Speed Of Light Measurements

Galileo

Aug 20, 1600

Method: Laterns, Speed: "fast"

Romer/Huygens

Oct 22, 1676

Method: Jovian moon occultation, Speed: 215,000 km/s

Bradley

Mar 11, 1729

Method: Aberration of Light, Speed: 301,000 km/s

Fizeau

Nov 4, 1849

Method: Spinning slotted wheel, Speed: 315,300 km/s

Michelson

Feb 5, 1879

Method: Rorating mirror, Speed: 299,910 km/s

Rosa

Dec 1, 1889

Method: Capacities method, Speed: 300,000 km/s

Comstock

Sep 20, 1890

Method: 18 star pairs, Speed: 300,560 km/s

Perot/Fabry

Sep 20, 1898

Method: Electrometric method, Speed: 299,730 km/s

Rosa/Dorsey

Jan 8, 1906

Method: Electrical method, Speed: 299,803 km/s

Mercier

Oct 9, 1923

Method: Electrical measurements, Speed: 299,700 km/s

Michelson/Birge

Aug 23, 1926

Method: Interferometer, Speed: 299,798 km/s

Karolus/Mittelstaedt

Mar 28, 1928

Method: Kerr Cell shutter, Speed: 299,778 km/s

Pease/Pearson

Mar 6, 1932

Method: Interferometer, Speed: 299,774 km/s

Essen/Gordon-Smith

Jan 30, 1947

Method: Microwave cavity, Speed: 299,792 km/s

Froome

Mar 6, 1958

Method: Interferometer, Speed: 299,792.50 km/s

Evenson

Oct 30, 1973

Method: Laser method, Speed: 299,792.467 km/s

Woods/Shotton/Rowley

Nov 4, 1978

Method: Laser method, Speed: 299,792.4588 km/s

International

Jul 11, 1983

Method: Definition, Speed: 299,792.458 km/s