5 ms·

Sure, but apparently the chance that it survives 476K year is > 0. That would imply that the chance of finding preserved wood anywhere in [11K .. 476K] is > 0 a

Sure, but apparently the chance that it survives 476K year is > 0. That would imply that the chance of finding preserved wood anywhere in [11K .. 476K] is > 0 as well. Given such a large period with nothing found in it, and given that in this period wood needed to survive considerable less long than 476K, makes me want to look for other explanations.

mysterydip 3y ago
If it was a burned structure, maybe the burning affected the measurement of the dating.
- Kye 3y ago
  I like to think the people who date these things can tell the difference between the carbon from burning and carbon-14. I'm not sure it's even used for something this old since AFAIK it only works so far back.
  - Bouncingsoul1 3y ago
    they got 'infinite' for all carbon dating. They derived the age from the sand layer the wood was found. I got this from reading the paper.
    - pulse7 3y ago
      Earth's crust is moving. Maybe the sand layers moved after the wood was placed there... and maybe the derived age is all wrong...
  - pvaldes 3y ago
    "Is not" what carbon 14 you find. Is what is lost what counts, because this is lost at a known rate. The less carbon you find the oldest the structure. So, first question: Is fire a known way to remove carbon from an organic structure? Uppercase YES. Second question, carbon 14 method has intervals of confidence. Show me the intervals
    - deleted 3y ago
      [deleted]
    - jasonwatkinspdx 3y ago
      And does fire somehow selectively eliminate c14 but not c12? Because that's the measurement we're making. It's irrelevant to the OP because radiocarbon dating doesn't go back that far, but your general skepticism is very much misplaced. The people who have been using and improving radiocarbon dating for the last century do in fact know more about it than your superficial armchair doubts.
      - pvaldes 3y ago
        > does fire somehow selectively eliminate c14 but not c12? Maybe, if we assume that C14 is not distributed homogeneously in the log; that is the logical assumption by default As we know that C14 had spikes in production in some particular years, Is trivial to assume that rings formed in those years stored more C14. The main question is if we have this years registered on our log or not. If we would have it; and they fall on the outer part of the log (AKA the partially charred part), then is perfectly doable
        jasonwatkinspdx 3y ago
        > Maybe, if we assume that C14 is not distributed homogeneously in the log; that is the logical assumption by default Perhaps read about the actual technique more? A tree will be at equilibrium with atmospheric c14 throughout its lifetime. > As we know that C14 had spikes in production in some particular years, Is trivial to assume that rings formed in those years stored more C14. We have very solid time series data on the background C14 levels from multiple independent techniques. Spectroscopy based methods count the total number of C14 atoms in the sample throughout its entire volume as well. > The main question is if we have this years registered on our log or not. If we would have it; and they fall on the outer part of the log (AKA the partially charred part), then is perfectly doable As I said above, the entire radiocarbon dating discussion is irrelevant to the original article. I just wanted to reply against zero content lowbrow dismissals of the technique in general. It's disappointing to see commentators here posting the exact same FUD as young earth creationists.
ReleaseCandidat 3y ago
I also don't know where they got the 11ka from? From the paper: The earliest known wood artefact is a fragment of polished plank from the Acheulean site of Gesher Benot Ya’aqov, Israel, more than 780 ka (refs. 2,3). Wooden tools for foraging and hunting appear 400 ka in Europe, China and possibly Africa. At Kalambo we also recovered four wood tools from 390 ka to 324 ka, including a wedge, digging stick, cut log and notched branch. So not exactly much, but there are other finds. But the problem is to not only find wood that is that old and has survived and has (clear) signs of human "tools", but had also been used for "structural" purposes. I also don't understand the general idea. So there are humans capable of generating tools out of stones (the oldest flint tools are 3 millions of years old), but the idea that they use these tools to work wood to help making something structural out of wood - like some notches to be able to easier put some sticks of wood together - is debatable? The problem for archeologists is of course to prove that these wooden "structures" existed by, well, finding traces(Oh, what a pun!) of them.
neilk 3y ago
But we're dealing with such small numbers and such perishable materials! This isn't like modern humans - billions of individuals each generating tons of waste materials over their lifetime, stuff like concrete, plastic, glass, and metals. This is a few hundred thousand individuals who are sometimes making things out of sticks, grasses, and hide. As far as I can tell from some quick googling, there only were ever a few hundred thousand homo heidelbergensis, and that's the high estimate. We only have a few hundred specimens of the bones of homo heidelbergensis and some of those are from extremely bizarre circumstances, like a pit in a cavern where people seem to have been deliberately disposed of. If we only have a few bits and pieces of bone left, consider how much less likely it is for a structure of plant and animal materials to survive. If it was in use by people, eventually it would wear out and be replaced, and get broken down to reuse its materials in various ways. If people abandon it, they probably won't bury it like they would a human being (very convenient to future archeologists). Abandoned structures will just stay on the surface, where the elements and decomposing organisms will eventually reduce it to dust. According to the researchers here, the wooden structures only survived due to being preserved in fine sediment in the water. So we're only ever going to find structures like this due to wildly improbable events. It's amazing we've found any!

mysterydip 3y ago

If it was a burned structure, maybe the burning affected the measurement of the dating.

Kye 3y ago
I like to think the people who date these things can tell the difference between the carbon from burning and carbon-14. I'm not sure it's even used for something this old since AFAIK it only works so far back.
- Bouncingsoul1 3y ago
  they got 'infinite' for all carbon dating. They derived the age from the sand layer the wood was found. I got this from reading the paper.
  - pulse7 3y ago
    Earth's crust is moving. Maybe the sand layers moved after the wood was placed there... and maybe the derived age is all wrong...
- pvaldes 3y ago
  "Is not" what carbon 14 you find. Is what is lost what counts, because this is lost at a known rate. The less carbon you find the oldest the structure. So, first question: Is fire a known way to remove carbon from an organic structure? Uppercase YES. Second question, carbon 14 method has intervals of confidence. Show me the intervals
  - deleted 3y ago
    [deleted]
  - jasonwatkinspdx 3y ago
    And does fire somehow selectively eliminate c14 but not c12? Because that's the measurement we're making. It's irrelevant to the OP because radiocarbon dating doesn't go back that far, but your general skepticism is very much misplaced. The people who have been using and improving radiocarbon dating for the last century do in fact know more about it than your superficial armchair doubts.
    - pvaldes 3y ago
      > does fire somehow selectively eliminate c14 but not c12? Maybe, if we assume that C14 is not distributed homogeneously in the log; that is the logical assumption by default As we know that C14 had spikes in production in some particular years, Is trivial to assume that rings formed in those years stored more C14. The main question is if we have this years registered on our log or not. If we would have it; and they fall on the outer part of the log (AKA the partially charred part), then is perfectly doable
      - jasonwatkinspdx 3y ago
        > Maybe, if we assume that C14 is not distributed homogeneously in the log; that is the logical assumption by default Perhaps read about the actual technique more? A tree will be at equilibrium with atmospheric c14 throughout its lifetime. > As we know that C14 had spikes in production in some particular years, Is trivial to assume that rings formed in those years stored more C14. We have very solid time series data on the background C14 levels from multiple independent techniques. Spectroscopy based methods count the total number of C14 atoms in the sample throughout its entire volume as well. > The main question is if we have this years registered on our log or not. If we would have it; and they fall on the outer part of the log (AKA the partially charred part), then is perfectly doable As I said above, the entire radiocarbon dating discussion is irrelevant to the original article. I just wanted to reply against zero content lowbrow dismissals of the technique in general. It's disappointing to see commentators here posting the exact same FUD as young earth creationists.

ReleaseCandidat 3y ago

I also don't know where they got the 11ka from? From the paper: The earliest known wood artefact is a fragment of polished plank from the Acheulean site of Gesher Benot Ya’aqov, Israel, more than 780 ka (refs. 2,3). Wooden tools for foraging and hunting appear 400 ka in Europe, China and possibly Africa. At Kalambo we also recovered four wood tools from 390 ka to 324 ka, including a wedge, digging stick, cut log and notched branch. So not exactly much, but there are other finds. But the problem is to not only find wood that is that old and has survived and has (clear) signs of human "tools", but had also been used for "structural" purposes. I also don't understand the general idea. So there are humans capable of generating tools out of stones (the oldest flint tools are 3 millions of years old), but the idea that they use these tools to work wood to help making something structural out of wood - like some notches to be able to easier put some sticks of wood together - is debatable? The problem for archeologists is of course to prove that these wooden "structures" existed by, well, finding traces(Oh, what a pun!) of them.

neilk 3y ago

But we're dealing with such small numbers and such perishable materials! This isn't like modern humans - billions of individuals each generating tons of waste materials over their lifetime, stuff like concrete, plastic, glass, and metals. This is a few hundred thousand individuals who are sometimes making things out of sticks, grasses, and hide. As far as I can tell from some quick googling, there only were ever a few hundred thousand homo heidelbergensis, and that's the high estimate. We only have a few hundred specimens of the bones of homo heidelbergensis and some of those are from extremely bizarre circumstances, like a pit in a cavern where people seem to have been deliberately disposed of. If we only have a few bits and pieces of bone left, consider how much less likely it is for a structure of plant and animal materials to survive. If it was in use by people, eventually it would wear out and be replaced, and get broken down to reuse its materials in various ways. If people abandon it, they probably won't bury it like they would a human being (very convenient to future archeologists). Abandoned structures will just stay on the surface, where the elements and decomposing organisms will eventually reduce it to dust. According to the researchers here, the wooden structures only survived due to being preserved in fine sediment in the water. So we're only ever going to find structures like this due to wildly improbable events. It's amazing we've found any!