But it would take a telescope with the effective diameter of the sun to actually take photographs of something the size of an elephant strolling on an exoplanet only 4.3 light-years away.

但是，假设距离我们仅有4.3光年远的一颗系外行星上，有一头徜徉漫步的大象，我们如果要拍到它，也得使用一个直径有太阳那么大的望远镜。

youdao

The amount of energy that a flywheel will store for a given change in speed depends on its inertia, which, in turn, depends on its mass and its effective diameter.

由于速度的特定变化飞轮存储的能量大小取决于其惯性，其惯性反过来取决于飞轮的质量与有效直径。

youdao

Using advanced technology, sewage capacity, non-clogging, effective through 30 to 80 mm diameter solid particles.

采用先进技术，排污能力强，无堵塞，能有效地通过直径30 ~ 80毫米的固体颗粒。

youdao

SKA's proponents are talking of scattering its sub-telescopes over an area of 1m square kilometres, which would create an effective diameter of about 1, 000km.

ECONOMIST: Radio telescopes

If the collecting area is in pieces, the effective diameter (the distance between the two most widely spaced pieces) can be several thousand kilometres.

ECONOMIST: Radio telescopes