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The barn is not listed on the official table of accepted non-SI units that is linked in the article...perhaps it was removed? I'll remove that statement in a while, unless someone objects. -- Bmk 14:52, 10 July 2006 (UTC)
It is still commonly used in high-energy physics, both particle and nuclear. —Preceding unsigned comment added by 137.138.77.201 ( talk) 13:00, 7 May 2009 (UTC)
I would like to offer, as a nuclear physicist, the barn was in my 3rd year textbook. furthermore it should not be denied SI status for having a humorous name.-- Fx303 ( talk) 04:50, 16 July 2009 (UTC)
The "barn" is a legitimate unit used all the time by nuclear physicists and particle physicists. It is a common everyday unit in the field and one cannot work without it. On the other hand, in 23 years in the field, I've never ever heard of "shed" or "outhouse", which seem like obvious joke terms to me. —Preceding unsigned comment added by 142.90.119.70 ( talk) 19:29, 9 September 2009 (UTC)
I agree with above. No-one uses "shed" or "outhouse" and including these terms in the main definition section makes Wikipedia look ridiculous. I suggest deletion of this sentence. (Searching arxiv.org for "outhouse" yields no results. Searching for "shed" isn't so easy because it occurs in phrases like "shed like on".) 92.20.226.103 ( talk) 02:06, 7 July 2012 (UTC)
I had it explained to me a few years back as this: researchers had expected that neutrons would have to have a direct strike on a nucleus to trigger the fission, but then found that it would still trigger it when passing close by. This meant that the cross-sectional area for triggering the reaction was much larger than expected - i.e. like hitting a barn door. I don't have any reference to back this up though, so I don't want to blindly change the explaination in the article. Andrewjrallan 14:50, 19 July 2006 (UTC)
I think it was in Fermi's biography that I read his code name for the Manhattan Project at Los Alamos was "Henry Farmer". And that the "barn" came from the old American baseball saying, "He couldn't hit the broad side of a barn." My Flatley ( talk) 16:28, 9 September 2009 (UTC)
Gold nuclear radius ~ 3 x 10-14 metres so about 10 barns??? Uranium nucleus is one barn? was looking for link or conversion factor for barns (area) to nuclear(atomic) radius. Gadolinium neutron absorption cross section (49000barn) versus (180 picometer) atomic radius. —Preceding unsigned comment added by Shjacks45 ( talk • contribs) 10:44, 1 July 2008 (UTC)
See shed - it says 10-48 m2, but if it is 10-24 b, then it should be 10-48 *cm*2, or 10-52 m2. See also Wikipedia entry for 'shed'. Main article corrected accordingly. —Preceding unsigned comment added by 24.61.45.41 ( talk) 03:06, 3 July 2008 (UTC)
Only hearsay. All I ever worked with was barns. I took a class in radiation effects on ferritic materials back in about 1985. Sheds came up in the class as being the same as a millibarn. Shortly afterwards, the question came up that if a shed was a millibarn, what was a microbarn. I was the only farm kid in the class, and the answer was obviously an outhouse. Not a chance at getting official verification.
If a shed was 10E-48 cm^2, it would be useful for neutrino cross sections. It would not be very useful for anything else. And an outhouse would still not be useful (as an outhouse has to be smaller than a shed). Fortran ( talk) 02:17, 4 January 2012 (UTC)
I changed the redirect from "Barns" from "Barn (unit)" to "Barn (disambiguation)", since I think those searching for "barns" are more likely to be interested in the buildings than the units of measurement. Giles Martin ( talk) 15:32, 1 April 2009 (UTC)
I found a press release from Fermilab to indicate how long it took to achieve a femtobarn and replaced the "citation needed". However the reference seems to indicate that run II started March 2001 and one femtobarn had been achieved by June 2005. This refutes the claim that it took over a decade. Perhaps the claim is including the time of run I (how long?). —Preceding unsigned comment added by 76.21.117.175 ( talk) 04:08, 9 April 2010 (UTC)
I couldn't find a reference for "silo". Anyone? — Preceding unsigned comment added by 129.217.129.134 ( talk) 19:08, 29 November 2011 (UTC)
> The "inverse femtobarn" (fb−1) is a measurement of particle collision events per femtobarn of target cross-section, and is the conventional unit for time-integrated luminosity.
It is true that the number of events in some channel is equal to N=I σ, where I is integrated luminocity and sigma the crosssection. But, that definition above is strictly speaking not correct. It confuses the cause and effect. The correct definition is the number of particles delivered divided by the area of the beam. It is called "integrated luminocity" and it does not depend on the target cross section. For example, in a fixed target experiment, it is the a measure of the beam , while the crosssection is a property of the target only. 112.80.242.190 ( talk) 02:16, 10 July 2013 (UTC)
Barn was originated by Fermi, as the uranium nucleus was 'as big as a BARN DOOR'. see
I suggest changing the wording in the article to reflect this, citing the above or a better source. GilesW ( talk) 14:26, 5 May 2014 (UTC)
1 km2 = 1 000 000 m2, not 1000, since it's defined as 1000 m × 1000 m. How come 1 kilobarn is 1000 barn?
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Does it make sense to add List of humorous units of measurement to the "See also" sections for this and shakes? -- ScratchMonkey ( talk) 11:53, 9 May 2021 (UTC)
![]() | This ![]() It is of interest to the following WikiProjects: | |||||||||||||
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The barn is not listed on the official table of accepted non-SI units that is linked in the article...perhaps it was removed? I'll remove that statement in a while, unless someone objects. -- Bmk 14:52, 10 July 2006 (UTC)
It is still commonly used in high-energy physics, both particle and nuclear. —Preceding unsigned comment added by 137.138.77.201 ( talk) 13:00, 7 May 2009 (UTC)
I would like to offer, as a nuclear physicist, the barn was in my 3rd year textbook. furthermore it should not be denied SI status for having a humorous name.-- Fx303 ( talk) 04:50, 16 July 2009 (UTC)
The "barn" is a legitimate unit used all the time by nuclear physicists and particle physicists. It is a common everyday unit in the field and one cannot work without it. On the other hand, in 23 years in the field, I've never ever heard of "shed" or "outhouse", which seem like obvious joke terms to me. —Preceding unsigned comment added by 142.90.119.70 ( talk) 19:29, 9 September 2009 (UTC)
I agree with above. No-one uses "shed" or "outhouse" and including these terms in the main definition section makes Wikipedia look ridiculous. I suggest deletion of this sentence. (Searching arxiv.org for "outhouse" yields no results. Searching for "shed" isn't so easy because it occurs in phrases like "shed like on".) 92.20.226.103 ( talk) 02:06, 7 July 2012 (UTC)
I had it explained to me a few years back as this: researchers had expected that neutrons would have to have a direct strike on a nucleus to trigger the fission, but then found that it would still trigger it when passing close by. This meant that the cross-sectional area for triggering the reaction was much larger than expected - i.e. like hitting a barn door. I don't have any reference to back this up though, so I don't want to blindly change the explaination in the article. Andrewjrallan 14:50, 19 July 2006 (UTC)
I think it was in Fermi's biography that I read his code name for the Manhattan Project at Los Alamos was "Henry Farmer". And that the "barn" came from the old American baseball saying, "He couldn't hit the broad side of a barn." My Flatley ( talk) 16:28, 9 September 2009 (UTC)
Gold nuclear radius ~ 3 x 10-14 metres so about 10 barns??? Uranium nucleus is one barn? was looking for link or conversion factor for barns (area) to nuclear(atomic) radius. Gadolinium neutron absorption cross section (49000barn) versus (180 picometer) atomic radius. —Preceding unsigned comment added by Shjacks45 ( talk • contribs) 10:44, 1 July 2008 (UTC)
See shed - it says 10-48 m2, but if it is 10-24 b, then it should be 10-48 *cm*2, or 10-52 m2. See also Wikipedia entry for 'shed'. Main article corrected accordingly. —Preceding unsigned comment added by 24.61.45.41 ( talk) 03:06, 3 July 2008 (UTC)
Only hearsay. All I ever worked with was barns. I took a class in radiation effects on ferritic materials back in about 1985. Sheds came up in the class as being the same as a millibarn. Shortly afterwards, the question came up that if a shed was a millibarn, what was a microbarn. I was the only farm kid in the class, and the answer was obviously an outhouse. Not a chance at getting official verification.
If a shed was 10E-48 cm^2, it would be useful for neutrino cross sections. It would not be very useful for anything else. And an outhouse would still not be useful (as an outhouse has to be smaller than a shed). Fortran ( talk) 02:17, 4 January 2012 (UTC)
I changed the redirect from "Barns" from "Barn (unit)" to "Barn (disambiguation)", since I think those searching for "barns" are more likely to be interested in the buildings than the units of measurement. Giles Martin ( talk) 15:32, 1 April 2009 (UTC)
I found a press release from Fermilab to indicate how long it took to achieve a femtobarn and replaced the "citation needed". However the reference seems to indicate that run II started March 2001 and one femtobarn had been achieved by June 2005. This refutes the claim that it took over a decade. Perhaps the claim is including the time of run I (how long?). —Preceding unsigned comment added by 76.21.117.175 ( talk) 04:08, 9 April 2010 (UTC)
I couldn't find a reference for "silo". Anyone? — Preceding unsigned comment added by 129.217.129.134 ( talk) 19:08, 29 November 2011 (UTC)
> The "inverse femtobarn" (fb−1) is a measurement of particle collision events per femtobarn of target cross-section, and is the conventional unit for time-integrated luminosity.
It is true that the number of events in some channel is equal to N=I σ, where I is integrated luminocity and sigma the crosssection. But, that definition above is strictly speaking not correct. It confuses the cause and effect. The correct definition is the number of particles delivered divided by the area of the beam. It is called "integrated luminocity" and it does not depend on the target cross section. For example, in a fixed target experiment, it is the a measure of the beam , while the crosssection is a property of the target only. 112.80.242.190 ( talk) 02:16, 10 July 2013 (UTC)
Barn was originated by Fermi, as the uranium nucleus was 'as big as a BARN DOOR'. see
I suggest changing the wording in the article to reflect this, citing the above or a better source. GilesW ( talk) 14:26, 5 May 2014 (UTC)
1 km2 = 1 000 000 m2, not 1000, since it's defined as 1000 m × 1000 m. How come 1 kilobarn is 1000 barn?
Hello fellow Wikipedians,
I have just modified one external link on Barn (unit). 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
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(last update: 5 June 2024).
Cheers.— InternetArchiveBot ( Report bug) 02:31, 15 July 2017 (UTC)
Does it make sense to add List of humorous units of measurement to the "See also" sections for this and shakes? -- ScratchMonkey ( talk) 11:53, 9 May 2021 (UTC)