Do you want me or your ally to refute this?

Quote your source for this. The Wikipedia quote you supplied said that 3.2km of core corresponded to 100,000 years. Elementary division shows that an "annual layer" in Greenland must therefore be 32mm after compression, not "a few millimeters".

I've told you I forget the exact number. that's the number used by deamiter.

 

[shernren]

Do you want me or your ally to refute this?

Go on, try. I'm rushing for class now though so it'll be a while before I can reply.

 

[ThaiDuykhang]

Go on, try. I'm rushing for class now though so it'll be a while before I can reply.

Where does the CO2 needed in photosynthesis for aquatic plants and algae which is equivalent to plants on land come from?

 

[shernren]

Where does the CO2 needed in photosynthesis for aquatic plants and algae which is equivalent to plants on land come from?

Mixture of young and old sources. Young - atmospheric contact in shallow waters. Old - due to the "reservoir effect", where carbon dioxide reacts with seawater to form dissolved inorganic carbon (DIC, mostly bicarbonate ions as far as I know) which may be buffered for a long time before entering the biosphere and thus may artificially lower the C-14/C-12 ratio. Next?

(The reason atmospheric CO2 does not experience this kind of buffering is that the atmosphere does not act as a medium of chemical reactions that are able to cause large quantities of CO2 to be sequestered i.e. locked away from entering the biosphere / biological carbon cycle for a long time.)

 

[Deamiter]

Okay, there's a whole lot of weird questions, and I don't have the time I did previously, but I'll try to address some.

First off, I Shernren is right on about C14 levels in the ocean. C14 is created in the atmosphere -- by solar radiation, and now by industrial pollution and nuclear tests (though there's very few these days). The C14 and C12 diffuse into the ocean at a certain rate (which changes over time but that's not important here). What IS important, is that the diffusion rate is much too low to create equilibrium in the ocean. Deep ocean waters will be unreached by the C14, so the C14 ratio decreases. Currents mix the ocean waters in pretty unpredictable ways -- and animals move through different zones freely so even if we COULD map the C14 ratios for each location day by day, it would be useless for the animals that moved from place to place.

Don't lie about a number used for ice-core dating. I never gave a number for Greenland -- just Antarctica. And I was citing ANNUAL precipitation, not the thickness of annual layers.

To be clear, yes, ice-core dating can be done in Greenland. However, it's ONLY done in the desert areas with very low precipitation. The plane was found on a coastal area that DOES get 5.5 feet of precipitation annually (probably much more). Whether you're doing it on purpose or not, you're assuming that the precipitation rate is constant everywhere on the Earth. So since your plane was covered by many feet in a place that gets LOTS of snow, you're trying to claim that an ice field that gets MILLIMETERS of snow annually should also accumulate a few feet a year?

It just doesn't make sense. I think you're catching on, so you're trying to confuse the issue, but the bottom line is that you brought up this plane to try to argue against ice core dating. When it was pointed out that ice core dating is done in areas with VERY little annual precipitation, you seem to conveniently avoid the fact that different parts of the Earth get different amounts of precipitation.

As for the snail, it's a case of totally misusing a tool (C14 dating). Plants get their carbon from the atmosphere. So trees are a really good source of C14 dating. Animals also get their C14 from living plants, so they're a good source of C14 dating too. But where does the snail's SHELL come from? The snail makes it ouf of mineral deposits it gets directly from surrounding sediment. So dating a snail's shell is like dating solid rock -- absolutely ridiculous. Further, if you're dating a snail that lives in the sea, you wouldn't even get accurate dates if you dated the live TISSUE. We already explained why this happens. If you dated a live snail (the tissue, not the shell) you'd get a date corresponding to current C14 ratios.

Finally, you keep throwing out numbers, but you've never once cited any of them. When you DO tell us what precisely has been dated, it always turns out to be something that wasn't a candidate for dating in the FIRST place. Anybody can misuse a tool to get ridiculous results!

 

[Deamiter]

[talking about tree rings]
Already refuted above
Look at these pictures.
http://web.utk.edu/~grissino/images/llc%20ring2.jpg
http://web.utk.edu/~grissino/images/ashland_hemlock2.jpg
from this site: http://web.utk.edu/~grissino/
what do you find? many rings look similar, right? given a particular ring, you can places it on many different places. it's quite arbitary, I can build them in a way to show the earth is older than 6000 years.

I thought this was worth a comment.

First of all, you've taken two random pictures off the internet to say that comparison is invalid. There are a couple problems with this.

1. The pictures aren't calibrated. There's no way to tell how wide the rings are in the second picture, so the pictures can't be compared.
2. They're very different types of trees. Different trees grow at different rates. They can still be COMPARED, but results aren't as conclusive.
3. We don't know where the trees came from. If one came from outside of London and the other from Edinburgh, the rings WILL be different, though HUGE events might still be noticable.

Yes, it's true that there are a lot of small and large rings. But the overall PATTERNS will be the same for similar trees from a similar area. It's these patterns that are extremely distinct. It's easy to sit in your armchair and say, "it can't work," but the technique has been shown for centuries to be accurate to account for events during our lifetime. You've got to come up with something better than, "This would disprove a 6000 year old Earth, so it must be false," or at best you're just denying something you've never studied -- not the most honest tactic in a debate.