Am I sure?  I&#x27;ve done no verification.  But while I&#x27;m occasionally frustrated with the holder of that account I&#x27;ve seen no particular reason to believe that they are not who they claim to be.  I am sure that the account holder claims to be Paul Lutus, as the link is on his profile.<p><i>&#x27;How is it possible that someone with a &quot;wide background in science&quot; has not heard about conservation of momentum?&#x27;</i><p>It&#x27;s probably not; but this comment thread (wading through the jibes, snipes, and nonsense) doesn&#x27;t seem to demonstrate with much clarity that he hasn&#x27;t.