For certain wavelengths of light, routers along that path would accept signals coming in from only one direction and send them off in only one direction.

这条链路上的路由器对某种特定波长的光束，只接受从一个方向进入的信号，也只向一个方向发送这些信号。

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A directional light doesn't have a position, only a direction.

定向光没有位置，只有方向。

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Regular light vibrates in all directions perpendicular to its direction of travel; polarized light, however, vibrates only in one plane.

正常光线向各个方向振动垂直的飞行；但是偏振光只有在一个平面上振动。

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For that to work, each lens must respond to light coming from only one direction.

ECONOMIST: Brittlestar eyes

And when such a collision does occur, the pattern of light produced gives away not only the type of neutrino, but the direction it was travelling in.

ECONOMIST: Neutrinos

It's another boat, traveling rapidly in the opposite direction, hugging the Brooklyn shore, with only the green starboard light visible.

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