The Baghdad battery has become the most mysterious artifact around which there are various myths and secrets. Where did ancient civilizations have knowledge about electricity? Could the battery have existed? Or maybe the vessel, found several centuries BC, was just a coincidence in appearance with a galvanic cell?
Mysterious vessel
While excavating the ruins of the 2000-year-old village of Kujut Rabu near Baghdad in 1936, workers discovered a very strange vessel. A 6 "(13 centimeters) high yellow clay pot was embedded with a 5" by 1.5 "copper sheet cylinder. The top edge of this cylinder was secured to the neck of the vessel with a lead-tin alloy similar to today's solder. The bottom of the copper cylinder was hermetically sealed with a copper disc. Inside the cylinder, an iron rod was placed in the center, hermetically sealed in the upper part with a resin similar to bitumen or asphalt. The rod was corroded with some kind of acidic electrolyte (such as acidic juice or vinegar).
The Baghdad battery is sometimes referred to as the Parthian battery and belongs to a number of artifacts created in Mesopotamia during the Parthian or Sassanid period (first centuries AD). These artifacts received more attention when the German historian Wilhelm Koenig found them in the collection of the National Museum of Iraq. He drew the attention of his colleagues to such unusual vases. Koenig carefully studied the object and came to the conclusion that the unusual ceramic vessel is nothing more than a real ancient electric battery. The potential difference between the copper cylinder and the iron rod made it possible for a weak electric current to flow, which was carried out by the electrolyte. The electrolyte was acidic juice, vinegar, or copper sulfate. In 1940, Koenig published an article in which he suggested that perhapsthese vases were used as electrochemical cells for electroplating silver objects with gold. If this assumption is correct, then these artifacts prove that people knew about electricity a couple of thousand years before the invention of the battery by Alessandro Volta in 1799.
The ancient battery in the Baghdad Museum, like others found in Iraq, dates from the Parthian occupation period between 248 BC and 226 AD. Koenig discovered in the Baghdad Museum silver-plated copper vases excavated in southern Iraq from Sumerian settlements that existed about 2500 BC. When tapped on the vase, blue plaque or film peeled off the surface, which is typical for electroplated silver plating on a copper base. Did the Parthians inherit batteries from one of the earliest known civilizations - the Sumerians?
In 1940, Willard, an engineer at the General Electric High Volatage Laboratory in Pittsfield, Massachusetts, studied Koenig's theories. Using detailed drawings, he made a copy of the Baghdad battery. Taking copper sulfate as an electrolyte, he received 0.5 volts of electricity. Later, in the 1970s, a German Egyptologist made an exact replica of a Baghdad battery and filled it with freshly squeezed grape juice. The battery produced 0.87 volts, which was enough to galvanize the silver statuette with gold.
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A drawing of the Baghdad battery.
These experiments proved that electric batteries could have been used 2,000 years before Volta's invention. In addition, in ancient Egypt, the use of electricity is depicted in wall paintings.
The use of mysterious devices in Ancient Egypt (Temple in Hator).
They also probably used batteries, as evidenced by the finds of products with traces of the electroplating method of applying precious metals in various places in Egypt.
Myths about "Baghdad batteries"
Arran Frouda, who researched the earliest batteries, is concerned that important archaeological and technological artifacts are now under threat of destruction due to the war in Iraq. War destroys not only people, armies. Culture, tradition and history are also in the line of fire. In the ancient land of Iraq, the Garden of Eden and the Tower of Babel are located. The country in which the hostilities were fought was not before the opening of Koenig. In 2003, during the war, Baghdad's battery was stolen from the National Museum of Iraq. Her whereabouts are still unknown.
For about 60 years after their discovery, Baghdad batteries have been shrouded in myths. Some argue that the batteries were not excavated but were found in the basement of the Baghdad Museum when Koenig became its director. Their age is also debatable. Although most sources attribute the batteries to the Parthian period, the reasons for this are not convincing. The Parthians were warriors and did not engage in science. While many of the archaeologists agree that the devices were actually batteries, not all support the hypothesis of what exactly they were used for. Ancient Persian science might not know about the principles of electricity and not use batteries as a galvanic cell. The process of electric current flow really requires two metals with different potentials and an electrolyte to redirect electrons between them. This could be the caseif the wires were found, but no wires were found anywhere near the batteries.
Possible applications
Some people believe that the batteries could be used in medicine. The ancient Greeks reduced pain by applying electric fish to the soles of their feet. The Chinese developed acupuncture and could apply acupuncture in combination with electric shock. This is confirmed by the discovery of needle-like objects near some of the batteries. Many scientists believe that batteries were used for electroplating. For example, gilding is used to make jewelry - the coating of jewelry with a thin layer of gold. There are two methods of gilding:
The precious metal flattened with a hammer into thin strips is applied to the product like foil;
Successively layers of precious metal are deposited by means of electrolytic deposition.
The first method is wasteful, and the second is more economical, which was welcomed in palaces, kingdoms and was the motivation to keep this method a secret. In experiments with copies of Baghdad batteries, using grape juice as an electrolyte, a thin layer of silver was applied to the surface with a thickness of only one ten thousandth of a millimeter. Higher voltage could be obtained by connecting several galvanic cells together. A serious drawback of the galvanic cell hypothesis was the lack of a large number of found products processed in this way.
The batteries could be used in magic rituals. For example, they could be used by priests in the temple, so that when a person touches a statue, a person receives a shock from a subtle current or a small flash of light. Even if the current was insufficient for a slight tingling sensation, it could be sufficient for a person's fingers to feel warmth from touching the divine statue, and the person himself was convinced of the power of the statue of God and religion. Perhaps such an idol or statue, with batteries hidden inside them, could be found if they survived the war in the Middle East. Then we can look at the evidence for the theory of the use of batteries in rituals. So far, we can only guess how else it was possible to use the mysterious vessels, and the mystery of the Baghdad battery remains unsolved.