then you put them next to other things

然后把它们放在其它物体旁边
and they're attracted or repelled,

它们就会互相吸引或者排斥
and you discover you're charging things,

你发现你能使物体带电
and that's how electricity was discovered.

这就是发现电的过程
But you don't have to have a cat;

但是你不一定要用猫
if you have a buffalo, you can take it with a buffalo,

假如你有一头水牛你可以拿琥珀和它摩擦
it still works.

一样有用
Then, you got to find out what you really need to find electric forces.

然后你就得搞清楚你是怎样发现电作用力的
But you find there is a new force

当你发现有一个新的力
and you know you've got a whole new force to study;

你就有一个全新的力需要研究
then you got to find out what's the cause of the force.

你必须找出是什么产生了这个力
It turns out, it's not the mass of the object,

结果发现不是物体的质量