Fizeau

Thus the speed of light which has been measured by observers such as Fizeau and Foucault reveals itself as a function of the gravitational constant of the earth, and hence has validity for this sphere only. 1 The same is true for Roemer's and Bradley's observations, none of which, after what we have stated earlier, contradicts this result.

Man or Matter Ernst Lehrs

Photography was in its infancy -- and the widespread use of photography in astronomy was still decades away -- when Fizeau and Foucault turned their camera toward the brightest object in Earth's sky.

April 2, 1845: Photographing the Sun, Measuring Speed of Light 2007

A few years later, Fizeau and Foucault were both experimenting with methods to determine the speed of light .

April 2, 1845: Photographing the Sun, Measuring Speed of Light 2007

Fizeau, bouncing a beam of light off a mirror and through a cogged wheel, determined a speed of 313,000 kilometers per second.

April 2, 1845: Photographing the Sun, Measuring Speed of Light 2007

In 1845, Hippolyte Fizeau and Léon Foucault had made an image of the sun.

The Mercury Visions of Louis Daguerre Dominic Smith 2006

In 1845, Hippolyte Fizeau and Léon Foucault had made an image of the sun.

The Mercury Visions of Louis Daguerre Dominic Smith 2006

In 1845, Hippolyte Fizeau and Léon Foucault had made an image of the sun.

The Mercury Visions of Louis Daguerre Dominic Smith 2006

Fortunately for Michelson, a Frenchman named Armand-Hippolyte-Louis Fizeau had been left a fortune by his father, a doctor, and used his time and money to pursue his interest in optics.

Euclid’s Window Leonard Mlodinow 2001

One answer was the ether drag theory provided by Fresnel and seemingly confirmed, though not with such precision, by Fizeau.

Euclid’s Window Leonard Mlodinow 2001

Fizeau was interested in particular in designing a terrestrial apparatus to measure the speed of light, an undertaking Galileo had once envisioned.

Euclid’s Window Leonard Mlodinow 2001