text:
The Lord of the Rings: The Battle for Middle-earth II

The Lord of the Rings: The Battle for Middle-earth II is a 2006 real-time strategy video game developed and published by Electronic Arts. The second part of the Middle-earth strategy game series, it is based on the fantasy novels The Lord of the Rings and The Hobbit by J. R. R. Tolkien and its live-action film series adaptation. It is the sequel to Electronic Arts' 2004 title The Lord of the Rings: The Battle for Middle-earth. Along with the standard edition, a Collector's Edition of the game was released, containing bonus material and a documentary about the game's development.

The story for The Battle for Middle-earth II is divided into Good and Evil Campaigns. The Good Campaign focuses on Glorfindel, an Elf who is alerted to a planned attack on the Elven sanctuary of Rivendell. With help from the Dwarves and other Good forces, the Elves attempt to eliminate Sauron and his army to restore peace in Middle-earth. In the Evil Campaign, Sauron sends the Mouth of Sauron and the Nazgûl to muster wild Goblins. With his army, Sauron moves forward with his plan to destroy the remaining Good forces in the North. The Windows version of the game was released in March 2006 and the Xbox 360 version was released in July 2006.

The Battle for Middle-earth II received generally favorable reviews from video game critics. Reviews praised the game's integration of the Lord of the Rings universe into a real-time strategy title, while criticism targeted the game's unbalanced multiplayer mode. The Battle for Middle-earth II received numerous awards, including the Editors' Choice Award from IGN. At the end of March 2006, The Battle for Middle-earth II reached fourth in a list of the month's best-selling PC games. A Windows expansion pack for the game was released in November 2006, called The Rise of the Witch-king, which features a new faction known as Angmar, new units, and several gameplay improvements. The official game servers were shut down for Windows in 2010 and Xbox 360 in 2011; however Windows users may still play online using unofficial game servers.

Gameplay

The Battle for Middle-earth II is a real-time strategy game. Similar to its predecessor, the game requires that the player build a base with structures to produce units, gather resources, research upgrades, and provide defenses. Units are used to attack the enemy and defend the player's base. Players win matches by eliminating all enemy unit producing structures. Unlike the first game, the player can build an unlimited number of structures anywhere on the map, allowing for more freedom in base building and unit production. Players can build walls to defend their base; however, the walls can only be constructed within a certain proximity to the player's fortress. They can also construct arrow and catapult towers on building plots around a fortress to provide defensive support and basic protection. Along with this, each factions' fortress is uniquely equipped with a special power reached only by purchasing necessary upgrades. The game's HUD, called the Palantír, shows the player's hero units and their abilities, a mini-map, and objectives.

Units are classified into one of several classes: infantry, ranged, pikemen, cavalry, or siege. Each unit class has unique strengths and weaknesses, emphasizing the importance of properly matching up units in battle to increase their effectiveness. Hero units are unique in that only one of each can be created; they consist of characters from the novel, such as Aragorn, Legolas, Gimli, Saruman, Nazgûl, Mouth of Sauron, Arwen, the Witch-king of Angmar, and Shelob, characters created for the game like Gorkil the Goblin King and Drogoth the Dragon Lord, or are created via the game's Hero Creator (only accessible via the PC version). If the player kills Gollum, a non-player character, they are rewarded with the One Ring. The item can be used to summon one of two ring heroes for a price of 10,000 resources, Galadriel and Sauron, depending on the player's faction. Ring heroes have extremely strong armor and powerful attacks, making them among the game's most over-powered units.

The War of the Ring mode carried over from the first game in the series combines turn-based strategy elements with real-time skirmishes. Middle-earth is divided into territories; players can construct buildings to produce troops only in a claimed territory. During each turn, the player can move their armies into neutral and enemy territories to take control of them. While neutral territories are conquered by simply entering them, enemy territories must be wrested from the other player by defeating them in a skirmish. Troops can be garrisoned in conquered territories to defend against enemy attacks. When the player chooses to attack another territory, or one of their territories is being invaded by an enemy, they can either simulate the match and let the computer determine the outcome, or play the match by commanding the units in real time. The winner of the skirmish gains the territory, and all surviving units gain experience points. To win the game, players must either control the enemy's capital territory, or take over a given number of territories in Middle-earth.

The Battle for Middle-earth II introduces three new factions with unique units and heroes: Goblins, Dwarves, and Elves. Rohan and Gondor are combined into one faction called Men of the West. Along with Mordor and Isengard from the first game, there are six playable factions. The troops of Gondor provide a solid offense and defense with standard infantry and archers, and the Rohirrim of Rohan act as elite cavalry. The Elven archers are effective at inflicting damage from a distance, and their support units, the Ents, can perform a combination of melee and siege attacks, they are often considered the strongest defensive faction due to their strong missile units and powerful 'silverthorn arrows'. Although slow and expensive, Dwarven infantry, pikemen, and axe-throwers are very powerful and well-armored allowing them to prevail in even the longest clashes with enemy troops. A collection of wild creatures and beasts of Middle-earth make up the Goblin faction, this includes Goblins, Trolls (particularly Cave Trolls, Attack Trolls, Mountain Trolls, Drummer Trolls, and Half-Troll Marauders), Giant Spiders, Mountain Giants, Dragons, and Fire Drakes, which are effective in large numbers. Their only advantage is that the goblin archer and soldier units are cheap to make at only 75 resources and build faster than other basic infantry. Isengard troops are highly trained Uruk-hai under Saruman's command. Berserkers are used by Isengard as one-man armies that move extremely fast and deal significant damage (particularly to enemy buildings and heroes). Additionally, Isengard is the only Evil faction that can build walls. Mordor forces are a mixture of Orcs, Men, Trolls, Mûmakil, and Sauron's lieutenants. Mordor Orcs have tough armor, making them useful for absorbing enemy damage while stronger units attack enemies. Trolls contribute greatly to the Mordor offensives, having strong melee attacks and the ability to throw boulders or wield trees like swords.

Plot
Set in the regions of northern Middle-earth, the game focuses on the events of the War in the North. For the sake of gameplay, the game takes several liberties with Tolkien's works and the film trilogy. Some characters were altered in their appearances, abilities, and roles; for instance, a combat role in the game is given to Tom Bombadil, a merry and mysterious hermit who appears in The Lord of the Rings but does not take part in the war. In addition, Tolkien's earlier novel The Hobbit lends several elements to the game, including characters such as the Giant Spiders from Mirkwood. The story for The Battle for Middle-earth II is divided into Good and Evil Campaigns. Both campaigns focus on the battles fought by the newly introduced factions: the Elves, Dwarves, and Goblins. The player goes through nine fixed missions on either Easy, Medium, or Hard difficulty mode. Narrated cutscenes provide plot exposition between missions.

Good Campaign
The Good Campaign opens after the Fellowship of the Ring has set out on their mission to unmake the One Ring of Power, with Elrond and Glóin planning the War in the North. The Elven hero Glorfindel discovers an impending attack on the Elven sanctuary of Rivendell. Thanks to the early warning, Elrond's forces in Rivendell manage to repel the Goblins' attacks. Following the battle, Elrond realizes that the Elves and Dwarves must join forces to purge the threat of Sauron's forces in the North.

The next battle takes place in the Goblin capital of Ettenmoors, where the Goblin fortress is destroyed and Gorkil the Goblin King is killed.

After their victory, the heroes are informed that the Goblins on Sauron's command enlisted the service of a Dragon named Drogoth who is laying waste to the Dwarves of the Blue Mountains. The heroes make their way to the Blue Mountains and help the Dwarven army defeat Drogoth and his Goblins.

The Grey Havens, an Elven port on the western shores, is attacked by the Corsairs of Umbar, allies of Sauron. The Dwarves, who have been reluctant to ally with the Elves, eventually decide to come to the aid of the Grey Havens. With the Goblins defeated and all of Eriador pacified, the Dwarven-Elven alliance is tested by Sauron's forces.

Mordor's overwhelming forces besiege the Lake Town of Esgaroth and the Dwarven city of Erebor. The Dwarven king Dáin leads a small group of Dwarves and men of Dale to defend their homeland and manage to eliminate the Mordor presence in Esgaroth but are forced to retreat back to Erebor to defend themselves against an overwhelming army led by the Mouth of Sauron. After a long battle against the Mouth of Sauron's army, Elven reinforcements from Mirkwood led by the Elven king Thranduil arrive and save the Dwarves, defeating the Mouth of Sauron and his army.

Elrond leads the first attack, but later, Thranduil, Glorfindel, Glóin, Arwen, and King Dáin all unite under the Dwarven-Elven alliance for a final battle in Dol Guldur, the stronghold of Sauron in Mirkwood, aided by the Ents and Eagles. The Good forces and their three combined armies overcome the defenses and destroy the fortress, eliminating the last threat in the North.

Evil Campaign
The Evil Campaign follows an alternative version of the War in the North.

Sauron sends the Mouth of Sauron and the Nazgûl to the North to muster wild Goblins. His lieutenants lead the Goblin army and the Trolls and launch an assault on the Elven forest of Lórien while freeing three trapped Mountain Giants. Despite heavy resistance, the forest is overrun with Celeborn slain and Galadriel having fled to Rivendell. Even Caras Galadhon collapses under the sheer force of the massive invasion. The Mouth of Sauron peers eagerly into the captured Mirror of Galadriel for his next attack as his Goblins celebrate their triumph over the Elves amidst the ruins of the once-mighty ancient stronghold.

Another group of Goblins led by the Goblin King Gorkil attacks the Grey Havens by land and sea. The Elven port is destroyed and captured, and the march across Eriador begins.

The Hobbits of the Shire are chosen as the next target. Gorkil's horde manages to crush the Hobbits and burn their country to the ground, but Saruman's servant Gríma Wormtongue suddenly appears with a large army of Isengard Uruks and claims the land for his master. The Goblins annihilate the well-trained army and kill Wormtongue, taking the Shire for themselves while enslaving the Hobbits.

Gorkil continues marching west and besieges Fornost, the fortified ruins of the ancient capitol of Arnor. The defenders, consisting of the Dúnedain and Dwarves led by Glóin, crumble under the relentless Goblin attacks, and Eriador falls under Goblin control.

Sauron launches a concurrent campaign east of the Misty Mountains. The orcs from Dol Guldur eliminate the Elves and the Ents that guard the Forest Road in Mirkwood, defeating the Elven lord Thranduil.

After the fall of Mirkwood, the Mouth of Sauron leads his horde to Withered Heath to recruit the Dragon Lord Drogoth after destroying the Dwarves in the area and freeing the captive Fire Drakes. The Mouth of Sauron wins Drogoth over by bringing some fire drakes that they freed from the Dwarves to him.

To finally rid Sauron and Middle Earth of the Dwarves, The Mouth of Sauron attacks the human city of Dale and the Dwarven stronghold of Erebor, led by King Dain.

For the final battle against the Good factions in the North, the Goblin horde and Sauron's forces from Mordor converge at Rivendell, the last surviving stronghold against Sauron in Middle-earth. Eagles, the Dead Men of Dunharrow, Galadriel and her surviving Elves, and the remnants of the Fellowship of the Ring arrive to help Arwen and Elrond, but Sauron (having attained full power through recovering the One Ring from the dead Frodo) and all his gathered forces of Goblins, Orcs, Trolls, Mountain giants, Spiders, Dragons, and Fellbeast enter the battle and completely destroy the remaining Good forces in the North. With Rivendell defeated, Sauron claims victory and darkness now falls all over Middle-earth.

Development
Tolkien Enterprises granted the publisher of The Battle for Middle-earth II, Electronic Arts, the rights to develop The Lord of the Games video games based on The Lord of the Rings books on July 22, 2005. This agreement was complementary to a separate arrangement made between the two companies in 2001. That agreement gave Electronic Arts the rights to build video games based on The Lord of the Rings film trilogy. The new deal gives Electronic Arts the opportunity to create video games with original stories tied closely with the Lord of the Rings universe. In the same announcement, Electronic Arts revealed two games that its EA Los Angeles division would be developing with the license: The Lord of the Rings: The Battle for Middle-earth II for Windows—a sequel to The Lord of the Rings: The Battle for Middle-earth—and The Lord of the Rings: Tactics for the PlayStation Portable.

On November 10, 2005, Electronic Arts announced that Hugo Weaving, who played Elrond in the Lord of the Rings film trilogy, would reprise his role as Elrond and be the lead voiceover talent in The Battle for Middle-earth II. During his voiceover session, he noted, "I always find voice work really fascinating because you are working on one element of your make up as an actor—focusing more intently on one part of your toolbox if you like—in a way so everything seems to go into producing that vocal effect. It really isn't just an effect, because it actually comes from a source which is a true continuation of that character."

On January 13, 2006, Electronic Arts reported that an Xbox 360 version of The Battle for Middle-earth II was under development, and it was promised to feature a "unique and intuitive control scheme" developed by video game designer Louis Castle, co-founder of the real-time strategy developer Westwood Studios. Players would be able to play online via the Xbox Live service. Castle was excited to port the game to a console, stating, "Living these cinematic battles in high-definition with stunning surround sound, all from the comfort of your living room couch on the Xbox 360, is an extraordinary experience. [...] Adding the ability to battle it out with friends via Xbox Live is also really exciting."

The game's water effects received substantial upgrades because of the large role naval battles play in The Battle for Middle-earth II. The developers endeavored to make the surface of oceans and lakes look realistic by using techniques similar to those applied in films when creating computer-generated ocean water. The digital water simulates deep ocean water by reflecting its surroundings on the surface, and wave technology was used to create large waves along coastlines to immerse the player in the game experience. Lost towns, corals, and fish were added underwater to add to the effect. Water was chosen as the first graphical component of The Battle for Middle-earth II to take advantage of DirectX 9 programmable shaders. These additions were part of an overall Electronic Arts strategy to continue the Lord of the Rings experience that began with the trilogy film series.

As cinematic director of The Battle for Middle-earth II, Richard Taylor was responsible for designing the game's opening and closing sequences, as well as campaign and mission introductions and endings. As the first Electronic Arts video game to be given free rein on material from The Lord of the Rings universe, several lands, characters, and creatures from the books appear visually for the first time in the game's cut scenes. Taylor considered it essential to use good graphical and audio combinations when telling a story, and he was pleased to have Weaving on the project as the primary storyteller.

Release and reception
The game was initially released by Electronic Arts for Windows in North America on February 28, 2006, and in the United Kingdom on March 3. It received a port for Xbox 360 in North America on July 5, and in the United Kingdom on July 14. Electronic Arts released a Collector's Edition that includes a bonus DVD with supplemental high-definition media such as the full original music score; in-game cinematics and trailers; the documentary The Making of The Battle for Middle-earth II; and The Art of the Game, a gallery featuring hundreds of cinematic paintings and concept art created for the game.

It was given generally favorable reviews, receiving an aggregated score of 84% at Metacritic for its Windows version. Praise focused on its successful integration of the Lord of the Rings franchise with the real-time strategy genre, while criticism targeted the game's unbalanced multiplayer mode. The Battle for Middle-earth II was given the Editor's Choice Award from IGN. At the end of its debut month of March 2006, The Battle for Middle-earth II reached fourth in a list of the month's best-selling PC games, while the Collector's Edition peaked at eighth place. In the second month after the game's release, The Battle for Middle-earth II was the 12th best-selling PC game, despite a 10% slump in overall game sales for that month. The game's computer version received a "Silver" sales award from the Entertainment and Leisure Software Publishers Association (ELSPA), indicating sales of at least 100,000 copies in the United Kingdom.

After playing the game, PC Gamer found little fault with it, calling it a very well-balanced game overall. The magazine also was pleased that the game's "production values [were] sky-high", with which GamesRadar agreed, explaining, "It's not often you come across an RTS with production values this high; every part seems to be polished till it shines." When compared to its predecessor, The Lord of the Rings: The Battle for Middle-earth, GamePro was convinced The Battle for Middle-earth II had improved upon the original in several fundamental ways. GameSpot believed that The Battle for Middle-earth II offered better gameplay and a much broader scope that encompassed more of Middle-earth.

Several critics praised the game's real-time strategy elements and graphics. IGN considered the high quality of The Battle for Middle-earth II proof that Electronic Arts was truly interested in building great real-time strategy games. Despite a few minor issues, GameZone was happy with the gameplay of The Battle for Middle-earth II, believing that the game did a good job of enabling the player to experience the turmoil of the fantasy world. They also admired the game's conversion for the Xbox 360 version, calling it "one of the best PC-to-console conversions" and praising the developers for a "commendable job of assigning actions to the 360 controller's eight buttons". The graphics were appreciated by ActionTrip, which found it "really hard not to drool over this game", commending the game's design and art team for doing a fabulous job on every location that appeared in the single-player campaign.

Playing within the universe of The Lord of the Rings was appealing to a number of reviewers, which found that it generally increased the game's entertainment value. PC Gamer shared this sentiment, calling Lord of the Rings "arguably the best fantasy universe ever", and GameZone asked the question, "What self-respecting Tolkien fan can be without this title?" The results also pleased 1UP.com, which was convinced that fans of The Lord of the Rings could not afford to miss purchasing the game. Game Revolution complimented the game's merge with the Lord of the Rings universe, observing that the franchise's mythology and the game's frenetic battles came together in a very satisfying bundle. The integration of The Lord of the Rings into a video game satisfied Game Informer, and the magazine predicted the game would be "another winner for Electronic Arts".

Despite positive reactions, reviewers brought up several issues with the game. The British video game publication PC Gamer UK was unhappy with the game, claiming that Electronic Arts chose to release a formulaic game because it was a safer choice than taking The Battle for Middle-earth II in another direction. PC Zone agreed with this view, claiming that although the game looked impressive, it took a by-the-numbers approach towards the real-time strategy genre in a "mindless sort of way", concluding that "in no way is it anywhere near the game we hoped for." The game's multiplayer portion disappointed GameSpy, which found it too unbalanced compared to the heroes, whom they considered to be too strong. Eurogamer considered the game to be of average quality, noting that there were no truly redeeming qualities.

The editors of Computer Games Magazine named The Battle for Middle-earth 2 the third-best computer game of 2006, and called it "undeniably a labor of love, a grand work of art and strategy."

The Smithsonian American Art Museum selected The Battle for Middle-earth 2 as one of 80 games spanning the past 40 years to be a part of The Art of Video Games exhibit that ran from March, 2012 to September 2012 in Washington, DC.

Post-release
Electronic Arts announced on July 27, 2006 that its EA Los Angeles studio would be releasing an expansion pack to The Battle for Middle-earth II titled The Lord of the Rings: The Battle for Middle-earth II: The Rise of the Witch-king. It was slated for release during the 2006 holiday season. The game, produced by Amir Rahimi, promised players the opportunity to fight in wars that precedes the events of the Lord of the Rings novels. The Rise of the Witch-king adds a new single-player campaign, new units, a new faction, and improved features. Its story follows the Witch-king of Angmar's "ascent to power, his domination of Angmar, and eventual invasion of Arnor, Aragorn's ancestral home". The game was sent to manufacturers on November 15, 2006, and was released on November 28.

On January 9, 2011, Electronic Arts announced that the online game servers would be shut down on January 11, 2011 for the Xbox 360 format of the game. The PC version of the game was shut down on December 31, 2010. Electronic Arts noted that their discontinuation of support for the game was partly because the licensing deal with New Line Cinema (holders of the Lord of the Rings license) had expired, which led them to no other option than to shut down all online services for the game.


text:
Talk:Aharonov–Bohm effect

Interpretation
The article states that "The underlying mechanism is the coupling of the electromagnetic potential with the complex phase of a charged particle's wave function". This requires a citation. Who says so and in what textbook or peer reviewed publication? Aoosten (talk) 00:33, 10 December 2013 (UTC)
 * You will be hard pressed to find a text that doesn't say it. Xxanthippe (talk) 04:47, 10 December 2013 (UTC).

This important statement should not be made anonymously, but should be backed up by one or more quotations. It is controversial because it does not explain the Aharonov-Bohm effect in terms of existing coupling of the electromagnetic potential to the charge-current. Thus it suggests that the effect involves some new electromagnetic effect.

Aoosten (talk) 14:26, 10 December 2013 (UTC) — Preceding unsigned comment added by 84.192.21.15 (talk) 07:56, 10 December 2013 (UTC)

Help & Warning !
I have heard that the magnetic monopole business which is stated is far from being accepted by the majority of physicists. Is there any proof that this magnetic monople stuff has any existence ? Honestly I doubt. —Preceding unsigned comment added by 84.97.205.102 (talk) 21:28, 4 November 2007 (UTC)
 * The monopoles described in this article are quasiparticles that crop up in condensed-matter physics quite often due to separation of equal but opposite magnetic charges, connected by a finite-width flux tube. They are thematically similar to 'true' monopoles but are in no way controversial. They cause a stir from time to time when someone reports experiments regarding Dirac strings as indicative of the discovery of real monopoles. A similar kerfuffle tends to occur when research regarding spin-charge separation is taken to indicate that electrons are composite particles. Note: I am not a licensed quantum mechanic. Eutactic (talk) 06:59, 4 June 2010 (UTC)

I don't think the magnetic monopole belongs in this article. Miguel (talk) 12:19, 4 January 2011 (UTC)

Comment: You are perfectly right, as there are no "magnetic monopole particles" (see Lorentz force)

LZob —Preceding unsigned comment added by 84.42.225.153 (talk) 08:56, 23 May 2011 (UTC)

long solenoid
It is NOT TRUE that a long solenoid does not cause a magnetic field outside of itself. There is a tiny right-hand field, as well as a (comparatively) large up-down field (description is very bad, but try to understand).
 * An ideal solenoid would indeed have no magnetic field outside of the solenoid. This is of course impossible to acheive in real life.  The original experiment didn't even use a solenoid so far as I know, but rather a thin whisker of magnetic material.  In theory the ideal AB experiment would have zero magnetic field outside, but here we just get into the experimental practicalities of negligible versus zero.  --Laura Scudder | Talk 20:09, 18 August 2005 (UTC)

Of course, as Laura S. and the earlier unsigner pointed out, it is not strictly zero. But it is very small. And just to dispel lingering doubts, people have redone the experiment with toroidal solenoids, which give an even better approximation to 0, and tested for dispersion in the AB effect, which dispersion should show up if the effect were due to any lingering, very mall E-M field. No dispersion has been found.

See http://xxx.tau.ac.il/abs/0708.2428v1 for an example of such testing.

204.119.233.212 (talk) 18:49, 29 July 2008 (UTC)

Help!
Could someone add something which explains this effect in layman's terms. I have a strong sense that this could have immense siginifance but as soon as the technical terms and algebraic equations turn up I'm left in the dust. Please could someone elucidate for a non-specialist, arts-background person like me? :-) ThePeg 28.7.2006

 * Another, in some ways better, summary is available at http://www.tau.ac.il/~quantum/publicat/topo-effects.html . I am working on gauge fixing right now; perhaps when I am at a good stopping point there I will try to improve this article.  Cheers, Michael K. Edwards 03:23, 20 October 2006 (UTC)

I think ThePeg may be asking for too much. How do you explain the AB effect without using the terms "E-M field", and "vector potential" and 'gauge'? And how do you describe these without some E-M coursework in your background, and at least as much vector calculus as in the marvellous little book, "Div, Grad Curl and all That"?

After all: the whole point of the AB effect is that the vector potential plays such a surprising role, instead of being the a convenience for computing E & B, as it usually appears in junior-level E&M courses. But without that background, how do you know to be surprised?

In fact, what I almost get from the article, but still don't quite get, is how the AB effect does not contradict gauge invariance. So clarification of that point would be welcome.

 * One way to do this is to express the interference effect between the two electron paths in the solenoid/double-slit setup as the flux of the magnetic field across any surface bounded by the two paths. The flux of the magnetic field is a gauge-invariant quantity - in fact, it can be measured independently by Faraday's Law of Induction. The Aharonov-Bohm effect is not so different after all from the electric field induced on a closed loop of wire going around a solenoid when the current on the solenoid is varied. The time-rate of change of the AB phase is Faraday's electromotive force. Miguel (talk) 12:33, 4 January 2011 (UTC)

Now for magnetic monopoles: the consensus now is that magnetic monopoles existed in the early universe, but have all decayed. So no, there aren't any of them anymore. But even the fact that they once did exist is enough to explain (per Dirac) why charge is quantized.

204.119.233.212 (talk) 18:51, 29 July 2008 (UTC)

Another Interpretation
The Feynman Lectures on Physics (Vol II, Sec 15-5), has a different interpretation from the one stressed here. The article says that the AB effect shows that knowledge of the classical electromagnetic field acting locally on a particle is not sufficient to predict its quantum-mechanical behavior. Feynman says that the AB effect shows that A is a "real" vector field. The effect on the phase of the interference pattern arises because the electron passes through regions of non-zero A. In my teaching, I have repeated Feynman's argument that A deserves to be thought of as a real field. It is A (and phi) that appear in Schroedinger's equation, not E and B. Another argument, by the way, is that A and phi form the four-vector, not E and B. Can anyone comment on this? I think it is worth noting. Timb66 (talk) 05:00, 11 April 2008 (UTC)

 * If you want to argue Feynman, remember that Feynman teaches quantum mechanics from the double-slit experiment, in which you cannot pretend to know the trajectory of the particle unless you measure it, which destroys the interference pattern. However, in the path integral approach to quantum mechanics you still have to consider the value of the action over any possible trajectory, and the action of a trajectory cannot be written in terms of the electromagnetic field but only in terms of the electromagnetic potential. A "deserves to be thought of as a real field" (and appears in the action) because it is the connection form of the electromagnetic gauge bundle. However, all its physical effects can be described in terms of the electromagnetic tensor F which is the curvature form of the bundle. And this includes the Aharonov-Bohm effect since, by Stokes' theorem, the Aharonov-Bohm phase shift between two paths with equal endpoints is proportional to the flux of the magnetic field through a surface bound by the two paths. Miguel (talk) 14:29, 4 January 2011 (UTC)

 * There is no contradiction between the article and Feynman. Classically, the vector potential only exerts a force on a particle through its curl (= B), and in regions of zero curl there is no classical possibility of any effect on the particle.  So, knowledge of the classical field acting locally on the particle is not sufficient to understand its quantum effect, as the article says.  (Much the same point can be found in the book by Peshkin and Tonomura, if I recall correctly.)

 * What this means is that not all physical effects of the electromagnetic field manifest themselves as forces. A shift in an interference pattern is a physical effect, but it is not interpretable as the effect of a force acting locally. Miguel (talk) 15:11, 4 January 2011 (UTC)

 * Feynman interprets this somewhat metaphysically as implying that the vector potential is "real" in a sense he defines (that it acts locally on the particle). In this sense, there are more "real" fields in quantum mechanics than in classical electrodynamics.  My own inclination (and, I suspect, that of many physicists), is that questions of what fields are "real" lead to the same philosophical confusion as 19th-century arguments about whether negative numbers and imaginary numbers are "real" things.  A is useful in describing physical laws that make accurate predictions, and that is enough.

 * Yes, A and φ form part of a four-vector. And E and B form parts of a rank-2 4-tensor.  These are both useful descriptions, but whether it makes one of the descriptions "more real" seems like another unresolvable metaphysical diversion.

 * This is not to say that Feynman's interpretation should not be noted in the article; it's another way of pointing out the significance of this phenomenon. I just don't think it should be put forth as a contrasting view, rather than as another spin on the same underlying idea.

 * —Steven G. Johnson (talk) 17:50, 11 April 2008 (UTC)

Hi Steven. Thanks for the response, which sounds sensible to me. I wrote an essay on the AB effect in my final year of undergrad (1987), and I recall that the Feynman position was the prevailing one at the time. I will try to dig out my essay. These days I am a humble astronomer and, though I teach senior-level EM, I have not looked into the AB effect since then. I agree this should go into the article. Feel free to do that, if you have the time! (I don't at the moment, I'm afraid). Timb66 (talk) 22:50, 18 April 2008 (UTC)

I think Timb66's point that usual interpretation of AB is that it demonstrates the reality of the A potential is correct, and is not sufficiently stressed by the article. Feynman deplored metaphysics, and if he thought that AB implied the reality of the underlying potentials (which he does -- he is quite clear about this in his lectures (II, 15-5)) then I think we should take his views seriously and represent them more clearly. --Michael C. Price talk 10:32, 16 August 2009 (UTC)

 * As the article points out, either the A field is real, or the physics is nonlocal. Which leads us down the EPR path... Miguel (talk) 14:29, 4 January 2011 (UTC)

More examples needed
I am currently trying to understand this phenomena, starting out from the example given in chapter 18 (By McEuen) in Kittel's Introduction to Solid State Physics, 8th Edition. This Wikipedia article does not seem to help very much, unfortunately. More examples would help - also external links would help, not just references to articles. —Preceding unsigned comment added by 130.225.102.1 (talk) 12:01, 25 April 2008 (UTC)

I second the motion: we need references to something more accessible than Physics Review articles. And the references should be numbered, at least some of them. I suggest ArchiveX as a possible source: not all the papers there are trash;)

204.119.233.212 (talk) 18:52, 29 July 2008 (UTC)

I agree that theb article is confusing. Luckily I already undertsand the AB effect, because I would never have understood it from this article. The language is a mess; when it talks about the "classical fields". What does that mean? The E and B fields, but not the A field? The A field was invented before QM, by Maxwell and Heaviside and others, and so is a classical field as well.

 * Classically, the E and B were "fields" and the φ and A were "potentials", so no confusion there unless you want to really split hairs with the more general meaning of "field" as "any scalar, vector or tensor-valued function varying across space and/or time". Miguel (talk) 14:33, 4 January 2011 (UTC)

Also, the very first sentence is confused.
 * The Aharonov–Bohm effect, sometimes called the Ehrenberg–Siday–Aharonov–Bohm effect, is a quantum mechanical phenomenon by which a charged particle is affected by electromagnetic fields in regions from which the particle is excluded.

Now what do they mean by unlinked term, electromagnetic fields? I guess they mean the E and B fields. But I have to guess, which is not a good sign. --Michael C. Price talk 11:02, 16 August 2009 (UTC)

Copyright problem removed
One or more portions of this article duplicated other source(s). Infringing material has been rewritten or removed and must not be restored, unless it is duly released under a compatible license. (For more information, please see "using copyrighted works from others" if you are not the copyright holder of this material, or "donating copyrighted materials" if you are.) For legal reasons, we cannot accept copyrighted text or images borrowed from other web sites or published material; such additions will be deleted. Contributors may use copyrighted publications as a source of information, but not as a source of sentences or phrases. Accordingly, the material may be rewritten, but only if it does not infringe on the copyright of the original or plagiarize from that source. Please see our guideline on non-free text for how to properly implement limited quotations of copyrighted text. Wikipedia takes copyright violations very seriously, and persistent violators will be blocked from editing. While we appreciate contributions, we must require all contributors to understand and comply with these policies. Thank you. Steve (talk) 18:52, 19 December 2009 (UTC)

I don't like your calling me out as all I've done is ask

See

If someone wants to rewrite the nano-ring section, please do, it's pretty bare right now. --Steve (talk) 18:52, 19 December 2009 (UTC)

Feynman's views
This text has been reverted with the claim that it is incorrect:
 * in contrast, the effect depends on A only in the region where the test particle is allowed. Therefore we can either abandon the principle of locality (which most physicists are reluctant to do) or we are forced to accept the realisation that the electromagnetic potential offers a more complete description of electromagnetism than the electric and magnetic fields can. In classical electromagnetism the two descriptions were equivalent. With the addition of quantum theory, though, the electromagnetic potential A is seen as being more fundamental or "real" ; the E and B fields can be derived from the potential A, but the potential can not be derived from the E and B fields. Furthermore some physical effects are dependent only on A, which the E and B fields are simply unable to account for.

Which bit is incorrect, aside from the last sentence, which is a bit simplistic? It comes from the Feynman lectures, Vol II, Sec 15 (10-14). --Michael C. Price talk 01:00, 14 February 2010 (UTC)

 * "The potential can not be derived from the E and B fields", for starters. The quoted sentence from the Feynman Lectures ("knowledge of the classical electromagnetic field acting locally on a particle is not sufficient to predict its quantum-mechanical behavior") is factually correct. It's phrased in such a way that one might conclude that some important information about A is missing from E and B, but it doesn't actually say that, and it happens to not be true.

 * What we're talking about here is just the nature of gauge fields. Here's a perhaps more understandable example from general relativity, which is a gauge theory of a slightly different kind. Around an infinite cylindrical cosmic string, the spatial geometry is a cone. Spacetime is Riemann-flat. A test particle initially at rest near the cosmic string will not fall toward it. In effect, there's no gravitational field. There is, however, an angular deficit. If two initially comoving objects pass the string on opposite sides, they will be moving towards each other on the other side, even though neither one encountered any curvature.

 * You can measure the angular deficit by integrating the metric on a loop around the string. Alternately, you can integrate the scalar curvature over a surface bounded by the loop (which necessarily intersects the string, which is the only place the curvature is nonzero). If you use the metric, you're integrating only over the region where the test objects travel, but you're using a field with unphysical degrees of freedom. If you use the curvature, you're using only the physical degrees of freedom, but integrating over a region where the test objects don't travel.

 * This is interesting stuff. But I would object if someone wrote, "this forces us to conclude that either general relativity is intrinsically nonlocal, or curvature alone is insufficient to understand gravity and the metric must be treated as real." I hope you see why. -- BenRG (talk) 02:20, 14 February 2010 (UTC)
 * I have a problem with your first sentence; you're saying that the potential A can be derived from E and B? This is impossible by virtue of the gauge symmetry of A.  It's interesting, you seem to be using the gauge freedom of A to argue against the reality of A, whereas Feynman / myself are explicit that this is irrelevant.  Feynman is explicit that gauge fields are "real".
 * The potential A can be derived from the E and B fields, known globally, up to an integration constant which is a manifestation of gauge freedom and which is not observable. The formulas for obtaining A from E and B should be in any decent classical E-M textbook. In classical newtonian gravity you can also deduce the gravitational potential from the gravitational accelaration field up to an additive constant of integration, which has no physical effects. But in fact, that constant adds to the quantum mechanical action of a non-relativistic particle in a newtonian gravitational potential, and so affects the frequency of oscillation of the wavefunction. It's just that there are no interference effects that can reveal the value of the additive constant. Though the newtonian gravitational phase can be observed in an interference experiment (the famous Colella-Overhauser-Werner neutron interferometry experiment). Miguel (talk) 14:45, 4 January 2011 (UTC)
 * Do you have the Feynman lectures handy? - I can supply more detailed quotes about the supremacy of A over E and B; Feynman is quite clear about this, makng the point repeatedly.--Michael C. Price talk 02:48, 14 February 2010 (UTC)
 * Some quotes:
 * ...is the vector potential a "real" field? ... a real field is a mathematical device for avoiding the idea of action at a distance. .... for a long time it was believed that A was not a "real" field. .... there are phenomena involving quantum mechanics which show that in fact A is a "real" field in the sense that we have defined it.... .... E and B are slowly disappearing from the modern expression of physical laws; they are being replaced by A and [the scalar potential]
 * --Michael C. Price talk 03:09, 14 February 2010 (UTC)

 * I'm not especially interested in whether A or E/B are real or not, and neither is Feynman. That's why he consistently puts scare quotes around "real". (I do have the Lectures handy.) He's taking a pragmatic view of things: instead of talking about what's "real", talk about what works well in the theory. A works better in QED and the Standard Model. I have no objection to that. I think you believe that I have something against A, and by mentioning that E/B contain the same information I'm trying to make A "look bad". It has nothing to do with that. I just want to mention that E/B contain the same information as A because it seems to be a common misconception that they don't. I don't care whether people use E/B; I don't want them to use E/B; I just want to clear up that misconception.

 * Furthermore, you still seem to want to include something in the article that's of the form "A is more real than E and B because E and B are derivable from A while A is not derivable from E and B". That's ridiculous and has nothing to do with what Feynman was talking about. Gauge symmetry is like Lorentz symmetry. Suppose I had a field P, and from that I could derive some object Q, and from Q I could rederive P up to a Lorentz transformation—in other words, I couldn't quite reproduce P because Q only tells me the relative motion of things, while P contains absolute velocities. Is P more real in that situation? Of course not. When I say that A can be rederived from E and B, I mean of course "every aspect of A that is relevant in any physical context whatsoever, including Aharonov–Bohm-type experiments". Are you sure you understand that there's no extra information about the world in A? It looks like you didn't understand it last August when you wrote the disputed text.

 * I would appreciate some comment on the bulk of my last reply, the GR part. -- BenRG (talk) 01:57, 15 February 2010 (UTC)
 * The GR argument is the same as the EM one, and my views are the same about both cases. I don't want to get distracted by GR, since all the issues are covered by the EM case, which is what this article is about, but I will add that yes, I would regard P as more real, especially since you need "spooky" action-at-a-distance if you just use Q.

 * As for how you are using "derived" / "rederived", it packs a lot of implications that will confuse readers. The fact remains that Au CANNOT be derived from E & B; this is just a mathematical truth that no amount of redefinitions can get around - you know this as well as I.  If you wish to say something else by this statement then say it explicitly.

 * Feynman couldn't be clearer on the subject, it's a straight choice between using the E & B fields (or Fuv) and action-at-a-distance or use local potentials, Au. The current wording in the article makes that clear.

 * As for your statement:

 * I just want to mention that E/B contain the same information as A because it seems to be a common misconception that they don't.

 * this is not true, for the reason I stated; you can't derive Au from E & B. But I know what you mean by this, you mean that Au contains no extra physical information.  But even this is debatable, given the "spooky" action-at-a-distance twist.  Mathematically, though, the statement is plain wrong, and we have to be clear about this.

 * --Michael C. Price talk 08:24, 15 February 2010 (UTC)

I got here from an announcement at WT:PHYS. What is the disagreement about, precisely? ― A._di_M. (formerly Army1987) 23:21, 15 February 2010 (UTC)

 * In the Coulomb gauge 3-vector A can be determined uniquely and explicitly from 3-vector B. Of course, for a general gauge one has to add the gradient of an arbitrary scalar gauge function. That is the reason for the indeterminacy. Xxanthippe (talk) 23:33, 15 February 2010 (UTC).

 * That's a good point; restrict the gauge enough and A becomes determinable from E & B. But Feynman's point (which is independent of the gauge principle) remains: using A avoids invoking action-at-a-distance and so, by Feynman's terminology, the A field is still more real than the E & B fields.--Michael C. Price talk 00:34, 16 February 2010 (UTC)
 * Actually, A is determined from B alone and not E. Xxanthippe (talk) 00:40, 16 February 2010 (UTC).
 * I'm using A as a short-hand for the four vector, Au, which includes the scalar potential. --Michael C. Price talk 00:59, 16 February 2010 (UTC)
 * In the Coulomb gauge the vector potential is determined by B alone and the scalar potential by the (instantaneous) charge density so that E does not get a look-in, formally at least. Xxanthippe (talk) 01:46, 16 February 2010 (UTC).
 * Yes, I should have said, restrict the gauge enough and Au becomes determinable from E, B and the charge density.--Michael C. Price talk 06:53, 16 February 2010 (UTC)
 * I think Xxanthippe's point is that in the Coulomb gauge, in order to find A0, E only appears in its divergence. ($$ \mathbf{A}(\mathbf{r}) = \int\frac{\nabla \times \mathbf{B}(\mathbf{r'})}{4\pi|\mathbf{r}-\mathbf{r}'|}d\mathbf{r}', \phi(\mathbf{r}) = \int\frac{\nabla \cdot \mathbf{E}(\mathbf{r'})}{4\pi|\mathbf{r}-\mathbf{r}'|}d\mathbf{r}'$$ or something like that, right?) ― A._di_M. (formerly Army1987) 15:57, 16 February 2010 (UTC)
 * Yes, with the qualification that in the equation for A the del operates on r (so it is best taken outside the integral) and in the equation for phi it acts on r prime. To be specific, like this (with all fields taken at the same and in gaussian units): $$ \mathbf{A}(\mathbf{r}) = \nabla \times\int\frac{ \mathbf{B}(\mathbf{r'})}{4\pi|\mathbf{r}-\mathbf{r}'|}d\mathbf{r}', \phi(\mathbf{r}) = \int\frac{\nabla' \cdot \mathbf{E}(\mathbf{r'})}{4\pi|\mathbf{r}-\mathbf{r}'|}d\mathbf{r}'$$

Xxanthippe (talk) 01:32, 17 February 2010 (UTC).
 * If I may act as devil's advocate: since, as seen above, A in the Coulomb gauge (and the Aharonov-Bohm effect is invariably discussed in the Coulomb gauge) is obtained explicitly from B and the potential in any other gauge is obtained by adding an arbitrary pure gauge term it is hard to see how A contains any more information than B. Xxanthippe (talk) 11:27, 19 February 2010 (UTC).
 * The fact is, to know A here you need to know B everywhere, so that argument only works if you admit action-at-a-distance. ― A._di_M. (formerly Army1987) 11:49, 19 February 2010 (UTC)
 * More clearly, if you consider a doughnut-shaped region of space, knowing Aμ     there gives more information than knowing F μν  there, doesn't it? To calculate the phase difference a charged particle picks when going round the ring, the former suffice, but the latter doesn't. That is the point.  ― A._di_M. (formerly Army1987) 12:21, 19 February 2010 (UTC)
 * There is certainly an asymmetry in that to calculate A you have to know B everywhere but to calculate B you have to know A only in the immediate vicinity, rembering, however, that A itself encodes B everywhere. However, I don't think that this leads to 'spooky action at a distance' for A any more than does the calulation of, say, the energy of a field by integrating its energy density over all space at the same time, although special relativity states that an observer can only know events that occur in his own light cone. Xxanthippe (talk) 01:40, 20 February 2010 (UTC).

An explicit example desirable; confusing description at present
It would be great if somebody could work out specific examples, with an actual model for B(r)/E(r), resulting A(r) and the phase change, for both the magnetic and particularly the electric effects.

The present description is not immediately obvious for the magnetic case, and look plain impossible for the electric effect!

Specifically: 1) Electric case: How can one "construct a situation" where the electric field (grad phi) is zero everywhere along a closed loop (the too paths with common start and end), yet the electric potential (phi) is different at different points along the paths??? The description of the speicific experiments looks quite cryptic, but whatever they were I doubt they fit the present description of the electrical AB effect, which is essentially trying to say one can make a=b and a!=b at the same time.

2) Magnetic case: To begin with, the statement that "ideal solenoid" has zero field outside of it is puzzling: shouldn't an ideal cylindrical solenoid have dipole-like field infinitely far away? Now, I'm OK with assuming that the field is zero either because it can be ideally shielded, or that it is zero because the solenoid in between the two paths is actually toroid. But then there appear fields  in opposing directions, so I don't see as totally obvious that their contributions do NOT cancel! Say, if you say calculate the net flux across any cross-section you will get zero.

The only more or less obvious scenario I can think of is an ideal toroid solenoid with one path going through the center of the torus and the other fully outside the torus -- but even then the field is non-zero due to the net current flowing along the _outer_ radius of the torus! Besides, this is not what the article presently describes.

So if anyone could specify a particular model geometry, with clear behavior of magnetic field both inside and outside the plane of drawing (NOT with magnetic field lines disappearing into we don't care where), and show why within a specific gauge A(r) becomes nonzero along the paths -- that would greatly help!!! —Preceding unsigned comment added by 64.149.234.79 (talk) 09:34, 23 October 2010 (UTC)

Philosophical issues not about relativity but about gauge invariance.
These paragraphs from the introduction are rather confused. I intend to rewrite them and I copy them here for discussion in case my version is later challenged:

 * The Aharonov–Bohm effect is important philosophically: the "classical" approach to physics is completely based on Newton's equation F = ma; so for centuries physics was all about forces, and the electric field E and the magnetic field B can be used to calculate the force on a charged particle. However, force is not a valid 4-vector in special relativity. Because of this, in special relativity it is difficult to calculate with forces. Since the E and B fields are force fields, they are also not valid special relativity 4-vectors: one can easily see this because the E and B fields one calculates or measures depend on velocity. Similarly in quantum mechanics particles are represented as waves, and it's difficult to describe how waves interact with forces. So in quantum mechanics one prefers to work with potential energy. In relativistic quantum mechanics, including quantum electro-dynamics, it's difficult to even speak of a force.
 * When formulating electrodynamics, one may choose to use either E and B, or the electric potential Φ and the magnetic (vector) potential A. Together, these quantities form a valid special relativistic 4-vector. However, this 4-vector is not uniquely determined, one may always add certain scalar or vector functions, derived from so-called gauge functions, to this 4-vector, and the resulting E and B fields will not change. For a long time people wondered if the A field was fundamental, even though it cannot be uniquely determined, or if it was just a mathematical trick.

The conceptual issues around the AB effect are not fundamentally about relativity, as the Aharonov-Bohm effect is observable experimentally at ordinary speeds and can be easily formulated in terms of the nonrelativistic Schrödinger equation.

The conceptual issue is properly about forces, fields, potentials and gauge invariance. I am editing accordingly. My first version is

 * The Aharonov–Bohm effect is important conceptually because it illustrates the physicality of electromagnetic potentials whereas previously it was possible to argue that only the electromagnetic field was physical and the electromagnetic potential was a mathematical construct (being non-unique, in addition to not appearing in the Lorentz Force formula). The non-uniqueness of the electromagnetic potential is a manifestation of electromagnetic gauge invariance, with the electric and magnetic fields and forces being gauge invariant and therefore directly observable in principle. The complex phase of the electron wavefunction is coupled with the electromagnetic potential and the Aharonov-Bohm effect can be illustrated by interference experiments.

If that is not clear enough it can be developed in the body of the article and explained a little better in the intro. It also needs to be wikified. Miguel (talk) 21:51, 1 January 2011 (UTC)

I shall delete the clause:
 * or more precisely: a certain gauge invariant quantitiy, ΦB

from the introduction. It has bothered me for awhile and no one had clarified it. Do you agree? -- cheers, Michael C. Price talk 08:07, 2 January 2011 (UTC)

 * Yes, I don't know what that was about. Miguel (talk) 11:08, 4 January 2011 (UTC)

Un-needed mystification
To return to my ramble of a year ago: It seems to me that there is some un-needed mystification about the magnetic vector potential in this article. In its irreducible form (i.e. one that cannot be reduced to a gradient) the vector potential is given by its Coulomb gauge version written above explicitly in my comment of 17 February 2010. This form shows that the vector potential A at a given point encodes (to the gradient of an arbitrary scalar function) the magnetic field B at every point in space, not just the point at which the vector potential is evaluated. So the phase shift of the electron wavefunction that give rise to the A-B effect depends on the magnetic field at every point in space. This result is hardly surprising because the electron wavefunction also exists at every point in space (with finite or zero amplitude). The objection that the expression for the Coulomb vector potential contains "action at a distance" because it contains an integral over B everywhere at the same time holds little weight because B everywhere is calculated from the Maxwell equations which themselves are causal. If B (and E) are known everywhere then everything is known about the system (at least so far as the A-B effect is concerned). No extra information is contained in A (or the scalar potential phi). It is only necessary to discuss the Coulomb gauge, because making a gauge transformation from the Coulomb gauge to any other gauge has no effect on the A-B phase shift, as we all know. Xxanthippe (talk) 05:47, 17 January 2011 (UTC).
 * What changes are you proposing? -- cheers, Michael C. Price talk 06:23, 17 January 2011 (UTC)
 * Not much, for the time being, as my views are not entirely in the mainstream. But the statement in the article that "the 4-potential cannot be derived from the E and B fields" needs to be clarified as it can be derived up to the gradient of an arbitrary scalar field. The arbitrary term is known as a pure gauge field and contributes nothing to any physical observable like the A-B phase shift. Xxanthippe (talk) 22:37, 17 January 2011 (UTC).
 * Well, "up to the gradient of an arbitrary scalar field" is a rather major caveat. Your final statement is just a restatement of the gauge principle, which (hopefully) is explained in its own article. -- cheers, Michael C. Price talk 07:29, 17 January 2011 (UTC)
 * The caveat is no more major that that for the constant of integration of an indefinite integral. Xxanthippe (talk) 08:41, 17 January 2011 (UTC).
 * A little bit more major, I think. But, regardless, forgetting about the constant can have serious consequences. Anyway, I stuck a link to gauge freedom in the statement in the article. -- cheers, Michael C. Price talk 08:58, 17 January 2011 (UTC)
 * Forgetting about the gradient of the arbitrary scalar field has no consequences at all for the A-B phase difference or any other physical observable. The magnetic vector potential (known everywhere) contains the same amount of physical information as the magnetic field (known everywhere). The A and B fields are just different ways of packaging the same physical information. Seen in this way, much of the mumbo-jumbo talked about gauge evaporates. Xxanthippe (talk) 09:10, 17 January 2011 (UTC).
 * People seem to have a problem with the requirement to "know the field everywhere". The point of the Aharonov-Bohn effect is that knowing the field locally is not sufficient. Under the Lorentz Force law all effects are purely pointwise. The Aharonov-Bohn effect requires you to know the field in an extended region and people are bothered by that. It's the famous EPR philosophical prejudice of naïve realism. Miguel (talk) 11:12, 20 January 2011 (UTC)
 * Yes, that is the point entirely. -- cheers, Michael C. Price talk 12:06, 20 January 2011 (UTC)
 * But you'll agree this has also nothing to do with potentials vs. fields, then. In the case of the Aharonov-Bohm double slit experiment you need to either know the A field over the entire loop formed by the two paths, or know the B field over an entire surface bound by the loop, because the observable quantity is the phase change around the loop. Miguel (talk) 20:02, 24 January 2011 (UTC)

 * Incorrect. There are not two paths. There are an infinite number of them as the electron wave function spreads everywhere. See Path integral formulation. Xxanthippe (talk) 02:26, 25 January 2011 (UTC).
 * Hair-splitting. With narrow slits and perfectly absorbing barriers, and under a saddle point approximation to the path integral, the interference pattern is dominated by two paths. Miguel (talk) 15:02, 25 January 2011 (UTC)
 * Irrelevant. -- cheers, Michael C. Price talk 08:12, 25 January 2011 (UTC)
 * Eh? AFAICS Miguel, your first sentence is contradicted by the second.-- cheers, Michael C. Price talk 00:47, 25 January 2011 (UTC)
 * It is not. Whether you describe the Aharonov-Bohn phase shift as the line integral of the potential or the flux of the field, it does not suffice to know the potential/field locally. The effect is not pointwise like the Loretz force, it is a global quantity associated to an extended loop or surface. Miguel (talk) 15:02, 25 January 2011 (UTC)
 * You said
 * But you'll agree this has also nothing to do with potentials vs. fields, then.
 * which I disagree with. But this seems a issue with the terminology which is not worth pursuing.  We agree on the physics. -- cheers, Michael C. Price talk 17:35, 25 January 2011 (UTC)
 * Only in the sense that the Stokes' theorem of calculus on manifolds is "a little bit more major" than the Fundamental theorem of calculus. Given a function in 1D, is there another function whose derivative is the original function? The answer is locally yes, up to a function whose derivative is zero (that is, a constant). Globally this may fail to hold. Given a vector field in 3D, is there another function whose grad/curl is the original function? The answer is locally yes, up to a function whose grad/curl is zero (that is, a constant/gradient). Globally this may fail to hold.

 * This has nothing to do with the gauge principle, yet. The gauge principle comes in in the following way. An Aharonov-Bohm potential is not globally a gradient, only locally. Is there any possible physical effect of this? On particles obeying the Lorentz force law, obviously not. The Aharonov-Bohm effect manifests itself as a shift in an interference pattern, not as a local force on a point particle. So it's only with quantum mechanics that there can be a physical effect in the absence of a nonzero electromagnetic tensor (thinking just right now I couldn't guarantee classical waves interacting with the electromagnetic field couldn't exhibit an Aharonov Bohm effect but it seems unlikely).

 * And here's where the gauge principle comes in: the line integral of the vector potential around a loop is a mysterious quantity physically, but mathematically it is the holonomy of a connection on a line bundle. And gauge invariance is a physical interpretation of the mathematical theory of bundles. It is actually not necessary to talk about gauge invariance or the gauge principle as a way to deduce electromagnetism from first principles. It can just as well be considered a property of the constructs used to describe experimental data. But it seems philosophically to have a lot explanatory power to reduce lots of disparate facts about electromagnetism to "quantities are physically observable if and only if they are gauge invariants of the electromagnetic line bundle". And it so happens that in the theory of line bundles not all gauge invariants are local quantities. Some of them are holonomies around noncontractible loops, hence the Aharonov Bohm effect in addition to the (fully local) Lorentz Force law. Miguel (talk) 18:23, 19 January 2011 (UTC)

The case that the solenoid is far from the two slit
I imagine the case that the solennoid is very far from the two slit.

In that case, Aharonov-Bohm effect continues or disappears?.

Custum quantum theory does'nt deal with the that case. .

Qauntum theory does'nt consider the distance between the solenoid betweeen thw slit.

If one knows the answer, contact me, mrhun@hanmail.net — Preceding unsigned comment added by Younghun park (talk • contribs) 03:20, 5 October 2011 (UTC)

 * The case of the solenoid far from the slit isn't interesting because then the particle can pass through the solenoid. The cool thing about the effect is that the particle responds to changes in a region it can't pass through.  — Laura Scudder | talk 21:02, 9 November 2012 (UTC)

 * Tthe whole point of the experiment is that the walls of the solenoid are made thick and dense enough that they are effectively impenetrable by electrons, so regardless of the distance the particles cannot pass through the solenoid. What matters is whether they can pass around the solenoid by two different paths, and in principle this could occur regardless of the distance from the slits to the solenoid.  — Steven G. Johnson (talk) 16:35, 10 November 2012 (UTC)

Article is misleading
See here why. Count Iblis (talk) 18:07, 28 October 2011 (UTC)
 * Very interesting. Tell me if I have understood this: the magnetic AB effect is caused by a temporary rotational differential in the solenoid, caused by the passage of the electron, which induces an entangled B field outside the solenoid? This entanglement vanishes after the electron has passed.-- cheers, Michael C. Price talk 06:09, 29 October 2011 (UTC)

What is the correct gauge?
Consider the classical electromagnetic maxwell equations: before this gauge-dependent effect was observed, people were free to choose their gauge (the specific choice of gauge (Lorentz gauge, Coulomb gauge, ...) was considered physically irrelevant); then this effect showed that the gauge does influence the physics (i.e. part or all of the degrees of freedom in choosing the gauge are eliminated). A pressing question is: which gauge or subclass of gauges is correct? Its like saying we can measure in some sense the gauge, but the page does not say what gauge/subclass of gauges was determined through the effect... — Preceding unsigned comment added by 213.49.90.66 (talk) 23:58, 21 April 2012 (UTC)
 * The IP spa misunderstands. The effect is gauge-invariant. Xxanthippe (talk) 00:18, 22 April 2012 (UTC).
 * "The effect is gauge-invariant." if I change my gauge such that E,B along the paths of electron dont change (by changing the B where the electron doesnt pass) but A does change our measurement changes => not gauge-invariant. The pre AB effect maxwell equations are gauge-invariant, The effect is not. — Preceding unsigned comment added by 213.49.90.66 (talk) 05:59, 22 April 2012 (UTC)
 * bump — Preceding unsigned comment added by 83.134.158.212 (talk) 10:12, 25 April 2012 (UTC)

 * The effect is gauge invariant. We say the effect as being caused by the four-potential, which has gauge freedom, because otherwise somehow the particle knows about electromagnetic fields in places it never goes, but when we do the calculations, all the observables end up depending only on gauge invariant quantities like the magnetic flux.  This is analogous to working a classic electrostatics problem, where you have some scalar electric potential that you are free to add any number to, because all the physical effects end up only depending on differences in potential.

 * I think the thing you're missing is that if you make a gauge transformation, E and B don't just stay the same along the particle's path, but everywhere, including inside the solenoid. — Laura Scudder | talk 21:00, 9 November 2012 (UTC)

Diagrams?
This article could use a few more diagrams. Please see here for some. I'll draw another soon for the double-slit interference of an electron beam around a solenoid, a separate one complete with a "magnetic wisker" (assuming that's the correct name for the thing to deflect the beam and shift the interference pattern...). Thanks, M∧Ŝc2ħεИτlk 06:34, 9 May 2013 (UTC)

A classical approach to the Aharonov-Bohm phase shift
There exists literature which contests the interpretation of the Aharonov-Bohm effect present in this article. I believe we should edit the article to reflect this.

 * [T]he persistence of the Aharonov-Bohm phase shift when the solenoid is surrounded by a conductor does not exclude a classical force-based explanation for the phase shift. At present there is no experimental evidence for the Aharonov-Bohm effect.

The author argues that there is plenty of experimental evidence for the phase shift itself but zero evidence for the quantum topological nature of the phase shift. The major argument is that the velocity fields of passing electrons penetrate even excellent conductors and that an ohmic conductor does not screen out the magnetic field of a passing charge; in fact, the author argues that the time-integral of the magnetic field of the passing charge in the material is invariant of the conductivity of the material.

See also Jackson chapter 14 -- velocity fields have no characteristic skin depth to them as they are not radiation fields. Destatiforze (talk) 19:50, 4 September 2016 (UTC)

Electric Effect
The explanatory text and equation should reference delta potential where appropriate, to correspond to the delta phase. As it stands, it looks as though there is a known 0 reference for V. Jim Bowery (talk) 03:51, 15 September 2020 (UTC)

A similar electric effect has been predicted but from what I read few years ago, it has not been observed contrarily to what's written, since what was thought to not present any force had indeed an electric field hidden. — Preceding unsigned comment added by Klinfran (talk • contribs) 23:20, 9 December 2017 (UTC)

Latest information on the A-B effect
THIS POST DOES NOT INVOLVE ORIGINAL RESEARCH! The two papers were published in May in Physical Review A, which is a top flight physics journal. Why the resistance to my post?

This discussion explains quite clearly why one should avoid discussing ones own original research in Wikipedia: https://academia.stackexchange.com/questions/26392/when-is-it-appropriate-to-add-references-to-own-papers-on-wikipedia Brienanni (talk) 21:05, 14 December 2017 (UTC)

I have removed OR inserted by IP spas from talk page. Original research is not appropriate for inclusion in either article space or talk space. Xxanthippe (talk) 21:54, 14 December 2017 (UTC).

THIS POST DOES NOT INVOLVE ORIGINAL RESEARCH! The two papers were published in May in Physical Review A, which is a top flight physics journal. Brienanni and Xxanthippe: please respond.

 * Please, provide links to the papers including the authors. If you are the author of the papers I will need to research the matter.  If they are peer reviewed then that may bypass the original research prohibition.  I don't currently know.  If you are an author even if not a contributing one then this may be a problem.  If you are not the principal author then we need to know why the material is being deleted.  You must document your references appropriately.  If you are asking for clarification then you deserve an answer.   Jobberone (talk) 10:33, 21 January 2018 (UTC)

What, you mean links like the ones it just took me about a minute to find? https://journals.aps.org/pra/abstract/10.1103/PhysRevA.95.052123, https://journals.aps.org/pra/abstract/10.1103/PhysRevA.95.052124. Why is citing these an issue? -- SarekOfVulcan (talk) 18:01, 23 January 2018 (UTC)
 * All that shows is that WP:ITEXISTS. There are 27,000 papers that mention the Aharonov Bohm effect. Are all to be included in the WP article? Precedent includes only the best-known ones. I don't know if 100 cites is sufficient but zero cites probably is not. Xxanthippe (talk) 02:42, 4 March 2018 (UTC).
 * Practice is to wait until papers have accumulated sufficient citations to demonstrate that they are significant. Wikipedia is not a link-farm. Xxanthippe (talk) 21:27, 23 January 2018 (UTC).

Thank you, everyone, for your posts. Please note -- I'll say it again for the third time -- this is not my work! Publication in a top flight physics journal -- which by its nature requires passing through a rigorous peer review process -- should more than sufficient. Quoting a such a peer-reviewed article is hardly makes a link farm. I think many of the comments here are tendentious and frankly irrational. I don't understand the motivation. (Posted by Murraydaw at 17:28, 31 January 2018.) — Preceding unsigned comment added by Murraydaw (talk • contribs)
 * Which practice is this you speak of? Peer reviewed papers are the gold standard for citations here, so there is nothing wrong with the edit. Darkness Shines (talk) 16:04, 13 February 2018 (UTC)
 * False claim. It is well-cited peer reviewed papers that are the gold standard. Try again when the paper has 100+ cites. Xxanthippe (talk) 21:35, 13 February 2018 (UTC).

Please show us where the Wikipedia standard for a citation is as you say (100+ citations). Murraydaw (talk) 22:24, 21 February 2018 (UTC)

Furthermore, you either must not really believe your claim or are just being irrational as you have not objected to the inclusion of Lev Vaidman's work (which has minimal citations), as someone else has already pointed out to you (and in your standard fashon you ignored). Don't take Lev off; his is excellent work. There is even a Physics Today cite which probabily has few reference but it is not even peer reviewed. Murraydaw (talk) 22:30, 21 February 2018 (UTC)
 * It took me ten seconds to google the title and find this. I'm restoring the edit with some minor changes to wording to make it more encyclopedic. I'm also going to leave this here: WP:BITE. ᛗᛁᛟᛚᚾᛁᚱPants   Tell me all about it.  13:39, 28 February 2018 (UTC)
 * Okay, it ended up being a major rewording once I viewed the text., I suggest you familiarize yourself with our norms of writing; writing on WP should not be done the same way once writes a paper. Papers are, by their nature, argumentative. They exist to persuade. Wikipedia exists merely to document. and ; if you two want to discuss whether or not this is WP:DUE, that's an open conversation. But the arguments I saw in the edit summaries are, frankly, bullshit.  ᛗᛁᛟᛚᚾᛁᚱPants   Tell me all about it.  13:48, 28 February 2018 (UTC)

 * I see three experienced editors -including an admin- and one new editor all asking for some discussion about this. I see nothing from the opposition except demonstrably false claims about WP policy. There needs to be discussion; if the edit warring continues without discussion I will ask another admin to step in to enforce our policies. ᛗᛁᛟᛚᚾᛁᚱPants   Tell me all about it.  22:15, 28 February 2018 (UTC)

 * Don't call me out esp when you haven't even tried to understand the dispute. I was asked to help find out why Murraydaw kept having his posts, edits, etc removed.  I don't care about the article as my field is medicine and particularly OB/GYN where my 6 years of formal postdoctoral training means nothing in Wikipedia.  I understand very little of the article as is.  I've mostly removed myself from trying to contribute my time here due to the attitudes and actions I see here.  And my financial contributions are infrequent and miniscule as well.  I suggest you spend your time explaining to Murraydaw why his contributions aren't allowed.  I don't care about WP:DUE and was never in a conversation with anyone in particular.  Don't ever threaten me again either.  Jobberone (talk) 03:24, 3 March 2018 (UTC)
 * Well, don't falsely accuse me of not understanding the dispute. You should certainly never simply make shit up by claiming I never even tried. I completely understand the dispute, and have already outlined it above. I have not threatened you, or anyone else, but have merely warned against continued edit warring: If you are unaware of the longstanding prohibition against edit warring here, you should probably rectify that immediately. In fact, the only comment I directed at you was to say that I am willing to discuss whether or not this content is WP:DUE. If you're unwilling to discuss, that's your prerogative, but your suggestion that I should instead explain to a new editor why a perfectly acceptable edit "isn't allowed," is just nonsensical. Every rationale given thus far for exclusion is either an unfounded or demonstrably false claim. ᛗᛁᛟᛚᚾᛁᚱPants   Tell me all about it.  14:54, 5 March 2018 (UTC)

User:MPantsI apologize for my adversarial position but you didn't know the full story which is not your problem. I should have told the participants I'd been asked to help and I replied I'd look at it.  My bad.  I took exception to being included in edit warring although you didn't mention anyone in particular but all (my opinion) in general.  I agree with you the reference/citation is fine.  There is no reason to delete his edit.[[User:MPants

 * Note: This discussion has been referenced in the Wikipedia talk:WikiProject Science discussions. Xxanthippe (talk) 21:50, 4 March 2018 (UTC).
 * Note: This discussion has been referenced in the Wikipedia talk:WikiProject Physics discussions. Xxanthippe (talk) 21:50, 4 March 2018 (UTC).

The arXiv, the repository of science reprints, has 675 reprints that mention the Aharonov-Bohm effect. The Google Scholar citation database cites 27,900 papers that mention the effect. I find that over 50 of these have more than 100 citations in the scholarly literature. I deduce that a paper with less than 100 cites is not within the top 50 cited papers in the field. Please could User:SarekOfVulcan or anybody else explain why the recently published papers promoted in this thread (which to my knowledge have not yet garnered any citations) be mentioned in the article on the Aharonov-Bohm effect while the other 27,800 are not? Xxanthippe (talk) 02:19, 6 March 2018 (UTC).
 * The following are citations used in this article which have (at least according to the Astrophysics Data System) have less than 100 cites:, , , , , , , , , , and . In addition, there are a number of popular-science articles used, which all undoubtedly have far fewer than 100 citations in the literature. If we held this standard to all our sources, we would have to gut this article.  ᛗᛁᛟᛚᚾᛁᚱPants   Tell me all about it.  14:30, 6 March 2018 (UTC)
 * What conclusion do you deduce from the data above that is relevant to your contention in this thread that the two recently published papers that you advocate for should be cited in the Aharonov-Bohm article? I see that there are 3556 papers that mention the A-B effect that have been published by the publisher of your two papers. Why are your two so special that they should be included in Wikipedia in preference to these others? Xxanthippe (talk) 03:06, 7 March 2018 (UTC).
 * They offer a new solution in which the phase shifts can be seen as the result of the vector potential acting upon either the electron or the solenoid. While that's hardly a groundbreaking finding, it has implications that reach outside the study of one little-publicized phenomenon in particle physics.. It's the first entirely quantum mechanical solution, and while it seems to suggest a paradigm that might not bear any resemblance to physical reality, it nonetheless exposes new pathways of investigation. It is precisely the sort of thing a physics major would want to read about if they used this article during their studies. ᛗᛁᛟᛚᚾᛁᚱPants   Tell me all about it.  13:51, 7 March 2018 (UTC)
 * Your personal opinions constitute WP:Original research and thereby are not a justification for inclusion of material in Wikipedia. To do that you need independent, reliable and in this case multiple sources that argue this viewpoint to justify inclusion. Xxanthippe (talk) 05:50, 8 March 2018 (UTC).
 * Nothing I said was proposed as article content. WP:OR only applies to article content, not talk page discussions. You've been here long enough to know this. As for your comments about weight: you're confusing WP:NOTABILITY and WP:WEIGHT; claims that multiple independent sources are required originate from the former, while the applicable one here is the latter. Again; you should already know this.
 * Unless you have a well-considered objection based solidly in policy which you have, until now been keeping secret, then the inclusion of this material has been sufficiently justified by any reasonable standard, and I don't feel the need to justify it any more. ᛗᛁᛟᛚᚾᛁᚱPants   Tell me all about it.  13:45, 8 March 2018 (UTC)

External links modified (January 2018)
Hello fellow Wikipedians,

I have just modified one external link on Aharonov–Bohm effect. Please take a moment to review my edit. If you have any questions, or need the bot to ignore the links, or the page altogether, please visit this simple FaQ for additional information. I made the following changes:
 * Added archive https://web.archive.org/web/20150318001011/http://www.fdavidpeat.com/bibliography/books/infinite.htm to http://www.fdavidpeat.com/bibliography/books/infinite.htm

When you have finished reviewing my changes, you may follow the instructions on the template below to fix any issues with the URLs.

Cheers.— InternetArchiveBot  (Report bug) 03:13, 22 January 2018 (UTC)

Very significant recent research results
There is some important research reported in (secondary source) https://phys.org/news/2019-09-exotic-physics-phenomenon.html ("Exotic physics phenomenon is observed for first time") and originally published in Science (   DOI: 10.1126/science.aay3183 Science Vol. 365, No. 6457). I suppose, how-ever, we will have to wait a while for secondary material to pile up before this is included, given the rancour seen on this talk page. Kdammers (talk) 02:15, 6 September 2019 (UTC)
 * Correct. New material will need to be supported by multiple, reliable and independent sources. Xxanthippe (talk) 02:21, 6 September 2019 (UTC).

 * Here's a start: https://scitechdaily.com/exotic-physics-phenomenon-involving-time-reversal-observed-for-first-time/ Kdammers (talk) 01:11, 9 September 2019 (UTC)
 * There is a long way to go. Let's wait for the citations WP:NOTNEWS. Xxanthippe (talk) 02:40, 9 September 2019 (UTC).

license: Creative Commons - Attribution Share-Alike - https://creativecommons.org/licenses/by-sa/4.0/

title: Talk:Aharonov–Bohm effect


text:
Johnny Dowd

Johnny Dowd (born John David Dowd; March 29, 1948, in Fort Worth, Texas) is an American alternative country musician from Ithaca, New York. Typical of his style are experimental, noisy breaks in his songs and strong gothic (in the sense of dark and gloomy) elements in the lyrics as well as in the music. There is also a strong undercurrent of black humor and the absurd in his work.

Although his early albums were most celebrated in the alternative country community, he has never quite fit into any particular genre. As a singer-songwriter, his music is most often compared to that of Tom Waits, Nick Cave and Captain Beefheart.

Early life
Born in Fort Worth, Texas in 1948, Dowd's family moved to Memphis, Tennessee in 1950, and then to his father's hometown of Pauls Valley, Oklahoma in 1953. He received a record player for Christmas in 1956 and began buying records at a local appliance store. Although the first LP he owned was by the Ray Conniff Singers, it was the music of Hank Williams, Elvis Presley, Ray Charles and James Brown, that changed his life. He cites James Brown's Live at the Apollo as his lifelong favorite album.

In 1965, along with his mother and sisters, Johnny returned to Memphis after his parents' divorce. After serving in the U.S. Army and living in California he drove across the United States in the early 1970s with longtime friend Dave Hinkle and settled permanently in Ithaca, New York where his mother and sisters had also relocated. Dowd and Hinkle began moving furniture for a living, later naming their business the Zolar Moving Company.

Band history
Dowd formed a band in the 1970s named The Jokers, which included Johnny (guitar), his sister Jennifer Edmondson (drums) and Dave Hinkle (bass). By 1988, the band had become Neon Baptist, who in addition to Dowd included Cally Arthur, Dave Hinkle, Mike Edmondson and Jennifer Edmondson, with Max Ormond and Kim Sherwood-Caso joining the band in later lineups. Neon Baptist was one of the founding acts of the GrassRoots Festival, where Dowd has performed annually since 1991.

By the time Neon Baptist disbanded in 1995, Dowd was recording songs alone in the office of his moving company. These songs first appeared in 1995 on a home-made demo cassette as Wrong Side of Memphis, which credited Dowd as a solo artist and featured Kim Sherwood-Caso on background vocals on two songs. Most of these tracks were either re-mixed or completely re-recorded for the CD version of the same album, which was initially pressed as a self-released CD and then officially released on Chicago's Checkered Past Records label in 1997. The album was also released on Koch Records in early 1998 and then in Europe on Munich Records. Favorable reviews led to some of his first European appearances in 1998.

In the wake of the critical acclaim for Wrong Side of Memphis, Dowd released his second album, Pictures From Life's Other Side, in 1999, also to positive reviews. That year also saw the first of Dowd's US and European tours. After the self-released, experimental Down In The Valley in 2000 came Temporary Shelter. A Dutch television documentary on Dowd was filmed in 2000, and in early 2001, The New York Times highlighted him as one of four "Country Singers Who Still Display a Country Heart".

Dowd's The Pawnbroker's Wife album was released in 2002, followed by Wire Flowers: More Songs from the Wrong Side of Memphis in 2003. That same year, he was handpicked by The Simpsons' creator Matt Groening, a self-described fan of Dowd's music, to perform in the All Tomorrow's Parties festival. He also made his major film appearance in 2003 with Searching for the Wrong-Eyed Jesus. The album Cemetery Shoes was released in 2004. Cruel Words, released in 2006, went on to win the Alt Country award in the 7th Annual Independent Music Awards the following year.

In 2006, Dowd, drummer Brian Wilson (aka Willie B) and Jim White formed the band Hellwood. Their album, Chainsaw of Life, was recorded in a cabin in New York, the walls of which were covered in musician obituaries. Hellwood toured the album in Europe. In April 2007, Dowd joined Beukorkest, a collaboration of various Dutch musicians and artists, for a nine-show tour of the Netherlands. In 2008, after an album of tracks from the tour was released, Beukorkest re-formed with a new team of musicians.

Dowd released A Drunkard's Masterpiece in early 2008 in the U.S., Canada and Europe, followed by a European tour in April and May. In October, he formed the trio Black Elastic with former bandmates Kim Sherwood-Caso on guitar and vocals and Mike Edmondson on guitar. After several shows in the Ithaca, New York area, an expanded Johnny Dowd band was formed, composed of Sherwood-Caso, Mike Stark (keyboards), Matt Saccuccimorano (drums) and Willie B (baritone guitar). The group released its debut album Wake Up the Snakes in 2010. Willie B plays drums and bass pedals on Dowd's Do the Gargon released in 2013. Dowd's solo album That's Your Wife On The Back Of My Horse was released in 2015 and featured on several tracks the singer/songwriter Anna Coogan from Ithaca. She is also a guest vocalist on Dowd's next album, 2016's Execute American Folklore. The album contains fourteen self-written tracks. All instruments on this album are played by Dowd and it showcases his ability to create an electronic sound.

On June 5, 2018, Dowd announced on his website that he is working on yet another new album, after the release of Twinkle Twinkle in January of the same year. According to Dowd, the record sounds like "a grungy garage rock thing, circa 1965." Kim Sherwood-Caso will, again, provide vocals on the album. On August 14, 2018, he wrote on his website that the new album will be released on March 1, 2019, titled Family Picnic. Twinkle Twinkle contained jazz and blues covers as well as new versions of traditionals. There is also one new self-penned song on the album. All (electronic) instruments on the album are played by Dowd with guest vocals by Anna Coogan and Michael Edmondson. All fourteen tracks on Family Picnic were written by Dowd; he also played guitar and keyboards on the album. Kim Sherwood-Caso provides backup vocals with Michael Edmondson. Edmondson also played guitar and xylorimba. The album was well received by critics. In November 2019, he released Live at GrassRoots 2006, recorded in Trumansburg, New York in July 2006. The set featured songs that would later turn up on his Wake Up the Snakes album and the Hellwood album Chainsaw of Life.

On March 18, 2021, Dowd announced on his website that he is working on material for a new album, titled Homemade Pie. The album was released in January 2022. On Homemade Pie, Dowd again collaborated with vocalist Kim Sherwood Caso, Willie B. on drums and Mike Edmondson on guitar and keyboard. Dowd himself was the main vocalist on the album and also played guitar and keyboard. He also wrote the lyrics and the music. The album received generally positive reviews. In September 2021, Dowd contributed the track "Farm Boy" on the album, The Wanderer - A Tribute to Jackie Leven. He also recorded a track with Sarah Corina, "Kiss The Sky", in December 2021.

His nineteenth solo studio album Is Heaven real? How would I know, was released to much acclaim in October 2023.

In 2009, Dowd was a judge for the eighth annual Independent Music Awards to support independent artists' careers.

Studio albums

 * Wrong Side of Memphis (Checkered Past - USA, Koch Records - USA, Munich Records - Europe) 1997, 1998 and 1998 respectively
 * Pictures from Life's Other Side (Koch Records - USA, Munich Records - Europe) 1999
 * Down in the Valley (self-released) 2000
 * Temporary Shelter (Munich Records - Europe, Koch Records - USA) 2000, 2001 respectively
 * The Pawnbroker's Wife (Munich Records - Europe, Catamount - USA) 2002
 * Wire Flowers: More Songs from the Wrong Side of Memphis (Munich Records - Europe) 2003
 * Cemetery Shoes (Munich Records - Europe, Bongo Beat Records - USA) 2004
 * Cruel Words (Bongo Beat Records - USA, Munich Records - Europe) 2006
 * A Drunkard's Masterpiece (Munich Records - Europe, Bongo Beat Records - USA) Spring 2008
 * Wake Up the Snakes (Munich Records) Spring 2010
 * More or Less -Poetry/Music- (Zylaxi Records) Spring 2010
 * No Regrets (Mother Jinx Records) Spring 2012
 * Do the Gargon (Mother Jinx Records) Summer 2013
 * That's Your Wife on the Back of My Horse (Mother Jinx Records) March 2015
 * Execute American Folklore (Mother Jinx Records) September 2016
 * Twinkle, Twinkle (Mother Jinx Records) January 2018
 * Family Picnic (Mother Jinx Records) March 2019
 * Homemade Pie (Mother Jinx Records) January 2022
 * Is Heaven real (How would I know) (Memphis Record Pressing) October 2023

Collaborations

 * Hellwood - Chainsaw of Life With Jim White and Willie B (Brian Wilson) (Munich, 2006)
 * Kiss The Sky With Sarah Corina (One track on SoundCloud, 2021)

Live albums

 * Johnny Dowd Live (self-released) 2001
 * Live at the Night & Day Cafe, Manchester, UK (self-released) 2005
 * Johnny Dowd Live at Schuba's 2000 (digital released) 2008
 * Ratten Spiegel (self-released) 2009
 * Live in Morgantown (Mother Jinx Records) December 2014
 * Live at Grassroots 2006 (self-released) 2019
 * Porchfest Live Show (self-released) 2023

45s/EPs

 * Hell or High Water/Divorce, American Style (Nicole, 1999)
 * Mother Love/Daddy's Girl (Sub Pop, 2001)
 * Lower Manhattan/Bozo (Angry Mom Records, 2012)
 * Xmas (Mother Jinx Records, 2021)

Exclusive tracks and guest appearances

 * Various - The UNSOUND(tm) Series Volume 2: Guitars! (To M'Lou Music, 1999)
 * Various - Awesome No. 1 (a Munich compilation) (Munich, 2001)
 * Various - Gimme Shelter 17 Amazing covers of classic songs by The Rolling Stones (Uncut 2002)
 * The Pine Valley Cosmonauts - The executioners last songs Vol. 1 (Bloodshot records, 2002)
 * Various - Hope isn't a Word (Comes with a Smile Vol. 11) (Comes with a smile, 2004)
 * Jim White Presents music from Searching for the Wrong-Eyed Jesus (Luaka Bop, 2005)
 * Chicken Legs Weaver - Nowhere (as producer) (Riverside records, 2006)
 * Mark Lotterman - Pain & Entertainment (The house of music, 2007)
 * Various - There's A Hole In Heaven Where Some Sin Slips Through: Townes van Zandt tribute (Glitterhouse records, 2007)
 * Jackie Leven - Oh What A Blow That Phantom Dealt Me! (Cooking Vinyl, 2007)
 * Jackie Leven - Lovers at the Gun Club (Cooking Vinyl, 2008)
 * Beukorkest - Der Kleine Hausmeister (Munich, 2008)
 * Soundtrack The Devil's Muse collaboration with David J Soundtrack included on Deluxe 2-Disc DVD Set (Halo 8, 2008)
 * Love and Rockets tribute album, "New Tales to Tell" track 2-05 (digital release only) Bound for Hell (with Billy Coté) (Justice Records, October 2009)
 * The Jeffrey Lee Pierce Sessions Project - We Are Only Riders  (Glitterhouse Records, 2009)
 * Anna Coogan & JD Foster - Birth of the Stars (Elevate, 2015)
 * The Wanderer - A Tribute to Jackie Leven - track Farm Boy (Cooking Vinyl, 2021)

Also appears on

 * Uncut February 2001 Track 7; Big Wave (UNCUT UG-26 32)(Uncut, 2001)
 * Balling The Jack (The Birth Of The Nu-Blues) Track 19; Picture From Life's Other Side (Ocho, 2002)
 * Total Lee! (Lee Hazlewood tribute) Track 5; Sleep in the Grass (City Slang Recordings, 2002)

DVDs

 * Searching for the Wrong-Eyed Jesus (2003), BBC documentary about roots music in the US hosted by Jim White, special guests besides Johnny Dowd are The Handsome Family, David Eugene Edwards and others.
 * Take Root festival 2004 Tracks 17 and 18; A Man and his Wife, Johnny B. Goode Recorded October 2, 2004 Assen, The Netherlands. (Music Matters, 2004)

Books

 * Johnny Dowd - Poems (self released, 2002) 15 Poems with Illustrations by Stahl Caso

title: Johnny Dowd


text:
Wikipedia:Experimental Deletion/XD2

=XD2=

eXperimental Deletion method XD2 applies templates and categories. It is slightly more complex than XD1, but the workload is less.

Instructions

 * 1) Blank the page, as before
 * 2) Add the template { { XD2}}
 * 3) Done!

Variations

 * Add some explanation why you deleted the page as well.

Pro&Con

 * Example page
 * You can look up pages deleted in this way in Category:XD2
 * less work than XD1
 * Pages deleted in this way do not become redlinked.
 * Other Pros and cons are as yet unknown. Try it out and report back on the talk page!

title: Wikipedia:Experimental Deletion/XD2


text:
Pretend (1952 song)

"Pretend" is a popular song, written in 1952 by Dan Belloc, Lew Douglas, Cliff Parman and Frank Levere.

The best-known recording, by Nat King Cole, was released by Capitol Records as catalog number 2346. It first reached the Billboard Best Seller chart on January 31, 1953, and lasted 20 weeks on the chart, peaking at No. 3. It also reached No. 2 on the UK Singles Chart in May 1953, just behind Frankie Laine's chart topping hit, "I Believe". Cole would later re-record the song for his 1961 album The Nat King Cole Story.

The recording by Ralph Marterie was released by Mercury Records as catalog number 70045. It reached the Billboard Best Seller chart on February 7, 1953 at No. 16, its only week on the chart.

The recording by Eileen Barton was released by Coral Records as catalog number 60927. It reached the Billboard Best Seller chart on March 7, 1953 at No. 18, its only week on the chart.

On the Cash Box chart, where all versions of the song were combined, the song reached a peak of No. 5 in 1953.

The song was subsequently recorded by Tab Smith, reaching No. 89 on the Billboard chart in 1957, and by Carl Mann (issued as catalog number 3546 by Philips International), reaching No. 57 on Billboard and No. 56 on Cash Box in 1959.

Alvin Stardust's version was a popular hit in the United Kingdom in 1981, when it reached No. 4 on the UK Singles Chart. This cover was largely based on Carl Mann's 1959 version of this song.

Recorded versions

 * Nat King Cole (1953)
 * Eileen Barton (1953)
 * Ralph Marterie (1953)
 * Henri Rene & His Orchestra feat Franz Dietschmann (zither solo) (1953)
 * Tab Smith (1957)
 * Carl Mann (1959)
 * Keely Smith (1959) on the album Be My Love
 * Georgia Gibbs (1959)
 * Tielman Brothers (1960) on the album Tielman On Stage
 * Brenda Lee (1960)
 * Gerry & The Pacemakers included it on the album How Do You Like It? (1963) and performed it live with The Everly Brothers in 1965 on Shindig!.
 * Johnny Preston released a version of the song on his 1960 album, Running Bear.
 * Buzz Clifford (1963)
 * Sammy Davis Jr., The Nat King Cole Songbook, (1965)
 * Marvin Gaye (1965)
 * Alvin Stardust (1981)
 * Don Williams (1995)
 * Barbra Lica (2012)

title: Pretend (1952 song)