# Talk:Christiaan Huygens

In case anyone else was wondering, here is a page and audio clip describing how to pronounce Huygens' name.

Excised rubbish:

He discovered and proved mathematically that the oscillation-time (or frequency) of a pendulum depends solely on its length, independent of the angle of swing. The popular notion up to then had held that the larger the swing, the longer the oscillation-time.
It is Galileo that is credited with finding that pendula have (almost) constant period; Huygens quantised the tiny dependency on amplitude and suggested a means of correcting it. (I believe it was a buffered ribbon suspension, but check his book to be sure. For the typical idealisation the bob must trace a cycloid -- see tautochrone -- and the buffers are the evolute, another cycloid.) It's of mostly theoretical interest because serious pendulum clocks are contrived to keep a small and constant amplitude, and real pendula are hardly the easily-analysed ideal; their bobs rotate, their suspensions are stiff and stretchy...
Huygens' most lasting contribution to horology may be a pulley arrangement used to maintain torque during winding. Kwantus 19:35, 2005 Feb 20 (UTC)

D'oh. I forgot the coilspring-and-balancewheel oscillator. Kwantus 22:52, 2005 Feb 22 (UTC)
I've replaced the color portrait with one that is known to be public domain. The old one was way better, though. If anyone can find out the relevant legal information (and maybe locate a better reproduction), it would be great to have the color one.--Bcrowell 03:46, 21 May 2005 (UTC)
Is the lack of a link to Huygens' principle deliberate?

It seems the images inserted just after the LIFE section name cause the [edit] tags to be placed bunched up in odd places. At least, when I take out the images the [edit] tags appear in the proper place. I have no idea what is going on. Perhaps someone who has run into this problem before can fix it. Vantelimus (talk) 05:21, 18 November 2009 (UTC)

According to this article

In 1673 he [Huygens] published his mathematical analysis of pendulums... It had been discovered that pendulums are not isochronous for swings; that is, their period depends on the width of swing. 
However, according to Marin Mersenne

He [Mersenne] also performed extensive experiments to determine the acceleration of falling objects by comparing them with the swing of pendulums, reported in his Cogitata Physico-Mathematica in 1644. He was the first to measure the length of the seconds pendulum, that is a pendulum whose swing takes one second, and the first to observe that a pendulum's swings are not isochronous as Galileo thought, but that large swings take longer than small swings.
The dates suggest that Mersenne was first.
Top.Squark (talk) 14:05, 30 July 2010 (UTC)

Mersenne was first to observe that pendulums are not isochronous.  Huygens is notable for proving it mathematically. Added supporting citations to article, and removed "contradiction" tag at top.  --ChetvornoTALK 15:22, 7 October 2010 (UTC)
Thx for clearing up this issue! Top.Squark (talk) 11:28, 15 October 2010 (UTC)

According to this article

He [Huygens] also invented numerous other devices, including a 31 tone to the octave keyboard instrument which made use of his discovery of 31 equal temperament.
According to 31 equal temperament

Nicola Vicentino produced a 31-step keyboard instrument, the Archicembalo, in 1555, but it was not until 1666 that Lemme Rossi first proposed an equal temperament of this order. Shortly thereafter, having discovered it independently, famed scientist Christiaan Huygens wrote about it also.
According to Lemme Rossi

Lemme Rossi... was the first to publish a discussion of 31 equal temperament, the division of the octave into 31 equal parts, in his Sistema musico, ouero Musica speculativa doue SI spiegano i più celebri sistemi di tutti i tre generi of 1666. This slightly predates the publication of the same idea by the eminent scientist Christiaan Huyghens.
My guess is that the later two articles are more accurate than this one, but none of the 3 cite a source on this
Top.Squark (talk) 17:17, 30 July 2010 (UTC)

We ought to have a source, but I see no contradiction between these articles, unlike what's noted in the hatnote at Christiaan Huygens. Rossi and Huygens both discovered, independently, the 31-EDO, and apparently Vicentino preceded both with this discovery. Rossi just was the first to publish it.
However, this page from the Huygens–Fokker Foundation states that Huygens "knew of the existence of Vicentino's archicembalo", so it would seem to be doubtful whether Huygens' contribution should be called a discovery at all.  --Lambiam 18:46, 15 April 2011 (UTC)
Surely this was not a discovery, but an invention?  Epzcaw (talk) 23:14, 15 September 2011 (UTC)
I agree that we ought to have a source, and I agree that there seems to be no contradiction -- as far as I can tell from the Nicola Vicentino article, Vicento described and actually built a 31-note-to-the-octave musical instrument, but the Lindley, Mark (1990) reference in the archicembalo implies that Vicento used some tuning system *different* from 31 equal temperament, so it seems possible that 31 equal temperament wasn't discovered / invented until much later. --DavidCary (talk) 23:52, 30 November 2018 (UTC)

Shouldn't the name of the force discovered by Huygens be the Centrifugal force, rather than the Centripetal force, since he called it a vis centrifuga, and it dealt with the expansion of the rotation radius.WFPM (talk) 19:56, 27 February 2011 (UTC)

The intro describes Huygens as (among other things) a writer of science fiction, but I don't see anything in the article that substantiates this. He did write a book presenting "conjectures" (his word) about inhabitants of other planets, but that book is not science fiction, any more than the WP page Extraterrestrial life is a work of science fiction. Perhaps he did other books which are science fiction, but for now I'm inclined to delete that statement from the intro. Kalidasa 777 (talk) 23:30, 2 May 2011 (UTC)

What the book cited says is that, probably due to the weight of René Descartes's other accomplishments, there was a school of research based on his physics.  He and his followers contributed, to some extent, directly to physics.
Partly from other sources, René Descartes' main contributions to physics were in mathematics and in the supporting and guiding philosophy, rather than in physics itself.  He said cogito ergo sum, which has been generalized to the anthropic principle that a a scientist may assume that the universe is such that it supports intelligent life.  He advanced the idea of searching for simple laws of physics.
David R. Ingham (talk) 04:26, 26 April 2012 (UTC)

This section seems to be poorly written and I have great reservations about the wording of this section, especially the last few line which are unreferenced. The referenced section cites a book by a Margaret Jacob. I looked for a google books preview to see what was actually presented but a preview was not available. The wording in the section is shoddy and seems to be a point-of-view edit with a severe lack of quotes for supposed lines of reasoning of Huygen; either he explicitly wrote what has been said in the section, or it didn't happen and is conjecture. There is nothing specifically in quotation marks, and it seems presumptuous to state those sentences as if it were Huygens line of reasoning. 
Does anyone have a copy of this book or post or a small snippet of what it says to confirm what has been entered in the section? Veritas Blue (talk) 11:56, 29 June 2012 (UTC)

Clifford Dobell in the book "Little animals" (1932) writes: "Christiaan Huygens never himself published any serious contributions to protozoology: and the records of his own observations, which were made in an attempt to repeat Leeuwenhoek's experiments, remained in manuscript and unknown until only a few years ago. Consequently, his private work had no influence whatsoever upon the progress of protozoology. Had it been published in his lifetime, it would have assured him a place in the very forefront of the founders of the science".
George F. Simmons in his book "Calculus Gems: Brief Lives and Memorable Mathematics" writes: "Among other things, he explained how microorganisms develop in water previously sterilized by boiling. He suggested that these creatures are small enough to float through the air and reproduce when they fall into the water, a speculation that was proved correct by Louis Paster two centuries later".
Maybe it's worth a mention? (since people mention Gauss discovery of the possibility of non-Euclidean geometries, even though it was also not published)
Or maybe it's not relevant?
I don't know... Just wanted to share :) Pedro Listel (talk) 05:18, 7 May 2013 (UTC)

The article says cycloid, but it seems like a catenary (it's also the description in commons and seems to match the descriptions in John Bukowski's article "Christiaan Huygens and the Problem of the Hanging Chain").
Pedro Listel (talk) 05:33, 7 May 2013 (UTC)

Yes, thanks, obviously intended as a catenary when you look at it. Charles Matthews (talk) 10:42, 12 May 2013 (UTC)

For the Gutenberg edition and the 1912 English edition of the Treatise on Light, the following errata list may be useful:

G.R. Putland, "Errata in various editions of Huygens' Treatise on Light", www.grputland.com, June 2016.
(I refrain from directly editing the article, due to a c.o.i.)  — Preceding unsigned comment added by 202.161.27.252 (talk) 09:57, 15 July 2016 (UTC) 
--- Minimal response made.  — Preceding unsigned comment added by 114.198.83.18 (talk) 09:07, 26 July 2016 (UTC) 

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What are those wrong pronunciations doing here? /ˈɦœyɣə(n)s/ is not the (so-called) Dutch pronunciation, it's the pronunciation. Do approximations have a place in Wikipedia?  — Preceding unsigned comment added by Upquark (talk • contribs) 14:12, 29 March 2018 (UTC) 

Dutch and Low German have regional versions of their own. I agree that the English versions are not used in Dutch.  — Preceding unsigned comment added by 86.180.30.37 (talk) 10:05, 23 June 2018 (UTC)
It is appropriate for WP to include common non-native (e.g. English) pronunciations of the name.  However, I agree that it might be misleading for the Dutch-native pronunciation to be excluded from the pronunciation options for English-speakers.
However, on the topic of Dutch pronunciation, how consistent is that?  The WP clip and one other that I found sound roughly like HOI-hwens, whereas there are three clips on forvo that sound distinctly closer to HAI-hwens.
For completeness I also found three clips on HowToPronounce with examples of English pronunciations that all sound like HAI-gens.
Sorry for using respelling rather than IPA.  I know IPA is better, but I'm also more likely to make a mistake in IPA.
—DIV (49.180.66.130 (talk) 12:17, 13 February 2021 (UTC))

What is the source of the claim "As a rationalist, he refused to believe in an immanent supreme being, and could not accept the Christian faith of his upbringing."? I found this article https://www.gewina-studium.nl/articles/10.18352/studium.9427/ which claims (on the base of Huygens's correspondence and his book Cosmotheoros) that Huygens's religious views was unorthodox, but "the concept of God was actually a crucial element in his understanding of the world".

The following was added to the lead by a new user.

NASA named the lander Huygens which landed on Titan, a moon of the planet Saturn  after the renowned physicist.
Should that be in the article? How? Where? Reference? --Gerda Arendt (talk) 09:32, 8 January 2019 (UTC)

This review is transcluded from Talk:Christiaan Huygens/GA1. The edit link for this section can be used to add comments to the review.
Reviewer: Hawkeye7 (talk · contribs) 18:31, 9 October 2021 (UTC)
Picking this one up. Hawkeye7 (discuss) 18:31, 9 October 2021 (UTC)
All looks fairly good.

Lead
Makes claims that are not in the body:
"who is widely regarded as one of the greatest scientists of all time and a major figure in the scientific revolution." This claim is in the lead , but not the body, and therefore is unsourced. You need to add appropriate evidence to the body.
Similarly, "His mathematical theory of light was initially rejected in favor of Newton's corpuscular theory of light, until Augustin-Jean Fresnel adopted
"Huygens was the first to idealize a physical problem by a set of parameters then analyze it mathematically"
Huygens's principle in 1818." is not in the body

"first to fully mathematize a mechanistic explanation of an unobservable physical phenomenon"
"In 1655, Huygens began grinding lenses with his brother Constantijn"
"Traité de la Lumière", "Horologium Oscillatorium" (for these I suggest removing the first mentions in parentheses), "pendulum clock" and "rings of Saturn" are doubly linked in the lead.
In the infobox, suggest changing "Titan" to "Discovery of Titan"
Body
Typos:
"favor" -> "favour"
"analyze" -> "analyse"
"labeled" -> "labelled"
"center" -> "centre"
"labeled" -> "labelled"
"honor" -> "honour"
"Using his modern telescope he succeeded in subdividing the nebula into different stars" Comma after "telescope"
"He then calculated that the angle of this hole was 1/27,664th the diameter of the Sun" Don't see the need for the math markup here
"home to Christiaan Huygens from 1688" -> "home of Huygens from 1688"
Duplicate links: Constantijn Huygens, Descartes, House of Orange, Leiden, Mersenne, catenary, The Hague, Pierre de Fermat, Frans van Schooten
, Louis XIV, Royal Society,  analytical geometry, Hofwijck, Archimedes, center of gravity, Grégoire de Saint-Vincent, approximation of the quadrature, Frans van Schooten , Cartesian, Henry Oldenburg, Journal des Sçavans, Galileo,  Lodewijk Huygens, pendulm, cycloid, caustic, catenary, balance spring, Robert Hooke, Académie des sciences, Iceland spar, evolutes,  Huygens–Fresnel principle, physical optics, Jean-Baptiste Colbert, Leibniz, Newton, analytic geometry, mathematical physics,  double refraction,

References
Last sentence of "Saturn's rings and Titan" is unreferenced.
Named after Huygens section in unreferenced
Remove the inline external links
Suggest using the citation template for fn 1
The "References" are not used in the article, so move them to the "Further reading" section (Except: Move Shapiro into fn 125)
Not all the journals have ISSNs. I like them because although not required n the Engluish Wikipedia, theye are required on other ones. Consider adding them where they are missing. But not a requirement at GA.
Remove the bare URLs from fn 10
fn 21, 93, 112, 116: page numbers required
fn 22, 24: "pg" should be "p."
fn 26: pp. 275–6 should be "pp. 275–276". Same for fn 34, 37, 39, 45, 51, 58, 60, 52, 85, 86, 88, 99, 105, 111, 132
fn 30 has a tag that should be resolved
fn 32 is a Master's thesis. WP:SCHOLARSHIP: Masters dissertations and theses are considered reliable only if they can be shown to have had significant scholarly influence. (Hate that one.)
fn 33: page range required. Same for 42, 90, 140
fn 40 points back to fn 27; should repeat to keep the style consistent
fn 46: Reformat as cite thesis and add page numbers
fn 72, 106, 129, 148, 150: Do we have ISBN, publication details?
fn 78: Fix the page numbering format
fn 91, 94, 95: What is Garber and Ayers?
fn 97: Remove the bare URL by using the template
fn 119: use the template to fix the format
fn 137 doesn't point there anymore; consider using fn 136 instead
Hawkeye7 (discuss) 19:52, 9 October 2021 (UTC)

@Hawkeye7: Thanks for your feedback. I will work on these issues shortly in the next few days and get back to you. Just a quick question: Is British spelling a requirement (e.g., favor = favour?) I didn't know it was, but if that's the case, I'll be happy to comply. Guillermind81 (talk) 14:27, 11 October 2021 (UTC)
It's not a requirement. If you want to use US spelling instead, simply tag the article with a {{use American English}} template. I thought that British English was more appropriate given the subject. Hawkeye7 (discuss) 18:06, 11 October 2021 (UTC)
@Hawkeye7: I've worked through your feedback and addressed most of the issues you encountered, with the exception of the Notes section. Given the deadline (7 days is tomorrow) and the amount of work involved, I won't be able to complete this section on time. Do note that most of these are legacy references that preceded my editing work. If I can get an extension, I promise I will work on them and make sure they are up to par.
Here are the changes made:
Lead:

Makes claims that are not in the body: "who is widely regarded as one of the greatest scientists of all time and a major figure in the scientific revolution." This claim is in the lead , but not the body, and therefore is unsourced. You need to add appropriate evidence to the body. Now under Legacy section.
Similarly, "His mathematical theory of light was initially rejected in favor of Newton's corpuscular theory of light, until Augustin-Jean Fresnel adopted. Now under Optics lead section.
"Huygens was the first to idealize a physical problem by a set of parameters then analyze it mathematically" Now under Pendulums section.
Huygens's principle in 1818." is not in the body. Corrected date to 1821 to match text under Optics lead section.
"first to fully mathematize a mechanistic explanation of an unobservable physical phenomenon" Now under Optics lead section.
"In 1655, Huygens began grinding lenses with his brother Constantijn" Added new language under Lenses section.
"Traité de la Lumière", "Horologium Oscillatorium" (for these I suggest removing the first mentions in parentheses),"pendulum clock" and "rings of Saturn" are doubly linked in the lead. Removed first two references, removed double links for the other two.
In the infobox, suggest changing "Titan" to "Discovery of Titan" Changed wording in infobox.
Body
Typos:

"favor" -> "favour"
"analyze" -> "analyse"
"labeled" -> "labelled"
"center" -> "centre"
"labeled" -> "labelled"
"honor" -> "honour" Changed to British spelling.
"Using his modern telescope he succeeded in subdividing the nebula into different stars" Comma after "telescope" Fixed.
He then calculated that the angle of this hole was 1/27,664th the diameter of the Sun" Don't see the need for the math markup here. Removed math markup.
"home to Christiaan Huygens from 1688" -> "home of Huygens from 1688" Fixed.
Duplicate links: Constantijn Huygens, Descartes, House of Orange, Leiden, Mersenne, catenary, The Hague, Pierre de Fermat, Frans van Schooten, Louis XIV, Royal Society, analytical geometry, Hofwijck, Archimedes, center of gravity, Grégoire de Saint-Vincent, approximation of the quadrature, Cartesian, Henry Oldenburg, Journal des Sçavans, Galileo, Lodewijk Huygens, pendulum, cycloid, caustic, balance spring, Robert Hooke, Académie des sciences, Iceland spar, evolutes, Huygens–Fresnel principle, physical optics, Jean-Baptiste Colbert, Leibniz, Newton, mathematical physics, double refraction. Fixed.
References

Last sentence of "Saturn's rings and Titan" is unreferenced. Added reference.
Named after Huygens section in unreferenced. Fixed.
Remove the inline external links. Fixed
Suggest using the citation template for fn 1. Not sure I understood how to do this.
The "References" are not used in the article, so move them to the "Further reading" section. Fixed.
Remove the bare URLs from fn 10. Fixed
fn 22, 24: "pg" should be "p." Fixed
fn 30 has a tag that should be resolved. Fixed
Thank you again for taking the time to review this article. Guillermind81 (talk) 00:28, 16 October 2021 (UTC)

No worries. Kudos for your work on this article. Do you intend to take it to FAC? Are you planning on working on other articles about scientists?
@Hawkeye7: Much appreciated. I do plan to take it to FAC once I get the other references fixed and perhaps add a bit more content here and there. I've been editing other scientists' entries (mostly ancient and Early Modern) that are in need of much work, but this was the first one that I felt was up to par.
Hawkeye7 (discuss) 01:05, 16 October 2021 (UTC)

I agree that it is up to par, and should pass FAC. Problems with the references led to me checking them more closely than I usually would at GA, but you will be grateful for it at FAC. Hawkeye7 (discuss) 21:54, 16 October 2021 (UTC)

GA review – see WP:WIAGA for criteria

Is it well written?
A. The prose is clear and concise, and the spelling and grammar are correct: 

B. It complies with the manual of style guidelines for lead sections, layout, words to watch, fiction, and list incorporation: 

Is it verifiable with no original research?
A. It contains a list of all references (sources of information), presented in accordance with the layout style guideline: 

B. All in-line citations are from reliable sources, including those for direct quotations, statistics, published opinion, counter-intuitive or controversial statements that are challenged or likely to be challenged, and contentious material relating to living persons—science-based articles should follow the scientific citation guidelines: 

C. It contains no original research: 

D. It contains no copyright violations nor plagiarism: 

Is it broad in its coverage?
A. It addresses the main aspects of the topic: 

B. It stays focused on the topic without going into unnecessary detail (see summary style): 

Is it neutral?
It represents viewpoints fairly and without editorial bias, giving due weight to each: 

Is it stable?
It does not change significantly from day to day because of an ongoing edit war or content dispute: 

Is it illustrated, if possible, by images?
A. Images are tagged with their copyright status, and valid fair use rationales are provided for non-free content: 

B. Images are relevant to the topic, and have suitable captions: 

Overall:
Pass or Fail: 

A recent article came out about the eyesight of Huygens as well as his equations on telescopes. Might be worth mentioning somewhere? This article is pretty well written so I do not dare to just cram it in. 
https://royalsocietypublishing.org/doi/10.1098/rsnr.2022.0054
https://phys.org/news/2023-03-eyeglasses-prescription-christiaan-huygens-years.html 161.72.23.153 (talk) 20:03, 2 March 2023 (UTC)

Hi,
Thanks for the article; it was very informative. I do think we should mention this in the main article briefly. I'm currently working on a separate entry on Huygens's astronomy, including his use of telescopes, so we can probably expand the content there. Guillermind81 (talk) 03:00, 4 March 2023 (UTC)

Did Huygens foresaw the intentional benefit – albeit uncomfortable for the rest of us – between military research mixed with constant wars and [civilian] research? 2A02:2F01:6B04:4300:15F8:33ED:45E1:7D74 (talk) 00:37, 15 February 2024 (UTC)

In the line below:
However, the aftermath of the Franco-Dutch War (1672–78), and particularly England's role in it, may have damaged his later relationship with the Royal Society. Robert Hooke, as a Royal Society representative, lacked the finesse to handle the situation in 1673.
Handle what situation? Danial Bass (talk) 16:36, 31 August 2024 (UTC)

It's not mentioned in the article what he died of. seefooddiet (talk) 10:34, 16 October 2024 (UTC)