Fascinating! I wonder if cloth artifacts, such as the Shroud of Turin, would also exhibit similar signatures. Though I have read some extremely compelling multi-disciplinary evidence exist to its authenticity to 1st century Judea, not a forgery.
huurtehoog 5 hours ago [-]
I find it infinitely fascinating that everything that ever happens leaves a trail of information that we keep getting better at querying.
From understanding what exactly stars are made of, to the evolution of life on Earth, and the exploits of humans living thousands of years ago.
It's really uncanny the unreasonable effectiveness of mathematics, something we made up by manipulating abstract symbols, in modelling and helping us understand the universe in every minute detail we care to inquire. Truly miraculous.
Lord-Jobo 3 hours ago [-]
Inherent principles exist in any really high resolution system that are so hard to control they can usually be tracked and manipulated but never completely controlled.
It’s why cancer is so prevalent and damn near unsolvable: an organism our size has about 7 octillion atoms, even forgetting the impacts of the stuff smaller than that. That’s 30ish trillion cells, many are multipurpose little motor vehicles inside our body running around doing stuff constantly.
It’s just so much STUFF happening, take the brain out of someone and leave them a vegetable digesting on a bed and they still burn hundreds of kcal a day, and that’s a highly efficient system millions of years in production.
So two things emerge from that, 1: extremely robust universal principles like electromagnetic gradients being used for travel, and 2: runaway feedback loops like black holes or cancerous cells.
What that means is that you can view mathematics as a spontaneous emergence FROM a high resolution system, or the inverse. We usually think of the inverse, because it seems like no matter what we discover in the system it can be explained by increasingly complex math.
But the inverse of that is very interesting to me: math emerges as a side effect from the high resolution system. It also passes the smell test, if you make a low resolution simulation of the solar system you will not see the effects of the high complexity systems, relativity works perfectly without any quantum dynamics.
I just love these kinds of chicken and egg problems.
huurtehoog 1 hours ago [-]
I think you're framing this as idealism vs materialism?
The debate is fascinating. I tend to be more of an idealist but I recognize that science is predicated on materialism. I believe we ought to find a complete explanation for how things work.
It is odd though that experimental data seem to indicate that at the quantum level locality is not preserved and there are no hidden variables thus non locality seems to be intrinsic to the universe. That would indicate to me that materialism is in serious trouble.
pif 3 hours ago [-]
Mathematics is a tool. What make such understanding possible are the relentless, disciplined, often-pointless-looking collection and categorization of data of any kind, by generations and generations of selfless scientists.
What prevents forgers from generating such magnetic fields? That might be worth while if people start to blindly believing that "pottery frozen magnetic fields are not possible to counterfeit". Note that "not possible to counterfeit" is not a claim in the article.
adrian_b 10 hours ago [-]
From TFA:
> “So it’s hard for us to be ahead of the forgers since they can read our papers and figure out ways to trick our methods.”
po1nt 11 hours ago [-]
I would love to see such counterfeiting. The gear they would need to get and the scientists.
awesomeusername 8 hours ago [-]
Some wire and DC? and Claude et al
bell-cot 6 hours ago [-]
> What prevents forgers from ...
Cost. Same as them fooling carbon dating, electron microscopes, isotope analysis, and a host of other techniques.
Forgery has always been about how cheaply you could make fakes, vs. the odds and consequences of them getting enough scrutiny to be identified as such.
brookst 6 hours ago [-]
It’s the banknote thing: at some point a great forgery costs more than the real thing.
Cthulhu_ 7 hours ago [-]
It's one of several techniques they can apply, at least. I for one don't even know why there's a forgery market for ancient pottery, or that there's a market for it.
p-e-w 7 hours ago [-]
> I for one don't even know why there's a forgery market for ancient pottery
Because people desire owning ancient pottery and are therefore willing to pay for it.
charlieyu1 4 hours ago [-]
Forgery is so ancient that we have forgery ancient items made in ancient times
mschuster91 7 hours ago [-]
> I for one don't even know why there's a forgery market for ancient pottery
People have paid top dollar for archeological artifacts for centuries. Humanity lost a lot of knowledge from graverobbers, illegal artifact hunting and unreported thefts of stuff getting exposed after stuff like forest fires.
fn-mote 4 hours ago [-]
> Humanity lost a lot of knowledge from graverobbers […]
Don’t forget the major scale destruction wrought by wars (religious and otherwise) - eg in the Middle East.
You might also want to count cultural theft. (Where are the gates of Babylon now??)
"Studying these layered strata is known as magnetostratigraphy and can be used to verify radioactive dating methods. Geologists used magnetostratigraphy to cross-check the dates of the Nakali Formation, where Nakalipithecus nakayamai’s jaw was found."
profsummergig 10 hours ago [-]
can this clue be circumvented by using magnets oriented in a certain way around the workshop while constructing the pottery?
comrade1234 10 hours ago [-]
There are two fields. The second very weak field is acquired over centuries, I assume when the piece is not moved. The primary stronger field is created when it's first formed. I think what you're talking about would orientate the primary field, not the weak field.
skew-aberration 10 hours ago [-]
The second field can probably be created by changing the first field while the piece is still cooling down.
userbinator 9 hours ago [-]
Because the location of the pole is constantly shifting, the TRM of ancient pottery points in a slightly different direction than that of pottery made today.
Did anyone else have a strong "WTF?" reaction upon reading that sentence? Yes, the pole has moved. No, it's completely irrelevant given that not every piece of pottery even manufactured at the same time is going to be fired in the exact same orientation relative to the pole.
The researchers determined that any sample older than a millennium had to be heated to at least 234 degrees Fahrenheit before its VRM was erased. New pottery samples’ VRMs, meanwhile, could be wiped at lower temperatures.
This was not about the magnetization during firing, but about the much weaker magnetization acquired later, while staying in the same position without being moved.
That weak magnetization happens below the Curie temperature. Actually, any magnetization happens below the Curie temperature. Heating above the Curie temperature just erases any previous magnetization. A material is easier to magnetize immediately below the Curie temperature, but it can be magnetized at any lower temperature. Thus the ceramics that contains iron oxides acquires an initial strong magnetization while cooling down, and a weaker superposed magnetization if it is not moved for a long time. The 2 magnetizations can be distinguished by having different directions, as the pottery stayed buried in a different orientation than when it had been fired.
Only pottery that has not been moved for a very long time acquires a strong enough secondary magnetization. So the test distinguished pottery that has been used recently from pottery that stayed buried for centuries, by the strengths of their secondary magnetizations, not by their primary magnetizations.
A weak magnetization can be erased by heating even below the Curie temperature (which completely erases any kind of magnetization), so this is how they tested. The ferromagnetic materials are divided into hard and soft. The former are used for things like permanent magnets, while the latter are used for things like transformers and inductors.
The difference between hard and soft magnetic materials is that the latter loose quickly their magnetization even at the ambient temperature. Most ferromagnetic materials, which have not been specifically designed to be as soft as possible or as hard as possible, have intermediate softness, i.e. they start to loose quickly their magnetizations at temperatures higher than the normal ambient temperatures, but still much lower than their Curie temperatures. The tested ceramics also behave like this.
Zitrax 7 hours ago [-]
Just curious, the heating to remove the VRM is that permanent so you can only check the authenticity once?
adrian_b 7 hours ago [-]
Yes, you are right, once the VRM is erased it is gone for good.
Though it is possible to test only a fragment of an object, but I do not know if the instruments that were used were sensitive enough to work with only a very small chip, which could be glued back, afterwards.
Many such ancient pottery objects are already broken, so they must be glued anyway, if a restoration is desired.
nmstoker 7 hours ago [-]
It strikes me as risky, if the item is in any way delicate or has absorbed water at all. But I'm no ceramics expert!
AdamN 7 hours ago [-]
Even when buried wouldn't their orientation shift over time from geological forces?
MadnessASAP 9 hours ago [-]
We should probably assume that the authors are aware of ceramics, Curie points, and the earth magnetic field. While the article isn't very clear on what effect causes the change in temperature needed to erase the VRM. I suspect is has something to do with how long the object has spent stationary with respect to the earth's field. At least that's my takeaway from having to periodically rotate magnetometers to prevent them from acquiring a bias.
Gibbon1 8 hours ago [-]
I'm reminded of thermoluminescence for dating objects. Radiation creates defects in the material over time. When heated the defects release light.
Imprecise but will fink on ceramics that were fired 30 years ago vs 3000 years ago. Difficulty you need to heat a fair sized sample.
"Reads article"
Impression, author didn't understand any of what he was told.
But yes similar, over time the object picks up a faint magnetic field superimposed on the one locked in when the ceramic was made.
mayneack 11 hours ago [-]
The method of seems to involve hearing the artifacts which seems plausibly risky for an ancient artifact.
Rendered at 16:10:08 GMT+0000 (UTC) with Wasmer Edge.
From understanding what exactly stars are made of, to the evolution of life on Earth, and the exploits of humans living thousands of years ago.
It's really uncanny the unreasonable effectiveness of mathematics, something we made up by manipulating abstract symbols, in modelling and helping us understand the universe in every minute detail we care to inquire. Truly miraculous.
It’s why cancer is so prevalent and damn near unsolvable: an organism our size has about 7 octillion atoms, even forgetting the impacts of the stuff smaller than that. That’s 30ish trillion cells, many are multipurpose little motor vehicles inside our body running around doing stuff constantly.
It’s just so much STUFF happening, take the brain out of someone and leave them a vegetable digesting on a bed and they still burn hundreds of kcal a day, and that’s a highly efficient system millions of years in production.
So two things emerge from that, 1: extremely robust universal principles like electromagnetic gradients being used for travel, and 2: runaway feedback loops like black holes or cancerous cells.
What that means is that you can view mathematics as a spontaneous emergence FROM a high resolution system, or the inverse. We usually think of the inverse, because it seems like no matter what we discover in the system it can be explained by increasingly complex math.
But the inverse of that is very interesting to me: math emerges as a side effect from the high resolution system. It also passes the smell test, if you make a low resolution simulation of the solar system you will not see the effects of the high complexity systems, relativity works perfectly without any quantum dynamics.
I just love these kinds of chicken and egg problems.
The debate is fascinating. I tend to be more of an idealist but I recognize that science is predicated on materialism. I believe we ought to find a complete explanation for how things work.
It is odd though that experimental data seem to indicate that at the quantum level locality is not preserved and there are no hidden variables thus non locality seems to be intrinsic to the universe. That would indicate to me that materialism is in serious trouble.
https://boards.straightdope.com/t/sound-recordings-on-ancien...
(sound recordings in clay)
> “So it’s hard for us to be ahead of the forgers since they can read our papers and figure out ways to trick our methods.”
Cost. Same as them fooling carbon dating, electron microscopes, isotope analysis, and a host of other techniques.
Forgery has always been about how cheaply you could make fakes, vs. the odds and consequences of them getting enough scrutiny to be identified as such.
Because people desire owning ancient pottery and are therefore willing to pay for it.
People have paid top dollar for archeological artifacts for centuries. Humanity lost a lot of knowledge from graverobbers, illegal artifact hunting and unreported thefts of stuff getting exposed after stuff like forest fires.
Don’t forget the major scale destruction wrought by wars (religious and otherwise) - eg in the Middle East.
You might also want to count cultural theft. (Where are the gates of Babylon now??)
Quoting my book:
"Studying these layered strata is known as magnetostratigraphy and can be used to verify radioactive dating methods. Geologists used magnetostratigraphy to cross-check the dates of the Nakali Formation, where Nakalipithecus nakayamai’s jaw was found."
Did anyone else have a strong "WTF?" reaction upon reading that sentence? Yes, the pole has moved. No, it's completely irrelevant given that not every piece of pottery even manufactured at the same time is going to be fired in the exact same orientation relative to the pole.
The researchers determined that any sample older than a millennium had to be heated to at least 234 degrees Fahrenheit before its VRM was erased. New pottery samples’ VRMs, meanwhile, could be wiped at lower temperatures.
That's a more useful difference which I would attribute to the ceramics having different Curie points in their compositions, and of course it's not something too difficult to change: https://en.wikipedia.org/wiki/Curie_temperature#Changing_a_m...
Incidentally, this effect of temperature on magnetism is how the https://en.wikipedia.org/wiki/Magneto-optical_drive media records data.
That weak magnetization happens below the Curie temperature. Actually, any magnetization happens below the Curie temperature. Heating above the Curie temperature just erases any previous magnetization. A material is easier to magnetize immediately below the Curie temperature, but it can be magnetized at any lower temperature. Thus the ceramics that contains iron oxides acquires an initial strong magnetization while cooling down, and a weaker superposed magnetization if it is not moved for a long time. The 2 magnetizations can be distinguished by having different directions, as the pottery stayed buried in a different orientation than when it had been fired.
Only pottery that has not been moved for a very long time acquires a strong enough secondary magnetization. So the test distinguished pottery that has been used recently from pottery that stayed buried for centuries, by the strengths of their secondary magnetizations, not by their primary magnetizations.
A weak magnetization can be erased by heating even below the Curie temperature (which completely erases any kind of magnetization), so this is how they tested. The ferromagnetic materials are divided into hard and soft. The former are used for things like permanent magnets, while the latter are used for things like transformers and inductors.
The difference between hard and soft magnetic materials is that the latter loose quickly their magnetization even at the ambient temperature. Most ferromagnetic materials, which have not been specifically designed to be as soft as possible or as hard as possible, have intermediate softness, i.e. they start to loose quickly their magnetizations at temperatures higher than the normal ambient temperatures, but still much lower than their Curie temperatures. The tested ceramics also behave like this.
Though it is possible to test only a fragment of an object, but I do not know if the instruments that were used were sensitive enough to work with only a very small chip, which could be glued back, afterwards.
Many such ancient pottery objects are already broken, so they must be glued anyway, if a restoration is desired.
Imprecise but will fink on ceramics that were fired 30 years ago vs 3000 years ago. Difficulty you need to heat a fair sized sample.
"Reads article"
Impression, author didn't understand any of what he was told.
But yes similar, over time the object picks up a faint magnetic field superimposed on the one locked in when the ceramic was made.