<i>&gt; ergo cold fusion IS (currently) theoretically impossible</i><p>You can&#x27;t qualify &quot;theoretically impossible&quot; with &quot;currently&quot;, because that concedes the point. Honest theorists don&#x27;t say something is &quot;impossible&quot; unless it is known to be impossible, period; not just &quot;our current theories can&#x27;t explain it&quot;, but &quot;our current theories, in regimes where they are well confirmed experimentally, contradict it&quot;.<p>For example, the scam about a &quot;water-fueled engine&quot; is theoretically impossible--it&#x27;s not just that our current theories of chemistry can&#x27;t explain how such a thing would work; it&#x27;s that our current theories of chemistry <i>can</i> explain, in detail, why such a thing <i>cannot</i> work, based on a huge body of experimental knowledge about chemical reactions involving water.<p>That is not the case with cold fusion. Our current theories can&#x27;t explain how it would work, but they also can&#x27;t rule it out. The regime in question is not well explored experimentally. Honest theorists don&#x27;t make claims about something being &quot;theoretically impossible&quot; if the regime in question is not well explored experimentally. They may say it is &quot;theoretically extremely unlikely&quot;, but that&#x27;s an opinion based on someone&#x27;s judgment about how likely it is that something new will turn up in this experimental regime that our current theories don&#x27;t cover. It&#x27;s not the same as &quot;impossible&quot;.