Researchers Spot Fake Ancient Pottery Using the Earth's Magnetic Field

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.

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.

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.”

I would love to see such counterfeiting. The gear they would need to get and the scientists.

> 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.

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.

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.

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.

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.