Talk:William Thomson

Quote frequently attributed to Lord Kelvin, mostly on Christian websites
"If you study science deep enough and long enough it will force you to believe in God." --71.126.51.182 08:03, 27 May 2009 (UTC)

"To measure is to know."
Does anybody know if "To measure is to know" is misattributed? --173.166.5.241 20:58, 10 November 2010 (UTC)

Nationality?
It says in the introduction of the article that Lord Kelvin was Scottish. The Wikipedia page for Lord Kelvin clearly states that he was born in Belfast and therefore could not be Scottish. 46.208.210.202
 * Belfast is the main city of the Ulster Scots people and that was his heritage. I have updated the page accordingly. Andrew Davidson (talk) 10:57, 27 June 2024 (UTC)

"Radio has no future"
That quote is usually attributed to him, but I could not find a primary source, and Radio does not cover it either. --Daniel Mietchen (talk) 06:37, 2 March 2014 (UTC)


 * Seems like it may be fake. For example, in one interview with Kelvin, http://zapatopi.net/kelvin/papers/interview_aeronautics_and_wireless.html, he's remarkably effusive about the prospects for radio. --Gwern (talk) 03:28, 29 November 2014 (UTC)

"X-rays will prove to be a hoax"
As above, usually attributed to him, but no clear primary source. Sometimes the two are said to have been stated together. --Daniel Mietchen (talk) 06:45, 2 March 2014 (UTC)


 * I looked a bit into this tonight (I was irritated by an uncritical quote in a book I'm reading on ketamine - 'surely such a great physicist is probably being misquoted or it's entirely made up, as I've found so many "dumb" quotes to have been'). This one is hard: an actual quote is hard to nail down, as checking through a few hundred hits in Google/Google Books/Google Scholar, it circulates in a number of variants, and the years attributed to it differ greatly (it has to be 1895 or 1896 because it only makes sense early on in the history of X-rays but some dates are as late as 1903), and naturally no one gives any primary references if they give any references at all; some quotes have no hits in Google Books earlier than 1980 or so, which made me suspicious that this was a secondary source summary which had ascended to an (apocryphal) quote. The En entry does at least cite Mould's A History of X-Rays and Radium with a Chapter on Radiation Units : 1895-1937, which is not available freely or as a used book on Amazon, but there is a snippet view on Google Books, which runs:
 * "Lord Kelvin was initially skeptical and regarded the announcement as a hoax (Thompson, 1910). However, this view is not entirely borne out by the letter Kelvin wrote Rontgen on January 17th, 1986, having acknowledged receipt of the paper and the radiographs in an earlier letter dated January ... [6th?] ..."
 * The 17th January Letter is available in Mould's other book, http://books.google.com/books?id=IXPz7bVR7g0C&lpg=PT24&ots=7wQ_IOsLMo&dq=kelvin%20roentgen%20january%201896&pg=PT31#v=onepage&q=Kelvin&f=false, as a picture, and the text runs basically:
 * "DEAR PROF. RONTGEN When I wrote to you thanking you for your kindness in sending me your paper and the photographs which accompanied it, I had only seen the photographs and had not had time to read the paper. I need not tell you that when I read the paper I was very much astonished and delighted. I can say no more now than to congratulate you warmly on the great discovery you have made, and to renew my thanks to you for your kindness in so early sending me your paper and the photographs. Believe me, yours very truly, Kelvin"
 * I can't figure out what the earlier letter was since I can't trick Google Books into showing the remaining sentence or two, but the 17 January letter certainly is positive.
 * The next lead is 'Thompson, 1910'; frustratingly, searching the book for 'Thompson' only turns up a book written before the discovery of X-rays and so can't possibly be right, but a search in Google for 'Thompson 1910 Kelvin' immediately reveals it must be the early biography of Kelvin by Silvanus P. Thompson, volume 2, and it's easy to find a hit for 'hoax' in it way down in the volume. It's not too easy to read the OCR but it's good enough that one can figure out the full context, which goes like this:
 * "When confronted with a new fact or discovery, Lord Kelvin's attitude of mind varied according to the circumstances of the case. Thus when Kerr in 1876 announced his discovery of electro-optic stress, Lord Kelvin was instantly and almost explosively excited ; he had predicted this very effect thirty years before, and had written of it to Faraday, who had himself looked for it in vain at a still earlier date. When Rontgen's discovery of the X-rays was announced at the end of 1895, Lord Kelvin was entirely sceptical, and regarded the announcement as a hoax. On the other hand, when Crookes first showed him the radiometer, one evening in 1874, he sat down watching it in perfect silence for nearly an hour, gazing at it, shading the light from it at intervals with his hand, or moving it towards the lamp or from it, and thinking thinking. Not even in 1906 was he satisfied that the true theory of the radiometer had ever been given. ...The year 1896, which was to witness the jubilee of Lord Kelvin s tenure of the Chair of Natural Philosophy, opened inauspiciously enough, for he was far from well that winter. All through December 1895 he complained at intervals of a tired leg, sore and painful at times, but just before Christmas, when he was purposing to leave Glasgow for Netherhall, an cedematous swelling, such as had troubled him much after the accident of 1861, caused his medical adviser to order him to keep his bed for several weeks. At the end of January there supervened a sharp attack of pleurisy. Though suffering much he bore his sufferings with great patience, and was greatly helped by his ability to sleep soundly. Except when the pleurisy was acute he worked at his notebook, dictated letters to his secretary, and took the keenest interest in the events of the hour, both scientific and political, as the following letters show...Eventually M. Lippmann took Lord Kelvin's place, and lectured on Colour Photography. The papers had been full of the wonders of Röntgen's rays, about which Lord Kelvin was intensely sceptical until Röntgen himself sent him a copy of his Memoir, whereupon he wrote : [letter excerpted previously] He wrote to Sir Joseph (now Lord) Lister on January 27 : Ask Rayleigh if he is not in a state of great excitement about Rontgen's X-rays. ...[and so on, including several letters about theoretical discussions as to the nature and behavior of X-rays]"
 * Now, in other passages, it seems Thompson knew Kelvin in person and had discussed many things with him, so this paraphrase or description as 'regarded the announcement as a hoax' may be personal first-hand knowledge (nothing about it indicates a source, no verb such as 'said' or 'wrote'); and this was published 3 years after Kelvin's death in 1907, so his memory should not have faded much. And in [volume 1] he says it's an authorized biography with access to personal papers:
 * "This Biography was begun in June 1906 with the kind co-operation of Lord Kelvin, who himself furnished a number of personal recollections and data. His death in December 1907 affected the project of the work by necessarily extending its scope to present a much more comprehensive account of his career than the sketch originally planned. The mass of letters, diaries, and other documents which he left became available for filling in the outlines, and the task of arrangement and selection from these greatly extended the period of preparation."
 * But that still leaves us with a problem: did Kelvin think it was a "hoax [by Rontgen? the newspapers?]" or was he "intensely skeptical"? I'm not sure.
 * Regardless, it seems clear that Thompson is the 'ur-citation' here; there there is no reliable primary source for any Kelvin quotation running "X-rays are a hoax"; and there's some reasonable doubt about what he actually believed in the short interval between reading newspaper articles (I think we've all had the experience of seeing newspaper articles on some new scientific proposal which bore scant resemblance to reality!) and getting Rontgen's paper & photos.
 * In editing the En entry, I've elected to split the difference by quoting together the two parts of the Thompson passages, to let the reader know that the source is Thompson and to show the two phrasings side by side. --Gwern (talk) 03:56, 29 November 2014 (UTC)

"If you cannot measure it, you cannot improve it"
This quote is attributed to Lord Kelvin in [//www.google.com/#q=Kelvin+cannot+measure+improve innumerable places on the Web] (sometimes with "can't" or "can not" in place of "cannot"), but curiously, it does not appear here on his Wikiquote page. It would be interesting to learn whether the quote is accurately attributed to him. — Jaydiem (talk) 14:47, 8 October 2014 (UTC)
 * Here is what Lord Kelvin actually said:
 * "In physical science the first essential step in the direction of learning any subject is to find principles of numerical reckoning and practicable methods for measuring some quality connected with it. I often say that when you can measure what you are speaking about, and express it in numbers, you know something about it; but when you cannot measure it, when you cannot express it in numbers, your knowledge is of a meagre and unsatisfactory kind; it may be the beginning of knowledge, but you have scarcely in your thoughts advanced to the state of Science, whatever the matter may be."
 * Source: "Electrical Units of Measurement" (1883) ~ DanielTom (talk) 17:18, 8 October 2014 (UTC)
 * Should this be added in the main page? Ooker (talk) 07:26, 1 October 2018 (UTC)