It's only when you look at its properties on really big cosmological length scales, billions of light-years across, that you start to see the accumulative effects of the dark energy.

只有当你在真的很大的宇宙尺度下才能看到它的性质，数十亿光年的跨度，你开始看到暗能量的累积影响。

This is why the dot product with a non unit vector can be interpreted as 1st projecting onto that vector, then scaling up the length of that projection by the length of the vector.

这就是为什么与非单位向量的点积可以解释为首先投影到该向量上 然后将该投影的长度乘以该向量的长度。