Talk:Half-life

message: The table at the top of the article simply illustrates the concept in numerical sequence. The introduction of 1/e (in red?) seems to serve no purpose and breaks the "halving sequence" the table illustrates - also the formatting creates errors. The use of math formatting for the simple fractions involved seems rather pointless. Restored original. Vsmith (talk) 13:30, 3 October 2013 (UTC)
thread_title:  Simple table at the top 

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thread_title:  External links modified 

message: Maybe it should explain how to find the half-life of a nth order reaction? NikolaiHo☎️ 21:47, 10 November 2017 (UTC)
thread_title:  More detail on rxn order 

message: I have boldly decided to delete the section on non-exponential decay. Some of it discusses multiple processes with different half lives, but that is covered better in the section Decay by two or more processes. Some of it is a vague  made-up example about puddles. And none of it is provided with sources. It is hard to see any use for such a concept, except as evidence of a deviation from exponential decay that needs to be explained. RockMagnetist(talk) 15:37, 27 April 2018 (UTC)
replies: text: I agree that it was mostly bad, but I'm thinking there's a core worth saving. So I just brought it back in a much much abbreviated version. Do you still dislike it? --Steve (talk) 00:54, 28 April 2018 (UTC)
replies: text: Well, I agree with the sentiment and maybe it will protect the article against a little nonsense. It would help if you could find a citation, although I think most people don't think it needs saying. I think I'll remove the link to Rate equation because I have been working on purging the idea from there too. RockMagnetist(talk) 02:03, 28 April 2018 (UTC)
replies: text: Apparently it's pretty common to talk about "first half life", "second half life", etc., in the context of non-exponential decay, even though I hadn't personally heard of it until now. So I put that in too. Google books gave quite a few references supporting this usage, and I just cited the first one on the list. --Steve (talk) 15:51, 28 April 2018 (UTC)
replies: text: Yes, I found some sources that use the dependence of half-life on source concentration to determine the rate equation. Sounds pretty clunky to me, but I guess we have to follow the sources ... RockMagnetist(talk) 18:23, 28 April 2018 (UTC)
thread_title:  Non-exponential decay 

message: I think this article needs expansion. Specifically, it tells us what half-lives are, how they are defined, and what concepts they are applied to, but the main problem I have is that after scanning the article, I find there is no content on the history of the term, its past definitions (if any), its etymology, or even when its usage became widespread, except for two very brief sentences, which are in the lead. I would expect an average reader to want at least some of what I am thinking, and certainly I would expect people specialized in nuclear physics or nuclear chemistry to want most—if not all—of that. What do you think? Gamingforfun365 02:48, 9 July 2019 (UTC)
thread_title:  Expansion 

message: Very sorry. Using a IP and no time do it myself now. But you know, when I search with google this article, even with the line-in-between, it gives only a screendefull of WP or al. Half-Life - the computer game. We gotta fix this :D Cheers.  — Preceding unsigned comment added by 85.76.35.47 (talk) 12:35, 18 September 2019 (UTC)
thread_title:  some page needed 

message: I would expect the number of dice in each column to decrease with every time step. I imagine this experiment was done by re-rolling the number of dice in the preceding column, and only keeping dice that had a number below a threshold (e.g., 3, 4). Therefore the number of dice should never increase. We should remove this figure. Or explain it much better. What was the algorithm for generating the figure? If one follows the link to the page describing the experiment, they describe the algorithm correctly, stating that they remove the "1" with each subsequent roll. But in each of their data columns, the numbers are not monotonically decreasing. So I think they goofed on the experiment and the figure. I propose we delete this figure and find a better one that explains the concept. Jaredroach (talk) 16:57, 3 July 2020 (UTC)
replies: text:  Sorry about the confusion.  The students brought up the dice that hit "1" at each role.  This is not half-life, but radiactivity, which also fall expenentially.  I have no opinion on whether or not the figure should be removed.--Guy vandegrift (talk) 04:18, 4 July 2020 (UTC)
thread_title:  Remove "Dice" Image? 

message: It seems that, at least for the muon, the mean (or 1/e) life is given. In most cases that makes sense, except for some reason, maybe it is Rutherford's fault, radioactivity is commonly described using half life. It seems that we need to be either consistent, or use both (like giving units in two or more different systems). Gah4 (talk) 02:11, 6 September 2021 (UTC)
thread_title:  mean lifetime 

message: There is a note that the article should cover the history of half-life better. It seems to me that exponential decay was not new with radioactivity, so why the use of half-life for it, instead of the more traditional exponential decay time, otherwise known as 1/e life? Is it Rutherford?  Or the Curies? In many cases, the constant is more obvious, such as RC for a discharging capacitor. The mechanism of radioactive decay isn't visible, so 1/e is less obvious, but otherwise would have been consistent. And it is sometimes used, at least for other than nuclear decay. Gah4 (talk) 11:47, 25 October 2021 (UTC)
thread_title:  history 

message: Half life as a measure of the stability of a nucleus  — Preceding unsigned comment added by 41.191.107.192 (talk) 18:00, 8 June 2022 (UTC)
thread_title:  Chemistry 

message: I was just reading the first sentence of article. By all means if someone is an expert on linguistics and English, correct me if I am wrong. I simply feel that the word "quantity" should maybe be followed by a word, even if in brackets (with an "e.g."), like "substance" or "material". 92.238.237.65 (talk) 17:24, 26 October 2022 (UTC)
thread_title:  First sentence, shouldn't the word "quantity" be followed by "of"? 

message: At the bottom of the # of half-lives elapsed chart there is the formula 1/2n for the "fraction left" column and 100/2n for the "percentage left" column. These formulas work for number of half lives: 1 and 2, but not: 0, 3, 4, 5, and so on. For example, 1/2(3) = 1/6, but the chart says 1/8. Am I missing something, or are these 2 formulas incorrect? 104.245.77.198 (talk) 05:18, 13 December 2022 (UTC)
replies: text: I believe the formula for the fl"fraction remaining column should be: N(t)=N0 x (1/2)^n, where N(t) is the total amount left, N0 is the beginning amount and n is the number of half-lives. The formula for percentage left would be the answer to the previous formula x 100. 104.245.77.198 (talk) 05:31, 13 December 2022 (UTC)
thread_title:  # of half-lives elapsed 

message: I think it should only come after the first sentence. How could this be fixed without changing how it appears on desktop? 94.133.46.118 (talk) 19:16, 11 April 2023 (UTC)
replies: text: @Gah4 94.133.46.118 (talk) 19:17, 11 April 2023 (UTC)
replies: text: @Steve @Gah4 94.133.46.118 (talk) 19:18, 11 April 2023 (UTC)
thread_title:  On mobile table appears on top before first sentence 

message: Should we propose a hatnote, to make it less-redundant, according to this guideline.
which renders
Similar to that, the article Ghost ship was modified to make it shortened, as an example of Wikipedia:Hatnote#Length and number. --168.194.148.255 (talk) 06:00, 19 July 2023 (UTC)
thread_title:  Hatnote