| RefNo | EC/1960/08 |
| Previous numbers | Cert XVI, 274; A02262 |
| Level | Item |
| Title | Essen, Louis: certificate of election to the Royal Society |
| Description | Certificate of Election |
| Citation | Distinguished for his work on the precise measurement of frequency and of the velocity of light. His ring crystal is the most precise crystal frequency standard. It shows a day-to-day consistency of 1 in 10 [to the power of] 9 and is only excelled as a time keeper by his recent development of a clock using a beam of caesium atoms. Essen and his collaborators have used these very precise methods of frequency measurement to improve the accuracy of measurement of the velocity of light by a factor of a hundred, to carry out a new form of the Michelson & Morley experiment and to measure the refactive index of gases in the microwave region to an accuracy of 1 in 10 [to the power of] 7. |
| Proposers | E C Bullard; Charles Darwin; G B B M Sutherland; H Spencer Jones; L F Bates; Ezer Griffiths; F P Bowden; Willis Jackson; T E Allibone; Norman P Allen; S Tolansky; G P Thomson; Edward V Appleton; B Lockspeiser; B Bleaney |
| AccessStatus | Open |
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Fellows associated with this archive
| Code | PersonName | Dates |
| NA2141 | Essen; Louis (1908 - 1997) | 1908 - 1997 |