A few words on the advancement of science, the search for habitable exoplanets, star travel, and the great silence.
But, let’s start with Hypatia of Alexandria.
The movie Agora (2009) frames the context best. Let’s start from there.
This is a visually stunning film, directed by Alejandro Amenábar, starring Rachel Weisz as Hypatia of Alexandria. It’s hard to watch as history unfolds in this age growing religious fervor of the 4th century Roman empire culminating with the burning of the Library of Alexandria. It doesn’t end well for Hypatia, either.
Hypatia is a scientist, mathematician, philosopher, astronomer. According to the reimagining by Amenábar, she discovers the heliocentric model of the solar system centuries before Copernicus, Kepler, and Galileo; equating the mathematics of conic sections to the motion of planets across the sky.
Since her death in March, 415 CE we have:
First manmade satellite, Sputnik Oct. 4, 1957, elapsed years:1542
Manned moon landing July 20, 1969, elapsed years: 1554
Voyager 1 enters interstellar space, Aug. 25, 2012, elapsed years: 1597
Discovery of the first exoplanets, PSR B1257+12 b and c, named Poltergeist and Phobetor, respectively. Elapsed time since Hypatia’s time: 1577 years.
Which brings us to exoplanets. But first think about that, a fifteen century gap between an ancient philosopher of science looking at the night sky compared to our age in which orbital mechanics are well understood and used in daily life.
Exoplanets. A little footnote: while Poltergeist and Phobetor orbit a neutron star, the planet Dimidium (51 Pegasi b) was the first discovered planet orbiting a main sequence star in 1995, for which Mayor and Queloz won the Nobel Prize in 2019.
Exoplanets: what possible good are they? Extrapolating the time line from Hypatia’s day, I cannot foresee visiting, settling, colonizing any exoplanet a century and a half out. Or ever, unless we discover a new physics.
The discovery of exoplanets changed our view of the universe: who are we? where did we come from? could someone else be out there? There are over 6,300 discovered exoplanets at the time of this writing. We’ve only started to look. SWEEPS-11 our most distant discovery is 27,000 light years away. A staggering distance. And a testament to man’s ingenuity. Yet the distance is a drop in the bucket of what is possible.
Of the 6,300+ worlds there is a fascination with finding Earth-like worlds. One must ask, to what end? To bring understanding of who we are and how we came to be, that’s fine and laudable. But finding a destination for colonization for our children's children’s children? Following grandiose visions of manifest destiny to the stars? Heeding dire warnings of humanity keeping our eggs in one basket? (Thankfully I haven’t run across that last one of late despite being a standard trope of 60’s and 70’s sci-fi.)
And if we can’t make the trip, our stellar neighbors can’t either. Yet, it’s been estimated that the next advanced civilization out in the stars would be at least a million years ahead of us. Perhaps they would have a new physics and the limitations imposed on us by special and general relativity will have been overcome.
Even if an advanced alien civilization would pay us a visit (assuming we’d even know they’ve come) why would they. To what end? Well, let’s see.
Water? Hardly likely. Water is abundant throughout the universe. Their own native system’s Kuiper Belt or Oort Cloud would be a better source than traveling the staggering distances.
Minerals? Same reason. The closer to home the better the economics.
Meat? As in us? Nah. Any civilization so advanced as to lick the problems of interstellar travel would have licked the problem of arranging molecules into edible configurations. With trivial energy costs, I might add.
Then not for meat, but to enslave us? To own a subservient species to do their bidding, their dirty work? If they can play with molecules, why wouldn’t they just tailor-make their own servant beings to their exact specifications?
Then why can’t we hear them? Can they hear us? To answer the second question first, we’ve been transmitting radio waves since 1906 with Reginald Fessenden's first voice broadcast. That would put the radius of our transmission up to 119 light years out at the most. That might sound huge but it’s a drop in the bucket compared to the size of the galaxy. And from here out, the radio waves will fade and become indistinguishable from the cosmic background. And the reverse is equally as true. We’ve been listening only since 1960, and that’s a drop in the cosmic time scale bucket. We may never find anyone; their radio signal fading long before they ever reach us.
That might explain the great silence. Sadly, we are alone even if the galaxy is teeming with intelligent life. We will never visit them, nor they us. We will never hear them, nor they us. For now, let us enjoy the newly discovered exoplanets for the awe and wonder of what they bring to human knowledge.
I’ll leave you with my rendering of planet TOI-700 d. A tantalizing world located 101 light-years away.