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<p>[QUOTE=&quot;-jeffB, post: 2762447, member: 27832&quot;]Everyone understands how grease behaves when you smear it around on a surface, and how water behaves when you do the same thing.</p><p><br /></p><p>I don&#039;t think everyone understands how each behaves when pushed against a metal planchet with many tons per square inch of pressure. (I certainly don&#039;t.)</p><p><br /></p><p>What I <i>do</i> know is that both are effectively <i>incompressible</i> at pressures like that, so I&#039;d expect them to behave similarly. They have different viscosities, but I don&#039;t think that would make much difference at those pressures and striking speeds.</p><p><br /></p><p>I don&#039;t think I agree that grease is &quot;a solid, not a liquid&quot;, but I don&#039;t have the material-science background to back it up.</p><p><br /></p><p>I do have enough chemistry background to know that water&#039;s boiling point under tons per square inch of pressure isn&#039;t 100C. I&#039;m sure the striking pressure is well above water&#039;s critical pressure (around a ton and a half per square inch), so any water on the planchet <i>can&#039;t &quot;boil&quot; at all</i> during striking. Supercritical fluids are really interesting, but again, I&#039;m in no position to teach about them.[/QUOTE]</p><p><br /></p>

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