Buchanan Renewables President Joel Strickland says it is a low-cost, intermediate solution to Liberia's energy needs, while repairs to the Mt.Coffee hydroelectric facility are at least five years away.

VOA: standard.2009.09.13

But the mathematicians told Dirac, "You cannot ignore the negative energy solution because it tells you there's a second solution and you cannot throw them out."

但数学家们告诉狄拉克,你不能忽略负的能量,因为数学告诉我有两个根,你不能随便丢掉

耶鲁公开课 - 基础物理课程节选

And it turns out the second solution, with negative energy, was when the theory is telling you, hey, there are particles and there are anti-particles, and the negative energy when properly interpreted will describe anti-particles.

结果,后来证明,第二个根,也就是能量为负的那个根,正是理论的关键,世界上既有粒子,也有反粒子,负能量就是用来解释反粒子的

耶鲁公开课 - 基础物理课程节选