Talk:Nuclear clock

A request has been made for this article to be peer reviewed to receive a broader perspective on how it may be improved. Please make any edits you see fit to improve the quality of this article.

Web search problem[edit]

Does anybody know how to search for "Nuclear clock" without getting thousands of results relating to the "Doomsday Clock"? 174.25.58.172 (talk) 02:44, 15 February 2017 (UTC)[reply]

(A bit late, but) Since there's only one isotope which is remotely practical, searching for "229m" and "thorium" works well for me. 97.102.205.224 (talk) 17:51, 1 May 2024 (UTC)[reply]

Category[edit]

Please add https://en.wikipedia.org/wiki/Category:Atomic_clocks 71.80.203.159 (talk) 05:00, 20 July 2020 (UTC)[reply]

Ionization energy[edit]

@Ehrenkater: You write: "Isn't the outer shell ionisation energy more relevant?". Er, yes, that's what the first ionization energy is. It's the minimum energy required to remove an electron from the atom, which is obviously going to be an outer-shell electron. I didn't feel the need to belabour the point. Can you clarify your question, or perhaps I should say clarify your confusion so I can phrase things to not send a reader down the false trail you appear to have found?

OK, fine, thanks for enlightening me.----Ehrenkater (talk) 15:20, 1 May 2024 (UTC)[reply]

Per this, I took the liberty of removing your request with a detailed edit comment. I hope that's okay. 97.102.205.224 (talk) 15:33, 1 May 2024 (UTC)[reply]

Thanks for the editing help. By the way, I've noticed that you really like bulleted lists, which is fine, but I've also noticed you seem to forget to add a line break after the list so that the following text is not made part of the last item. It's a minor problem and easily fixed, but you might want to avoid it to begin with. 97.102.205.224 (talk) 15:08, 1 May 2024 (UTC)[reply]

Apologies for forgetting this, I usually remember.----Ehrenkater (talk) 15:20, 1 May 2024 (UTC)[reply]

Constrained?[edit]

The first sentence of Nuclear_clock#The_history_of_229mTh is odd. It reads "Since 1976, the 229Th nucleus has been known to possess a low energy excited state,[31] the excitation energy of which was constrained to be 10 eV in 1990.[32]". I don't believe that anyone has the power to affect the excitation energy. Maybe it means "assessed", or "estimated"? Maproom (talk) 07:19, 2 May 2024 (UTC)[reply]

@Maproom: That's standard physics MOS:JARGON for "we haven't found it, but we've ruled out..."; see Special:Search/observational constraint. Which, I've just noticed, is not listed at Constraint (disambiguation) and should be! It's already used a fair bit in in Wikipedia, e.g. in Age of the universe and Neutrino#Detectors near artificial neutrino sources, but you're right about the lay implication. Thank you for pointing out the problem! To ask someone not as steeped in technical literature, what does the qualifier "observational constraint" imply to you? 97.102.205.224 (talk) 14:45, 2 May 2024 (UTC)[reply]

I wasn't aware of the phrase "observational constraint". I would have guessed it meant something like "we cannot observe the item at night"; but from what you say, it's like "our observations imply that it weighs less than 5g". (I studied physics at university from 1969 to 1971.) Maproom (talk) 15:10, 2 May 2024 (UTC)[reply]

@Maproom: I've fixed this article, but thanks for your insights on lay meaning. This is going to be tricky. Physicists and astronomers use "constraint" all the time to describe, basically "we looked, and didn't find, so therefore we've excluded the following possibilities...". See e.g. dark matter, axion or the references in weakly interacting massive particle (which I notice avoids the word in the article text).

I should mention that the "didn't find" part is not technically true; a constraint can be derived from any observation or non-observation. It just generally means a loose bound, and so is often derived from non-observations. 97.102.205.224 (talk) 18:45, 2 May 2024 (UTC)[reply]