15. Water Found on Moon, Researchers Say
By Sakae Gustafson
Sculpture of Sir Isaac Newton (with prism), Trinity College Ante-Chapel. 1755, Louis-Francois Roubiliac (detail)
On 13 November 2009, NASA announced ‘a new chapter in our understanding of the moon’.[ii] The crash of a satellite and the resulting plume of moon dust testified to the presence of water through spectrometry. Originating in Isaac Newton’s paper on Opticks, spectrometry measures the colour of light reflected or absorbed by materials as evidence of their composition.[iii]
Spectrometry began with Newton’s manipulations of glass prisms. Six prisms owned by Newton are known, all similar to what looks to the modern observer to be a Jenga piece grasped by Newton in the pictured sculpture. The seventh prism of uncertain provenance resides in Trinity College library.[iv]
Roubiliac’s sculpture interpreted Newton’s version of the discovery, which he condensed into an episode of experimentation with a novelty prism brought home from Stourbridge Fair.[v] Newton’s letter to the Royal Society begins ‘in the beginning of the Year 1666 . . . I procured me a Triangular glass-Prisme’. In gravitational theory, an apple served as legend’s catalyst. In optics, Newton’s account of the discovery glossed over seven years of ‘thinking on it continuously’.[vi]
Image attribution: adapted from Vysotsky (Wikimedia)
[i] Chang, Kenneth. The New York Times, November 13, 2009.
[iii] ‘A letter of Mr. Isaac Newton, Professor of the Mathematicks in the University of Cambridge…’, 31 December 1671, Volume 6 Issue 80, The Royal Society; Newton’s experiments with prisms likely began in his undergraduate years at Cambridge. His ‘Letter’ of 1672 first established his reputation among European scholars; see Fara, Patricia. 2015. ‘Newton shows the light: a commentary on Newton (1672) ‘A letter … containing his new theory about light and colours…’’, The Royal Society.
[iv] Mills, A.A. 1981. ‘Newton’s prisms and his experiments on the spectrum’.
[vi] Westfall, Richard S. 1980. ‘Newton’s Marvelous Years of Discovery and Their Aftermath: Myth versus Manuscript’. Isis , Vol. 71, No. 1 (March) pp. 109-121.