translation.en: So you're reusing your energy five or six times, and that brings the efficiency up between 30 and 40 percent It's a little known, but brilliant, genius invention of Robert Stirling that takes the hot air engine from being somewhat impractical -- like I found out when I made the real simple version in high school -- to very potentially possible, once you get the efficiency up, if you can design this to be low enough cost.
translation.zh: 你就能够重复使用你的能量5-6次。 将效率提高到30-40个百分比。 这项Rober Stirling 的发明很少被人知道，但却非常的聪明地 将热空气机从不实用-- 就如我在高中时所认为的那样-- 变为非常地有潜力， 一旦你可以以较低的投入设计出这种引擎，那么效率就会提高了。