There will be no simple explanation for the unusual seasons of George R.R. Martin’s addictive Game of Thrones (other than: it’s a fantasy.) Bummer.
(Second book in the series. Not as awesome as the first, but still compulsively readable.)
In these books, “summers can last for years and winters a lifetime”. How?
Let’s start with our planet. You know the earth has a tilt, right? Summer in the northern hemisphere occurs when the sun’s rays hit the north more directly and the days are longer. Six months later earth has moved to the other side of the sun. Now the sun's rays hit the north on a more extreme angle, the days are shorter, and we have winter. Here’s a nifty graphic from Zoom Astronomy:
The earth zips around the sun in 365 days and so this pattern repeats every year. Fab.
Could we create years-long seasons by adjusting the tilt of the earth? A changing axial tilt is not out of the question. According to Wikipedia, the earth’s tilt or obliquity varies from 22° 38’ to 24° 21’. On other planets the variation is more extreme. Mar’s obliquity may vary “between 11° and 49° as a result of gravitational perturbations from other planets.”
Yet there are problems with simply increasing the tilt to make the winter more harsh. The variation I mention above for earth’s tilt happens every 41 thousand years. In our fantasy world, we need the axis tilt to change from say 23° (summer years) to 25° (winter years) within a couple of years. Second, the position of earth’s tilted axis stays constant as the earth orbits the sun. If we look at the axis over the course of a year, we get a slice of penne pasta:
Yummy. So if you increase the tilt to create an extreme winter for the north, it would be followed by a sizzling hot summer six months later. What we really need is an axis that keeps the northern hemisphere tilted away from the sun’s direct rays all year long. Then the axis rotated around the sun would form a bowl (leaving the southern hemisphere with a long, long summer.) Bowl, pasta. I need lunch.
I’m not astronomer, so I can’t tell you if this is possible. Perhaps some “gravitational perturbations” from nearby planets could help. This is a fantasy world, so you could play with the solar system. Plus, the moon could become a factor by increasing its size and/or its distance from fantasy earth. But here’s the kicker. Our fantasy seasons are not cyclic. Summers are shorter (5 to 15 years) and winters longer (15 to 50 years). So putting the explanation on planetary movements (which are cyclic) is tricky.
(If you really want to stretch you brain, read about Milankovitch cycles. Besides axial tilt, eccentricity and precession of the earth’s orbit can affect climatic pattern. To contract your brain, go read up on Mila Kunis.)
So if I continue this quest, I’d study the onset of ice ages and maybe El Niño/La Niña events. But I really need to get (a life) back to writing and lock my (inner nerd in a closet) energies onto worlds of my creation.
What's distracting you these days?
Wednesday, August 31, 2011
Tuesday, August 16, 2011
I would like to thank (curse) my good friend Dawn for (destroying any chance I had at accomplishing anything for the next month by) lending me the first in the George R.R. Martin's Game of Thrones series.
Game of Thrones kicks some serious chain-mail-clad booty. It is incredibly (addictive—like crack, only worse) engrossing. If you have ever considered writing a book from multiple points of view, this is your master class in that endeavor. Each segment ends with the reader panting to know what comes next. Then you’re shoved on to another scene.
Cliffhangers at chapter endings are nothing new. In fact, they may be a requirement these days. The brilliant part of Martin's writing is getting you quickly engaged with the next scene. So, even though you left your favorite character on death’s doorstep, you can let it go because you desperately need to know what the despicable villain is plotting in the current scene. For 800 plus pages, Martin leaps from character to character without dropping the reader—a feat equal to someone skipping a stone across a lake fifty-plus times.
Another talent of Martin’s is world building. Game of Thrones is rooted in medieval times with fantasy creatures—dragons and zombie-like ‘Others’—rumored to be dead for hundreds of years, but on the rise. Outside the familiar parameters of castles, kings, swords, horses, brothels, squires, and whatnot, very few things are unique to Martin. But you wouldn’t want an author to reinvent and rename everything; the burden on the reader would be too great. Small touches make all the difference from ‘Ser’ instead of Sir, to ‘lion-lizard’ for alligator, and the ‘dire-wolves’—a breed of large, deadly beasts supernaturally loyal to their masters.
One alteration, in particular, caught my fancy: winter and summer don’t come in predicable cycles or last for a few months. Teens have lived the bulk of their lives in summer. ‘Winter is coming’ is spoken with equal parts dread and reverence for an event that may last for several years up to an eternity.
As a former scientist, I just had to figure out how this might be possible. I know, it’s a fantasy. Why quibble over the length of summer when bloody dragons are sucking milk from the heroine’s breast? But still, the story inhabits a world with one sun and one moon—a world with a cold north and a warm south. The characters observe their yearly name day. Day and night occur just as they do for us mere mortals, so how could this crazy weather happen?
To be continued . . .
See, I told you cliffhangers were obligatory!