The sky is teeming with life

The sky is teeming with life. Our Milky Way Galaxy alone has more Earth-like planets around sun-like stars than the number of humans who have ever lived. Including the planets in the Goldilocks zones around other glowing bodies expands the list of sites hospitable to life as we know it. Maybe we could count them on all the human fingers there ever were. Our Milky Way is just one of billions of galaxies—each with it’s own cloud of habitable planets. Life is everywhere out there.

If life is common, why haven’t we found it yet? Are aliens ignoring us or avoiding us? Or are space and time just too vast for a chance encounter?

Cosmic distance scales are as incomprehensible. Even the shortest interstellar hops take hundreds of thousands years. With nothing remotely detectable to recommend it, Earth would be just one among billions of candidate planets to visit. Why bother? We’re way out in the diffuse suburbs of the galaxy. Certainly there’s a better selection of planets nearer the dense core of the galaxy. Alien visitors would need technology far beyond our own. Those in Dead Astronauts were a hundred times ahead of us. Their journey from the nearest star still took a thousand years. A thousand years and the gross national product—they’d need a pretty good reason to take such a trip

Maybe a call would be faster and cheaper. It would go through at light speed without costing an arm and a leg—or whatever aliens have. Cosmic distances challenge signals too. Each bit of a signal is a pulse of energy. As the signal spreads out, that energy stretches over a wider area. The signal fades like your favorite radio station as you drive out of town. Focusing could help—if we were the target—but there are limits. Light can’t focus like it did in high school science. Quantum mechanics imposes a minimum spot size. The bigger the optics and the shorter the light’s wavelength: the smaller the spot. The alien visitors in Dead Astronauts used the system we would need if we went to visit them: a xenon fluoride ultraviolet excimer laser and mirrors the size of a football field. That’s what it would take for ET to phone home.

Would our neighbors even have noticed us yet? We’re a flash in the pan. Think about cosmic time as a line stretching from the Big Bang in Los Angeles to today in New YorkCity. Things would be hot and moving fast in Los Angeles. The first stars would begin to form before San Bernardino. The swirling cloud that would become our sun and its solar system would appear in southern Illinois. Dinosaurs would arise around Jersey City—thirty miles from the end of the line. Humans would evolve over the Hudson River—a third of a mile ago. Science has only been studying the sky since Galileo’s telescope—five inches back. Radio transmission started two inches ago. We’ve started listening in the last inch. What if they called while there was nobody here to answer the phone?

You won’t hear them. You won’t see them. But they’re there. There’s life strewn all across the sky. Earth is not unique. It’s just one of billions of planets filled with intelligent beings all wondering Are we alone? The answer is NO.