Are We Alone in This Universe.........?

I don’t know, and neither does anybody else. Anyone who says the probability is high is making a computational error. And all the evidence from people who claim they were abducted by aliens likely comes from people who have difficulty distinguishing reality from vivid dreams. (Psychologists know that this is a fairly common syndrome.)

There is no evidence for advanced extraterrestrials, and Enrico Fermi asked the obvious question: if they exist, why don’t we have overwhelming evidence? But perhaps their home is too far away for them to actually reach us. That’s the thesis of SETI, the Search for Extraterrestrial Intelligence. There is a famous formula called the Drake Equation that argues that the probability of such creatures is high. But the Drake equation does not make a compelling case. The problem is that we don’t really understand one of the terms in the equation: the probability that simple organic compounds, such as amino acids, will ever come together to form a molecule that can reproduce, such as RNA. We have no idea how that happened. The probability could be as low as ${10}^{-100}$. In that case, we might indeed be alone in the universe.

I am reminded of a story about a silicon-based life form. Some time in the future a very smart computer baby asks its mommy and daddy, “Who was the first computer? How did our life form come about?” The daddy answers, “We don’t know. We can understand how microprocessors can evolve and become supercomputers and eventually a being such as you and me, but we can’t figure out how that original microprocessor came about. Maybe it was spontaneous, just a bunch of silicon atoms happening to come together. But calculations show that is quite unlikely.”

The mommy and daddy have no idea that the first microprocessor was constructed by a former carbon-based life form. And I suspect that our RNA and DNA did not come together spontaneously, but resulted from some smaller organism, maybe a prion that after it evolved destroyed (ate?) all the other prions—just as the silicon-based computers in the story destroyed the carbon-based form that created it.

-Richard Muller