Wednesday 18 April 2012

de Broglie Wavelength

Louis Victor Pierre Raymond duc de Broglie (1892-1987), or simply just Louis de Broglie, was born in Dieppe, France and is most famous for his theory on particle-wave duality in 1924.  As well. for receiving a Nobel prize in 1929 "for his discovery of wave nature of electrons."  He studied in Paris until 1909 and then went to the University of Sorbonne to take an interest in literary studies and history.  He graduated in 1910 with an Arts degree; but, he found himself interested in sciences and at 21 years old, in 1913, he got his second degree.

In 1924, de Broglie delivered his thesis on "Researches on the quantum theory" to the science faculty at the Paris University.  He suggested that if a light could behave as a particle then particles should be able to behave as waves.  He was then convinced that the production of a wave can be associated with the motion of a particle, whether it be a photon, proton or an electron.  He started by assigning a frequency to a wave that accompanied a particle through space and time; then related that wave with the motion of the particle and then actually measured the wave. de Broglie was then able to come up with a mathematical equation that described his idea about photons.
λ = wavelength (in meters)
h = Planck's constant
m = mass of moving particle (in kg)
v = velocity of moving particle (m/s)

At the time, this idea seemed very ridiculous to other scientist but it only took a couple of years to confirm de Broglie's wavelength equation theory.