You know the drill, it goes all the way back to Star Trek TOS.

The Drake Equation is a mathematical formula for estimating the number of intelligent alien civilizations humanity could communicate with.

Props to Dr. Frank Drake for being the first to give this topic some serious thought.

And props to him recognizing it’s impossible to derive an answer from it.

That hasn’t stopped science-fictioneers and popular science writers from speculating, or folks like Enrico Fermi from asking, “Where is everybody?”

Bottom line: We have a single reference point.

Us.  Our civilization.  This planet.  This solar system.  This galaxy.

Trying to extrapolate from that is like trying to figure out how to circumnavigate the world by sea using a thimble of water as our model.

In other words, utterly futile.

There’s a lot of unknowns rendering the Drake equation pointless and the Fermi Paradox pointlessness squared.

We know nothing about the conditions required for life to originate.

A current assumption is that evolution got an impetus thanks to lunar tidal effects, that the agitation of our primordial oceans sped up the mixing and matching of inert molecules into the first proto-life, and that rising and falling tides sped up the expansion of life to land by killing off any organisms that couldn’t survive low tide.

But what are the odds of that happening elsewhere?  The current hypothesis is that a moon-less Earth was clobbering in a collision with a Mars-size plan et fairly early in the formation of the solar system, and said collision was not so great to utterly destroy both planets, but just hard enough to knock loose a molten mass that perfectly fell into orbit around the Earth – a fraction more energy and it would sail off into space, a fraction less and it would eventually crash back on Earth.

Mighty fine shootin’, pod-nuh.

Of the three Earth-size bodies in our solar system, one apparently had surface water and a thicker atmosphere in the distant past but lost it due to its gravity packing only 38% the pull of ours (Mars), while another with 91% of our gravity is a broiling hellhole with a dense heat-trapping carbon dioxide atmosphere 92 times more dense than ours with an average temperature of 870 degrees Fahrenheit / 465 degrees Celsius (Venus).

In fairness, let us note that Venus lays just withing the edge of our system’s habitable zone (i.e., the range where surface water can exist on a world with a viable atmosphere), while Mars lays at the very outermost edge.

Once again Earth is the “just right” Goldilocks world in the middle.

But water brings up the next problem with speculation on intelligent life.

We assume water and carbon atoms and DNA and cell structure are needed for life to exist because we are the only example we have to go on.

Who says?

I’ll concede water and carbon sure make life as we know it easier to form, but that’s the kicker, isn’t it?

In trillions of galaxies with hundreds of billions of stars apiece, who know what conditions exist for life as we don’t know it?

Consider:  We require oxygen to exist.  Oxygen is the second most corrosive known element.  It’s so corrosive it can even kill organisms evolved to exist on this planet.

We have no idea how the presence of oxygen or water might affect evolution on other worlds in other solar systems. 

Maybe we’re typical.

Maybe we’re rare.

We don’t know.

Another issue is that of metabolism.  How might other forms of life perceive the universe around them?  Robert L. Forward’s novel Dragon’s Egg postulated a race of beings that live at such as fast rate of metabolism that they live and think a million times faster than humans;  conversely there are stories  about intelligent aliens who react so slowly to the universe around them that human civilizations rise and fall before they can finish saying, “Hello.”

And beyond the self-centered arrogance in presuming alien life would be similar enough to us for communication to be theoretically possible, who are we to judge at what technological level a civilization finds comfortable and sustainable?  For that matter, who are we to decree they must communicate using the same technology we do?

And that’s not taking into account that radio and television broadcasting is only about 125 years old.  Samuel Morse’s invention of the telegraph in the United States (similar efforts were independently developed in Germany at the same time) dates from 1837 yet fell out of favor in little more than a century and are now supplanted entirely by digital communications.  Even if using similar systems to ours, the radio / television window may open and shut just as rapidly for other civilizations.

All this is tertiary to even more basic issues: 

How do we define life?

How do we define intelligence?

For all we know, clouds may be alive and intelligent, capable of thinking great thoughts, feeling magnificent emotions, but because we can’t perceive anything in them that resembles organic life like us, we don’t even consider the possibility.

For all we know there’s a shadow biosphere here on Earth we’re completely oblivious to.  The universe might be crowded with life forms we simply can’t recognize as life.

For all we know, we know nothing.

“Man is the measure of all things,” said Protagoras.

Only on this world.

And even then, only maybe…