&gt; <i>Theories that you can either prove or disprove and theories that bring no progress.</i><p>Of course you can &quot;prove&quot;&#x2F;&quot;disprove&quot; them, otherwise they wouldn&#x27;t be discussed by scientists but by philosophers or theologians. For theories to be different, there must be an experiment that in principle could be done, for which each of them predicts different result. If we get around doing that expriment, we&#x27;ll learn which theory is the right model.<p>This is an universal principle of science and applies at every level - both fundamentals and macro&#x2F;practical.