<story><title>Akin&apos;s Laws of Spacecraft Design</title><url>http://spacecraft.ssl.umd.edu/old_site/academics/akins_laws.html</url></story><parent_chain></parent_chain><comment><author>btilly</author><text>I love #6. &lt;i&gt;(Mar&apos;s Law) Everything is linear if plotted log-log with a fat magic marker.&lt;/i&gt;&lt;p&gt;People say lol a lot when they didn&apos;t really.  But I really did at that one.  Because I know exactly why it is true.  What&apos;s going on is that you have a high order term that dominates the big-O.  As long as that is anything of the form x^k it will be linear, and the lower order terms will show up as minor deviations, which the magic marker smoothes out.&lt;p&gt;Since big-O scaling terms of that form arise in a lot of different equations, it is very common that real data DOES show up as a (reasonably) straight line on a log-log graph.  And the slope of that approximate line tends to be very useful to know.&lt;p&gt;But if you see data set after data set plotted on log-log with magic marker lines drawn, it is easy to ridicule the phenomena. :-)</text></comment>
<story><title>Akin&apos;s Laws of Spacecraft Design</title><url>http://spacecraft.ssl.umd.edu/old_site/academics/akins_laws.html</url></story><parent_chain></parent_chain><comment><author>wlesieutre</author><text>&amp;#62; In nature, the optimum is almost always in the middle somewhere. Distrust assertions that the optimum is at an extreme point.&lt;p&gt;This one caught my eye as being only half right. As you increase something, you may get better performance up to a point but then see it level off and decrease. For instance, you could increase the fuel capacity by a factor of 10, but then you&apos;d need a larger engine, more powerful thrusters to maneuver it, etc.&lt;p&gt;On the other hand, the lower bound of &quot;don&apos;t do that at all&quot; is &lt;i&gt;frequently&lt;/i&gt; optimal. A lot of these cases are things that you&apos;d intuitively see as stupid ideas (ie &quot;how many lead weights should we bolt on to the fins&quot;), but in other cases they aren&apos;t. Like a fish that evolved away its eyes because they were no longer useful. (&lt;a href=&quot;https://en.wikipedia.org/wiki/Amblyopsidae&quot; rel=&quot;nofollow&quot;&gt;https://en.wikipedia.org/wiki/Amblyopsidae&lt;/a&gt;)&lt;p&gt;If you took the &quot;law&quot; too literally, you&apos;d be distrustful of saying &quot;These eyes aren&apos;t doing anything, let&apos;s have 0 of them.&quot; Don&apos;t be afraid to remove wasteful features.</text></comment>