And, ALSO as with gravitation, this force has its own proportionality constant.

和重力一样，这种力 它有自己的比例常数。

This ingenious little equation relates mass and energy by a simple proportionality constant, and thanks to Einstein we know that constant is the square of the speed of light, or c2.

这个巧妙的小方程通过一个简单的比例常数将质量和能量联系起来，感谢爱因斯坦， 我们知道该常数是光速的平方， 或 c2。

The equation uses a proportionality constant called the Hubble parameter, which says that for every million light-years of distance from us, a galaxy is moving away at an additional 21 kilometers per second.

该方程式使用一个称为哈勃参数的比例常数，它表示距离我们每百万光年的距离， 一个星系以每秒 21 公里的额外速度移动。