why can we see any stars at all?

NYTimes |  You might think the discovery of microbes on Mars or fish in the oceans of Jupiter’s moon Europa would have scientists dancing in the streets. And you would probably be right.

But not everyone agrees that it would be such good news. For at least one prominent thinker, it would be a “crushing blow.”

That would be Nick Bostrom, a philosopher at the University of Oxford and director of the Future of Humanity Institute there, one of the great pessimists of this or any other age.

In an article published in Technology Review in 2008, Professor Bostrom declared that it would be a really bad sign for the future of humanity if we found even a microbe clinging to a rock on Mars. “Dead rocks and lifeless sands would lift my spirit,” he wrote.

Why?

It goes back to a lunch in 1950 in Los Alamos, N.M., the birthplace of the atomic bomb. The subject was flying saucers and interstellar travel. The physicist Enrico Fermi blurted out a question that has become famous among astronomers: “Where is everybody?”

The fact that there was no evidence outside supermarket tabloids that aliens had ever visited Earth convinced Fermi that interstellar travel was impossible. It would simply take too long to get anywhere.

The argument was expanded by scientists like Michael Hart and Frank Tipler, who concluded that extraterrestrial technological civilizations simply didn’t exist.

The logic is simple.