17.33 Lord Kelvin and flying machines

William Thomson, (Lord Kelvin, Kelvin of Largs)

William Thomson was one of the most famous physicists of the 19th century. He was born in 1824 and graduated in mathematics, from the University of Cambridge, in 1845. By 1846 he was Professor of Natural Philosophy (the contemporary name for physics) at the University of Glasgow in Scotland. He was made Sir William Thomson in 1866 and Lord Kelvin (the name by which he is most usually known) in 1892.

His fame continues – the Kelvin scale of temperature (post 16.34) is named after him and in 1971 his picture appeared on a Scottish banknote. (It was not until 2017 that James Clerk Maxwell, born in 1831, was considered for a picture on a Scottish banknote -see post 16.11 to find out something about him. Isaac Newton, born 1643, didn’t appear on an English banknote until 1978 – see posts 16.2, 16.11 and 16.16 for more information about his work.)

However, in 1895, Kelvin confidently stated that “heavier-than-air flying machines are impossible”. This was despite Daniel Bernoulli publishing his equation (post 17.15), that is used to explain why planes fly (post 17.16), in 1738. Kelvin continued to make confident statements. In 1900, he told the British Association for the Advancement of Science that, “There is nothing new to be discovered in physics now. All that remains is more and more precise measurement.” In 1891 Ludwig Boltzmann (post 16.22) was already suggesting ideas that led to the quantum theory (posts 16.2 and 16.29) that was to revolutionise physics in the 20th century.

Even in 1895, you didn’t need to know about Bernoulli to know that Kelvin was wrong. It should have been evident to anyone who had seen a bird flying that mechanisms existed that could be used to make a flying machine (see post 17.32). Perhaps Kelvin thought that living things were somehow different (see post 16.18). But the sketches of Leonardo da Vinci (1452-1519) strongly suggest that he could see similarities between machines and the mechanisms involved in the motion of living things. (Interestingly, the connection between living things and machines appears sometimes in works of art – as in many steampunk sculptures.)

Why did people take Kelvin seriously? Because he was a famous scientist!

And we continue to make this mistake even now! Newspapers sometimes report daft ideas from (usually aging) famous scientists that we are expected to take seriously.

When you read that a famous scientist has made a weird statement about something like colonizing other planets, ask yourself the questions below.

Question 1. How reliable is the article you are reading likely to be? (See post 17.9).

Question 2. Is the famous scientist better qualified than any other intelligent person to comment on this subject? Remember that many problems the world faces involve economic, financial, social and ethical factors and cannot be solved by science alone (post 16.32).

Above all, remember that science develops not by accepting authority but by thinking for ourselves (post 17.9).

Returning to Lord Kelvin, perhaps he should have spent less time making predictions and more time watching birds!


Related posts

17.25 Diminishing deception
17.9 Scientists believe that…
17.1 It’s obvious
16.41 Physics, chemistry and biology
16.32 Faith in science
16.22 Science can’t explain everything
16.15 Science education
16.11 Giving a scientist a job

Follow-up posts

20.4 Questionnaires



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