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After comparing articles from Encarta Encyclopedia, and this one, Wikipedia, I noticed that the date of James Chadwick's death differed from one to the other. In Encarta, it said tha tChadwick died December 10th, whereas here it said July 24th. — Preceding unsigned comment added by 216.16.55.2 ( talk) 23:32, 22 November 2004 (UTC)
In the header (1891) and in the box on the right of the bio (1872). -- 125.60.241.188 ( talk) 21:58, 30 September 2008 (UTC)
The Cambridge Section is word for word from its link. Is that okay? —Preceding unsigned comment added by 206.82.20.126 ( talk) 17:10, 15 September 2009 (UTC)
The text formerly stated that Dr. Chadwick discovered nuclear fission and that he received the Nobel Prize for this. He did not, and I have corrected this.
Dr. Chadwick discovered the
neutron in 1932, and he won the
Nobel Prize in Physics for this achievement in
1935. In any case, this was an eartshaking discovery, and it was one of the top discoveries in Physics between 1930 and 1941. There is no need to exaggerate about Dr. Chadwick.
Nuclear fission was not observed until about 1940 by
Otto Hahn and his associates in Germany. Interestingly, based on the limited amount that he published. Hahn won the
Nobel Prize in Chemistry in 1944, despite the fact that several Nobel Prize awards were cancelled during World War II. Meanwhile, during the Manhattan Project in America, a HUGE amound of progress was made in deep secrecy on nuclear fission, including the world's first
nuclear reactor, which "went critical" in a
chain reaction in December 1942. By the end of 1944, a HUGE amount of progress has been made towards producing atomic bombs in the United States, including large reactors in
Washington State that were producing
plutonium-239 by the kilogram.
The nuclear reactor project in Chicago was carried out by a team lead by
Enrico Fermi who has won the Nobel Prize in Physics in 1938, but the plutonium production, separation, and purification project was a completely American one lead by
Glenn T. Seaborg, who later won the Nobel Prize in Chemistry in 1951 and General
Leslie Groves. The separation of the minority of
U-235 atoms by electromagnetic means in
Tennessee relied on word that had been done by
Ernest O. Lawrence, an American who had won the Nobel Prize in Physics in 1939.
A big step in nuclear physics from the British Isles came beginning in about 1946 (post-war), when John Cockroft (England) and Ernest Walton (Ireland), working together, made many discoveries in the transmutation of elements. They won the Nobel Prize in Physics in 1951. (The doubtless duplicated a lot of work that had been carried out in great secrecy by Seaborg, Lawrence, and others during the Manhattan project. For example, Seaborg was a member of the teams that discovered neptunium, plutonium, curium, americium, and several other transuranium elements. On the other hand, Cockroft and Walton might have made discoveries with some of the lighter elements.)
98.67.171.176 (
talk)
03:17, 15 August 2012 (UTC)
Headbomb { talk / contribs / physics / books} 14:43, 14 August 2014 (UTC)
I've been poking at the article on Norman Feather. The Chadwick article makes no mention of the education/advising of students such as Feather at Cavendish. This activity was important to Cavendish scientific goals, paid great dividends later on, and was an important aspect of Chadwick's activities at Cavendish. Chadwick and Rutherford looked after the doctoral students as a team - selecting research topics for them that were the focus of Cavendish interests at the time. Chadwick was famous for his student training laboratory in the attic of Cavendish. The article in Proc. Roy. Soc. on the neutron was actually one of a trio of papers, back-to-back (arrangedby Rutherford to be published in record time apparently), the second of which is by Feather on neutron induced disintegrations - the point being that Chadwick was not operating in a vacuum with his discovery of the neutron. Also, I suspect the experiment that prompted by the discovery of the neutron was by the Joliet/Curies, who misinterpreted the neutron as a gamma ray - if so then the Chadwick article has an error there. See Ettore_Majorana. The article might also benefit from a "See Also" section, that might include the link to e.g., well known Chadwick students like Feather. Just some thoughts... Bdushaw ( talk) 07:15, 22 August 2014 (UTC)
See also the Feather Oral History regarding the neutron discovery, etc.: http://www.aip.org/history/ohilist/4599_1.html Bdushaw ( talk) 07:39, 22 August 2014 (UTC)
I should read things more carefully...I stand corrected on my comments above regarding students. (!) Bdushaw ( talk) 07:47, 22 August 2014 (UTC)
We were using the image from the Nobel site bio as our lead image. This seems to have been one of several portraits shot by Howard Coster as there's another one at the NPG. There was some discussion of this in the FAC and this came to head when it was deleted at commons yesterday. I'm making a note here so we can return to the matter when the copyright on those images expires.
I substituted a crop of the picture of Chadwick with Groves. This was in TIF format like the original, which we use in the section about the Manhattan Project. Today, these have been changed to equivalents in JPEG format. This is a compressed format which is supposed to save space and so load time. So it's puzzling that, for the lead image, the TIFF file is smaller than the equivalent JPEG — 686K vs 735K. I don't suppose it's a big deal but I'd like to understand this better. Andrew ( talk) 11:55, 21 October 2014 (UTC)
Hawkeye7 ( talk) 12:58, 21 October 2014 (UTC)
I've been contemplating the brief history of the neutron as a composite of the proton and electron from the time of its discovery until it was recognized as a thing on its own. I think this article has it about right with the emphasis on the mass of the neutron compared to proton. I write because the article states that both Bohr and Heisenberg saw the neutron as elementary, whereas I don't think Heisenberg did. There is a careful review at this reference, Brown and Rechenberg (1996) cited in the neutron article. This article cites Heisenberg's famous trio of papers - but those were rather tortured insofar as the electron was concerned. He still explicitly saw the neutron as a composite, I believe; or at least didn't quite know what to think. (Bohr I know nothing of.) I would suggest a different approach, which I am considering for the neutron article - the 7th Solvay conference had this issue front and center. So one may discuss the issue generally, without claims as to who believed what (which is likely to be incorrect - these guys were nothing if not cautious and flexible). The second factor, which I think must be mentioned, was the Fermi paper where he described how beta decay can occur by the creation of an electron, thus finally explaining where those pesky electrons came from. The Chadwick and Goldhaber paper on the mass of the neutron seems to embrace this (correct) theory wholesale. Between the mass results and the Fermi paper, the neutron as a composite was finished. I know of no big paper in which this was explicitly concluded, though (other than Chadwick and Goldhaber), that the community embraced as the definitive statement.
On the Fermi paper, this article presently has "The continuous spectrum of beta radiation, which Chadwick had reported in 1914, was explained by Wolfgang Pauli in 1930 by recourse to another hypothetical neutral particle, which Fermi named the neutrino in 1934." That seems not quite right to me - Pauli suggested, with great tentativeness, the neutrino idea. Fermi put the neutrino on rigorous theoretical foundation. I think Pauli would object to the suggestion that he "explained", as too strong a word, but I can't really speak for Pauli, of course. Bdushaw ( talk) 03:09, 9 February 2015 (UTC)
The biography of Lise Meitner has a discussion of the neutron as composite at the 7th Solvay conference. LINK to relevant paragraphs on googlebooks (what a resource!) Bdushaw ( talk) 12:09, 9 February 2015 (UTC)
I've revised the Neutron#Proton.E2.80.93neutron_model_of_the_nucleus page with a narrative that I think is correct, maybe. See what you think. One want to be brief, but also accurate...its a challenge. Bdushaw ( talk) 03:55, 10 February 2015 (UTC)
I've reworked the paragraph on the estimation of mass; hope that's o.k. I believe it now reflects the sequence of events - the Chadwick/Goldhaber estimate was the first accurate value for the mass of the neutron. I was not sure of where the values for m_n came from in the original paragraph - I've included the values that I see in the original papers by Chadwick and Chadwick/Goldhaber. Bdushaw ( talk) 05:52, 13 February 2015 (UTC)
Hans Falkenhagen discovered neutron in the same time as Chadwick.-- 79.119.208.152 ( talk) 15:37, 25 February 2015 (UTC)
This is the
talk page for discussing improvements to the
James Chadwick article. This is not a forum for general discussion of the article's subject. |
Article policies
|
Find sources: Google ( books · news · scholar · free images · WP refs) · FENS · JSTOR · TWL |
![]() | This article is written in British English, which has its own spelling conventions (colour, travelled, centre, defence, artefact, analyse) and some terms that are used in it may be different or absent from other varieties of English. According to the relevant style guide, this should not be changed without broad consensus. |
![]() | James Chadwick is a featured article; it (or a previous version of it) has been identified as one of the best articles produced by the Wikipedia community. Even so, if you can update or improve it, please do so. | ||||||||||||||||||||||||
![]() | This article appeared on Wikipedia's Main Page as Today's featured article on October 20, 2014. | ||||||||||||||||||||||||
|
![]() | This ![]() It is of interest to multiple WikiProjects. | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
|
After comparing articles from Encarta Encyclopedia, and this one, Wikipedia, I noticed that the date of James Chadwick's death differed from one to the other. In Encarta, it said tha tChadwick died December 10th, whereas here it said July 24th. — Preceding unsigned comment added by 216.16.55.2 ( talk) 23:32, 22 November 2004 (UTC)
In the header (1891) and in the box on the right of the bio (1872). -- 125.60.241.188 ( talk) 21:58, 30 September 2008 (UTC)
The Cambridge Section is word for word from its link. Is that okay? —Preceding unsigned comment added by 206.82.20.126 ( talk) 17:10, 15 September 2009 (UTC)
The text formerly stated that Dr. Chadwick discovered nuclear fission and that he received the Nobel Prize for this. He did not, and I have corrected this.
Dr. Chadwick discovered the
neutron in 1932, and he won the
Nobel Prize in Physics for this achievement in
1935. In any case, this was an eartshaking discovery, and it was one of the top discoveries in Physics between 1930 and 1941. There is no need to exaggerate about Dr. Chadwick.
Nuclear fission was not observed until about 1940 by
Otto Hahn and his associates in Germany. Interestingly, based on the limited amount that he published. Hahn won the
Nobel Prize in Chemistry in 1944, despite the fact that several Nobel Prize awards were cancelled during World War II. Meanwhile, during the Manhattan Project in America, a HUGE amound of progress was made in deep secrecy on nuclear fission, including the world's first
nuclear reactor, which "went critical" in a
chain reaction in December 1942. By the end of 1944, a HUGE amount of progress has been made towards producing atomic bombs in the United States, including large reactors in
Washington State that were producing
plutonium-239 by the kilogram.
The nuclear reactor project in Chicago was carried out by a team lead by
Enrico Fermi who has won the Nobel Prize in Physics in 1938, but the plutonium production, separation, and purification project was a completely American one lead by
Glenn T. Seaborg, who later won the Nobel Prize in Chemistry in 1951 and General
Leslie Groves. The separation of the minority of
U-235 atoms by electromagnetic means in
Tennessee relied on word that had been done by
Ernest O. Lawrence, an American who had won the Nobel Prize in Physics in 1939.
A big step in nuclear physics from the British Isles came beginning in about 1946 (post-war), when John Cockroft (England) and Ernest Walton (Ireland), working together, made many discoveries in the transmutation of elements. They won the Nobel Prize in Physics in 1951. (The doubtless duplicated a lot of work that had been carried out in great secrecy by Seaborg, Lawrence, and others during the Manhattan project. For example, Seaborg was a member of the teams that discovered neptunium, plutonium, curium, americium, and several other transuranium elements. On the other hand, Cockroft and Walton might have made discoveries with some of the lighter elements.)
98.67.171.176 (
talk)
03:17, 15 August 2012 (UTC)
Headbomb { talk / contribs / physics / books} 14:43, 14 August 2014 (UTC)
I've been poking at the article on Norman Feather. The Chadwick article makes no mention of the education/advising of students such as Feather at Cavendish. This activity was important to Cavendish scientific goals, paid great dividends later on, and was an important aspect of Chadwick's activities at Cavendish. Chadwick and Rutherford looked after the doctoral students as a team - selecting research topics for them that were the focus of Cavendish interests at the time. Chadwick was famous for his student training laboratory in the attic of Cavendish. The article in Proc. Roy. Soc. on the neutron was actually one of a trio of papers, back-to-back (arrangedby Rutherford to be published in record time apparently), the second of which is by Feather on neutron induced disintegrations - the point being that Chadwick was not operating in a vacuum with his discovery of the neutron. Also, I suspect the experiment that prompted by the discovery of the neutron was by the Joliet/Curies, who misinterpreted the neutron as a gamma ray - if so then the Chadwick article has an error there. See Ettore_Majorana. The article might also benefit from a "See Also" section, that might include the link to e.g., well known Chadwick students like Feather. Just some thoughts... Bdushaw ( talk) 07:15, 22 August 2014 (UTC)
See also the Feather Oral History regarding the neutron discovery, etc.: http://www.aip.org/history/ohilist/4599_1.html Bdushaw ( talk) 07:39, 22 August 2014 (UTC)
I should read things more carefully...I stand corrected on my comments above regarding students. (!) Bdushaw ( talk) 07:47, 22 August 2014 (UTC)
We were using the image from the Nobel site bio as our lead image. This seems to have been one of several portraits shot by Howard Coster as there's another one at the NPG. There was some discussion of this in the FAC and this came to head when it was deleted at commons yesterday. I'm making a note here so we can return to the matter when the copyright on those images expires.
I substituted a crop of the picture of Chadwick with Groves. This was in TIF format like the original, which we use in the section about the Manhattan Project. Today, these have been changed to equivalents in JPEG format. This is a compressed format which is supposed to save space and so load time. So it's puzzling that, for the lead image, the TIFF file is smaller than the equivalent JPEG — 686K vs 735K. I don't suppose it's a big deal but I'd like to understand this better. Andrew ( talk) 11:55, 21 October 2014 (UTC)
Hawkeye7 ( talk) 12:58, 21 October 2014 (UTC)
I've been contemplating the brief history of the neutron as a composite of the proton and electron from the time of its discovery until it was recognized as a thing on its own. I think this article has it about right with the emphasis on the mass of the neutron compared to proton. I write because the article states that both Bohr and Heisenberg saw the neutron as elementary, whereas I don't think Heisenberg did. There is a careful review at this reference, Brown and Rechenberg (1996) cited in the neutron article. This article cites Heisenberg's famous trio of papers - but those were rather tortured insofar as the electron was concerned. He still explicitly saw the neutron as a composite, I believe; or at least didn't quite know what to think. (Bohr I know nothing of.) I would suggest a different approach, which I am considering for the neutron article - the 7th Solvay conference had this issue front and center. So one may discuss the issue generally, without claims as to who believed what (which is likely to be incorrect - these guys were nothing if not cautious and flexible). The second factor, which I think must be mentioned, was the Fermi paper where he described how beta decay can occur by the creation of an electron, thus finally explaining where those pesky electrons came from. The Chadwick and Goldhaber paper on the mass of the neutron seems to embrace this (correct) theory wholesale. Between the mass results and the Fermi paper, the neutron as a composite was finished. I know of no big paper in which this was explicitly concluded, though (other than Chadwick and Goldhaber), that the community embraced as the definitive statement.
On the Fermi paper, this article presently has "The continuous spectrum of beta radiation, which Chadwick had reported in 1914, was explained by Wolfgang Pauli in 1930 by recourse to another hypothetical neutral particle, which Fermi named the neutrino in 1934." That seems not quite right to me - Pauli suggested, with great tentativeness, the neutrino idea. Fermi put the neutrino on rigorous theoretical foundation. I think Pauli would object to the suggestion that he "explained", as too strong a word, but I can't really speak for Pauli, of course. Bdushaw ( talk) 03:09, 9 February 2015 (UTC)
The biography of Lise Meitner has a discussion of the neutron as composite at the 7th Solvay conference. LINK to relevant paragraphs on googlebooks (what a resource!) Bdushaw ( talk) 12:09, 9 February 2015 (UTC)
I've revised the Neutron#Proton.E2.80.93neutron_model_of_the_nucleus page with a narrative that I think is correct, maybe. See what you think. One want to be brief, but also accurate...its a challenge. Bdushaw ( talk) 03:55, 10 February 2015 (UTC)
I've reworked the paragraph on the estimation of mass; hope that's o.k. I believe it now reflects the sequence of events - the Chadwick/Goldhaber estimate was the first accurate value for the mass of the neutron. I was not sure of where the values for m_n came from in the original paragraph - I've included the values that I see in the original papers by Chadwick and Chadwick/Goldhaber. Bdushaw ( talk) 05:52, 13 February 2015 (UTC)
Hans Falkenhagen discovered neutron in the same time as Chadwick.-- 79.119.208.152 ( talk) 15:37, 25 February 2015 (UTC)