“No thank you,” the Captain demurred. “We like corporeality, and do not find your means of conveyance desirable or convenient.”

“But it is ecologically and cosmologically sound! Your method, to the contrary, is polluting and harmful.”

This caught our attention. Only folk who have sensitivity to environmental concerns are allowed to colonize, lest we ruin the new planets we take under our care. This is not simply a matter of morality, but of self-interest, since our grandchildren will inherit the worlds we leave behind.

Still, the star-probe’s statement confused us. This time, I replied for the crew.

“Polluting? All we do is implode temporary micro black holes behind us and surf ahead on the resulting recoil of borrowed space-time. What can be polluting about adding a little more space to empty space?”

“Consider,” the COP probe urged. “Each time you do this, you add to the net distance separating your origin from your destination!”

“By a very small fraction,” I conceded. “But meanwhile, we experience a powerful pseudo-acceleration, driving us forward nearly to the speed of light.”

“That is very convenient for you, but what about the rest of us?”

“The… rest… The rest of whom?”

“The rest of the universe!” the probe insisted, starting to sound petulant. “While you speed ahead, you cause the distance from point A to point B to increase, making it marginally harder for the next voyager to make the same crossing.”

I laughed. “Marginally is right! It would take millions of ships… millions of millions… to begin to appreciably affect interstellar distances, which are already increasing anyway, due to the cosmological expansion—”