**de Broglie's Quantum Equations**

**"**When you can measure what you are speaking about and express it in numbers, you know something about it.**"** - Lord Kelvin ( 1824 - 1907 )

**§ A short excerpt from "What is matter?", by Erwin Schrödinger, 1952:**

**"**We no longer contrast matter with forces and field of force as different entities, we know now that these concepts have to be merged. It is true, we call a spatial region free of matter, call it empty if there is nothing but a gravitational field. But space is never really empty because even far away in the universe there is starlight, and that is matter [ ... ] **"**

source: Erwin Schrödinger, 1952
Audio - document from the lecture **"**Was ist Materie?**"**
English translation: taken from the lecture
**"**Our Conception of Matter**"** given in 1952 organized by Rencontres Internationales de Genève, Geneva, Switzerland

**§ de Broglie's Quantum Equation:**

**Examples of Determining de Broglie's Wavelength**^{∗}

**Problem 1:** Find the de Broglie wavelength of a wave - particle whose total energy,

is .

**Solution:**

**Problem 2:** Find the de Broglie wavelength of earth whose rest or proper mass is .

**Solution:**

^{∗}

note: some of these examples are used in the future upcoming Relativity Calculator Mac application for de Broglie's quantum equations.

**§ References:**

**"**Recherches Sur la Théorie des Quanta**"**, par M. Louis de Broglie, Annales de Physique, 10^{e}Série, Tomé III, Janvier - Février, 1925, pgs 21 - 128, the original French version of de Broglie's original 1927 Phd. thesis- A translated version of de Broglie's original 1927 Phd. thesis, by A.F. Kracklauer, 2004