Magazine article American Scientist


Magazine article American Scientist


Article excerpt

Alone in the Universe?

To the Editors:

I found Howard A. Smith's article "Questioning Copemican Mediocrity" (July-August) interesting, especially the discussion of the radius within which we might reasonably hope to communicate with alien life forms. His article also reminded me why I've long thought that the last term in the Drake Equation, which famously estimates the number of intelligent extraterrestrial civilizations in our galaxy, is the most significant in understanding the Fermi Paradox.

Among the many factors in the equation that Frank Drake considered in 1961, the length of time that a technological civilization releases detectable signals into space now seems the weakest link. We have been releasing such radio signals for barely more than 100 years. It seems possible that within another 100 years there will be no one left on Earth sending such signals. Our exploding population, rapid exhaustion of the necessary resources to support a technological civilization, already visible destruction of a climate and environment that can sustain life on Earth, and threats of nuclear annihilation-all of these suggest that perhaps no technological civilization that evolves anywhere in the universe lasts long enough to broadcast its existence for a sufficient amount of time to be found by another short-lived technological civilization.

I presume that whatever direction evolution might take on other planets will be governed by the same principles that Charles Darwin discovered here on Earth. Like us, such planets' intelligent species (if any) will find it difficult or even'impossible to overcome their tendency to overpopulate a?id overexploit their ecological niche, ultimately leading to their rapid extinction or reduction to a pretechnological state of living. If there is intelligent life on other planets, it is most likely to be either preindustrial or post-technological. In either case, we wouldn't be likely to find it.

If my speculations are true, Smith's plea that we treat our special planet with more respect takes on even greater significance. We may indeed be alone, but in case we are not, perhaps we should try harder to last long enough to be found.

John Cushing

Evergreen State College (Emeritus)

Bend, Oregon

Dr. Smith responds:

I thank Dr. Cushing for his comments.

I think that the most uncertain factors in the Drake Equation are the ones estimating the proportion of planets harboring conscious life, because we know the least about them. Regarding the lifetime of civilizations, however, Stephen Hawking famously echoes sentiments similar to Dr. Cushing's when he speaks out against contacting aliens. He simplistically claims that because they will be much more advanced than we are and presumably will have also evolved through Darwinian processes, they will be, to his way of thinking, dangerously violent.

I am more hopeful than either Dr. Cushing or Hawking; after all, evolutionary biologists have pointed out that sentiments such as altruism and gratitude are also the products of evolution. My opinion is that if an advanced civilization is able to last more than a few millennia without destroying itself or its world, it will have learned how to master its negative impulses. Perhaps the biggest benefit we can derive from challenging our cosmic mediocrity is the added impetus to learn this lesson ourselves.

To the Editors:

In his recent feature, Howard A. Smith seems to be asserting that the fact of something being rare means that it is necessarily special. …

Search by... Author
Show... All Results Primary Sources Peer-reviewed


An unknown error has occurred. Please click the button below to reload the page. If the problem persists, please try again in a little while.