So when you spin them… they both wobble around a reference axis.

所以当你旋转它们的时候… … 它们都绕着参考轴摆动。

It balances itself around a line, a center point that physicists call the reference axis.

它绕着一条线来保持自我平衡，物理学家称之为参考轴的中心点。

But once you spin football in the air, it's reference axis gets a little more complicated.

但是一旦你在空中旋转橄榄球，它的参考轴就变得有点复杂了。

The ball takes off, pointing towards the air pushing against it, wobbling around its reference axis.

球起飞时指向空气，空气推着它，绕着参考轴摆动。

Gravity is pulling straight down, and the top is fighting this by spinning around wobbling around this vertical line, this reference axis.

重力是垂直向下的，顶部通过绕着这条垂直线摆动来对抗重力，即这条参考轴。

The air molecules like the tap on the table, the ball is going to want to wobble around its center line, its reference axis.

空气分子就像桌子上的水龙头，球会绕着它的中线——它的参考轴——摆动。