THE ISRAELI STUDY EXAMINED EVENTS IN THE BIBLICAL BOOK OF KINGS USING THE EARTH'S MAGNETIC FIELD.

By JUDY SIEGEL-ITZKOVICH, January 4, 2024 13:42, Updated: January 4, 2024 18: 08, one of the incinerated mud bricks studied. , (photo credit: Dr. Yoav Vaknin)

Researchers from Tel Aviv University (TAU), Hebrew University of Jerusalem (HU), Bar-Ilan University (BIU) in Ramat Gan, and Ariel University in Samaria made these findings.

Researchers at four Israeli universities have corroborated the events described in the Second Book of Kings in the Bible-the conquest of the Philistine city of Gath by Hazael, King of Syria—using a "breakthrough" technology based on measurements of magnetic fields recorded in burning bricks.

The discovery, made by scientists from Tel Aviv University (TAU), Hebrew University of Jerusalem (HU), Bar-Ilan University (BIU) in Ramat Gan, and Ariel University in Samaria, will allow archaeologists to identify the burnt material found inside the excavation.and calculate their combustion temperature.

"Applying thermal demagnetization to archaeological materials: a tool for detecting burnt clay and estimating its combustion temperature", write they in an article published in the journal PLOS ONE. They also stated that their findings were important to determine the intensity of the fires and the extent of damage in Gath, the largest and most powerful city in the country at the time.

The researchers used their method to find what was found in ancient Gath (Tell es-Safi, located between the cities of Ashkelon and Beit Shemesh in central Israel), validating the Biblical record: "approximately at this time."The King of Aram Hazael attacked Gath and took it. He then returned to Jerusalem (2 Kings 12, 18).

They explain that, unlike previous methods, the new technique has the ability to measure the combustion temperature of materials, such as mud bricks, even at relatively low temperatures of up to 200 degrees Celsius. This information can be very important for understanding the results.

According to local geology, the clay is rich in magnetic iron minerals. However, all iron-containing clay minerals are generally heated to temperatures between 150°C and 700°C.

This multidisciplinary study was led by Dr. Yoav Vaknin of the Nadler Tau Institute of Archeology, the Entin Faculty of Humanities, and the Hu palaeomagnetic Laboratory. Prof. Ron Shaar of the HU Earth Sciences Institute; Prof. Erez Ben-Yosef and Prof. Oded Lipschits from the TAU Institute; Prof. Aren Maeir of the Department of land studies of Israel Martin (Szusz) BIU; and Dr. Adi Eliyahu Behar from the Department of studies and archaeology of the Land of Israel Ariel and the Department of Chemical Sciences.

Lipschits explains that mud bricks were the main building material in much of the Land of Israel during the bronze and Iron Ages. This inexpensive and easily accessible material is used to build walls in most buildings, sometimes on a stone foundation. Therefore, it is very important to understand the technology used in the manufacture of this brick.

At the same time, the inhabitants of other countries, such as Mesopotamia, which had difficult masonry, would burn mud bricks in kilns to make them stronger.

This method has been going on since Biblical times.

Vaknin added, "This technique is mentioned in the story of the Tower of Babel in Genesis, "they said to each other," Come on, let's make bricks and burn them to the ground, so they use bricks for Stone."

However, many researchers believe that this technology did not arrive in Israel until the Roman conquest, as the population still used sun-dried mud bricks. When bricks are found in archaeological excavations, several questions must be asked. First, has the brick been burned, and if so, was it burned at a previous burn site or in the event of a fire causing damage at the site? Our method has the ability to give a definite answer.

"The clay from which the bricks are made contains millions of ferromagnetic particles-minerals with magnetic properties that behave like so many small "compasses" or magnets," explains Vaknin. The new method relies on magnetic field measurements that are recorded and "locked" inside the bricks as they are burned.

The orientation of these magnets is almost random in sun-dried mud bricks, thus negating each other. Therefore, the brick magnetic signal is very weak and not uniform overall. These magnetic particles release a magnetic signal when they are heated to 200°C or more, as happens in a fire. At some point, this magnetic signal is statistically aligned with the Earth's magnetic field. As the brick cools, its magnetic signal locks into place previously, producing a strong, uniformly oriented magnetic field that can be measured with a magnetometer. This clearly indicates that the brick has been burned.

In the second step of their work, the researchers used a process known as thermal demagnetization to gradually "erase" the brick's magnetic field. This process requires heating the bricks in a special oven in a palaeomagnetic laboratory, which neutralizes the Earth's magnetic field. The magnetic signal released by the heat arranges itself randomly. The total magnetic signal then becomes weak and loses its orientation.

Vaknin continued, " We are doing the process gradually. At first, we heated the sample to a temperature of 100°C, which released the signal of only a small part of the magnetic minerals. We then cooled it and measured the remaining magnetic signal. We then repeated the procedure at 150°C, 200°C, and so on, continuing in small steps up to 700°C."

The temperature at which the signal from each mineral is "unlocked" is approximately equal to the temperature at which it was originally "locked", and ultimately, the temperature at which the magnetic field was completely erased during the original fire.

The researchers tested this method in the laboratory. They fired mud bricks under controlled temperature and magnetic field, measured their magnetic field, and then gradually removed them. They found that the bricks actually demagnetized at the temperature at which they were burned, suggesting that this method worked.

Vaknin states that their approach allows the identification of combustion occurring at much lower temperatures than other methods. Most of the techniques used to identify burnt bricks are based on actual changes in minerals that typically occur at temperatures higher than 500°F.

Changes caused by the absorption of infrared radiation by various minerals are one of the common methods for identifying mineralogical changes occurring in clay, which is the main component of mud bricks. This method was used in this study to verify the results of the magnetic method.

"We can begin to detect changes in magnetic signals at temperatures as low as 100 degrees Celsius, and from 200 degrees Celsius and above, the findings are convincing," Behar said. Their new method is much more sensitive than others because it targets changes in the intensity and orientation of magnetic signals, which occur at much lower temperatures.

This method can determine the place where the brick has cooled down. Vaknin stated that when a brick was burned in a kiln before construction, it recorded the direction of the Earth's magnetic field at a certain time and place. "In Israel, this means to the North and down, but when builders take bricks from the kiln and build a wall, they put them in a random orientation, thereby scrambling the recorded signal. On the other hand, when a wall is burned on site, as it might be when it is demolished

Having shown the method to be valid, the researchers used it to solve a specific archaeological problem: were certain brick structures found in Tell es-Safi, known as the Philistine city of Gath, the home of Goliath, built of pre-burned bricks or burned at the site? A common theory, based on the Bible, historical sources, and carbon-14 dating, attributes the destruction of the building to the murder of Gath by Hazael, King of Damascus, around 830 BC. However, previous papers by researchers, including Maeir BIU, who heads the Tell es-Safi excavation, show that the building did not burn down but rather collapsed for decades, and that the burnt bricks found inside the Te building if this is true, this will be the first example of brick-burning technology in Israel.

To resolve the differences, the research team used a new technique on samples of the Tell es-Safi wall and debris that collapsed alongside it. Confirmation of this finding is that the magnetic field of all collapsed bricks and rubble is oriented to the North and down. Vaknin stated that their findings indicate that the bricks burned and cooled in-situ, right where they were found, that is, in a large fire in the building itself, which collapsed within a few hours.

If a brick is burned in a furnace and then laid on a wall, its magnetic orientation will change irregularly. In addition, collapsed debris would have a random magnetic orientation if the structure collapsed over time and not in a single fire event. We believe that the main factor that led to the misinterpretation of our colleagues was their inability to identify combustion at temperatures below 500°C. Due to the increased heat, the material at the bottom of the structure burns out at a relatively low temperature, below 400°C. As a result, this material was not found to burn in previous studies, which suggests that the fire did not destroy the structure.

At the same time, the bricks at the top of the wall, where temperatures were much higher, underwent mineralogical changes and were therefore identified as burned, leading the researchers to conclude that they had been burned in the kiln prior to construction. He says, "Our method allowed us to find out that all the bricks in the walls and rubble had burned out during the fire: those at the bottom burned out at relatively low temperatures, and those found in higher layers or falling from above burned out at temperatures higher than 600 degrees Celsius."

"It is very important to review the conclusions of previous studies and sometimes even refute previous interpretations, even if they come from your own school," says Maeir. "Our findings are critical to deciphering the intensity of the fires and the scope of destruction in Gath, the largest and most powerful city in the Land of Israel at the time, as well as understanding the building methods prevailing in that era."

"Beyond their historical and archaeological significance, ancient building methods also have substantial ecological implications," Ben-Yosef said. In the past, fuel-intensive brick-burning techniques may have resulted in significant deforestation and even the loss of tree species in the region.

For example, the ancient copper industry in the Timna Valley still exploited some types of trees and shrubs, and the industry itself eventually collapsed when its natural sources of fuel ran out. We found that the technology of burning bricks was probably not used in the Land of Israel during the reign of the Kings of Judah and Israel.

News Sources :  https://www.jpost.com/archaeology/article-780745