8 ms·

Not to be that guy, but I’m really starting to question the accuracy of dating techniques when they publish finds like this. This finding is only significant b

Not to be that guy, but I’m really starting to question the accuracy of dating techniques when they publish finds like this. This finding is only significant because of the age, but have we ever verified our dating techniques over 5k years? 10k years? What’s to say that the hot desert sun and strange weather patterns, radiation or whatever couldn’t skew the dating and mean this bone is just some traveller from a mere 1-2k years ago. It seems further unlikely that such a bone from, 85k y/ago as they say, would be so close to the surface. Ftn In mechanical engineering we don’t ever “trust” the calculations until they are thoroughly validated with ie strain gauges. And more often than not we discover our assumptions were wrong. So I suppose a similar thing applies here in dating science, except, it’s impossible to validate for another thousand centuries. It seems backwards to hinge all our science on it when (AFAICT) it hasn’t even been validated itself!

Xeoncross 8y ago
As a developer, I see the absolute broken processes and driving forces in the software world and assume that it's not just unique to us. Apparently every other field is also overloaded with bugs, improper testing, and bad assumptions.
- dwaltrip 8y ago
  If our knowledge is so incorrect, how did you manage to send your comment to me from across the world? The sentiment you are expressing is very tempting, but it doesn't give credit to the knowledge we have actually acquired. It's difficult to discern between the many levels of partial knowledge (as all knowledge is partial), but it's what we must do.
  - IncRnd 8y ago
    Bugs, improper testing, and bad assumptions are not the same as incorrect knowledge.
    - Xeoncross 8y ago
      @dwaltrip saw and replied to my comment before I made a change in wording.
  - taneq 8y ago
    Because everything required to do that is testable. Radiocarbon dating is not just untested on the timescales we're using, but can probably be confounded by all sorts of things. It's a pretty good guess, and matches up with a lot of other stuff we know, but it's still a guess.
    - dwaltrip 8y ago
      Sources? I'm pretty sure you are significantly overstating the uncertainty. The word "guess" is very misleading here. Direct, completely unmediated observation is not the only way to acquire knowledge. It is definitely a very good method. However, we humans are also incredibly good at finding clever, credible ways of inferring things from indirect clues.
      - oldandtired 8y ago
        There are enough anomalies in dating methods to question them. At the time scales we are looking at, we have little or no knowledge of the actual circumstances of the environment at the time. Every kind of dating methodology that goes outside of human history relies on very specific assumptions. If we are wrong about any of those assumption then our dating methodologies become unreliable. Even inside human history, we make various guesses about when various events take place. The extant records that we use to date any particular item or event lead us, in many cases, to a best guess. How accurate this guess is - well, who really knows. Quite often, there is conflict over when or even if certain events have occurred in the past. This is the nature of the lack of easily obtained records of the past. Even when there is extent documentation available, there is still conflict. I take all the prognostications of dates in the far past as a guess, since we don't really know. > However, we humans are also incredibly good at finding clever, credible ways of inferring things from indirect clues. We are not as clever or even credible in a lot of what we do as humans. We are far too biased and political even in the fields of science and technology. That is just a part of our nature. If you looked at all the controversies over the last, what, 300 years, or we could look back over the last 2500 years and we'll see this rear its head many, many times. I have stated the position that we should not be concerned that we are certain, but put in the efforts to keep investigating all areas for insight and further knowledge. It really doesn't matter if our models are incomplete and wrong as long as we keep moving forward. It's when we are certain that we lose the ability to move forward. In many areas in science (even in technology) we have become "certain" that our theories and models are correct. This is a problem and we need to address this.
- toomanybeersies 8y ago
  Standard physics isn't really up for question. Newtons Laws still apply in the general case. My teachers never pretended that quantum physics was a fully understood, concrete field. A lot of what they said was prefixed with "we don't really know if this is how it works, but this is the model".
  - dragonwriter 8y ago
    > Newtons Laws still apply in the general case. No, they apply (or, rather, are reasonable approximations) in the specific case of objects that aren't too small, and that don't move too fast relative to each other, etc. That is, the common case, but not the general one.
    - dbasedweeb 8y ago
      That sounds good, and is true, but comes with blistering caveats. First, the general case as he puts it, covers every macroscopic objects on and including Earth. It also covers microscopic objects until you reach particles, again on Earth, because of the energy scales involved. Everything from molecules to mammoths fit into this general case. If you charitably interpret “standard physics” [1] to include Relativistic and Quantum physics, then you cover everything in the universe that isn’t a black hole or less than or equal to 1.6x10^-45 meters, or at energies associated with the Planck epoch of the Big Bang. We’re talking about archaeology, which is notably unconcerned with black holes or anything with a detectable de Broglie wavelength. I think that if were not going to be pedantic, and accept that we’re talking about physics as applied to Classical objects like finger bones, he’s right and there is little debate to be had. It we want to be a little pedantic we can say that QM is just about the best tested theory ever, and the rounding error left to quibble over isn’t a factor here. If we want to be super pedantic we can point out that the “common” case on the scale of the universe is ultimately quantum-gravitational and therefore subject to physics that is not understood. Of course that majority is at distance scales we can’t access, or at energies or seem since the first second after the Big Bang. In that very very pedantic case you’re just as wrong as he is, but I think you’d rightly argue that it’s a pointless distinction in context. I’d agree with you. [1] Standard physics isn't really up for question. Newtons Laws still apply in the general case.
- AlotOfReading 8y ago
  Archaeologist turned embedded dev here. It's not limited to software. But dating is one of the things we understand very well. The key is an immense, globally consistent data set collected by thousands of idiots (like me) who trekked to the ends of the earth for a sample or two. That data came from dozens of sources (soils, charcoal deposits, rocks, lake cores, tree cores, ice cores, bones, literature, oral histories, artifacts, etc), each with their formation processes and interpretive challenges. In some cases (such as radio- or thermo- dating), the process depends primarily on fundamental physical processes. If these models are wrong, We got incredibly lucky building computers and space probes on the same concepts. But we can compare cross-check that data with processes observable today (like erosion, sedimentation, dendrochronology, cores... etc). Those data sets are globally consistent. But, we can go a step further and cross-check both of them with ab initio computer models and human sources with all the context that implies. As expected, they pretty much all work out. Virtually every area of science has contributed to the modern understanding of dating. If something is fundamentally wrong in that understanding, it would be exciting to put it mildly. And yes, there are issues as well. I could go on for hours about them. But archaeology is both an old field and a highly self-critical one. Any idea that's survived awhile is probably either "close", wrong in some very subtle ways, or extraordinarily attractive to our particular, western academia.
dwaltrip 8y ago
Have you researched any of the science behind the dating techniques?
- aetherspawn 8y ago
  Yes, I am about to complete my second bachelors degree in engineering and have done a basic level of research Re: dating techniques and know that most dating techniques rely on atomic properties which could also (but currently understood not to?) be affected by ie alpha/b/UV radiation. Or perhaps even exposure to ie bacteria (we are only really beginning to understand the interaction between bacteria and atomic level structures .. as apparent by some headlines in last 5/y or so) But I am by no means what you might classify as qualified or moderately familiar in this field.
  - nonbel 8y ago
    I once tried to look into this and came away thinking it was all very circular (tree rings calibrated to archeology used to calibrate radioisotopes used to calibrate tree rings). There seemed to be a lot of room for cherry picking which data was "good" vs "corrupted" until everything matched up. Also it seemed to rely a lot on calibrating to the "known" date of ancient egyptian artifacts, which were in turn originally dated using the bible. Ie, if a radioisotope date from an artifact with a "known" date disagreed with that, it would be rejected. I remember this guy being an important player: https://en.wikipedia.org/wiki/Joseph_Justus_Scaliger https://en.wikipedia.org/wiki/Joseph_Justus_Scaliger Maybe I am just remembering it wrong or didn't look hard enough...
    - paulryanrogers 8y ago
      IIRC, Egyptian sources were used because the consistency of Nile River flooding meant their calendars are likely the most accurate.
      - nonbel 8y ago
        Interesting, but I don't really follow how flooding would be any more helpful than the seasons in general.
StanislavPetrov 8y ago
I'm also skeptical of the accuracy of these dating techniques until we have more evidence that corroborates their findings. That being said, I'm also very skeptical of the prevailing existing theories about the distant past as well. The dearth of concrete evidence from the distant past necessarily makes it difficult or impossible to make definitive statements. Skepticism and demand for evidence should always be our guiding light, no matter how widely accepted a theory is.
roywiggins 8y ago
I can't say anything about this particular method, but as far as I know generally dating methods are tested against each other. For instance, when you dig something out if the ground, you can get a rough idea of how old it is just by looking at the layers of rock and material above and below it. We know something about how fast these layers can be deposited, and usually stuff further down is older (not always, but if the layering is disturbed there's often evidence of it). So if you find that your dating method makes no sense for objects with an obvious date range (based on where you find them) then your dating method is probably broken. Obviously then if you take a leap over to objects that you find that you can only date in one way, you are taking a leap of faith. But in a few years, dating methods will come along that might let you test it in a different way entirely and either corroborate your first date or contradict it.
- mygo 8y ago
  layering, if the ground is undisturbed, can only tell us how old something at least is. The object itself could be older than the soil it was found in. Take for example how every ancient artifact in a museum is older than the soil it sits upon. So it has its limits. Who is to say that some dead guy’s finger wasn’t handed down for millennia before getting picked up during a raid and tossed on the ground on the journey back as worthless junk? We can’t fathom.
- TangoTrotFox 8y ago
  There is the risk of cascading errors. You can take many examples of beliefs that persisted for many decades, or even centuries in times past, that were simply wrong. But these wrong beliefs were often supported by layer after layer of corroborating evidence. The issue of course is that a derivative measurement takes the original measurement as a given, and then creates new formulae based on the result of the first - so you end up with two things corroborating the same view, even though its wrong. So I guess the question is what measurements are completely and absolutely independent? I don't recall in strata aging if the formation rate was alone used to determine age - so far as I recall the ages were dated by cross referencing known 'benchmarks', but then you've just created this very effect by assuming the age and then using that calibrate your method. And for what it's worth, I am not suggesting that the dating or other methods are incorrect here. Just pointing out some possible issues in this logic.
flukus 8y ago
Perhaps you need to turn that skepticism inward. There are good answers to your questions. Yes the dating techniques are verified by corroborating it with a lot of other evidence such as tree rings as well as other dating methods, it's also well corroborated with entirely different fields like geology, history and physics. As for being close to the surface, there are quite a few geological process that can come into play. There are places on earth that have fossils hundreds of millions of years old on the surface. This is not in any way remarkable. > So I suppose a similar thing applies here in dating science, except, it’s impossible to validate for another thousand centuries This sounds alarmingly like an argument you'd get out of Ken Ham. Are you a creationist that has trouble accepting an earth older than 6000 years? The debating style of asking seemingly probing yet actually well understood questions screams creationist (and climate change denialist) as well. You also fit the profile of creationist and climate change deniers, engineers that think they're smarter than the actually are and don't know what they don't know. As for finds like this, despite the headline it's completely unremarkable and fits easily within what we know of human migrations: https://en.wikipedia.org/wiki/File:Human_migration_out_of_Africa.png https://en.wikipedia.org/wiki/File:Human_migration_out_of_Af...
- aetherspawn 8y ago
  This kind of comment is flammatory and against HN etiquette (and should be removed).
  - flukus 8y ago
    I know you claim to be skeptical but see evidence to the contrary. You're not skeptical of yourself and of your limited knowledge and your not skeptical of your need to be skeptical (there are no extraordinary claims in this discovery). I see no evidence that you are responding in good faith to any flaws in your reasoning, you're continuing to make an argument from incredulity. So I'm sorry if you're not a creationist (not as sorry as I'd be if you were), but when you look like a duck, argue like a duck and respond like a duck I start getting that duck vibe. How about you respond to the points in your post: > Not to be that guy, but I’m really starting to question the accuracy of dating techniques when they publish finds like this. Why when they publish finds like this? There is nothing extraordinary about these finds, they sit comfortably inside what we know of human migrations. > This finding is only significant because of the age, but have we ever verified our dating techniques over 5k years? 10k years? You're arguing against archaeology, geology, history and nuclear physics here. Do you think all these branches of science are being dishonest? > It seems further unlikely that such a bone from, 85k y/ago as they say, would be so close to the surface. Why do you find this surprising? There a quite a few geological process that can result in this. Nearly all fossils we find are quite close to the surface.
abritinthebay 8y ago
> but have we ever verified our dating techniques over 5k years? 10k years? Yes. > What’s to say that the hot desert sun and strange weather patterns, radiation or whatever couldn’t skew the dating Lots. For a start - only one of those would possibly affect the outcome of testing and would also be detectable. > It seems further unlikely that such a bone from, 85k y/ago as they say, would be so close to the surface Your incredulity doesn't affect the outcome one way or another and unless you want to dispute the fact that artifacts that are much older are often found on or close to the surface it's not based in any way to the real world. > In mechanical engineering we don’t ever “trust” the calculations until they are thoroughly validated And neither does the science around these dating techniques. In fact they're usually better supported than any engineering is. > It seems backwards to hinge all our science on it when (AFAICT) it hasn’t even been validated itself! And here's the thing: You're incredibly misinformed and that's why it makes no sense to you.
- deleted 8y ago
  [deleted]
- taneq 8y ago
  > And neither does the science around these dating techniques. In fact they're usually better supported than any engineering is. Given that the results of most if not all engineering can be directly tested, this seems unlikely.
  - sten 8y ago
    I believe his point is that these methods are contentious for various reasons (religious objection being an example) so they have been heavily scrutinized and where exceptions have been found so have explanations. While most engineering doesn't receive the same level of attention, even if it could.
- aetherspawn 8y ago
  > In fact they're usually better supported than any engineering is. I don’t care who supports what in engineering. If you put a dozen [gauges, potentiometers, accelerometers] on a truck and drive it for 1,000,000km varying conditions and the data matches up with the cross derivation for each instruments relation to the other, it is no longer a case of “who supports” -> it is either _fact_ or not and completely indisputable. But it doesn’t become “supported” data for dropping said truck out of a plane. That’s lunacy - a dozen things not accounted-for in the normal model will occur. Our models might hold for a few thousand years, maybe even 10k .. but how many times have we dated an >20k year artifact under varying conditions and been able to validate it without relying on another model? Or as they would say about FEA, crap in, crap out (even though multiple models may agree, none are validated in such a method).
gus_massa 8y ago
Hey! I'm usually that guy, but in they are they are using "optically stimulated luminescence". https://www.usu.edu/geo/luminlab/whatis.html https://www.usu.edu/geo/luminlab/whatis.html https://en.wikipedia.org/wiki/Luminescence_dating https://en.wikipedia.org/wiki/Luminescence_dating I'm not an expert in the subject an I'm not an archeologist, but the method sounds good. One of the parts is the decay of radioactive atoms. This is a very well known subject, it's very easy to model and it is not affected by pressure or temperature (unless you use ridiculous huge amounts). The other part is about electrons trapped in the defects of crystals, and the conduction and valence band of crystals. This is also a well known subject, but it's more difficult to model. So IIUC after measuring the amount of "trapped" light they must irradiate each sample to calibrate the "trapping" ability of the material. This is not affected by usual variations of pressure and temperature. In particular the energy of the photons in sunlight is very different from the photons due to normal levels of heat. (At high temperature like more than 500°C or 900°F, that is possible near a fire, the difference between the energy of the photons is not so much and you have https://en.wikipedia.org/wiki/Thermoluminescence_dating https://en.wikipedia.org/wiki/Thermoluminescence_dating . But the heat below a few inches of the floor under sunlight is not enough.) As I said, I'm not an expert, but it looks like they are combining well known techniques and I guess that if you can enclose a bunch of Ph.D. students in a lab for 20 years with proper equipment, a few interesting samples and enough food, they will be able to rediscover this method. If you want to find something shady here, I'd look at > [Katerina] Harvati, who wasn’t involved in the research, said she would be cautious in definitively assigning the finger fossil a Homo sapiens identity due to the fact that its shape overlaps with other hominin species. [...]
- aetherspawn 8y ago
  Thanks for the writeup. Makes sense, but requires some further thought on my part (re: comments below on validation using multiple methods). Also I have no problem with the biology aspect as it is trivially verified what a human (or otherwise) bone looks like, composition etc
- lurquer 8y ago
  Dude in a caravan 100 years ago gets finger cut off while harnessing camel. Buried finger in sand. At night. (thus leaving the sand 'unbleached' as the term is used in the optical luminescence field.) Occam's razor.
slowmovintarget 8y ago
“Beyond 40,000 years old, the sample is so small, and the contamination risk so great, that the margin of error is thousands of years. It would be like having a watch that told you day and night.”[1] [1] http://discovermagazine.com/2016/jul-aug/scientific-dating-methods http://discovermagazine.com/2016/jul-aug/scientific-dating-m...
- flukus 8y ago
  The quote is irrelevant, it's taken from a section about radiocarbon dating which wasn't used here. They used Uranium series dating which according to your own source: > The uranium-thorium method is often helpful for dating finds in the 40,000- to 500,000-year-old range, too old for radiocarbon but too young for K-Ar or Ar-Ar.
amelius 8y ago
I see more problems in deriving migration patterns by looking at a single individual ...

Xeoncross 8y ago

As a developer, I see the absolute broken processes and driving forces in the software world and assume that it's not just unique to us. Apparently every other field is also overloaded with bugs, improper testing, and bad assumptions.

dwaltrip 8y ago
If our knowledge is so incorrect, how did you manage to send your comment to me from across the world? The sentiment you are expressing is very tempting, but it doesn't give credit to the knowledge we have actually acquired. It's difficult to discern between the many levels of partial knowledge (as all knowledge is partial), but it's what we must do.
- IncRnd 8y ago
  Bugs, improper testing, and bad assumptions are not the same as incorrect knowledge.
  - Xeoncross 8y ago
    @dwaltrip saw and replied to my comment before I made a change in wording.
- taneq 8y ago
  Because everything required to do that is testable. Radiocarbon dating is not just untested on the timescales we're using, but can probably be confounded by all sorts of things. It's a pretty good guess, and matches up with a lot of other stuff we know, but it's still a guess.
  - dwaltrip 8y ago
    Sources? I'm pretty sure you are significantly overstating the uncertainty. The word "guess" is very misleading here. Direct, completely unmediated observation is not the only way to acquire knowledge. It is definitely a very good method. However, we humans are also incredibly good at finding clever, credible ways of inferring things from indirect clues.
    - oldandtired 8y ago
      There are enough anomalies in dating methods to question them. At the time scales we are looking at, we have little or no knowledge of the actual circumstances of the environment at the time. Every kind of dating methodology that goes outside of human history relies on very specific assumptions. If we are wrong about any of those assumption then our dating methodologies become unreliable. Even inside human history, we make various guesses about when various events take place. The extant records that we use to date any particular item or event lead us, in many cases, to a best guess. How accurate this guess is - well, who really knows. Quite often, there is conflict over when or even if certain events have occurred in the past. This is the nature of the lack of easily obtained records of the past. Even when there is extent documentation available, there is still conflict. I take all the prognostications of dates in the far past as a guess, since we don't really know. > However, we humans are also incredibly good at finding clever, credible ways of inferring things from indirect clues. We are not as clever or even credible in a lot of what we do as humans. We are far too biased and political even in the fields of science and technology. That is just a part of our nature. If you looked at all the controversies over the last, what, 300 years, or we could look back over the last 2500 years and we'll see this rear its head many, many times. I have stated the position that we should not be concerned that we are certain, but put in the efforts to keep investigating all areas for insight and further knowledge. It really doesn't matter if our models are incomplete and wrong as long as we keep moving forward. It's when we are certain that we lose the ability to move forward. In many areas in science (even in technology) we have become "certain" that our theories and models are correct. This is a problem and we need to address this.
toomanybeersies 8y ago
Standard physics isn't really up for question. Newtons Laws still apply in the general case. My teachers never pretended that quantum physics was a fully understood, concrete field. A lot of what they said was prefixed with "we don't really know if this is how it works, but this is the model".
- dragonwriter 8y ago
  > Newtons Laws still apply in the general case. No, they apply (or, rather, are reasonable approximations) in the specific case of objects that aren't too small, and that don't move too fast relative to each other, etc. That is, the common case, but not the general one.
  - dbasedweeb 8y ago
    That sounds good, and is true, but comes with blistering caveats. First, the general case as he puts it, covers every macroscopic objects on and including Earth. It also covers microscopic objects until you reach particles, again on Earth, because of the energy scales involved. Everything from molecules to mammoths fit into this general case. If you charitably interpret “standard physics” [1] to include Relativistic and Quantum physics, then you cover everything in the universe that isn’t a black hole or less than or equal to 1.6x10^-45 meters, or at energies associated with the Planck epoch of the Big Bang. We’re talking about archaeology, which is notably unconcerned with black holes or anything with a detectable de Broglie wavelength. I think that if were not going to be pedantic, and accept that we’re talking about physics as applied to Classical objects like finger bones, he’s right and there is little debate to be had. It we want to be a little pedantic we can say that QM is just about the best tested theory ever, and the rounding error left to quibble over isn’t a factor here. If we want to be super pedantic we can point out that the “common” case on the scale of the universe is ultimately quantum-gravitational and therefore subject to physics that is not understood. Of course that majority is at distance scales we can’t access, or at energies or seem since the first second after the Big Bang. In that very very pedantic case you’re just as wrong as he is, but I think you’d rightly argue that it’s a pointless distinction in context. I’d agree with you. [1] Standard physics isn't really up for question. Newtons Laws still apply in the general case.
AlotOfReading 8y ago
Archaeologist turned embedded dev here. It's not limited to software. But dating is one of the things we understand very well. The key is an immense, globally consistent data set collected by thousands of idiots (like me) who trekked to the ends of the earth for a sample or two. That data came from dozens of sources (soils, charcoal deposits, rocks, lake cores, tree cores, ice cores, bones, literature, oral histories, artifacts, etc), each with their formation processes and interpretive challenges. In some cases (such as radio- or thermo- dating), the process depends primarily on fundamental physical processes. If these models are wrong, We got incredibly lucky building computers and space probes on the same concepts. But we can compare cross-check that data with processes observable today (like erosion, sedimentation, dendrochronology, cores... etc). Those data sets are globally consistent. But, we can go a step further and cross-check both of them with ab initio computer models and human sources with all the context that implies. As expected, they pretty much all work out. Virtually every area of science has contributed to the modern understanding of dating. If something is fundamentally wrong in that understanding, it would be exciting to put it mildly. And yes, there are issues as well. I could go on for hours about them. But archaeology is both an old field and a highly self-critical one. Any idea that's survived awhile is probably either "close", wrong in some very subtle ways, or extraordinarily attractive to our particular, western academia.

dwaltrip 8y ago

Have you researched any of the science behind the dating techniques?

aetherspawn 8y ago
Yes, I am about to complete my second bachelors degree in engineering and have done a basic level of research Re: dating techniques and know that most dating techniques rely on atomic properties which could also (but currently understood not to?) be affected by ie alpha/b/UV radiation. Or perhaps even exposure to ie bacteria (we are only really beginning to understand the interaction between bacteria and atomic level structures .. as apparent by some headlines in last 5/y or so) But I am by no means what you might classify as qualified or moderately familiar in this field.
- nonbel 8y ago
  I once tried to look into this and came away thinking it was all very circular (tree rings calibrated to archeology used to calibrate radioisotopes used to calibrate tree rings). There seemed to be a lot of room for cherry picking which data was "good" vs "corrupted" until everything matched up. Also it seemed to rely a lot on calibrating to the "known" date of ancient egyptian artifacts, which were in turn originally dated using the bible. Ie, if a radioisotope date from an artifact with a "known" date disagreed with that, it would be rejected. I remember this guy being an important player: https://en.wikipedia.org/wiki/Joseph_Justus_Scaliger https://en.wikipedia.org/wiki/Joseph_Justus_Scaliger Maybe I am just remembering it wrong or didn't look hard enough...
  - paulryanrogers 8y ago
    IIRC, Egyptian sources were used because the consistency of Nile River flooding meant their calendars are likely the most accurate.
    - nonbel 8y ago
      Interesting, but I don't really follow how flooding would be any more helpful than the seasons in general.

StanislavPetrov 8y ago

I'm also skeptical of the accuracy of these dating techniques until we have more evidence that corroborates their findings. That being said, I'm also very skeptical of the prevailing existing theories about the distant past as well. The dearth of concrete evidence from the distant past necessarily makes it difficult or impossible to make definitive statements. Skepticism and demand for evidence should always be our guiding light, no matter how widely accepted a theory is.

roywiggins 8y ago

I can't say anything about this particular method, but as far as I know generally dating methods are tested against each other. For instance, when you dig something out if the ground, you can get a rough idea of how old it is just by looking at the layers of rock and material above and below it. We know something about how fast these layers can be deposited, and usually stuff further down is older (not always, but if the layering is disturbed there's often evidence of it). So if you find that your dating method makes no sense for objects with an obvious date range (based on where you find them) then your dating method is probably broken. Obviously then if you take a leap over to objects that you find that you can only date in one way, you are taking a leap of faith. But in a few years, dating methods will come along that might let you test it in a different way entirely and either corroborate your first date or contradict it.

mygo 8y ago
layering, if the ground is undisturbed, can only tell us how old something at least is. The object itself could be older than the soil it was found in. Take for example how every ancient artifact in a museum is older than the soil it sits upon. So it has its limits. Who is to say that some dead guy’s finger wasn’t handed down for millennia before getting picked up during a raid and tossed on the ground on the journey back as worthless junk? We can’t fathom.
TangoTrotFox 8y ago
There is the risk of cascading errors. You can take many examples of beliefs that persisted for many decades, or even centuries in times past, that were simply wrong. But these wrong beliefs were often supported by layer after layer of corroborating evidence. The issue of course is that a derivative measurement takes the original measurement as a given, and then creates new formulae based on the result of the first - so you end up with two things corroborating the same view, even though its wrong. So I guess the question is what measurements are completely and absolutely independent? I don't recall in strata aging if the formation rate was alone used to determine age - so far as I recall the ages were dated by cross referencing known 'benchmarks', but then you've just created this very effect by assuming the age and then using that calibrate your method. And for what it's worth, I am not suggesting that the dating or other methods are incorrect here. Just pointing out some possible issues in this logic.

flukus 8y ago

Perhaps you need to turn that skepticism inward. There are good answers to your questions. Yes the dating techniques are verified by corroborating it with a lot of other evidence such as tree rings as well as other dating methods, it's also well corroborated with entirely different fields like geology, history and physics. As for being close to the surface, there are quite a few geological process that can come into play. There are places on earth that have fossils hundreds of millions of years old on the surface. This is not in any way remarkable. > So I suppose a similar thing applies here in dating science, except, it’s impossible to validate for another thousand centuries This sounds alarmingly like an argument you'd get out of Ken Ham. Are you a creationist that has trouble accepting an earth older than 6000 years? The debating style of asking seemingly probing yet actually well understood questions screams creationist (and climate change denialist) as well. You also fit the profile of creationist and climate change deniers, engineers that think they're smarter than the actually are and don't know what they don't know. As for finds like this, despite the headline it's completely unremarkable and fits easily within what we know of human migrations: https://en.wikipedia.org/wiki/File:Human_migration_out_of_Africa.png https://en.wikipedia.org/wiki/File:Human_migration_out_of_Af...

aetherspawn 8y ago
This kind of comment is flammatory and against HN etiquette (and should be removed).
- flukus 8y ago
  I know you claim to be skeptical but see evidence to the contrary. You're not skeptical of yourself and of your limited knowledge and your not skeptical of your need to be skeptical (there are no extraordinary claims in this discovery). I see no evidence that you are responding in good faith to any flaws in your reasoning, you're continuing to make an argument from incredulity. So I'm sorry if you're not a creationist (not as sorry as I'd be if you were), but when you look like a duck, argue like a duck and respond like a duck I start getting that duck vibe. How about you respond to the points in your post: > Not to be that guy, but I’m really starting to question the accuracy of dating techniques when they publish finds like this. Why when they publish finds like this? There is nothing extraordinary about these finds, they sit comfortably inside what we know of human migrations. > This finding is only significant because of the age, but have we ever verified our dating techniques over 5k years? 10k years? You're arguing against archaeology, geology, history and nuclear physics here. Do you think all these branches of science are being dishonest? > It seems further unlikely that such a bone from, 85k y/ago as they say, would be so close to the surface. Why do you find this surprising? There a quite a few geological process that can result in this. Nearly all fossils we find are quite close to the surface.

abritinthebay 8y ago

> but have we ever verified our dating techniques over 5k years? 10k years? Yes. > What’s to say that the hot desert sun and strange weather patterns, radiation or whatever couldn’t skew the dating Lots. For a start - only one of those would possibly affect the outcome of testing and would also be detectable. > It seems further unlikely that such a bone from, 85k y/ago as they say, would be so close to the surface Your incredulity doesn't affect the outcome one way or another and unless you want to dispute the fact that artifacts that are much older are often found on or close to the surface it's not based in any way to the real world. > In mechanical engineering we don’t ever “trust” the calculations until they are thoroughly validated And neither does the science around these dating techniques. In fact they're usually better supported than any engineering is. > It seems backwards to hinge all our science on it when (AFAICT) it hasn’t even been validated itself! And here's the thing: You're incredibly misinformed and that's why it makes no sense to you.

deleted 8y ago
[deleted]
taneq 8y ago
> And neither does the science around these dating techniques. In fact they're usually better supported than any engineering is. Given that the results of most if not all engineering can be directly tested, this seems unlikely.
- sten 8y ago
  I believe his point is that these methods are contentious for various reasons (religious objection being an example) so they have been heavily scrutinized and where exceptions have been found so have explanations. While most engineering doesn't receive the same level of attention, even if it could.
aetherspawn 8y ago
> In fact they're usually better supported than any engineering is. I don’t care who supports what in engineering. If you put a dozen [gauges, potentiometers, accelerometers] on a truck and drive it for 1,000,000km varying conditions and the data matches up with the cross derivation for each instruments relation to the other, it is no longer a case of “who supports” -> it is either _fact_ or not and completely indisputable. But it doesn’t become “supported” data for dropping said truck out of a plane. That’s lunacy - a dozen things not accounted-for in the normal model will occur. Our models might hold for a few thousand years, maybe even 10k .. but how many times have we dated an >20k year artifact under varying conditions and been able to validate it without relying on another model? Or as they would say about FEA, crap in, crap out (even though multiple models may agree, none are validated in such a method).

gus_massa 8y ago

Hey! I'm usually that guy, but in they are they are using "optically stimulated luminescence". https://www.usu.edu/geo/luminlab/whatis.html https://www.usu.edu/geo/luminlab/whatis.html https://en.wikipedia.org/wiki/Luminescence_dating https://en.wikipedia.org/wiki/Luminescence_dating I'm not an expert in the subject an I'm not an archeologist, but the method sounds good. One of the parts is the decay of radioactive atoms. This is a very well known subject, it's very easy to model and it is not affected by pressure or temperature (unless you use ridiculous huge amounts). The other part is about electrons trapped in the defects of crystals, and the conduction and valence band of crystals. This is also a well known subject, but it's more difficult to model. So IIUC after measuring the amount of "trapped" light they must irradiate each sample to calibrate the "trapping" ability of the material. This is not affected by usual variations of pressure and temperature. In particular the energy of the photons in sunlight is very different from the photons due to normal levels of heat. (At high temperature like more than 500°C or 900°F, that is possible near a fire, the difference between the energy of the photons is not so much and you have https://en.wikipedia.org/wiki/Thermoluminescence_dating https://en.wikipedia.org/wiki/Thermoluminescence_dating . But the heat below a few inches of the floor under sunlight is not enough.) As I said, I'm not an expert, but it looks like they are combining well known techniques and I guess that if you can enclose a bunch of Ph.D. students in a lab for 20 years with proper equipment, a few interesting samples and enough food, they will be able to rediscover this method. If you want to find something shady here, I'd look at > [Katerina] Harvati, who wasn’t involved in the research, said she would be cautious in definitively assigning the finger fossil a Homo sapiens identity due to the fact that its shape overlaps with other hominin species. [...]

aetherspawn 8y ago
Thanks for the writeup. Makes sense, but requires some further thought on my part (re: comments below on validation using multiple methods). Also I have no problem with the biology aspect as it is trivially verified what a human (or otherwise) bone looks like, composition etc
lurquer 8y ago
Dude in a caravan 100 years ago gets finger cut off while harnessing camel. Buried finger in sand. At night. (thus leaving the sand 'unbleached' as the term is used in the optical luminescence field.) Occam's razor.

slowmovintarget 8y ago

“Beyond 40,000 years old, the sample is so small, and the contamination risk so great, that the margin of error is thousands of years. It would be like having a watch that told you day and night.”[1] [1] http://discovermagazine.com/2016/jul-aug/scientific-dating-methods http://discovermagazine.com/2016/jul-aug/scientific-dating-m...

flukus 8y ago
The quote is irrelevant, it's taken from a section about radiocarbon dating which wasn't used here. They used Uranium series dating which according to your own source: > The uranium-thorium method is often helpful for dating finds in the 40,000- to 500,000-year-old range, too old for radiocarbon but too young for K-Ar or Ar-Ar.

amelius 8y ago

I see more problems in deriving migration patterns by looking at a single individual ...