I&#x27;m upvoting based on this sentence:<p>&gt;  Beeckman understood that, lacking lasers, the basis of any good scientific experiment should always involve explosions of some kind; thus, his experiment involved detonating gunpowder.<p>Incidentally, it&#x27;s quite interesting to me that the most accurate measurements of <i>c</i> are actually indirect measurements.  See <a href="https:&#x2F;&#x2F;en.wikipedia.org&#x2F;wiki&#x2F;Speed_of_light" rel="nofollow">https:&#x2F;&#x2F;en.wikipedia.org&#x2F;wiki&#x2F;Speed_of_light</a>