Are we alone? Some hope we are. Some pray we are not. It is possibly the most human of questions we pose to search for a cosmic answer. Beyond crop circles, UFO sightings, your brother's theories about the pyramids and a neighbor's conspiracy tales, Carl Sagan reminds us, "Extraordinary claims require extraordinary evidence."
Perhaps our evidence lies in the language of mathematics, regarded by many as the universe's Rosetta Stone.
"Nature's great book is written in mathematical symbols." Galileo Galilei
If nature is mathematics, then our evidence could be whatever computation we put our faith in. And, as it turns out, most of the complexities of our world, and thus worlds yet to be discovered, can be simply stated.
Here are some of the numbers:
The Drake Equation: NL
The number of civilizations in the galaxy is approximately equal to the average lifetime, in years, of a civilization.
The universe is made up of a trillion galaxies. It is for all intents and purposes infinite. G.F.R. Ellis and G.B. Brundrit of The University of Cape Town argued that in an infinite universe anything that can happen will happen, and happen infinitely often.
The first century B.C. Roman Writer and Philosopher Titus Lucretius Carus stated:
"It is in the highest degree unlikely that this earth and sky is the only one to have been created and that all those particles of matter outside the Earth are accomplishing nothing."
But the above mathematical arguments are not evidence, only logic.
Aliens hoping for contact would try to make their messages easy to understand.
Certainly, mysteries abound. Etruscan records are, as yet, unable to be translated. They consist of 281 handwritten lines on linen, assumed to be part of a book cut into strips and used to wrap an Egyptian mummy. The Voynich manuscript was written in a language with no other known example. Dated, as early as 1586, the manuscript is one hundred-plus pages and written in script.
Richard Fynnman, Nobel Prize Winning physicist once remarked that there is enough energy in a cubic meter of spaceany space, anywhere to boil all the oceans of the world. If this can be tapped, travel to the planets and even the stars will become less expensive and easier. Heck, I'd settle for a cheaper way to get groceries at the grocery store.
Are these mysteries evidence that either we have been visited by or that technology could exist to be visited by extraterrestrials?
Lynn Harper, NASA Ames Research Center, states, "Comets and meteroids are nature's enforcers, bringers of water and photocells, destroyers of species, enablers of intelligence, harbingers of change."
Dr. Ben Bova says in his book "Faint Echoes, Distant Stars" that it has been estimated that 40,000 tons of extraterrestrial material (mostly microscopic dust particles) bombard the Earth each year.
Perhaps a living cell is among the yearly extraterrestrial debris. Or, perhaps, we are all extraterrestrials here as a result of an ancient bombardment of our planet by comets and meteroids that planted the seeds of our existence.
Could the most compelling evidence come from ancient accounts?
"Reports of flying craft and human-like occupants trace back to antiquity. Reports merge with religion or superstition in a seamless manor. Most striking biblical account is in Ezekiel who describes an encounter with four flying wheel-shaped craft full of eyes' that turned as they went' and out of which stepped the likeness of a man.'" From the book "Are We Alone?" by Paul Davies.
Some is evidence of a kind, but certainly not the extraordinary evidence called for by Carl Sagan and others. The old adage may prove true in this case "seeing is believing." If you do spot an alien, be sure to ask him or her for some evidence; a mysterious manuscript, maybe; or a new technology we all can't live without, like Velcroe.
On a more serious note, I think the only way we will better understand the universe, ourselves, and be able to interpret the evidence we might happen across will be to bring Astronomy into our schools.
"Astronomy is not taught in the public schoolsa student can pass from first to twelfth grade without ever encountering any of the findings or reasoning processes that tell us where we are in the universe, how we got there, and where we are likely to be going" Carl Sagan
Perhaps our heirs will look to the stars one day in search of their survival. I hope they will be able to read the signs.