John Aitken (scientist)

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John Aitken
John Aitken
Born	8 September 1839 Falkirk, Scotland
Died	14 November 1919
Nationality	Scotland
Fields	physics
Known for	cloud physics aerosol

John Aitken (1839-1919) (born Falkirk, Scotland), one of the founders of cloud physics and aerosol science, was a Scottish physicist and meteorologist who built the first apparatus to measure the number of dust and fog particles in the atmosphere. One of his experiments conducted with a self-designed apparatus provided the first evidence of new particle formation in the atmosphere. This work was documented in an article titled On some nuclei of cloudy condensation, in the 39th volume of the Transactions of the Royal Society of Edinburgh published in 1898.

John Aitken was the author of a number of important pioneering discoveries "On Dust, Fogs and Clouds" (The title of an 1880 article he penned). As early as 1874, Aitken had concluded that when water vapor in the atmosphere condenses, it must condense on some solid particle, and thus, without the presence of dust and other aerosol particles in the air, there would be no formation of fog, clouds, or rain. In 1884, he concluded that the brilliant colors often seen in the sunset are due to the refraction of light by dust particles in the upper atmosphere. In 1917, Aitken was awarded the Royal Medal of the Royal Society.

Today, his name is given by atmospheric scientists to the smallest atmospheric aerosol particles ('Aitken nuclei'), those with a radius less than 0.1 micrometers. This size range include the newly nucleated particles whose existence Aitken demonstrated.

[edit] References

Atmospheric Chemistry and Physics, Second Edition, Seinfeld and Pandis, 2006.
Encyclopedia Britannica [1].
Podzimek, J., 1989: John Aitken's Contribution to Atmospheric and Aerosol Sciences—One Hundred Years of Condensation Nuclei Counting. Bull. Amer. Meteor. Soc., 70, 1538–1545. [2]
http://www.geo.ed.ac.uk/scotgaz/people/famousfirst928.html

[edit] Bibliography of Aitken's Papers

Aitken, J. 1880. On dust, fogs, and clouds. Proceedings of the Royal Society of Edinburgh (1880-1881) 11(108):14-18; 122-126.

Aitken, J. 1883. On dust, fogs, and clouds. Transactions of the Royal Society of Edinburgh 30(1):337-368.

Aitken, J. 1887. Note on hoar-frost. Proceedings of the Royal Society of Edinburgh 14(2):121-125.

Aitken, J. 1889. On improvements in the apparatus for counting the dust particles in the atmosphere. Proceedings of the Royal Society of Edinburgh 16(129):134-172.

Aitken, J. 1889. On the number of dust particles in the atmosphere. Transactions of the Royal Society of Edinburgh 35:1-19.

Aitken, J. 1890. On the number of dust particles in the atmosphere of certain places in Great Britain and on the continent, with remarks on the relation between the amount of dust and meteorological phenomena. Proceedings of the Royal Society of Edinburgh (1889-1890) 17(130):193-254.

Aitken, J. 1890. On the number of dust particles in the atmosphere of certain places in Great Britain and on the continent, with remarks on the relation between the amount of dust and meteorological phenomena. Nature 41(1061):394-396.

Aitken, J. 1891. On a simple pocket dust-counter. Proceedings of the Royal Society of Edinburgh (1890-1891) 18(February):39-52.

Aitken, J. 1891. On a method of observing and counting the number of water particles in a fog. Proceedings of the Royal Society of Edinburgh (1890-1891) 18:259-262.

Aitken, J. 1891. On the solid and liquid particles in clouds. Transactions of the Royal Society of Edinburgh 36:313-319.

Aitken, J. 1892-95. On some observations made without a dust counter on the hazing effect of atmospheric dust. Proceedings of the Royal Society of Edinburgh 20:76-93.

Aitken, J. 1893. Particles in fogs and clouds. Transactions of the Royal Society of Edinburgh 37(20):413-425.

Aitken, J. 1894. Dust and meteorological phenomena. Nature 49(1275):544-546.

Aitken, J. 1895. On the number of dust particles in the atmosphere of certain places in Great Britain and on the continent, with remarks on the relation between the amount of dust and meteorological phenomena. Transactions of the Royal Society of Edinburgh 37(3):17-49; (28):621-693.