Editing 1740 in science (section)

==Physics==
* [[Jacques-Barthélemy Micheli du Crest]] creates a spirit thermometer, making use of two fixed points, 0 for "Temperature of earth" based on a cave at [[Paris Observatory]] and 100 for the heat of boiling water.<ref>{{cite book|last=Hutton|first=Charles|title=A Philosophical and Mathematical Dictionary: Volume 2|year=1815|publisher=S. Hamilton|location=Weybridge, Surrey|page=509|url=https://books.google.com/books?id=lsdJAAAAMAAJ}}</ref>
* [[Émilie du Châtelet]] publishes ''Institutions de Physique'', including a demonstration that the [[kinetic energy|energy of a moving object]] is proportional to the square of its velocity (E<sub>k</sub> = {{frac|1|2}}mv²).
* [[Louis Bertrand Castel]] publishes ''L'Optique des couleurs'' in [[Paris]], including the observation that the colours of white light split by a [[Prism (optics)|prism]] depend on distance from the prism.