The answer is in the center of mass.

答案就是质心。

There's a simple way to figure out where the center of mass is.

有一个简单的方法找出质心。

Within a given supercluster, all galaxy motions will be directed inward, toward the center of mass.

而在超星系团内部，所有星系都是向内部质心运动。

Three times heavier and the center of mass will be three times closer. And so on.

重三倍，质心的位置就进三倍，以此类推。

The center of mass is a pointsomewhere along the plank that holds the two kids where their average weight falls.

质心是跷跷板上支撑两个孩子平均重量的一个点。

An important thing to note is that we measure gravity from the center of mass of an object, not its surface.

需要注意的一件重要的事情是，我们测量引力是从一个物体质量的中心点开始的，而不是从它的表面开始。

So, what is the center of mass?

那么，什么是质心？

I like to think of as the center of mass of evidence.

我喜欢将其视为证据的中心。

In these situations, it’s more useful to describe what the center of mass is doing.

在这些情况下， 描述质心在做什么更有用。

In these situations, it's more useful to describe what the center of mass is doing.

在这些情况下，更多的描述是有用的 质心的动作。

One way to think of the center of mass of an object is the average position in an object of all its mass.

考虑物体质量中心的一种方法是考虑物体所有质量的平均位置。

They deduced the center of mass between the two heavyweights and found that Andromeda may indeed be twice as massive as the Milky Way.

他们根据二者的重量级推导出质心，然后发现仙女座也许真的是银河系的2倍。

Timing and smooth execution are essentials in a sport but understanding enough physics, particularly the torques in the center of mass is also necessary.

在一项运动中，时机和流畅的执行是必不可少的，但了解足够的物理，特别是质心的扭矩也是必要的。

That means the center of mass will be two thirds of the way along the stick, closer to the 4 kilogram ball.

这意味着质心将位于杆的三分之二位置，更靠近 4 公斤重的球。

We also talked about the differences between elastic and inelastic collisions, and how to calculate the center of mass of a system.

我们还讨论了弹性碰撞和非弹性碰撞之间的区别，以及如何计算系统的质心。

It's actually, they're both rotating around the center of mass of their combination, that just happens to be so much closer to Earth.

事实上，它们都围绕其组合的质心旋转，而质心恰好离地球更近。

It’s like each piece of mass pulls on the center of mass a little bit, so parts with more mass end up pulling harder and moving it closer.

这就像每一块质量都会稍微拉动质心，所以质量更大的部分最终会更用力地拉动并使它靠得更近。