De Broglie's proposal
• Louis de Broglie (1892-1987) was a physicist famous for his quantum theories and his terrible haircut.
• FUN FACT: It's pronounced "de Broy"
• In 1923, he published several papers on light quanta and prepared his doctoral thesis, in which he whined that nobody has managed to prove whether light was a particle or a wave.
• His stroke of genius came when he equated the energy of mass and the energy of a wave
(1)
$$E = hf | E = mc^2$$
(2)
\begin{align} \therefore hf = mc^2 \end{align}
(3)
\begin{align} mc = \frac{hf}{c} \end{align}
(4)
\begin{align} \therefore p = \frac{hf}{c} \end{align}

#### de Broglie's proposal

• Through that he claimed that: "All matter has both particle and wavelike properties.
• He developed the idea mathematically, linking all mass with a wavelength known as matter waves.
• This wavelength can be found by:
(5)
\begin{align} \lambda = \frac{h}{mv} \end{align}
• Where:
• $\lambda$ is the "de Broglie wavelength (m)
• h is Planck's constant ($6.626 \times 10^{-34}$
• m is the mass of the object (kg)
• v is the object's velocity ($ms^{-1}$)
• de Broglie's proposal revolutionised modern physics and gave birth to the new field of quantum physics.
• Quantum Physics was a field where the wave-particle duality of matter is focused on.
• de Broglie's mathematical delvings and his proposal that electrons could be diffracted had great impact on the scientific community.
• This new field of physics attracted other major scientists, like Pauli, Heisenberg, Schrodinger, Dirac and others.
• These scientists developed a detailed theory known as quantum mechanics
• Quantum mechanics describes a set of physical laws that apply to objects smaller than the size of an atom.
• Also, it is shown later that De Broglie's allowed Bohr's stationary states to be adequately explained.
page revision: 4, last edited: 03 Nov 2011 06:08