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Iron Age Potters Accidentally Recorded the Strength of Earth's Magnetic Field (npr.org)
Solandri writes: We've only been able to measure the Earth's magnetic field strength for about two centuries. During this time, there has been a gradual decline in the field strength. In recent years, the rate of decline seems to be accelerating, leading to some speculation that the Earth may be losing its magnetic field -- a catastrophic possibility since the magnetic field is what protects life on Earth from dangerous solar radiation. Ferromagnetic particles in rocks provide a long-term history which tells us the poles have flipped numerous times. But uncertainties in dating the rocks prevents their use in understanding decade-scale magnetic field fluctuations.
Now a group of archeologists and geophysicists have come up with a novel way to produce decade-scale temporal measurements of the Earth's magnetic field strength from before the invention of the magnetometer. When iron-age potters fired their pottery in a kiln to harden it, it loosened tiny ferromagnetic particles in the clay. As the pottery cooled and these particles hardened, it captured a snapshot of the Earth's magnetic field. Crucially, the governments of that time required pottery used to collect taxed goods (e.g. a portion of olive oil sold) to be stamped with a royal seal. These seals changed over time as new kings ascended, or governments were completely replaced after invasion. Thus by cross-referencing the magnetic particles in the pottery with the seals, researchers were able to piece together a history of the Earth's magnetic field strength spanning from the 8th century BCE to the 2nd century BCE. Their findings show that large fluctuations in the strength of the magnetic field over a span of decades are normal. The study has been published in the journal PNAS.
Now a group of archeologists and geophysicists have come up with a novel way to produce decade-scale temporal measurements of the Earth's magnetic field strength from before the invention of the magnetometer. When iron-age potters fired their pottery in a kiln to harden it, it loosened tiny ferromagnetic particles in the clay. As the pottery cooled and these particles hardened, it captured a snapshot of the Earth's magnetic field. Crucially, the governments of that time required pottery used to collect taxed goods (e.g. a portion of olive oil sold) to be stamped with a royal seal. These seals changed over time as new kings ascended, or governments were completely replaced after invasion. Thus by cross-referencing the magnetic particles in the pottery with the seals, researchers were able to piece together a history of the Earth's magnetic field strength spanning from the 8th century BCE to the 2nd century BCE. Their findings show that large fluctuations in the strength of the magnetic field over a span of decades are normal. The study has been published in the journal PNAS.
Then how do you explain the fact that clay with the same seal displays very similar effects, and with different seals display different effects, with the magnitude of the effect lining up with the years indicated by the seals on the pots?
How do we boost the strength far enough to eliminate cancer?
In short: you can't. Cosmic radiation is just a small part of the complex system that can trigger cancer. Other aspects include: genetic make-up, environment (carcinogens) and the inherent error rate in the DNA copying machinery (missense, frameshifts, slippage, etc) [to name a few off the top of my head - I don't treat cancer]. And before you go down there....those imperfect copies are what leads to genetic variation (important to fend off predators both macro and microscopic) and evolution. Cancer is just about inevitable in any DNA based system
. . . . back in my Geophysics days (early 1980s), we already knew that the current planetary magnetic field was in decline, and we were approaching a pole reversal "real soon now" (in Geologic timeframe, not human timeframe. . ).
Heck, we were routinely measuring fossilized magnetic remnant fields in far older rocks, not just strength, but orientation as well. And finding the proper orientation of the sample was always difficult, generally required microscopic examination of a thin slice of the sample. The advantage of pottery for recent sampling, is that it is far easier to determine the orientation of the sample. . .
It's in the actual paper - unfortunately it seems paywalled, I don't know if there's an arXiv equivalent for this stuff but the table on page 4 is pretty conclusive - about 100 samples split into age categories based on their stamps.
Are you sure that the Curie point was named after Marie?
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Just checked. It's named after Pierre Curie
https://en.wikipedia.org/wiki/...
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