The alpha particles emitted by uranium and thorium were energetic and ionizing enough to create electron hole pairs in the silicone.

铀和钍发射的阿尔法粒子能量大， 电离性强， 足以在硅中形成电子空穴对。

So just as an example, a supermassive black hole pair that are orbiting each other with a period of 30 years would have a gravitational wave frequency of one nano hertz.

以 30 年为周期的一对互相围绕旋转的超大质量黑洞，其引力波频率为 1 纳赫兹。