La Lettre de l'Académie des sciences n°37-38

37 38

La Lettre

Augustin Fresnel

(1788-1827)

Thomas Young

(1773-1829)

In France, Augustin Fresnel developed the wave

model at a contest launched by the Académie des

Sciences. In parallel, Thomas Young conducted

his work in England.

Wave VS corpuscular theories

Young and Fresnel had to fight to impose this model, as evidenced by the story of Poisson’s bright spot,

which introduces members of the Académie who were most... bright.

1819 was the year, and the Académie des Sciences had sponsored a contest on the diffraction of light, in

other words, on the fact that, in the zone of transition between the shadow of a screen and an illuminated

zone, fringes are observed, that is, alternating shadows and light. Fresnel, a young and brilliant mind

educated of the École polytechnique, and who was a student

of the member of the Académie Arago, presented a

memoir describing his experiments and giving

the problem a complete mathematical

treatment, based on a convincing

wavemodel. Manymembers of the

Académie, though, were eminent

scientists, whose works were

based on Newton’s mechanics,

and they would not admit that

Fresnel questioned their hero,

even in a field other than mechanics.

Siméon Denis Poisson, one of the