Baghdad Battery
Encyclopedia
The Baghdad Battery, sometimes referred to as the Parthian Battery, is the common name for a number of artifacts created in Mesopotamia
Mesopotamia
Mesopotamia is a toponym for the area of the Tigris–Euphrates river system, largely corresponding to modern-day Iraq, northeastern Syria, southeastern Turkey and southwestern Iran.Widely considered to be the cradle of civilization, Bronze Age Mesopotamia included Sumer and the...

, during the dynasties of Parthia
Parthia
Parthia is a region of north-eastern Iran, best known for having been the political and cultural base of the Arsacid dynasty, rulers of the Parthian Empire....

n or Sassanid period (the early centuries AD), and probably discovered in 1936 in the village of Khuyut Rabbou'a
Khujut Rabu
Khujut Rabu is a local area to the South-East of Baghdad, Iraq, near the town of the present-day Salman Pak. Also Khujut Rabua. In ancient times this was the location of Ctesiphon and Seleucia on the Tigris. This area was the capital city of the Parthian Civilization...

, near Baghdad
Baghdad
Baghdad is the capital of Iraq, as well as the coterminous Baghdad Governorate. The population of Baghdad in 2011 is approximately 7,216,040...

, Iraq
Iraq
Iraq ; officially the Republic of Iraq is a country in Western Asia spanning most of the northwestern end of the Zagros mountain range, the eastern part of the Syrian Desert and the northern part of the Arabian Desert....

. These artifacts came to wider attention in 1938 when Wilhelm König
Wilhelm König
Wilhelm König was a German archaeologist.A painter by profession, König was also interested in natural science. In 1931 he was elected assistant to the German leader of the Baghdad Antiquity Administration as head of the laboratory...

, the German
Germany
Germany , officially the Federal Republic of Germany , is a federal parliamentary republic in Europe. The country consists of 16 states while the capital and largest city is Berlin. Germany covers an area of 357,021 km2 and has a largely temperate seasonal climate...

 director of the National Museum of Iraq
National Museum of Iraq
The National Museum of Iraq is a museum located in Baghdad, Iraq. It contains precious relics from Mesopotamian civilization.-Foundation:...

, found the objects in the museum's collections. In 1940, König published a paper speculating that they may have been galvanic cell
Galvanic cell
A Galvanic cell, or Voltaic cell, named after Luigi Galvani, or Alessandro Volta respectively, is an electrochemical cell that derives electrical energy from spontaneous redox reaction taking place within the cell...

s, perhaps used for electroplating
Electroplating
Electroplating is a plating process in which metal ions in a solution are moved by an electric field to coat an electrode. The process uses electrical current to reduce cations of a desired material from a solution and coat a conductive object with a thin layer of the material, such as a metal...

 gold
Gold
Gold is a chemical element with the symbol Au and an atomic number of 79. Gold is a dense, soft, shiny, malleable and ductile metal. Pure gold has a bright yellow color and luster traditionally considered attractive, which it maintains without oxidizing in air or water. Chemically, gold is a...

 onto silver
Silver
Silver is a metallic chemical element with the chemical symbol Ag and atomic number 47. A soft, white, lustrous transition metal, it has the highest electrical conductivity of any element and the highest thermal conductivity of any metal...

 objects. This interpretation continues to be considered as at least a hypothetical possibility. If correct, the artifacts would predate Alessandro Volta
Alessandro Volta
Count Alessandro Giuseppe Antonio Anastasio Gerolamo Umberto Volta was a Lombard physicist known especially for the invention of the battery in 1800.-Early life and works:...

's 1800 invention of the electrochemical cell
Electrochemical cell
An electrochemical cell is a device capable of either deriving electrical energy from chemical reactions, or facilitating chemical reactions through the introduction of electrical energy. A common example of an electrochemical cell is a standard 1.5-volt "battery"...

 by more than a millennium.

Description and dating

The artifacts consist of terracotta pots approximately 130 mm (5 in) tall (with a one-and-a-half-inch mouth) containing a copper
Copper
Copper is a chemical element with the symbol Cu and atomic number 29. It is a ductile metal with very high thermal and electrical conductivity. Pure copper is soft and malleable; an exposed surface has a reddish-orange tarnish...

 cylinder
Cylinder (geometry)
A cylinder is one of the most basic curvilinear geometric shapes, the surface formed by the points at a fixed distance from a given line segment, the axis of the cylinder. The solid enclosed by this surface and by two planes perpendicular to the axis is also called a cylinder...

 made of a rolled-up copper sheet, which houses a single iron
Iron
Iron is a chemical element with the symbol Fe and atomic number 26. It is a metal in the first transition series. It is the most common element forming the planet Earth as a whole, forming much of Earth's outer and inner core. It is the fourth most common element in the Earth's crust...

 rod. At the top, the iron rod is isolated from the copper by bitumen plugs or stoppers, and both rod and cylinder fit snugly inside the opening of the jar, which bulges outward toward the middle. The copper cylinder is not watertight, so if 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
Electrochemical cell
An electrochemical cell is a device capable of either deriving electrical energy from chemical reactions, or facilitating chemical reactions through the introduction of electrical energy. A common example of an electrochemical cell is a standard 1.5-volt "battery"...

. This has led some to believe lemon juice
Lemon juice
The lemon fruit, from a citrus plant, provides a useful liquid when squeezed. Lemon juice, either in natural strength or concentrated, is sold as a bottled product, usually with the addition of preservatives and a small amount of lemon oil.-Uses:...

, grape juice
Grape juice
Grape juice is obtained from crushing and blending grapes into a liquid. The juice is often sold in stores or fermented and made into wine, brandy, or vinegar. In the wine industry, grape juice that contains 7-23 percent of pulp, skins, stems and seeds is often referred to as "must"...

, or vinegar
Vinegar
Vinegar is a liquid substance consisting mainly of acetic acid and water, the acetic acid being produced through the fermentation of ethanol by acetic acid bacteria. Commercial vinegar is produced either by fast or slow fermentation processes. Slow methods generally are used with traditional...

 was used as an acid
Acid
An acid is a substance which reacts with a base. Commonly, acids can be identified as tasting sour, reacting with metals such as calcium, and bases like sodium carbonate. Aqueous acids have a pH of less than 7, where an acid of lower pH is typically stronger, and turn blue litmus paper red...

ic electrolyte
Electrolyte
In chemistry, an electrolyte is any substance containing free ions that make the substance electrically conductive. The most typical electrolyte is an ionic solution, but molten electrolytes and solid electrolytes are also possible....

 solution to generate an electric current
Electric current
Electric current is a flow of electric charge through a medium.This charge is typically carried by moving electrons in a conductor such as wire...

 from the difference between the electrochemical potentials of the copper and iron electrode
Electrode
An electrode is an electrical conductor used to make contact with a nonmetallic part of a circuit...

s.

König thought the objects might date to the Parthian
Parthian Empire
The Parthian Empire , also known as the Arsacid Empire , was a major Iranian political and cultural power in ancient Persia...

 period (between 250 BC and AD 224). However, according to St John Simpson of the Near Eastern
Ancient Near East
The ancient Near East was the home of early civilizations within a region roughly corresponding to the modern Middle East: Mesopotamia , ancient Egypt, ancient Iran The ancient Near East was the home of early civilizations within a region roughly corresponding to the modern Middle East: Mesopotamia...

 department of the British Museum
British Museum
The British Museum is a museum of human history and culture in London. Its collections, which number more than seven million objects, are amongst the largest and most comprehensive in the world and originate from all continents, illustrating and documenting the story of human culture from its...

, their original excavation and context were not well-recorded (see stratigraphy), so evidence for this date range is very weak. Furthermore, the style of the pottery (see typology
Typology (archaeology)
In archaeology a typology is the result of the classification of things according to their characteristics. The products of the classification, i.e. the classes are also called types. Most archaeological typologies organize artifacts into types, but typologies of houses or roads belonging to a...

) is Sassanid (224-640).

Most of the components of the objects are not particularly amenable to advanced dating methods
Archaeological science
Archaeological science, also known as archaeometry, consists of the application of scientific techniques to the analysis of archaeological materials. Archaeometry is now considered its own scientific field. The UK's Natural and Environmental Research Council provides funding for archaeometry...

. The ceramic pots could be analysed by thermoluminescence dating
Thermoluminescence dating
Thermoluminescence dating is the determination, by means of measuring the accumulated radiation dose, of the time elapsed since material containing crystalline minerals was either heated or exposed to sunlight...

, but this has not yet been done; in any case, it would only date the firing of the pots, which is not necessarily the same as when the complete artifact was assembled. Another possibility would be ion
Ion
An ion is an atom or molecule in which the total number of electrons is not equal to the total number of protons, giving it a net positive or negative electrical charge. The name was given by physicist Michael Faraday for the substances that allow a current to pass between electrodes in a...

 diffusion
Diffusion
Molecular diffusion, often called simply diffusion, is the thermal motion of all particles at temperatures above absolute zero. The rate of this movement is a function of temperature, viscosity of the fluid and the size of the particles...

 analysis, which could indicate how long the objects were buried.

Electrical

Copper and iron form an electrochemical couple, so that, in the presence of any electrolyte
Electrolyte
In chemistry, an electrolyte is any substance containing free ions that make the substance electrically conductive. The most typical electrolyte is an ionic solution, but molten electrolytes and solid electrolytes are also possible....

, an electric potential
Electric potential
In classical electromagnetism, the electric potential at a point within a defined space is equal to the electric potential energy at that location divided by the charge there...

 (voltage) will be produced. König had observed a number of very fine silver objects from ancient Iraq that were plated with very thin layers of gold, and speculated that they were electroplated using batteries
Battery (electricity)
An electrical battery is one or more electrochemical cells that convert stored chemical energy into electrical energy. Since the invention of the first battery in 1800 by Alessandro Volta and especially since the technically improved Daniell cell in 1836, batteries have become a common power...

 with these as the cells. After the Second World War, Willard Gray demonstrated current production by a reconstruction of the inferred battery design when filled with grape juice
Grape juice
Grape juice is obtained from crushing and blending grapes into a liquid. The juice is often sold in stores or fermented and made into wine, brandy, or vinegar. In the wine industry, grape juice that contains 7-23 percent of pulp, skins, stems and seeds is often referred to as "must"...

. W. Jansen experimented with benzoquinone (some beetle
Beetle
Coleoptera is an order of insects commonly called beetles. The word "coleoptera" is from the Greek , koleos, "sheath"; and , pteron, "wing", thus "sheathed wing". Coleoptera contains more species than any other order, constituting almost 25% of all known life-forms...

s produce quinone
Quinone
A quinone is a class of organic compounds that are formally "derived from aromatic compounds [such as benzene or naphthalene] by conversion of an even number of –CH= groups into –C– groups with any necessary rearrangement of double bonds," resulting in "a fully conjugated cyclic dione structure."...

s) and vinegar in a cell and got satisfactory performance.

However, even among those believing the artifacts to be electrical devices, electroplating as a use is not well-regarded today. 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 untouchable evidence to support the electroplating theory." The gilded objects that König thought might be electroplated are now believed to have been fire-gilded (with mercury
Mercury (element)
Mercury is a chemical element with the symbol Hg and atomic number 80. It is also known as quicksilver or hydrargyrum...

). Reproduction experiments of electroplating by Arne Eggebrecht consumed "many" reproduction cells to achieve a plated layer just one micrometre thick. Other scientists noted that Eggebrecht used a more efficient, modern electrolyte; using only vinegar, the battery is very feeble.

Non-electrical

Skeptical archaeologists see the electrical experiments as embodying a key problem with experimental archaeology
Experimental archaeology
Experimental archaeology employs a number of different methods, techniques, analyses, and approaches in order to generate and test hypotheses, based upon archaeological source material, like ancient structures or artifacts. It should not be confused with primitive technology which is not concerned...

, saying that such experiments can only show that something was physically possible, but do not confirm that it actually occurred. Further, there are many difficulties with the interpretation of these artifacts as galvanic cells:
  • The bitumen completely covers the copper cylinder, electrically insulating it, so no current can be drawn without modifying the design.
  • There are no wires or conductors with them.
  • No widely accepted electrical equipment is associated with them. (Controversial stone reliefs
    Dendera light
    The "Dendera light" is a term used to describe a supposed ancient Egyptian electrical lighting technology depicted on three stone reliefs in the Hathor temple at the Dendera Temple complex located in Egypt...

     depicting arc light
    Arc Light
    Arc Light is the debut novel by Eric L. Harry, a techno-thriller about limited nuclear war published in 1994 and written in 1991-2.As China and Russia clash in Siberia in June 1999, nuclear missiles strike the United States. The U.S. retaliates against Russia, and World War III begins...

    s have been suggested, however the voltages obtained are orders of magnitude below what would be needed to produce arc lighting ).
  • A bitumen seal, being thermoplastic
    Thermoplastic
    Thermoplastic, also known as a thermosoftening plastic, is a polymer that turns to a liquid when heated and freezes to a very glassy state when cooled sufficiently...

    , is excellent for forming a hermetic seal
    Hermetic seal
    A hermetic seal is the quality of being airtight. In common usage, the term often implies being impervious to air or gas. When used technically, it is stated in conjunction with a specific test method and conditions of usage.-Etymology :...

     for long-term storage. It would be extremely inconvenient, however, for a galvanic cell, which would require frequent topping up of the electrolyte
    Electrolyte
    In chemistry, an electrolyte is any substance containing free ions that make the substance electrically conductive. The most typical electrolyte is an ionic solution, but molten electrolytes and solid electrolytes are also possible....

     (if they were intended for extended use).


The artifacts strongly resemble another type of object with a known purpose — namely, storage vessels for sacred scroll
Scroll
A scroll is a roll of parchment, papyrus, or paper, which has been drawn or written upon.Scroll may also refer to:*Scroll , the decoratively curved end of the pegbox of string instruments such as violins...

s from nearby Seleucia on the Tigris
Seleucia on the Tigris
Seleucia , also known as Seleucia on the Tigris, was one of the great cities of the world during Hellenistic and Roman times. It stood in Mesopotamia, on the west bank of the Tigris River, opposite the smaller town of Ctesiphon, in present day Babil Governorate, Iraq.-Seleucid empire:Seleucia,...

. Those vessels do not have the outermost clay jar, but are otherwise almost identical. Since it is claimed these vessels were exposed to the elements, it is possible that any papyrus
Papyrus
Papyrus is a thick paper-like material produced from the pith of the papyrus plant, Cyperus papyrus, a wetland sedge that was once abundant in the Nile Delta of Egypt....

 or parchment
Parchment
Parchment is a thin material made from calfskin, sheepskin or goatskin, often split. Its most common use was as a material for writing on, for documents, notes, or the pages of a book, codex or manuscript. It is distinct from leather in that parchment is limed but not tanned; therefore, it is very...

 inside had completely rotted away, perhaps leaving a trace of slightly acidic organic
Organic matter
Organic matter is matter that has come from a once-living organism; is capable of decay, or the product of decay; or is composed of organic compounds...

 residue.

In the media

The idea that the battery could have produced usable levels of electricity has been put to the test at least twice.

On the 1980 British Television series Arthur C. Clarke's Mysterious World
Arthur C. Clarke's Mysterious World
Arthur C. Clarke's Mysterious World is a thirteen part British television series looking at unexplained phenomena from around the world. It was produced by Yorkshire Television for the ITV network and first broadcast in September 1980....

, Egyptologist
Egyptology
Egyptology is the study of ancient Egyptian history, language, literature, religion, and art from the 5th millennium BC until the end of its native religious practices in the AD 4th century. A practitioner of the discipline is an “Egyptologist”...

 Arne Eggebrecht used a recreation of the battery, filled with grape juice
Grape juice
Grape juice is obtained from crushing and blending grapes into a liquid. The juice is often sold in stores or fermented and made into wine, brandy, or vinegar. In the wine industry, grape juice that contains 7-23 percent of pulp, skins, stems and seeds is often referred to as "must"...

, to produce half a volt
Volt
The volt is the SI derived unit for electric potential, electric potential difference, and electromotive force. The volt is named in honor of the Italian physicist Alessandro Volta , who invented the voltaic pile, possibly the first chemical battery.- Definition :A single volt is defined as the...

 of electricity, demonstrating for the programme that the battery could electroplate
Electroplating
Electroplating is a plating process in which metal ions in a solution are moved by an electric field to coat an electrode. The process uses electrical current to reduce cations of a desired material from a solution and coat a conductive object with a thin layer of the material, such as a metal...

 a silver
Silver
Silver is a metallic chemical element with the chemical symbol Ag and atomic number 47. A soft, white, lustrous transition metal, it has the highest electrical conductivity of any element and the highest thermal conductivity of any metal...

 statuette in two hours, using a gold
Gold
Gold is a chemical element with the symbol Au and an atomic number of 79. Gold is a dense, soft, shiny, malleable and ductile metal. Pure gold has a bright yellow color and luster traditionally considered attractive, which it maintains without oxidizing in air or water. Chemically, gold is a...

 cyanide
Cyanide
A cyanide is a chemical compound that contains the cyano group, -C≡N, which consists of a carbon atom triple-bonded to a nitrogen atom. Cyanides most commonly refer to salts of the anion CN−. Most cyanides are highly toxic....

 solution. Eggebrecht speculated that museums could contain many items mislabelled as gold when they are merely electroplated. However, doubt has recently been cast on the validity of these experiments.

The Discovery Channel
Discovery Channel
Discovery Channel is an American satellite and cable specialty channel , founded by John Hendricks and distributed by Discovery Communications. It is a publicly traded company run by CEO David Zaslav...

 program MythBusters
MythBusters
MythBusters is a science entertainment TV program created and produced by Beyond Television Productions for the Discovery Channel. The series is screened by numerous international broadcasters, including Discovery Channel Australia, Discovery Channel Latin America, Discovery Channel Canada, Quest...

 determined that it was indeed plausible for ancient people to have used the Baghdad Battery for electroplating or electrostimulation. On MythBusters 29th episode (March 23, 2005), ten hand-made terracotta jars were fitted to act as batteries. Lemon juice
Lemon juice
The lemon fruit, from a citrus plant, provides a useful liquid when squeezed. Lemon juice, either in natural strength or concentrated, is sold as a bottled product, usually with the addition of preservatives and a small amount of lemon oil.-Uses:...

 was chosen as the electrolyte
Electrolyte
In chemistry, an electrolyte is any substance containing free ions that make the substance electrically conductive. The most typical electrolyte is an ionic solution, but molten electrolytes and solid electrolytes are also possible....

 to activate the electrochemical reaction between the copper and iron. Connected in series, the batteries produced 4 volts of electricity.

The show's research staff proposed three possible uses: electroplating
Electroplating
Electroplating is a plating process in which metal ions in a solution are moved by an electric field to coat an electrode. The process uses electrical current to reduce cations of a desired material from a solution and coat a conductive object with a thin layer of the material, such as a metal...

, medical pain relief (through acupuncture
Acupuncture
Acupuncture is a type of alternative medicine that treats patients by insertion and manipulation of solid, generally thin needles in the body....

), and religious experience
Religious experience
Religious experience is a subjective experience in which an individual reports contact with a transcendent reality, an encounter or union with the divine....

. It was discovered that, when linked in series, the cells indeed had sufficient power to electroplate a small token. For acupuncture, the batteries produced a "random" pulse that could be felt through the needles; however, it began to produce a painful burning sensation when the batteries were grounded to two needles at once. For the religious experience aspect of the batteries, a replica of the Ark of the Covenant
Ark of the Covenant
The Ark of the Covenant , also known as the Ark of the Testimony, is a chest described in Book of Exodus as solely containing the Tablets of Stone on which the Ten Commandments were inscribed...

 was constructed, complete with two cherubim. Instead of linking the cherubim's golden wings to the low-power batteries, an electric fence
Electric fence
An electric fence is a barrier that uses electric shocks to deter animals or people from crossing a boundary. The voltage of the shock may have effects ranging from uncomfortable, to painful or even lethal...

 generator was connected. When touched, the wings produced a strong feeling of tightness in the chest. Although the batteries themselves had not been used, it was surmised that any form of electrical sensation from them could equate to the divine presence
Divine presence
Divine presence, presence of God, or simply presence is a concept in religion, spirituality, and theology that deals with the omnipotent ability of a god and/or gods to be "present" with human beings...

 in the eyes of ancient people. In the end, the Baghdad Battery myth was found plausible on all three accounts.

See also

  • Dendera light
    Dendera light
    The "Dendera light" is a term used to describe a supposed ancient Egyptian electrical lighting technology depicted on three stone reliefs in the Hathor temple at the Dendera Temple complex located in Egypt...

  • Galvanization
    Galvanization
    Galvanization is the process of applying a protective zinc coating to steel or iron, in order to prevent rusting. The term is derived from the name of Italian scientist Luigi Galvani....

  • History of electromagnetism
  • History of the battery
    History of the battery
    The history of the development of electrochemical cells is crucial to the scientific study and industrial applications of electricity, for prior to the rise of electrical grids around the end of the 19th century, they were the main source of electricity...

  • Leyden jar
    Leyden jar
    A Leyden jar, or Leiden jar, is a device that "stores" static electricity between two electrodes on the inside and outside of a jar. It was invented independently by German cleric Ewald Georg von Kleist on 11 October 1745 and by Dutch scientist Pieter van Musschenbroek of Leiden in 1745–1746. The...


Further reading

  • Von Handorf, D E., The Baghdad battery - myth or reality?. Plating and Surface Finishing (USA). Vol. 89, no. 5, pp. 84–87. May 2002

External links

The source of this article is wikipedia, the free encyclopedia.  The text of this article is licensed under the GFDL.
 
x
OK