It is locally convex in the sense that it has no loops and the curvature never changes sign.

它的局部是凸的，因为它没有环路，且曲率永远不会改变符号。

The hyperbolic surface, which has so-called negative curvature because its surface curves up and down at the same time, like a saddle.

双曲曲面，即通常所称的负曲率，因为它的表面同时向上和向下弯曲，就像一个马鞍。

Curvature of the surface prevents slump block from becoming completely detached.

表面的曲率防止滑塌块完全脱离。

If the universe has a positive curvature, it's a closed universe.

正曲率的宇宙是封闭的宇宙。

It goes back... Actually, some of you may be able to see the curvature.

它回来了。，事实上，你们有些人，也许能看到曲率。

Matter, energy and dark energy all produce curvature in space-time, however.

而事实上，物质、能量和暗能量在时空中都会产生弯曲。

Any farther away, and the system encounters problems due to the curvature of the earth.

由于地球表面弯曲，距离更远时，系统就遇到问题。

Because at that height you can see the blackness of space and the curvature of the earth.

因为在那个高度你可以看到太空的漆黑和地球的轮廓。

Technically, it occurs when the rate of curvature between 2 continuous surfaces are the same.

从技术上讲，当两个连续曲面拥有同样的曲率时才会出现。

Negative curvature is a little trickier to visualize. The most common description is a saddle.

了解负曲率宇宙要动点脑筋，最常见的描述就是它像马鞍。

Rickets is a degenerative bone condition that can lead to curvature of the spine and bone fractures.

佝偻病是一种骨髓退化状态，它会导致脊椎和骨质结构的弯曲。

the radius of curvature of our arc, which is also an air track, equals 115 plus or minus five meters.

,这个弧度的半径，也是个空气轨道，等于115上下5米。

The light gradually fades along the curvature of the Earth, until it is pitch black on the night side.

的照耀下像上了一层暖色的颜料。 日光在地球表面的弯曲下逐渐消失，直到另一头漆黑一片。

In a negative curvature model, two lines that would be parallel on a flat plane will extend away from each other.

在负曲率模型下，平面上平行的两条线可能彼此远离。

Space can have positive curvature, like the surface of a sphere, or negative curvature, like the surface of a saddle.

空间可以向球面一样有正的曲率，也可以像马鞍面一样有负的曲率。

When it is curved, the law of its curvature seems to be at the least of the first and at the most of the second order.

当它是曲线的时候，其弯曲的法则看起来至少是一阶至多是二阶。

Researchers coordinate the curvature of the lens and the detector in order to create an image that is magnified and in-focus.

研究者通过调节镜头和感光元件的曲率，就能产生可放大和聚焦的图像。

The curvature of the earth is clearly visible, highlighted by the electric blue of the atmosphere just above the horizon.

地球的轮廓清晰可见，被地平线上的铁蓝色大气层照亮。

The bowl's curvature is like a rule that inputs the marble's entry point and returns the lowest point, the bottom of the bowl.

碗的曲率就像是一个规则，输入弹球的入口点，然后返回最低点，即碗底。

A more complicated curvature would be like a function that inputs an entry point and returns one of several local lowest points.

更为复杂的曲率将类似于一个函数，它输入一个入口点并返回几个局部最低点中的其中之一。

These waves of curvature in space-time are known as gravitational waves and will temporarily distort any object they pass through.

使时空弯曲的波纹被称为引力波，引力波能使任何穿过它的物体暂时扭曲变形。

While another features a bend of green light following the curvature of the earth and almost appearing to slice through the starry sky.

另一张图片上绿光跟随大地弯曲，在布满星星的夜空这些绿光好像变成了一片一片。

An American science student has captured images of the curvature of the Earth after sending a balloon into space on a shoestring budget.

美国一名理科生投入小成本向太空发射了一个气球，拍摄到地球表面图像。

Aurora-inspiring: This image shows the green beam of the Northern Lights cutting through the night sky as it tracks the curvature of the earth.

神奇的极光：这张照片显示，绿色的极光穿过夜空，随着大地的曲线弯曲。

Then, with a few assumptions about the curvature and contents of the universe, they can reconstruct the positions of those objects from redshifts.

然后，通过一些关于宇宙曲率和内容的假设，科学家们能够重建这些物体的位置。