# Who is the person behind the so-called “Boure's Law”?

When I was in college, specifically in Rigid Body Kinematics, I was taught that Boure's law or formula, which looks something along these lines: $$\left(\frac{\mathrm{d}\boldsymbol{\omega}}{\mathrm{d} t}\right)_{\text{fixed}}=\left(\frac{\mathrm{d}\boldsymbol{\omega}}{\mathrm{d} t}\right)_{\text{moving}}+\boldsymbol{\Omega}\times\boldsymbol{\omega}$$ which is pretty standard, and I'm sure it appears in most syllabi. It provides a way to calculate the derivative (in this case, the time derivative) of a vector respect the absolute frame of reference, given the derivative with respect to a moving inertial frame. Another similar example can be seen in this question.

My question is however who is Boure? Is it Bouré instead? Who used it for the first time instead of the more widespread total or absolute derivative, and when? Years later I only get a few results for this obscure naming. If I've tagged this question incorrectly or this is not the place to ask this, please tell me. Thanks.

• Which college textbook? – Qmechanic Apr 14 at 20:17
• It isn’t called that my country. Google seems to know nothing about “Boure’s law”, “Boure’s formula”, “Bouré’s law”, or “Bouré’s formula” so “obscure naming” is a good description. My guess is that this person is from whatever country the textbook author is from. I would have thought Euler found this formula, so it might be a French vs. German attribution issue. Of course, many formulas are found multiple times by multiple people, working independently without knowledge of the others. – G. Smith Apr 14 at 20:57
• Hi, perhaps your question is more suited for hsm.stackexchange.com? – Dvij D.C. Apr 14 at 22:54

## 1 Answer

This appears to be a case where a formula is named in one country, and those influenced by it, because a discoverer was from that country. However, other countries don't deem the formula significant enough to merit being named.

In this case, the above formula was discovered by the Frenchman Edmond Bour, and is known as the Bour formula. Notably, the Wikipedia page that formula appears on is only available in French.

The formula is also named in Spanish, however the surname is spelled Boure not Bour (see e.g. here and here).

• Thanks for the answer, Nick. You extinguished a long-time question of mine. Maybe the change from Bour to *Boure was a typo that passed down from books to teachers to students, etc.; or a way to make it sound more French? – sware Apr 15 at 12:38