Song-1

"Not every alternate world has airships, but the stereotype has some basis in fact."

— Alric Pabst, BREACH operative

Summary

In 1041, a Chinese alchemist took some rare clays, dried and ground them, added a few other elements, and created a powder that, he suspected, would have medicinal value. He placed it in a tightly-sealed iron flask for later testing. Meanwhile, so the legend says, his cat knocked the flask into a bowl of hot coals used for heat. When the alchemist returned, he found the flask floating up near the ceiling. When he tried to pull it down, it took some effort; as much effort as trying to lift a sturdy brick. Releasing it caused to it 'fall' upwards again. So it began.

The powder, when heated, produced a gas that provided bouyancy far in excess of Baseline's helium or hydrogen. Controlling it was another matter. As it cooled and condensed, the vessel it was contained in would fall; the same occurred as the vapor slowly leaked through any opening, even in the tiny ones surrounding the flask's stopper. It took many years, and many errors (some of them rather fatal) before a mechanism of precise control could be had, with a complex system of burners to warm the powder and gain lift, and water sprays (ironically built from the same pump technology as the early flamethrower. Near the end of the reign of Emperor Renzong, the first Chinese sky-ships took flight. They used sails for forward motion, combined with giant paddles of silk that could be used as 'oars' by banks of strong crewmen. From this vantage point, they could rain down arrows, rocks, burning coals, grenades, and so on, the iron cylinders (sealed with pitch and other chemicals discovered during the decades of research) resistant to all but the largest hurled ammunition. The wooden hulls of the craft were somewhat less so, and the more armored they were, the larger the lifting cylinder needed to be, which made controlling its temperature more complex, and its inertia greater - it was weight that was reduced, no mass.

Despite these limits, the advantage was overwhelming. Terrain mattered little. Rivers, mountains, and swamps could be crossed with ease. The Song Dynasty's reluctance towards war took a sharp decline; its two northern rivals quickly agreed to terms after the airships demonstrated their ability to travel too high to be reached, then drop close enough to bombard targets deep inside another's territory.

Rather than the slow dynastic collapse of Baseline, the 12th century brought expansion and power. By the start of the 13th century, Song controlled territory across most of Southeast Asia, ruling as far west as the west coast of India. The poor reception given to Buddhist missionaries who traveled past these borders into the Middle East and Europe has caused significant anger, and it is only the complexities of logistics and lines of communication that are slowing appropriate retribution.

It is inevitable that the secret of the lifting gas will be learned, despite the draconian measures used to keep it hidden. (This is also a key logistical factor; as the powder is manufactured in only a few secret facilities deep in the empire's heart, they cannot build either defensive or offensive craft near their far-flung borders, and the overall speed is on par with a typical sailing vessel. The advantage of ignoring terrain (at least that under two miles high, the current limit) is obviously of great benefit, but it doesn't free the Song from the same limits as other pre-industrial empires.)

BREACH

Some at BREACH have noted that if the breach point opened in the Americas, or Australia, or Siberia, they might not have found any discrepancies and not explored too much further. As it was, the point opened in Venice, in local year 1245. Things seemed close to Baseline, until they heard priests railing about Buddhism, and they noticed the wide range of Chinese products in the marketplaces, brough back from the Middle Eastern nations that traded with the westernmost parts of the Song Empire. They quickly picked apart which of the trader's tales were lies, exaggerations, or myth, and which had kernels of truth.

Which left the problem of getting to the borders of Song and beginning long-term infiltration. Invariably, others would be, too. The route was going to be long and dangerous, either following the Silk Road into the heart of the Song Empire, or travelling across the Persian Gulf to the easternmost extants of the Empire, roughly (based on trader's tales and crude maps) where Karachi exists on Baseline. The expense and time would be great, relative to BREACH's resources, but a core faction of NATO's leadership is willing to bear the cost, as it's certain the Chinese will be doing so. (A rumor is spreading in the Venice markets that some Buddhist monks have converted quite passionately to Christianity and seek to return home as missionaries, if only the Pope will give them transport and guards for their long journey...)

World Type

Alternate History, Alternate Physics

Divergence

1041

Current Year

1245

TL

3^

Tech Notes

Here, China has taken the lead in developing and improving gunpowder for war, and has started to build rockets with explosive warheads -- a small leap since 'slow fuse' technology has already been developed by them on Baseline. The precision of these fuses, and the math needed to calculate things like travel time so they detonate at the best point are still very rough, but the Hindu numeric system is spreading back to the homeland, and this convergence of the need for more precise artillery calculation and a numeric system tremendously simplifying calculation will likely lead to the creation of calculus within the next decade or two.

Mechanically, "lifting gas" is probably about 10x more potent than helium or hydrogen, as recommend in GURPS Spaceships, but I might need to make it more to fit the established setting.