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The number is 1.022 Mev, a little over one Mev, not one thousand Mev. pstudier 20:50, 2003 Dec 8 (UTC)
Correct me if I'm wrong – I'm not a particle physicist – but isn't the positron supposed to have a spin of ±1/2?
No, you mistake the positron for the neutrino. How could the positron have spin +or- half, if so it could never be responsoble for the annihalation of it's anti-particle the electron User:62.253.219.130 11:14, 3 December 2004
Electrons and Positrons both have spin of 1/2. To annihalate, an electron must meet a positron with opposite spin, that is, an electron with spin +1/2 must meet a positron with spin -1/2. This event gives off two photons, each of which have spin of 1. So one photon will have spin of +1 and the other -1. See Spin (physics). pstudier 23:14, 2004 Dec 3 (UTC)
Q: The negative spin relates to the negative, or reverse, time factor in the calculations, if I am not completely mistaken. If I am not mistaken, does this mean that the positron is supposed to travel... well, you know... backwards in time?
At the Christie Hospital North West Medical Physics Open Evening last night, the speaker was talking about PET scanning and running a slide show, and on one of the slides was, in big(~20cm on a ~1m high screen) letters http://en.wikipedia.org/wiki/Positron. Boffy b 12:35, 2005 Mar 18 (UTC)
While I can't find a source for this (not normally a good sign), I was under the impression that a 'hole' in an otherwise electron-saturated lattice is also sometimes called a positron; Relative to the lattice it has an electropositive charge (zero rather than -1). I also thought this was the (pseudo)scientific explanation of the Asimov/Star Trek android brain - the more the android learns, the less energy it needs to store the information, and a magnetic bottle wouldn't be required inside the machine to prevent the brain from annihilating everything else. Can someone confirm or deny either of these? [I also checked for pseudopositron as the right word for this kind of phenomenon, but there doesn't seem to be anything else on the web using that term.] Cyrek 23:26, 1 June 2006 (UTC)
Positron has opposite parity as the electron. I would add this but I know nothing about it other than its true (probably). Fresheneesz 07:34, 9 June 2006 (UTC)
Skobeltsyn page says he observed the positron in 1923. This page says 1929. Which date is correct? Marcreif ( talk) 12:14, 26 April 2016 (UTC)Marcreif
I find that Eddington in "Further Notes on the Radiative Equilibrium of Stars" (Monthly Notes of the Royal Astronomical Society, 77, p. 611), published in 1917, mentions "positive and negative electrons occasionally anulling each other" as a source of stellar energy. What is this, if not antimatter (or some way-advanced prediction of something like it)? -- Tardis 02:07, 10 July 2006 (UTC)
Bvcrist 20:56, 11 August 2006 (UTC)
In this very good articles it is stated (as practically everywhere else) that "Feynman, and earlier Stueckelberg, proposed an interpretation of the positron as an electron moving backward in time,[6] reinterpreting the negative-energy solutions of the Dirac equation. Electrons moving backward in time would have a positive electric charge."
Actually, A.S.Eddington in his Presidential address to the Mathematical Association, delivered on 5 January 1931 (The End of the World: from the Standpoint of Mathematical Physics, Nature, Supplement, no. 3203, 21 March, 1931) said the following. "I was once asked a ribald question: How does an electron (which has not the resource of consciousness) remember which way time is going? Why should it not inadvertently turn around and, so to speak, face time the other way? Does it have to calculate which way entropy is increasing in order to keep itself straight? I am inclined to think that an electron does something of that sort. For an electric charge to face the opposite way in time is the same thing as to change the sign of the charge. So if an electron mistook the way time was going it would turn into a positive charge. Now, it has been one of the troubles of Dr. P.A.M. Dirac that in the mathematical calculations based on his wave equation the electrons do sometimes forget themselves in this way. As he puts it, there is a finite chance of the charge changing sign after an encounter. You must understand that they only do this in the mathematical problem, not in real life". 91.55.175.213 ( talk) 11:08, 18 October 2013 (UTC)
Why is half of a scientific article devoted to "The positron in fiction"... Who really cares if the positron was in some dumb anime show. Positron Annihilation Spectroscopy isn't even mentioned in the article. I would rewrite it myself but I don't have any expertise on the subject.
This is why people on the internet shouldn't be allowed to write encylopedias... No matter what the article is about it is going to be packed full of references to shitty cartoons and ghostbusters by some stupid geek. —The preceding unsigned comment was added by 81.152.10.161 ( talk • contribs) .
I'm currently studying physics at A2, and have come across what seems to be a logical contradcition. If protons are positively charged and electrons negatively charged, why do the electrons leave the nucleus in Beta decay? Please someone help! 80Turnbull 21:57, 16 November 2006 (UTC)80Turnbull
The copyright notice of the image "Cloud chamber - visible trace of positron" [1] says that the copyright is expired because more than 70 years have passed since the author's death. Since Anderson died in 1991, this is obviously false. Also, the picture is upside-down. 147.142.160.134 17:57, 13 January 2007 (UTC)
i am a 16 year old boy at Manchester Grammar School but have a wide knowledge of the sub atomic world. in the Standford Linear Accelerator Center for example accelerating electrons into positrons i have read that this forms pure energy. they cn thn re-matarialize into the same constituents, i.e a positron and an electron. theoretically wouldnt this mean that this cycle can be a continous cycle occuring an infinite number of times as the positron will always encounter an electron and therefore could'nt there be a continual liberation of energy, which we all know is impossible? lastly as the positron-electron energy re-materializes it is said that it can also form a muon and an antimuon. what i cannot comprehend is how it can re-materialize into something that is 200 times (or of that order) bigger than the original mass of the constituents? question by Mark Ramotowski. —The preceding unsigned comment was added by Rambatino ( talk • contribs) 23:25, 8 May 2007 (UTC).
Message to the 16 year old poster: Why did you bother to capitalize "Manchester Grammar School" but not your sentences? And why bother with periods? If you want your writing to be as readable as possible, please use traditional punctuation. Obviously Manchester Grammar School doesn't teach grammar. And what is "could'nt"? The apostrophe stands for a missing letter, in this case "o", but you did not mean "couldont" did you? Why "wouldnt"? And your careful capitalization of "Manchester Grammar School" makes a mockery of your cn, thn. Why not save more precious keystrokes by writing "Mnchstr Grmr Skl"? Your posting makes you appear dumb/unintelligent. Sorry, but in this case your mobile phone ABC syntax or "Internetese" medium of communication becomes the message, rather than your deep discussion about nature. — Preceding unsigned comment added by 76.176.184.100 ( talk) 16:17, 13 December 2011 (UTC)
⋅This article is almost completely unreferenced, does not have a summary introduction separate from the minimal main content, and is dominated by unreferenced trivia, apparently selected on the base that the word "positron" is there somewhere. Needs more on physics, less on entertainment.
Jimfbleak (
talk)
08:57, 14 December 2007 (UTC)
i feel that this is a very important topic, as the experimental discovery of the positron was a huge success for theoretical physics, and believe the positron is an important antiparticle, please revert or discuss if you diagree. It is however a shame the quality of the article does not represent the importance, and hope someone has the time that i dont to improve it 193.60.83.241 ( talk) 11:56, 14 May 2008 (UTC)
Is it time to reassess this article for "good article" status? It has been two years... -RadicalOne• Contact Me• Chase My Tail 03:08, 20 January 2010 (UTC)
She likes it. :) -RadicalOne• Contact Me• Chase My Tail 15:49, 22 January 2010 (UTC)
It would be. One could spend hours getting their tail in knots just trying to justify it. -RadicalOne• Contact Me• Chase My Tail 00:45, 25 January 2010 (UTC)
I have added another step in the story between Dirac's 1929 paper and Anderson's discovery in 1932. I found a paper he wrote in 1931 in which he explicitly predicts the existence of an "anti-electron", that it should have the same mass as the electron, and that it would mutually annihilate with an electron. To avoid problems of WP:PRIMARY, I have included a book reference to corroborate my reading of the original paper. CosineKitty ( talk) 02:35, 11 February 2010 (UTC)
Is there a reference concerning the positron that explains the positron acceleration procedure? I don't see anything in the article that explains that. How does Fermilab do it? WFPM ( talk) 11:39, 21 May 2010 (UTC)
The Positron source (at Fermilab), per (National Geographic May.1985), is said to be created from Beryllium (EO4Be9). Thus the source of the Positron from within the atom would have to be from one of the Neutrons. However since it is positively charged, it is not understood how it it is impelled in the opposite direction from the electron by the (electrostatic?) directional acceleration system of the electrons. WFPM ( talk) 18:57, 17 August 2010 (UTC)
The article should probably mention Patrick Blackett and Giuseppe Occhialini who did secondary results that confirmed and popularised the discovery of the positron, although Anderson is correct credited as the initial discoverer. - 93.97.122.93 ( talk) 16:57, 28 May 2010 (UTC)
In 1.2 Experimental clues and discovery, it says Dmitri Skobeltsyn used a bubble chamber while the article bubble chamber says it was invented in 1952... I suppose it was a cloud chamber, can you confirm ? —Preceding unsigned comment added by AiméCésar ( talk • contribs) 17:55, 9 August 2010 (UTC)
The positron and electron both have a "fractional version" of their mass in the Infobox. The note mentions that this is just another way of writing the decimal value, so it doesn't add any information. I've never heard of it being used and I haven't seen it on any other Wikipedia page, so I don't understand why it is useful to have it. I have no formal education in this area, but I have been reading a lot on the subject, so I expect that most people will not know what this value means for the positron. Can somebody please explain what this information means for the positron and add it to the page, or remove it if there's no reason to have it? — SkyLined ( talk) 07:17, 3 August 2011 (UTC)
References
The mass in the box on this page needs to be updated to correspond to the same (more recent) source as that of the electron page, since a casual user may look up both positron and electron and think that the two have (very slightly) different masses (as I did before digging into the sources). David.S.Hollman ( talk) 14:57, 30 January 2012 (UTC)
I'm not entirely sure what the caption is referring to; it'd be helpful to have clarification on either the picture itself, or for the caption to be more clear. 86.163.71.158 ( talk) 20:51, 6 May 2012 (UTC)
Dmitri Skobeltsyn and Chung-Yao Chao are both dated as "1929" for the first observations. Can someone please look into the exact dates, as in month and day, so we can know who really observed it first? DrZygote214 ( talk) 23:02, 10 September 2014 (UTC)
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Who observed what when has been discussed on this talk page regarding the discovery of the positron. But, in reading this article, it remains puzzling as to why Dmitri Skobeltsyn is not given credit for the discovery of the positron. Did he not do anything with his cloud-chamber observations of 1929? Perhaps not publish them? Anyway, right now, the article confusing on this matter. Attic Salt ( talk) 13:57, 5 August 2018 (UTC)
The infobox currently quotes the very precisely known electron mass as positron mass. I don't think this is the right way. It is known that electron and positron mass agree within an uncertainty of 8e-9 (see Review of Particle Properties) So this should be the precision given in the infobox, not the much smaller value for the electron. -- Wassermaus ( talk) 17:53, 20 July 2024 (UTC)
![]() | Positron was a good articles nominee, but did not meet the good article criteria at the time. There may be suggestions below for improving the article. Once these issues have been addressed, the article can be renominated. Editors may also seek a reassessment of the decision if they believe there was a mistake. | |||||||||
| ||||||||||
![]() | Facts from this article were featured on Wikipedia's Main Page in the " On this day..." column on August 2, 2011, August 2, 2012, August 2, 2017, August 2, 2018, and August 2, 2020. |
![]() | This ![]() It is of interest to the following WikiProjects: | ||||||||||
|
The number is 1.022 Mev, a little over one Mev, not one thousand Mev. pstudier 20:50, 2003 Dec 8 (UTC)
Correct me if I'm wrong – I'm not a particle physicist – but isn't the positron supposed to have a spin of ±1/2?
No, you mistake the positron for the neutrino. How could the positron have spin +or- half, if so it could never be responsoble for the annihalation of it's anti-particle the electron User:62.253.219.130 11:14, 3 December 2004
Electrons and Positrons both have spin of 1/2. To annihalate, an electron must meet a positron with opposite spin, that is, an electron with spin +1/2 must meet a positron with spin -1/2. This event gives off two photons, each of which have spin of 1. So one photon will have spin of +1 and the other -1. See Spin (physics). pstudier 23:14, 2004 Dec 3 (UTC)
Q: The negative spin relates to the negative, or reverse, time factor in the calculations, if I am not completely mistaken. If I am not mistaken, does this mean that the positron is supposed to travel... well, you know... backwards in time?
At the Christie Hospital North West Medical Physics Open Evening last night, the speaker was talking about PET scanning and running a slide show, and on one of the slides was, in big(~20cm on a ~1m high screen) letters http://en.wikipedia.org/wiki/Positron. Boffy b 12:35, 2005 Mar 18 (UTC)
While I can't find a source for this (not normally a good sign), I was under the impression that a 'hole' in an otherwise electron-saturated lattice is also sometimes called a positron; Relative to the lattice it has an electropositive charge (zero rather than -1). I also thought this was the (pseudo)scientific explanation of the Asimov/Star Trek android brain - the more the android learns, the less energy it needs to store the information, and a magnetic bottle wouldn't be required inside the machine to prevent the brain from annihilating everything else. Can someone confirm or deny either of these? [I also checked for pseudopositron as the right word for this kind of phenomenon, but there doesn't seem to be anything else on the web using that term.] Cyrek 23:26, 1 June 2006 (UTC)
Positron has opposite parity as the electron. I would add this but I know nothing about it other than its true (probably). Fresheneesz 07:34, 9 June 2006 (UTC)
Skobeltsyn page says he observed the positron in 1923. This page says 1929. Which date is correct? Marcreif ( talk) 12:14, 26 April 2016 (UTC)Marcreif
I find that Eddington in "Further Notes on the Radiative Equilibrium of Stars" (Monthly Notes of the Royal Astronomical Society, 77, p. 611), published in 1917, mentions "positive and negative electrons occasionally anulling each other" as a source of stellar energy. What is this, if not antimatter (or some way-advanced prediction of something like it)? -- Tardis 02:07, 10 July 2006 (UTC)
Bvcrist 20:56, 11 August 2006 (UTC)
In this very good articles it is stated (as practically everywhere else) that "Feynman, and earlier Stueckelberg, proposed an interpretation of the positron as an electron moving backward in time,[6] reinterpreting the negative-energy solutions of the Dirac equation. Electrons moving backward in time would have a positive electric charge."
Actually, A.S.Eddington in his Presidential address to the Mathematical Association, delivered on 5 January 1931 (The End of the World: from the Standpoint of Mathematical Physics, Nature, Supplement, no. 3203, 21 March, 1931) said the following. "I was once asked a ribald question: How does an electron (which has not the resource of consciousness) remember which way time is going? Why should it not inadvertently turn around and, so to speak, face time the other way? Does it have to calculate which way entropy is increasing in order to keep itself straight? I am inclined to think that an electron does something of that sort. For an electric charge to face the opposite way in time is the same thing as to change the sign of the charge. So if an electron mistook the way time was going it would turn into a positive charge. Now, it has been one of the troubles of Dr. P.A.M. Dirac that in the mathematical calculations based on his wave equation the electrons do sometimes forget themselves in this way. As he puts it, there is a finite chance of the charge changing sign after an encounter. You must understand that they only do this in the mathematical problem, not in real life". 91.55.175.213 ( talk) 11:08, 18 October 2013 (UTC)
Why is half of a scientific article devoted to "The positron in fiction"... Who really cares if the positron was in some dumb anime show. Positron Annihilation Spectroscopy isn't even mentioned in the article. I would rewrite it myself but I don't have any expertise on the subject.
This is why people on the internet shouldn't be allowed to write encylopedias... No matter what the article is about it is going to be packed full of references to shitty cartoons and ghostbusters by some stupid geek. —The preceding unsigned comment was added by 81.152.10.161 ( talk • contribs) .
I'm currently studying physics at A2, and have come across what seems to be a logical contradcition. If protons are positively charged and electrons negatively charged, why do the electrons leave the nucleus in Beta decay? Please someone help! 80Turnbull 21:57, 16 November 2006 (UTC)80Turnbull
The copyright notice of the image "Cloud chamber - visible trace of positron" [1] says that the copyright is expired because more than 70 years have passed since the author's death. Since Anderson died in 1991, this is obviously false. Also, the picture is upside-down. 147.142.160.134 17:57, 13 January 2007 (UTC)
i am a 16 year old boy at Manchester Grammar School but have a wide knowledge of the sub atomic world. in the Standford Linear Accelerator Center for example accelerating electrons into positrons i have read that this forms pure energy. they cn thn re-matarialize into the same constituents, i.e a positron and an electron. theoretically wouldnt this mean that this cycle can be a continous cycle occuring an infinite number of times as the positron will always encounter an electron and therefore could'nt there be a continual liberation of energy, which we all know is impossible? lastly as the positron-electron energy re-materializes it is said that it can also form a muon and an antimuon. what i cannot comprehend is how it can re-materialize into something that is 200 times (or of that order) bigger than the original mass of the constituents? question by Mark Ramotowski. —The preceding unsigned comment was added by Rambatino ( talk • contribs) 23:25, 8 May 2007 (UTC).
Message to the 16 year old poster: Why did you bother to capitalize "Manchester Grammar School" but not your sentences? And why bother with periods? If you want your writing to be as readable as possible, please use traditional punctuation. Obviously Manchester Grammar School doesn't teach grammar. And what is "could'nt"? The apostrophe stands for a missing letter, in this case "o", but you did not mean "couldont" did you? Why "wouldnt"? And your careful capitalization of "Manchester Grammar School" makes a mockery of your cn, thn. Why not save more precious keystrokes by writing "Mnchstr Grmr Skl"? Your posting makes you appear dumb/unintelligent. Sorry, but in this case your mobile phone ABC syntax or "Internetese" medium of communication becomes the message, rather than your deep discussion about nature. — Preceding unsigned comment added by 76.176.184.100 ( talk) 16:17, 13 December 2011 (UTC)
⋅This article is almost completely unreferenced, does not have a summary introduction separate from the minimal main content, and is dominated by unreferenced trivia, apparently selected on the base that the word "positron" is there somewhere. Needs more on physics, less on entertainment.
Jimfbleak (
talk)
08:57, 14 December 2007 (UTC)
i feel that this is a very important topic, as the experimental discovery of the positron was a huge success for theoretical physics, and believe the positron is an important antiparticle, please revert or discuss if you diagree. It is however a shame the quality of the article does not represent the importance, and hope someone has the time that i dont to improve it 193.60.83.241 ( talk) 11:56, 14 May 2008 (UTC)
Is it time to reassess this article for "good article" status? It has been two years... -RadicalOne• Contact Me• Chase My Tail 03:08, 20 January 2010 (UTC)
She likes it. :) -RadicalOne• Contact Me• Chase My Tail 15:49, 22 January 2010 (UTC)
It would be. One could spend hours getting their tail in knots just trying to justify it. -RadicalOne• Contact Me• Chase My Tail 00:45, 25 January 2010 (UTC)
I have added another step in the story between Dirac's 1929 paper and Anderson's discovery in 1932. I found a paper he wrote in 1931 in which he explicitly predicts the existence of an "anti-electron", that it should have the same mass as the electron, and that it would mutually annihilate with an electron. To avoid problems of WP:PRIMARY, I have included a book reference to corroborate my reading of the original paper. CosineKitty ( talk) 02:35, 11 February 2010 (UTC)
Is there a reference concerning the positron that explains the positron acceleration procedure? I don't see anything in the article that explains that. How does Fermilab do it? WFPM ( talk) 11:39, 21 May 2010 (UTC)
The Positron source (at Fermilab), per (National Geographic May.1985), is said to be created from Beryllium (EO4Be9). Thus the source of the Positron from within the atom would have to be from one of the Neutrons. However since it is positively charged, it is not understood how it it is impelled in the opposite direction from the electron by the (electrostatic?) directional acceleration system of the electrons. WFPM ( talk) 18:57, 17 August 2010 (UTC)
The article should probably mention Patrick Blackett and Giuseppe Occhialini who did secondary results that confirmed and popularised the discovery of the positron, although Anderson is correct credited as the initial discoverer. - 93.97.122.93 ( talk) 16:57, 28 May 2010 (UTC)
In 1.2 Experimental clues and discovery, it says Dmitri Skobeltsyn used a bubble chamber while the article bubble chamber says it was invented in 1952... I suppose it was a cloud chamber, can you confirm ? —Preceding unsigned comment added by AiméCésar ( talk • contribs) 17:55, 9 August 2010 (UTC)
The positron and electron both have a "fractional version" of their mass in the Infobox. The note mentions that this is just another way of writing the decimal value, so it doesn't add any information. I've never heard of it being used and I haven't seen it on any other Wikipedia page, so I don't understand why it is useful to have it. I have no formal education in this area, but I have been reading a lot on the subject, so I expect that most people will not know what this value means for the positron. Can somebody please explain what this information means for the positron and add it to the page, or remove it if there's no reason to have it? — SkyLined ( talk) 07:17, 3 August 2011 (UTC)
References
The mass in the box on this page needs to be updated to correspond to the same (more recent) source as that of the electron page, since a casual user may look up both positron and electron and think that the two have (very slightly) different masses (as I did before digging into the sources). David.S.Hollman ( talk) 14:57, 30 January 2012 (UTC)
I'm not entirely sure what the caption is referring to; it'd be helpful to have clarification on either the picture itself, or for the caption to be more clear. 86.163.71.158 ( talk) 20:51, 6 May 2012 (UTC)
Dmitri Skobeltsyn and Chung-Yao Chao are both dated as "1929" for the first observations. Can someone please look into the exact dates, as in month and day, so we can know who really observed it first? DrZygote214 ( talk) 23:02, 10 September 2014 (UTC)
Hello fellow Wikipedians,
I have just modified 4 external links on Positron. 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:
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regular verification using the archive tool instructions below. Editors
have permission to delete these "External links modified" talk page sections if they want to de-clutter talk pages, but see the
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(last update: 5 June 2024).
Cheers.— InternetArchiveBot ( Report bug) 22:18, 21 January 2018 (UTC)
Who observed what when has been discussed on this talk page regarding the discovery of the positron. But, in reading this article, it remains puzzling as to why Dmitri Skobeltsyn is not given credit for the discovery of the positron. Did he not do anything with his cloud-chamber observations of 1929? Perhaps not publish them? Anyway, right now, the article confusing on this matter. Attic Salt ( talk) 13:57, 5 August 2018 (UTC)
The infobox currently quotes the very precisely known electron mass as positron mass. I don't think this is the right way. It is known that electron and positron mass agree within an uncertainty of 8e-9 (see Review of Particle Properties) So this should be the precision given in the infobox, not the much smaller value for the electron. -- Wassermaus ( talk) 17:53, 20 July 2024 (UTC)