&gt; the absence of known danger is not the same as safety.<p>Feynman had some interesting comments on this problem regarding NASA&#x27;s &quot;it worked ok last time&quot; approach to risk assessment before the Challenger Disaster.<p><a href="https:&#x2F;&#x2F;www.youtube.com&#x2F;watch?v=4kpDg7MjHps#t=150" rel="nofollow">https:&#x2F;&#x2F;www.youtube.com&#x2F;watch?v=4kpDg7MjHps#t=150</a>