Post by ShadowReine on Sept 30, 2008 18:30:41 GMT -5
Thread is Pern's enemy. It is the dominant, overwhelming force that molds Pernese life, culture and customs.
In a stable cycle, the Red Star takes two hundred and fifty turns to orbit Rukbat, Pern's primary, on a highly elliptical orbit. Thread does not come from the Red Star, but is dragged in by it from the system's Oort cloud. For fifty of those turns, the Red Star is close enough for Thread to jump to Pern.
Thread is best classed as a fungus. It is capable of rapidly consing anything carbon-based. It forms hard ovoids that when they reach certain temperature hatch to form wriggling strands. It is these strands that 'fall' like rain through the atmosphere.
Fortunately, Pern is far from ideal conditions for Thread. A piece of Thread will consume what it touches, grow rapidly, but die within a few hours. Unfortunately, a single strand of Thread is more than enough to consume a cow. Or a full grown dragon.
Also acting in Pern's favor is the fact that hatched Thread requires both heat and oxygen...and quite a bit of both. If the air temperature is below freezing (not common in northern winters) the Thread will freeze and then crumble into 'crackdust', which is not only harmless but slightly beneficial to cropland. Thread will also literally drown in heavy rain. Finally, Thread that lands in the ocean drowns rapidly. It is generally then consumed by fish...and even dolphins and firelizards (This is probably the origin of the myth that firelizards will eat -live- Thread).
A live Fall will, left unfought, devastate the area affected in much the way a forest fire will. It consumes grass, trees and shrubs, but often passes over seeds and sometimes even root systems....and most Pernese plants produce seeds that can stay dormant for decades, sprouting only once the pass itself is over.
Fighting Thread, therefore, is to protect humans, their crops and livestock, rather than the Pernese ecosystem, which is well adapted to the threat. (In fact, in some areas, humans have had to resort to controlled burns to simulate the effect of Thread).
The colonists created biological defenses. One is a form of grub, engineered from the Thread itself, that forms a symbiotic relationship with plants...in exchange for a leaf here and there, it exudes enzymes that induce temporary rapid growth, allowing an individual plant to survive and recover. The grubs were originally introduced only on the southern continent. Parts of the north are now grubbed, but the organism spreads and breeds very slowly. Ista has not been grubbed.
Grubs, however, do not protect humans or livestock. Stone walls do, and the Pernese live underground or in stone buildings.
Dragons are the active defense against Fall. Fall was originally fought using airsleds and flamethrowers, but as fuel was a limited resource, the colonists again turned to biology.
The Weyr, thus, is the first line of defense against a live Fall.
When a Weyr musters, the able bodied dragonriders go aloft in wings, each led by an experienced bronze or brown rider. The blues and greens fly in shifts, each flying half of the Fall. In fact, their stamina is not that much lower than the bronzes and browns, but their agility is greater. The blues and greens do the fancy flying while the bronzes and browns anchor the line. As a result, they fly faster.
Below the fighting wings fly the Queen's Wing and the Weyrling Wing.
The Queen's Wing is led by the Weyrwoman, unless she is grounded, in which case a different goldrider will take over. The golds do not chew firestone, instead, their riders carry flamethrowers. Pregnant female riders and ones recovering from injuries also fly the safer duty of the Queen's Wing. The Weyrling wing is led by the Weyrlingmaster. It assists the Queen's Wing, and consists of weyrlings who are getting their first taste of live fall and younger riders under sixteen, who tend to be less steady.
Both of these wings have the duty of taking out Thread that escapes the fighting wings.
Once the Fall has passed, the holders on the ground emerge from their shelters, but the war is not over. Able bodied volunteers with agenothree sprayers...which produce a low temperature flame that is less likely to set fire to fields and orchards than the more powerful flamethrowers used by the queen riders...patrol the land and kill any Thread the riders may have missed before it can burrow into the ground and damage root systems.
Firelizards, who originally evolved the ability to flame to protect their own eggs, will often assist their bonded owners. In more southern weyrs, it's not at all uncommon to see entire fairs in formation filing the gaps left by the larger dragons...with even wild animals joining in. Ground crew regulars will often pay good marks for an egg or two.
In a stable cycle, the Red Star takes two hundred and fifty turns to orbit Rukbat, Pern's primary, on a highly elliptical orbit. Thread does not come from the Red Star, but is dragged in by it from the system's Oort cloud. For fifty of those turns, the Red Star is close enough for Thread to jump to Pern.
Thread is best classed as a fungus. It is capable of rapidly consing anything carbon-based. It forms hard ovoids that when they reach certain temperature hatch to form wriggling strands. It is these strands that 'fall' like rain through the atmosphere.
Fortunately, Pern is far from ideal conditions for Thread. A piece of Thread will consume what it touches, grow rapidly, but die within a few hours. Unfortunately, a single strand of Thread is more than enough to consume a cow. Or a full grown dragon.
Also acting in Pern's favor is the fact that hatched Thread requires both heat and oxygen...and quite a bit of both. If the air temperature is below freezing (not common in northern winters) the Thread will freeze and then crumble into 'crackdust', which is not only harmless but slightly beneficial to cropland. Thread will also literally drown in heavy rain. Finally, Thread that lands in the ocean drowns rapidly. It is generally then consumed by fish...and even dolphins and firelizards (This is probably the origin of the myth that firelizards will eat -live- Thread).
A live Fall will, left unfought, devastate the area affected in much the way a forest fire will. It consumes grass, trees and shrubs, but often passes over seeds and sometimes even root systems....and most Pernese plants produce seeds that can stay dormant for decades, sprouting only once the pass itself is over.
Fighting Thread, therefore, is to protect humans, their crops and livestock, rather than the Pernese ecosystem, which is well adapted to the threat. (In fact, in some areas, humans have had to resort to controlled burns to simulate the effect of Thread).
The colonists created biological defenses. One is a form of grub, engineered from the Thread itself, that forms a symbiotic relationship with plants...in exchange for a leaf here and there, it exudes enzymes that induce temporary rapid growth, allowing an individual plant to survive and recover. The grubs were originally introduced only on the southern continent. Parts of the north are now grubbed, but the organism spreads and breeds very slowly. Ista has not been grubbed.
Grubs, however, do not protect humans or livestock. Stone walls do, and the Pernese live underground or in stone buildings.
Dragons are the active defense against Fall. Fall was originally fought using airsleds and flamethrowers, but as fuel was a limited resource, the colonists again turned to biology.
The Weyr, thus, is the first line of defense against a live Fall.
When a Weyr musters, the able bodied dragonriders go aloft in wings, each led by an experienced bronze or brown rider. The blues and greens fly in shifts, each flying half of the Fall. In fact, their stamina is not that much lower than the bronzes and browns, but their agility is greater. The blues and greens do the fancy flying while the bronzes and browns anchor the line. As a result, they fly faster.
Below the fighting wings fly the Queen's Wing and the Weyrling Wing.
The Queen's Wing is led by the Weyrwoman, unless she is grounded, in which case a different goldrider will take over. The golds do not chew firestone, instead, their riders carry flamethrowers. Pregnant female riders and ones recovering from injuries also fly the safer duty of the Queen's Wing. The Weyrling wing is led by the Weyrlingmaster. It assists the Queen's Wing, and consists of weyrlings who are getting their first taste of live fall and younger riders under sixteen, who tend to be less steady.
Both of these wings have the duty of taking out Thread that escapes the fighting wings.
Once the Fall has passed, the holders on the ground emerge from their shelters, but the war is not over. Able bodied volunteers with agenothree sprayers...which produce a low temperature flame that is less likely to set fire to fields and orchards than the more powerful flamethrowers used by the queen riders...patrol the land and kill any Thread the riders may have missed before it can burrow into the ground and damage root systems.
Firelizards, who originally evolved the ability to flame to protect their own eggs, will often assist their bonded owners. In more southern weyrs, it's not at all uncommon to see entire fairs in formation filing the gaps left by the larger dragons...with even wild animals joining in. Ground crew regulars will often pay good marks for an egg or two.