Yeah, good. So, they're actually helium atoms, helium ions. And this wasn't really important for the studies, it didn't matter that didn't know what they are but it's nice to kind of know now - that we do know what they were using.

氦粒子，这对他们的研究并不重要,他们并不需要知道它是什么,但我们最好知道,他们当时用的是什么。

麻省理工公开课 - 化学原理课程节选

Some people may wonder why we in the Northern Hemisphere have our spring and summer when our planet is far away from the sun. (Equally confusing: our fall and winter come when we are near to the sun.) Shouldn't proximity to that nice warm ball of sunshine predict our seasons?

NPR: Not All Seasons Are Created Equal