Progress with a Determination of the Speed of Light

1972 ◽  
pp. 305-310
Author(s):  
T. G. Blaney ◽  
C. C. Bradley ◽  
G. J. Edwards ◽  
D. J. E. Knight
Keyword(s):  
Speed Of Light

The Optical Measurement of Lapse Rate *

1950 ◽  
Vol 31 (2) ◽  
pp. 51-55 ◽  
Author(s):  
Robert G. Fleagle
Keyword(s):  
Optical Measurement ◽  
Vertical Gradient ◽  
Lapse Rate ◽  
Speed Of Light ◽  
Indirect Methods ◽  
Reliable Determination ◽  
Air Density ◽  
Lapse Rates ◽  
The Relationship

The need for reliable determination of the temperature of the air very near the ground and the difficulties inherent in measurement of this quantity by the ordinary indirect methods are pointed out. It is suggested that the dependence of the speed of light on air density provides a convenient method for the determination of the temperature near the ground by direct measurement of the lapse rate, and evidence is given from other papers to show that this is feasible where the vertical gradient of humidity is not great. The relationship between apparent elevation and lapse rates of temperature and vapor pressure is derived, and the relationship is illustrated by the results of computations.

scholarly journals Radar determination of the Astronomical Unit

1965 ◽  
Vol 21 ◽  
pp. 177-215
Author(s):  
Irwin Shapiro
Keyword(s):  
Time Delay ◽  
Astronomical Unit ◽  
Speed Of Light ◽  
Comprehensive Review ◽  
A Value ◽  
The Earth ◽  
Lincoln Laboratory ◽  
Data Yield ◽  
Shift Data

A comprehensive review is given of the Earth-Venus measurements made with the Lincoln Laboratory Millstone radar in 1959 and 1961. The time-delay and Doppler shift data yield a value for the Astronomical Unit of 499.0052 ± 0.001 light-sec. Using 299 792.5 km/s for the speed of light leads to an AU of 149 598 000 ± 300 km. With the radius of Earth taken as 6 378.15 km, the solar parallax then becomes 8″.79416 ± 0″.00002. This value is consistent with measurements made at various other laboratories to about one part in 105.

Measurement of the speed of light I. Introduction and frequency measurement of a carbon dioxide laser

1977 ◽  
Vol 355 (1680) ◽  
pp. 61-88 ◽  
Keyword(s):  
Carbon Dioxide ◽  
Carbon Dioxide Laser ◽  
Frequency Measurement ◽  
Laser Frequency ◽  
Absorption Cell ◽  
Speed Of Light ◽  
Centre Frequency ◽  
Harmonic Mixing

This, and part II following, describe a determination of the speed of light made by measuring the frequency and wavelength of radiation from a CO 2 laser. This laser was operated on the 9.3 μm R(12) transition, and stabilized by reference to fluorescence in an external CO 2 absorption cell. The laser frequency was measured via a sequence of harmonic-mixing stages involving the HCN and H 2 O lasers as transfer oscillators, and was found to be 32 176 079 482 ± 14 kHz ( ± 4.2 parts in 10 10 ). A correction to this value of — 10 kHz is necessary to obtain the centre frequency of the CO 2 reference transition. The wavelength measurements and value of c are described in part II.

Determination of the Constancy of the Speed of Light

1964 ◽  
Vol 54 (2) ◽  
pp. 147 ◽  
Author(s):  
G. C. Babcock ◽  
T. G. Bergman
Keyword(s):  
Speed Of Light

A Determination of the Speed of Light by the Phase-Shift Method

1969 ◽  
Vol 37 (8) ◽  
pp. 816-822 ◽  
Author(s):  
John Rogers ◽  
Ronnie McMillan ◽  
Robert Pickett ◽  
Richard Anderson
Keyword(s):  
Phase Shift ◽  
Speed Of Light ◽  
Shift Method ◽  
Phase Shift Method
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