Бағдат батареясы: Көне электрохимиялық жасуша туралы күмәнді жәдірелер

Set of artifacts purported to form an ancient electrochemical cell

The Baghdad Battery is the name given to a set of three artifacts which were found together: a ceramic pot, a tube of copper, and a rod of iron. It was discovered in present day Khujut Rabu, Iraq in 1936, close to the metropolis of Ctesiphon, the capital of the Parthian (150 BC – 223 AD) and Sasanian (224–650 AD) empires, and it is believed to date from either of these periods. Similar artifacts have been found at nearby sites. Its origin and purpose remain unclear. It was hypothesized by Wilhelm König, at the time director of the National Museum of Iraq, that the object functioned as a galvanic cell, possibly used for electroplating, or some kind of electrotherapy, but there is no electroplated object known from this period, and the claims are near universally rejected by archaeologists. An alternative explanation is that it functioned as a storage vessel for sacred scrolls. The artifact disappeared in 2003 during the US led invasion of Iraq. W. B. Hafford gives context to the discovery of the artifacts in his reaction video to Milo Rossi's video on the subject.

Its origin and purpose remain unclear. offering the hypothesis that they may have formed a galvanic cell, perhaps used for electroplating gold onto silver objects. This interpretation is rejected by skeptics. Corrosion of the metal and tests both indicate that an acidic agent such as wine or vinegar was present in the jar.

After the Second World War, Willard Gray demonstrated current production by a reconstruction of the inferred battery design when filled with grape juice. W. Jansen experimented with benzoquinone (some beetles produce quinones) and vinegar in a cell and got satisfactory performance. In 1978, Arne Eggebrecht, a past director of the Roemer und Pelizaeus Museum Hildesheim reportedly reproduced the electroplating of gold onto a small statue. There are no (direct) written or photographic records of this experiment. In an article from the BBC, Dr Bettina Schmitz, a researcher based at the same museum, said, "There does not exist any written documentation of the experiments which took place here in 1978 The experiments weren't even documented by photos, which really is a pity I have searched through the archives of this museum and I talked to everyone involved in 1978 with no results."

König himself seems to have been mistaken on the nature of the objects he thought were electroplated. They were apparently fire gilded (with mercury). Paul Craddock of the British Museum said "The examples we see from this region and era are conventional gold plating and mercury gilding. There's never been any irrefutable evidence to support the electroplating theory". Paul T. Keyser of the University of Alberta noted that Eggebrecht used a more efficient, modern electrolyte, and that using only vinegar, or other electrolytes available at the time assumed, the battery would be very feeble, and for that and other reasons concludes that even if this was in fact a battery, it could not have been used for electroplating. However, Keyser still supported the battery theory, but believed it was used for some kind of mild electrotherapy such as pain relief, possibly through electroacupuncture.

A bitumen seal, being thermoplastic, would be extremely inconvenient for a galvanic cell, which would require frequent topping up of the electrolyte for extended use.

The artifacts are similar to other objects believed to be storage vessels for sacred scrolls from nearby Seleucia on the Tigris. The object was looted along with thousands of other artifacts from the National Museum during the 2003 invasion of Iraq. In March 2012, Professor Elizabeth Stone of Stony Brook University, an expert on Iraqi archaeology, returning from the first archaeological expedition in Iraq after 20 years, stated that she does not know a single archaeologist who believed that these were batteries.

The Discovery Channel program MythBusters built replicas of the jars to see if it was possible for them to have been used for electroplating or electrostimulation. On MythBusters 29th episode (23 March 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. Connected in series, the battery produced 4 volts of electricity. When linked in series, the cells had sufficient power to electroplate a small token and to deliver current to acupuncture type needles for therapeutic purposes, but not enough to deliver an electric shock to MythBusters co host Adam Savage who was instead pranked by co hosts who hooked him up to a 10,000 volt cattle fence shock generator. Archaeologist Ken Feder commented on the show noting that no archaeological evidence has been found either for connections between the jars (which would have been necessary to produce the required voltage) or for their use for electroplating.