Talk:Chicago Pile-1

message: How can CP-1 be the first reactor (first critical in later 1942), when the Leipzig Pile L-IV already had an criticality accident on June 23 1942? --46.5.104.58 (talk) 06:40, 30 September 2013 (UTC)
replies: text: It wasn't a criticality accident. Per List of military nuclear accidents: "During the inspection, air leaked in, igniting the uranium powder inside. The burning uranium boiled the water jacket, generating enough steam pressure to blow the reactor apart. Burning uranium powder scattered throughout the lab causing a larger fire at the facility." Hawkeye7 (talk) 00:52, 3 December 2015 (UTC)
thread_title:  The first reactor? 

message: According to this article that appeared in the new Scientist magazine, there were two primary control systems for the control rods, one electrically controlled with a knob/variable resistor from the balcony and the other titled "zip" (probably so named due to the sound wire makes when running over a pulley at an accelerating rate) under the watchful eye of the SCRAM man/axe man to cut the line/wire. 
While for finer control of the neutron rate than the electrically operated dial or knob system may have provided, George Weil operated the last "rod" or more accurately a plank. Incrementally inching it out with Fermi overlooking his progress. So there were 3 human operated control "rods" in total.
Secondly, the call for lunch at 11:30 was not random as the article in its present state suggests, but occurred right after the automated control system dropped a control rod into the fail-safe postion, doing so because it was set on too fine a hair trigger/too sensitive to neutron rates. So you see, they were slowly ramping up the reactor to a self-sustaining point and then all of a sudden this safety system wipes out all their work! So it was time to take a break and start all over again! As it was, it appears they were 2nd time lucky. Who needs to wait for third anyway?
See the bottom of page 1 and the top of page 2.
http://www.waltpatterson.org/georgeweil.pdf
New Scientist 30 November 1972
Moreover the paper "The first reactor" published on the 40th anniversary in 1982 also has similar info. Along with the galvanometer chart of neutron intensity, or in the authors poetic terms, the reactors "birth certificate".
185.51.75.43 (talk) 12:06, 24 March 2016 (UTC)
replies: text: Added to the article. Hawkeye7 (talk) 01:06, 25 March 2016 (UTC)
thread_title: 2 Type of control systems & the curious lunch call

message: The documentation of the building and operation of the pile described bricks of (processed) Uranium Oxide (which the Oxygen in the Oxide would be similar in moderation capability as the graphite) and some Uranium. 
Phrase "neutron-producing uranium pellets" is scientifically inaccurate, doesn't appear in the documentation. Purified Uranium (with decay products found in ore removed) is essentially non-radioactive: the radiation counts for natural Uranium are masked by natural radioactivity from Cosmic Rays, Potassium-40, et al. U-238, 99.2752% natural abundance, radioactive half life is about the age of the Earth. Of the small number of Uranium atopms that do decay, most decay by alpha emmission and only less than .01% by spontaneous fission (which emits neutrons). A neutron source (Berylium/Polonium probably;Little Boy:"Polonium for the initiators") was introduced to initiate reaction, standard practice for all Uranium reactors. Plutonium on the other hand with a 24,000 yr half life and typically decays by spontaneous fission, is its own neutron source and does not need initiation.
References:
* http://www.uchicago.edu/features/how_the_first_chain_reaction_changed_science/
* http://www.osti.gov/accomplishments/documents/fullText/ACC0044.pdf  includes "Fermi's own words" "initiator"
Shjacks45 (talk) 14:06, 4 November 2013 (UTC)
replies: text: While that is the way I would do it, I cannot find a reference to the use of a polonium-berrylium (or polonium-radium) initiating source. The initiators used in Little Boy and Fat Man bombs were developed at los Alamos in 1944. I cannot find a reference to it in the sources you supply. Hawkeye7 (talk) 01:05, 25 March 2016 (UTC)
thread_title:  Accuracy? 

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thread_title:  External links modified 

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thread_title:  External links modified 

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thread_title:  External links modified 

message: The story that SCRAM referred to a "safety control rod axe man" is apocryphal and has no sources whatsoever. There are numerous sources for this being nothing more than an urban legend, I would like to point to this one in particular, where a historian apparently spoke to several scientists who were present the day of the test: https://public-blog.nrc-gateway.gov/2011/05/17/putting-the-axe-to-the-scram-myth/
I am confused about why the article seems to refer to the axe-man story as fact and refers to it in several places, without any sources.
Sopwerdna (talk) 03:01, 27 May 2017 (UTC)
replies: text: I cannot express how tired I am of claims that articles are unsourced when there are footnotes. Hawkeye7 (talk) 03:42, 27 May 2017 (UTC)
thread_title:  SCRAM axe-man story 

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thread_title:  External links modified 

message: Is there a good reason this article uses DMY dates like "2 December 1942" rather than MDY dates like "December 2, 1942"? The latter is suggested by MOS:DATETIES. —BarrelProof (talk) 05:13, 2 December 2017 (UTC)
replies: text: The former is suggested by WP:MILFORMAT though, which I think applies here. --John (talk) 14:32, 2 December 2017 (UTC)

text: While I might have chosen American, and I think I and others did early on, the editor who did the most work to bring it up to good and featured chose Mil format, which seems not unreasonable, and it has been stable at that. Alanscottwalker (talk) 15:28, 2 December 2017 (UTC)
replies: text: Thanks for the replies. I hadn't noticed the remarks about special treatment for military topics. —BarrelProof (talk) 04:24, 3 December 2017 (UTC)
thread_title:  Date format 

message: On a scientific article, why are we using imperial units first? To most of our target audience, degrees Fahrenheit are as useful as ells. --John (talk) 13:43, 2 December 2017 (UTC)
replies: text: It's from the source. Rhodes didn't identify where he got it from, so there is a lingering suspicion in my mind that it was originally Celsius. I've flipped the display order.  Hawkeye7 (discuss) 20:19, 2 December 2017 (UTC)
thread_title:  MOS:UNIT 

message: The fact that it fired in 1942 is major, and so should be in top of the lead. -DePiep (talk) 00:49, 3 December 2017 (UTC)
replies: text: When it reached criticality is in the very first paragraph of the lead - that's top enough. Alanscottwalker (talk) 00:54, 3 December 2017 (UTC)
replies: text: Why ever would one mention "first" without the era specififcation? -DePiep (talk) 00:56, 3 December 2017 (UTC)
replies: text: Era?  It's a thing.  Perhaps you mean World War II era, but that is also mentioned in the lead paragraph. Alanscottwalker (talk) 00:59, 3 December 2017 (UTC)
replies: text: 1942 is major. Dec 2 is irrelevant (to lead). Really , dec 2 should not be in there. Time of X also relevant? No. -DePiep (talk) 01:03, 3 December 2017 (UTC)
replies: text: 1942 is there in the lead, December 2 to be encyclopedic and give correct information (which is actually a date that every source states) is important.  It is not the first reactor of 1942, it's not the first reactor of any one year, it's the first reactor of all the years, succinctly, it's the first reactor. Alanscottwalker (talk) 01:10, 3 December 2017 (UTC)

text: Because we already said it was first in the same paragaph. Alanscottwalker (talk) 01:15, 3 December 2017 (UTC)
thread_title:  1942 

message: I'm fairly sure the equation for critical radius in the Design section is incorrect. The units don't even work. It's got length on the left and area on the right hand side. I can't seem to find the reference online, or I'd fix it myself. Could someone check this?
Fcrary (talk) 21:35, 6 December 2017 (UTC)
replies: text: I have the book here. The formula is correct; it is the next line that is in error. M is the average distance that a neutron travels before it is absorbed. I have corrected the article.   Hawkeye7 (discuss) 23:52, 6 December 2017 (UTC)
thread_title:  Incorrect equation in Design section 

message: I've made some edits to the lead. The previous version had a lot of information that was not particularly relevant (e.g., weights of materials given in multiple units of measure), and lacked a lot of information that was needed in order to put the project in perspective and explain its significance. For example, it had lacked any mention of the fact that the uranium was not enriched.--76.169.116.244 (talk) 05:02, 25 January 2019 (UTC)
thread_title: edits to lead

message: I recently made an edit to the page changing "University of California" to "University of California, Berkeley", because UC Berkeley is no longer referred to as the "University of California", which only refers to the university system. This edit was reverted by {u|EEng}.
Historically, UC Berkeley was referred to as the University of California, but since its renaming in 1958 and the founding of the University of California (the school system), Berkeley is no longer referred to as the University of California. Doing so is ambiguous and incorrect. This is why I made this edit. 
The passage in question refers specifically to UC Berkeley because, at the time, the University of California was UC Berkeley. Emilio Segrè and Glenn Seaborg were not scientists in the UC system, they were scientists at UC Berkeley.
I know anecdotal evidence isn't suitable for an encyclopedia, but after living in California for 18 years, doing research with some of the UCs, applying to UC Berkeley itself, I can say for certain that UC Berkeley is not called the University of California. All of this can be verified by reading the sources, or knowing anything about the way the university system in California works. 
 {Talk}  20:38, 9 November 2019 (UTC)
replies: text: The problem with those edits is that, at the time of the events in question, the university was simply the "University of California."  Those events predate the formation of the UC system.  So the edits are anachronistic.  Best to have the embedded link to UC Berkley but have the text refer simply to UC. NPguy (talk) 20:56, 9 November 2019 (UTC)
replies: text:  That's a fair point. I still think that it is ambiguous and should be referred to as UC Berkeley within the text of the article.  {Talk}  21:13, 9 November 2019 (UTC)

text: Well I grew up in Berkeley, attended Berkeley, and briefly taught at Berkeley; my mother graduated from Berkeley (twice) and worked for Berkeley; and my uncle was the budget director for the entire UC system. So I can assure you that you don't know what you're talking about, not least in your reference to . There is one president, one board of regents, andthough the phrase University system lends bureaucratically desirable ambiguity on the question of whether each campus is itself a "university" controlling its own affairsone university. EEng 20:57, 9 November 2019 (UTC)
replies: text:  The problem with referring to it as the "University of California" is that it is ambiguous. Most readers will not understand that it is referring to Berkeley specifically. The research was done through UC Berkeley and not through the university system.  {Talk}  21:13, 9 November 2019 (UTC)
replies: text: And most readers will not understand that "University of Chicago" refers to a football stadium. So what? EEng 21:21, 9 November 2019 (UTC)
replies: text:  I'd argue that you should specifically refer to the University of Chicago football stadium rather than just calling it the University of Chicago, since it is also ambiguous. Wikipedia is supposed to be an encyclopedia, and as such, it should be as unambiguous as possible.  {Talk}  21:24, 9 November 2019 (UTC)
replies: text: Well, I don't intend to say all the ways I know Berkeley, but my editorial opinion for this article is 'University of California' is just fine for old Cal. Alanscottwalker (talk) 21:31, 9 November 2019 (UTC)
replies: text: I think that's fine for normal conversation, but in an encyclopedia we should try to be unambiguous.  {Talk}  21:33, 9 November 2019 (UTC)
replies: text: It is unambiguous enough already. -- Alanscottwalker (talk) 21:47, 9 November 2019 (UTC)

text:  According to Wikipedia:College and university article advice, under College and University Articles, point 5 states that "For universities that are part of a larger system, in general the university name is followed by a comma and the name of the city in which the institution is located. For example, University of California, Berkeley and University of California, San Diego." This makes it pretty clear that it should say University of California, Berkeley.  {Talk}  21:33, 9 November 2019 (UTC)
replies: text: No.  Although your link is wrong, that's an article title convention, we are not talking about article title, we are talking about running prose.  In running prose no need to stop the flow by adding this unneeded detail.  Alanscottwalker (talk) 21:40, 9 November 2019 (UTC)
replies: text: Oh, that's a good point. I still think that it should be referred to as UC Berkeley in the text. I understand that many people will understand that it refers to Berkeley, but not everyone is from California and not everyone understands that the University of California is not the name of any university. Personally, I also think it gives off connotations that Berkeley is the UC and all others are inferior, but that might just be because I'm tired of Berkeley kids acting all high-and-mighty (not referring to you, EEng, just my personal experience). The UCs in other articles are referred to specifically using their campus, and it isn't exactly clear whether or not this article is referring to the UC system or the Berkeley campus.  {Talk}  21:47, 9 November 2019 (UTC)
replies: text: Well, actually, Berkeley is unambiguously the elite among the UC campuses, like it or not. And don't worry about hurting my feelings -- my degree's from Harvard so I get my high-and-mighty that way. Anyway, why not always specifically say that work was done not just at UC, not just UC Berkeley, but specifically in the UC Berkeley Physics department? We don't want people thinking it was all of UC Berkeley when it was really just this or that department. EEng 22:13, 9 November 2019 (UTC)

text: The article does not need any of that detail.  It's difficult to see anyone actually going, 'oh my god, it's Berkeley, I'm so confused' --nothing about the actual context requires such minutia of geography, nor organizational history.  Alanscottwalker (talk) 22:23, 9 November 2019 (UTC)
replies: text: For my entire life, UC has referred to the university system, and not UC Berkeley specifically. Had I not known already that the research was done at Berkeley, I would have thought that the UC system itself did the research. We're also not getting into minutia here, that's quite a bit reductive. It's literally just the name of the campus.  {Talk}  23:11, 9 November 2019 (UTC)
replies: text: The sentence is not talking about your life, it's talking about other peoples lives in 1940.  This was the University of California in 1940, the organizational chart that developed since does not change that. It's wholly unreasonable to think that the University of California did not exist in 1940, and it's literally fine if you think the University's organization did the work, the university's organization did do the work. The University of California, however you in particular think about it, traces its history to 1868. -- Alanscottwalker (talk) 13:49, 10 November 2019 (UTC)

text: As others have noted, this is an historical article. The usual practice is to use the names which were used at the time of the events described. German nuclear research in 1930s and 40s was conducted at the Kaiser Wilhelm Institute. No one says it was done at one of the Max Planck Institutes, despite the fact that that's what KWI was renamed after the war. If we insisted on the current names, we'd probably have to say most of the work in question was done at Lawrence Berkeley National Laboratory (the Radiation Laboratory was up the hill where LBNL currently is, not on campus.) And, a contemporary event, I guess military historians would have to talk about the Battle of Volgograd. That would be seriously anachronistic. Fcrary (talk) 22:39, 9 November 2019 (UTC)

text: That's a fair point. Maybe we could change it to "University of California (now known as University of California, Berkeley)" as a decent middle ground, or LBNL as you suggest.  {Talk}  23:11, 9 November 2019 (UTC)
replies: text: I wasn't suggesting we use LBNL. I was pointing out how anachronistic it would be. Ernest Lawrence never worked at a laboratory named after himself. His name didn't get attached to it until after his death. Implying otherwise would just be weird and confusing. I wouldn't complain too much about the parenthetical, but I think it's unnecessary. The link points to the article on UCB and this is an article on the Chicago pile. The word "California" only appears twice, so this level of specificity about UC campuses may be a bit much. Or perhaps call it the "University of California's Radiation Laboratory", since that's what it was called at the time and doesn't imply the whole UC system. Fcrary (talk) 00:33, 10 November 2019 (UTC)
replies: text: University of California Radiation Laboratory is an existing redirect and is indeed the right thing to use. (And I see the COMMA BERKELEY forces have been at work there as well .) EEng 01:16, 10 November 2019 (UTC)
thread_title:  University of California vs. University of California, Berkeley 

message: Hallo!: If Neutrons are 'discrete' particles, meaning it exist in units, not in fractions of units: How can be said a Uranium atom emits in fission an average of 2.4 neutrons? You can indicate this type of figures as an average for a mass of several atoms, but from a single atom, simply, neutrons can not be fractioned, or exploded, or smashed or cut or broken. Could it? Blessings +
:It's an average dude. Hawkeye7 (discuss) 11:22, 1 October 2021 (UTC)
replies: text: To be more specific, a uranium atom can fission in several different ways and they don't produce the same number of neutrons. Any one of those reactions only produces an integral number of neutrons. But when you average over all the reactions, weighted by their probability, you get a non-integral number of neutrons. Fcrary (talk) 18:01, 1 October 2021 (UTC)
thread_title:  Neutron Count Doubt