Photo of a positron. Removed white background, derived from another photo.
English: Cloud chamber photograph of the first positron ever observed. The thick horizontal line is a lead plate. The positron entered the cloud chamber in the lower left, was slowed down by the lead plane, and curved to the upper left. The curvature of the path is caused by an applied magnetic field that acts perpendicular to the image plane. The higher energy of the entering positron resulted in lower curvature of its path. Original caption: A 63 million volt positron (Hρ = 2.1×105 gauss-cm) passing through a 6 mm lead plate and emerging as a 23 million volt positron (Hρ = 7.5×104 gauss-cm). The length of this latter path is at least ten times greater than the possible length of a proton path of this curvature.
Datum
Photographed 2. avgusta 1932. Published 15. marca 1933.
Vir
Anderson, Carl D. (1933). "The Positive Electron". Physical Review43 (6): 491–494. DOI:10.1103/PhysRev.43.491.
Obtained from American Physical Society, March 5, 2008. The copyright for the periodical containing this picture, if renewed, would have had to be renewed in 1960 or 1961. I checked the Catalog of copyright entries for Periodicals in 1960 and 1961, http://onlinebooks.library.upenn.edu/cce/, but The Physical Review is not listed there. Therefore, the copyright on the entire issue of The Physical Review, including this picture, has expired.
Druge različice
Ta datoteka je izvlečena iz naslednje predstavnostne datoteke
To delo je v javni domeni, ker je bilo objavljeno v Združenih državah Amerike med letoma 1929 in 1963, in čeprav je morda imelo oznako avtorskega dela, avtorske pravice niso bile podaljšane. Za dodatno razlago glejte Commons:Hirtle chart in dnevnike podaljšanja avtorskih pravic. Upoštevajte, da je to delo morda še vedno varovano v jurisdikcijah, ki za dela iz ZDA ne upoštevajo pravila krajšega roka (glede na datum avtorjeve smrti), kot so Kanada (70 let p. s. a.), celinska Kitajska (50 let p. s. a., ne pa tudi Hongkong ali Makav), Nemčija (70 let p. s. a.), Mehika (100 let p. s. a.), Švica (70 let p. s. a.) in druge države z individualnimi pogodbami.
Datoteka vsebuje še druge podatke, ki jih je verjetno dodal za njeno ustvaritev oziroma digitalizacijo uporabljeni fotografski aparat ali optični bralnik. Če je bila datoteka pozneje spremenjena, podatki sprememb morda ne izražajo popolnoma.