Look at them, the bugs. Humans have used everything in their power to extinguish them: every kind of poison, aerial sprays, introducing and cultivati… - Liu Cixin

Ye felt this interminable wave was an abstract view of the universe: one end connected to the endless past, the other to the endless future, and in the middle only the ups and downs of random chance — without life, without pattern, the peaks and valleys at different heights like uneven grains of sand, the whole curve like a one-dimensional desert made of all the grains of sand lined up in a row, lonely, desolate, so long that it was intolerable.

The key is to set up some rules: which combinations of motion vectors are “healthy” and “beneficial,” and which combinations are “detrimental” and “harmful.” The former receive a survival advantage while the latter are disfavored.

In technological terms, space voyages and environmental protections seem different in character, with the former being intense, high speed, and adventurous, with connotations of state-of-the-art technology, while the latter is a gentle green public-service activity, one which, though involving technology, doesn’t give the impression of being as difficult as the former.
But that is only an impression. The true situation is: If we want to achieve the present targets for environmental protection, the technology needed is more difficult to develop than that for large-scale interplanetary travel.