In the spirit of last Tuesday’s post on global warming and greenhouse gases and the current changing of the seasons (something affecting both hemispheres, mind you), I thought I’d write about a few things we human beings take for granted about Gaia.  One thing is the tilt of the planet’s axis.  Gaia’s is optimal.  It’s the Goldilocks Principle all over again: too little tilt and the equatorial zones could become too hot, with maybe sweltering jungles or dry deserts; too much tilt and the winters everywhere could become too harsh, perhaps making the planet like that Ice Planet in Star Wars (probably without the white apes, because they wouldn’t have anything to eat).

We often complain about the seasons.  My friendsl have likely heard me say, “Gee, I wish it was between 65 and 75 and sunny all year around.”  I’d qualify this by recognizing the need for rain, but raining only at night would be nice, wouldn’t it?  Medellin, Colombia falls into that temperature range most of the time, but temperature in Colombia is a strong function of altitude, which means other parts of the country can be sweltering.  That’s one way to avoid some effects of no axis tilt—just throw some high mountains into the mix.  But high altitudes can cause problems.  People have nosebleeds even in Denver.  Elderly Bogotanos (residents of Colombia’s capital) are often advised to retire to lower altitudes if they can, especially if they have cardiac problems.  Equatorial countries experience many of the effects that an E-type planet with little or no axis tilt might have.

We only have one Earth and one history, so to make a bold statement like “the Industrial Revolution couldn’t have occurred in tropical climates” allows no statistical test for its validity.  The fact is, it did occur in northern climates.  Considering that many of the equatorial peoples were colonial subjects of northern countries more interested in raw products to feed their factories than developing industries in tropical climes, it’s arrogant to propose any such thesis.  In Sing a Samba Galactica, I turned this around for that reason, settling the New Haven colonists in the equatorial zone.  Of course, they were almost forced to settle there because of the axis tilt.  Yet the climate didn’t hinder the colony’s industrial development, made safer by their ET friends’ ability to play nice with the environment.

Other things besides axis tilt can affect a planet’s charm for future colonists.  Arid conditions all over the planet would certainly hamper development.  Frank Herbert knew this, so the planet in the Dune series survived on spice mining, much like certain countries around our world have become rich exporting oil.  The other extreme, too much precipitation, could be just as inhibiting.  The only uncompleted part of the Pan American Highway lies between Peru and Colombia’s Pacific Coast.  The jungle there grows so fast that it returns within days after clearing terrain for a highway.

Settlers arriving in the Delta Pavonis solar system (again Samba) had to make a difficult choice.  One planet in that system was a water-world completely covered by seas—no land was available.  (A lonely water-world without Kevin Costner—imagine!)  Another was more like primitive Earth—plenty of land available but a toxic atmosphere.  They chose the second planet and called it Sanctuary.  After a 100+ year journey, they didn’t want to pull up stakes and go to another solar system.  But they needed land, even if they had to live in domes.

Delta Pavonis (Sanctuary’s star) and 82 Eridani (New Haven’s star) were chosen because they are close and very similar to Earth’s sun.  At the time I wrote the “Chaos Chronicles Trilogy,” extrasolar planets hadn’t been discovered, so I assumed new techniques that would allow scientists to make a selection of nearby stars as targets for colonization precisely because they had E-type planets (planets like Earth).  This trilogy spans a lot of time in futuristic human history, so it wasn’t that bold to imagine these techniques would be available.  Little did I know that scientific progress would come so fast.

Of course, humans can live on planets that don’t have stars similar to ours.  I have a hard time even imagining planetary orbits in multiple star systems (binary star systems are quite common), let alone people living on them, but I can imagine another Gaia farther out from a hotter star or closer in to a colder star.  I can even imagine people living on a satellite of a J-type planet that happens to be in the E-zone (J for Jupiter or Jovian).  That happens several times just in Samba.  If you’ve followed the adventures of Dr. Carlos, you’ll know they’re common in my fictional universe.

Scientists have discovered many extrasolar planets, that is, planets outside our own solar system.  That other planets exist is now verified—it’s no longer sci-fi.  Even if some of them are Earth-size, will they be as hospitable as Gaia?  With the discussion above, it’s easy to see that the odds are slim.  Gaia is special.  That said, there are many stars similar to ours just in our galaxy and, if the extrasolar planets’ local abundance holds true within the larger galaxy, those slim odds become near certainty.  That’s the peculiar thing about statistics.  Even if the distribution of Earth-size planets is a simple Gaussian, the tails of the distribution will still contain many, many hospitable planets.  The problem is covering the vast distances to arrive there—right now, that possibility is science fiction.

And so it goes…

This entry was posted on Tuesday, October 7th, 2014 at 4:00 am and is filed under Science, Writing. You can follow any responses to this entry through the RSS 2.0 feed. Both comments and pings are currently closed.