maximus otter
Recovering policeman
- Joined
- Aug 9, 2001
- Messages
- 14,653
New research on ancient Mesopotamia has uncovered evidence of an ancient magnetic phenomena, providing a way to delve deeper into one of the most fascinating periods in human history.
Scientists have analyzed ancient bricks from Mesopotamia and revealed just how dramatic an ancient spike in Earth’s magnetic field, some 3,000 years ago, truly was.
Items like bricks or pottery were often made with grains of magnetic rock that, when heated and then cooled, keep a signature of the geomagnetic conditions of the time.
“At very high temperatures, the objects are memoryless. But as the temperature drops it picks up a memory of the Earth’s magnetic field that it was sitting in at the time,” Philip McCausland of Canada’s Western University said.
Researchers used ancient bricks from Mesopotamia (which overlaps modern-day Iraq) containing iron oxide to investigate field strength. By systematically removing the ancient magnetic signature from small fragments of the bricks through heating and cooling, then reheating the bricks and replacing the magnetic field with one produced in the lab, they could get a ratio between the object's magnetic charge in the past and under laboratory conditions.
This told researchers that these bricks were fired at a time when the Earth’s magnetic field was more than one and a half times what it is today, during a period known as the Levantine Iron Age geomagnetic anomaly.
https://www.vice.com/en/article/4a3...f-mysterious-magnetic-anomaly-scientists-find
maximus otter
Scientists have analyzed ancient bricks from Mesopotamia and revealed just how dramatic an ancient spike in Earth’s magnetic field, some 3,000 years ago, truly was.
CREDIT: MATTHEW D. HOWLAND
Items like bricks or pottery were often made with grains of magnetic rock that, when heated and then cooled, keep a signature of the geomagnetic conditions of the time.
“At very high temperatures, the objects are memoryless. But as the temperature drops it picks up a memory of the Earth’s magnetic field that it was sitting in at the time,” Philip McCausland of Canada’s Western University said.
Researchers used ancient bricks from Mesopotamia (which overlaps modern-day Iraq) containing iron oxide to investigate field strength. By systematically removing the ancient magnetic signature from small fragments of the bricks through heating and cooling, then reheating the bricks and replacing the magnetic field with one produced in the lab, they could get a ratio between the object's magnetic charge in the past and under laboratory conditions.
This told researchers that these bricks were fired at a time when the Earth’s magnetic field was more than one and a half times what it is today, during a period known as the Levantine Iron Age geomagnetic anomaly.
https://www.vice.com/en/article/4a3...f-mysterious-magnetic-anomaly-scientists-find
maximus otter