Born 1892 to a French noble family. De Broglie (pron 'de Broy') served as a radio communications technician during WWI, and it was in this capacity that he acquired the interest in physics that would win him the Nobel Prize in 1929. When de Broglie submitted his PhD thesis in 1924 he proposed the revolutionary idea that all matter displays wavelike behavior. This proposition caused much debate, but the examining committee approved de Broglie's doctorate despite the notable lack of evidence supporting his thesis. In 1927 experimental evidence verified de Broglie's proposal for electrons. Today his theory is generally accepted and is one of the basic propositions underlying modern quantum physics.

Louis de Broglie was a French physicist, most famous for his theories on what would become known as wave mechanics.

De Broglie was born Louis Victor Pierre Raymond duc de Broglie to Victor, Duc de Broglie and Pauline d'Armaillé, in Dieppe, France on 1892-08-15 and died in Paris on 1987-03-19.

For a really comprehensive bio of De Broglie, as well as his nobel lecture in pdf and his nobel banquet speech, see reference 1

De Broglie's work in physics:

"As in my conversations with my brother we always arrived at the conclusion that in the case of X-rays one had both waves and corpuscles, thus suddenly ... I got the idea that one had to extend this duality to material particles, especially to electrons. And I realised that, on the one hand, the Hamilton-Jacobi theory pointed somewhat in that direction, for it can be applied to particles and, in addition, it represents a geometrical optics; on the other hand, in quantum phenomena one obtains quantum numbers, which are rarely found in mechanics but occur very frequently in wave phenomena and in all problems dealing with wave motion."
De Broglie, 1963

This notion of extending the observed wave/particle duality of photons to include all particles is what De Broglie is remembered for . The first mention of the theory was presented as a note found in Comptes rendus, 1923. (Reference 2) His thesis "Recherches sur la Théorie des Quanta", ("Research on the Quantum Theory") for which he was awarded his PhD in 1924, included a more detailed explanation of the theory in the first chapter.

In his work, De Broglie derived the relation for the energy of a photon,

νh=E=mc2, giving λ=h/mc

Where E is energy, ν is frequency, h is Planck's constant, m is relativistic mass, c is the speed of light and λ is the associated wavelength.

He then extended this, by intuitive analogy, to apply to all particles. This produced what is now known as De Broglie's Relation:


Where p is the particle's momentum.

The theory was not taken seriously by the scientific community at first, but made its way into the hands of Albert Einstein who both read and built upon De Broglie's work. This in turn caught Erwin Schrodinger's eye, and it inspired him to begin work which resulted in wave mechanics.

De Broglie's work also explained Bohr's assumption about the angular momentum of electrons orbiting an atomic nucleus. This explanation is based upon the fact that if an electron is a wave, it would have to arrange itself about the nucleus in such a way as to reinforce itself and not create destructive interference.

It was the verification by C J Davisson & Lester Germer in the United States and George Thomson in Scotland of the wave nature of the electron (through experiments in electron diffraction by crystals) in 1927 that validated his theory. This final vindication ultimately won him the Nobel prize in physics in 1929 "for his discovery of the wave nature of electrons".

"He might not deserve his Ph.D., but you should at least give him a Nobel Prize."
Albert Einstein (from metafist's deleted node.)


  1. Nobel eMuseum -
  2. Comptes Rendus Note - Vol. 177, 1923, pp. 507-510 -
  3. Brittanica Nobel Prize -

Sections of my old article lie beneath... really needs significant manipulation to be any good.

Relativistic theory predicts that setting this particle in motion increases its relativistic energy, tending to infinity as we approach 'c'.

This increase in energy will cause time dilation which will increase the period and thus decrease the frequency of the wave nature of that particle. (they are inversely proportional)

A look at equation 1 will reveal that something wicked this way comes. From equation 1 the decrease in frequency should correlate to a decrease, not an increase in energy.

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