The Baghdad Battery is the common name for a number of artifacts created in Mesopotamia, possibly during the Parthian or Sassanid period (the early centuries AD). These jars were probably discovered in 1936 in the village of Khuyut Rabbou'a, near Baghdad. These artifacts came to wider attention in 1938 when Wilhelm König, the German director of the National Museum of Iraq, found the objects in the museum's collections. In 1940 König published a paper speculating that they may have been galvanic cells, perhaps used for electroplating gold onto silver objects.[1] This interpretation continues to be considered as at least a hypothetical possibility.If correct, the artifacts would predate Alessandro Volta's 1800 invention of the electrochemical cell by more than a millenium.
The artifacts consist of ~130mm (~5 inch) tall terracotta jars (with a one and a half inch mouth) containing a copper cylinder made of a rolled-up copper sheet, which houses a single iron rod. At the top, the iron rod is isolated from the copper by asphalt plugs or stoppers, and both rod and cylinder fit snugly inside the opening of the jar which bulges outward towards the middle (reverse hourglass shape). The copper cylinder is not watertight, so when the jar was filled with a liquid, this would surround the iron rod as well. The artifact had been exposed to the weather and had suffered corrosion, although mild given the presence of an electrochemical couple. This has led some scholars to believe lemon juice, grape juice, or vinegar was used as an acidic agent to jumpstart theelectrochemical reaction with the two metals
On MythBusters' 29th episode (which aired on March 23, 2005), ten hand-made terracotta jars were fitted to act as batteries. Lemon juice was chosen as the electrolyte to activate the electrochemical reaction between the copper and iron. (Oddly enough, it was discovered that a single lemon produced more voltage than one of the batteries). When all of the batteries were linked together in series, they produced upwards of 4 volts. Then, the major question was, "What were these ancient batteries used for?"
On MythBusters' 29th episode (which aired on March 23, 2005), ten hand-made terracotta jars were fitted to act as batteries. Lemon juice was chosen as the electrolyte to activate the electrochemical reaction between the copper and iron. (Oddly enough, it was discovered that a single lemon produced more voltage than one of the batteries). When all of the batteries were linked together in series, they produced upwards of 4 volts. Then, the major question was, "What were these ancient batteries used for?"
An article taken from wikipedia~(http://en.wikipedia.org/wiki/Baghdad_Battery)
No comments:
Post a Comment