Template talk:Periodic table legend/Age of discovery

Periodisation of discoveries
Regarding the periodisation, the half-century marks roughly follow a table published on IUPAC's website, except that we make a further break at 1700. This nicely sets apart "alchemy" from "chemistry" (of course the one transitioned into the other gradually, but because there were no discoveries between phosphorus in 1669 and cobalt in 1735, it's not a bad idea). Thereafter we break the history into half-century tranches, except for 1700–1799 (because except for cobalt, all the discoveries in this period were after 1750; creating a colour for one element is a bit silly).

The breaks at 1850 and 1900 roughly correspond to natural paradigm shifts, the former better than the latter. The 1850 break reflects when all the common elements had been discovered and spectroscopy was needed to get much further. As for 1900, it is a little bit too late for the discovery of radioactivity (which went into discovering atomic number and artificial transmutation), but this is inevitable because the noble gases were found so late: xenon's discovery predated polonium's by literally a single day(!), so even though they could be cut apart from each other, it would be too forced and artificial. Of course there was not really a paradigm shift afterwards, and we are still transmutating elements ourselves to continue (although you can correctly say that just after World War II, no one looked down on artificial elements anymore, having heard of the power of plutonium, whereas before then some did consider them as not on a par with natural elements). Thereafter, we just go by 50-year breaks to continue the illustration, not reflect changes in thinking about what an element is and how to classify them. Double sharp (talk) 11:01, 13 January 2023 (UTC)


 * Without analysing your post here, I add this: I was pondering already longtime to color these by discovery method not years. So that for example spectroscopy stands out meaningful. The "legend" (much text = OK) then can roughly add the era. Woldn't that also solve issues like Xe/Po more gently? DePiep (talk) 12:33, 13 January 2023 (UTC)

Two thoughts
@Double sharp: Thoughts? YBG (talk) 15:00, 18 January 2024 (UTC)
 * 1) I'd like to trim the descriptions significantly and change the legend to a 3-column table: (1) Years (colored) (2) Number of elements (3) Description with style="white-space:nowrap"
 * 2) I also think it would be helpful to change the legend colors to something more reflective of a series so it would be obvious in the PT which element colors were earlier than the others.
 * For some months at least I've been unhappy with the colour scheme here, so you have my support for 2. Regarding the descriptions, I do feel like they get at natural gaps (apart from the one to "recent synthesis", but catching the ones from our century seems reasonable anyway), so first I'd like to see what you have in mind. :) Double sharp (talk) 15:40, 18 January 2024 (UTC)
 * I'm not proposing any change in the time periods, just shortening the descriptive test. YBG (talk) 15:44, 18 January 2024 (UTC)
 * Yes, and the descriptive text currently explains why the time periods get at natural gaps. That's why I wanted to see your shortened version first. :) Double sharp (talk) 16:51, 18 January 2024 (UTC)

@Double sharp: Have a look at the mock-up at the sandbox at this permalink. The wiki-markup is pretty horrid, it is copy/pasted directly from a MS-Word document. If adopted, it would be cleaned up first. YBG (talk) 04:41, 19 January 2024 (UTC)
 * I like it! Just one change is needed IMO (based on a lack of clarity in the original): for 1600-1799 it should rather be "...reject Aristotle's idea of 'element' in favour of Lavoisier's". Double sharp (talk) 17:27, 19 January 2024 (UTC)
 * Yea, I wondered about that. I think I’ll just leave out Lavoisier
 * How’s this for colors?
 * Pre-1600
 * 1600-1799
 * 1800-1849
 * 1850-1899
 * 1900-1949
 * 1950-2000
 * Since 2000
 * YBG (talk) 20:58, 20 January 2024 (UTC)
 * Another question: what do you think of DePiep’s idea of coloring by discovery method? YBG (talk) 21:09, 20 January 2024 (UTC)
 * I like the colours. To my taste, it'd be a bit difficult to say how many of the pre-1800 elements were discovered. Many were not isolated till later, and their "discovery" was more of a matter of people figuring out what the basic constituents of matter were. Double sharp (talk) 05:01, 21 January 2024 (UTC)