For one thing, it's not a perfect circle, it's quite an elongated ellipse.

至少不是一个标准的形，而更像是一个拉长的椭。

Remember too that the Moon's orbit around the Earth is an ellipse.

同样要记住的是，亮绕地球的公转道是个椭。

This ellipse has an important property called eccentricity.

椭有一个重要的性质，叫做离心率。

Not only that, the Moon orbits the Earth on an ellipse.

不仅如此，球绕地球公转的道是椭形的。

As Kepler showed, the earth's orbit is an ellipse, with the sun at one of the two focal points.

就像开普勒曾指出的，地球的道是个椭，相对以太阳为中心绕起来的话有两个焦点。

As the planet orbits the star, it makes a big circle (or ellipse) .

当行围绕恒运行时，它会形成一个大(或椭)。

Now, Newton predicted that the orbit of Mercury was an oval, or as scientists like to say " an ellipse."

牛顿预测的道是椭的，或者用科学家惯用的词，“椭形”。

Instead, they generally have a stretched version of a circle, which is technically called an ellipse.

相反，它们通常有一个形的拉伸公转，也就是椭。

It has two points, called foci, which act as a combined center for an ellipse.

它有两个点，称为焦点，作为一个椭的联合中心。

An ellipse with zero eccentricity would just be a regular old circle.

偏心率为零的椭就是一个普通的。

An ellipse is an asymmetrically shaped closed oval.

任何椭都是对称封闭的椭形。

The equation is a way to compare these axes to describe how squashed the ellipse is.

这个方程是比较这些轴来描述椭扁平度的一种方式。

And b is the semi-minor axis, or half the distance along the short axis of the ellipse.

b 是半短轴，或者说椭短轴的距离的一半。

Eccentricity measures how flattened an ellipse is compared to a circle.

偏心率衡量的是椭与相比的扁平度。

And as if they were cuboidal cells that got stretched tall, their nuclei also are stretched into an ellipse.

由于它们是立方体细胞，被拉伸得很高，它们的细胞核也被拉伸成椭形。

As eccentricity increases, the ellipse gets flatter and flatter until it just looks like a line.

随着偏心率的增加，椭会变得越来越平，直到它看起来像一条线。

Well, an ellipse is a shape that resembles a kind of squashed circle.

椭是一种类似于被压扁的的形状。

Its foci are two points within the ellipse that describe its shape.

它的焦点是椭内描述其形状的两个点。

Simply put, eccentricity tells how much the ellipse deviates from a perfect circle.

简单地说，离心率表示椭与正的偏离程度。

To those wondering what an extreme ellipse could be, there's a great example to look at Halley's Comet.

对于那些想知道什么是极端椭的人来说，有一个很好的例子，那就是哈雷彗。