Gunpowder is sulfur, saltpeter, and charcoal in a one-to-two-to-three ratio. The formula is simple and catchy, and many can recite it; this is the ratio of components involved in the reaction. In actual preparation, there is a more optimal mass ratio, which Aegon also remembers: 2:15:3. Besides remembering the formula, he also knows that 'sulfur' and 'charcoal' are elemental sulfur and carbon, and 'saltpeter' is potassium nitrate. Writing the reaction equation for explosion is not an issue—there's nothing to boast about, it's basic knowledge learned in high school.
However, knowing the principle is one thing, and immediately producing a large amount of usable gunpowder is another—after all, he wasn't a chemistry or geology major, nor had he ever made the stuff himself.
Even if he could make it... he wouldn't immediately produce gunpowder.
The reason is simple: this stuff is too destructive, and he is currently 'living under someone else's roof,' essentially protected by the Iron Throne, especially its official representative, Eddard—even though the latter might not realize it. This objective fact won't change just because Aegon is familiar with the plot, or even secretly 'saved' the former. Before he controls a force that obeys and completely belongs to him, producing gunpowder would be entirely making a wedding dress for someone else. As long as the news leaks, the new invention will be seized by the ruling class of this world and used in their wars against each other in a matter of minutes—and explosions are indiscriminate. His greatest reliance as a 'neutral' Night's Watch member, navigating among various forces, is balance. Once this balance is broken and the seven major powers go to war, except for the Northern Army who might show mercy, others won't care whether you are a protector of humanity or a guardian of The The Wall. If caught in the war, losing the legion's assets would be secondary; if he were unlucky enough to be killed by something he brought into this world, that would be a huge joke.
As a transmigrator, Aegon wouldn't refuse to have sex with beautiful women. As for experiencing two armies exchanging artillery fire on the battlefield... although it sounds like 'a man's romance,' if he were to participate, he'd rather not.
...
The most idealized future is that after his force takes shape, he finds a reliable backer or simply establishes his own power... and then unveils the ultimate weapon at the most critical moment: If the Seven Kingdoms ultimately do not erupt in civil war, then deploy it in actual combat when the White Walkers truly attack; if war still breaks out, then rise up amidst the chaos and quickly let all parties experience 'Quantity is truth, range is justice' before they can also acquire gunpowder technology through other means, crushing all opponents and threats like dry weeds. After that, he will quickly find a way to shed his Night's Watch identity and reach the pinnacle of life in one fell swoop—whether to continue enjoying life in this other world or search for a way to transmigrate back will be entirely up to him.
Alas, Aegon couldn't help but think of the standard setup for transmigration farming novels: if he had transmigrated into a Prince with subordinates and a fief from the start, things wouldn't be so complicated.
***
Daydreaming and planning for a future too far off are meaningless. Aegon showed goodwill towards the Pyromancers, not only wanting to win over a few of them for his own use and ensure he could rely on these primitive chemists to quickly produce gunpowder when necessary, but also for a more direct reason: to contribute to the defense of The The Wall. Wildfire, a super dangerous item in the warm South, could be used directly as a liquid explosive on the cold The The Wall, provided sufficient caution was taken.
While Aegon was waiting for the first Night's Watch Industry factory to be built and begin production, he tinkered with the bottle of Wildfire he had bought. Each time, he poured out a few milliliters for various experiments and attempts.
"Don't get too close," Aegon instructed Arya, who was eagerly watching his self-destructive experiments. "If I catch fire, use the bucket of water over there to douse me!"
The girl giggled and agreed. In her eyes, it was quite normal for her adventurer Master to want to play with fire.
Under the protection of careful caution and various preventive measures, this small act of self-destruction did not injure anyone. Soon, Aegon came to some conclusions:
Firstly, this stuff is much less dense than water, which is obvious; light oil is bound to be lighter than water—not only can it float on water, but it can also burn despite water's cooling effect. This is why Tyrion was able to use it to burn Stannis's fleet in the original plot. Secondly, this stuff is super flammable—aside from body temperature being unable to ignite it, it's almost never peaceful: it ignited when dripped onto hot ground; it ignited after being exposed to sunlight for half a minute; it ignited when he snapped his fingers nearby, generating a little heat from friction... Although he didn't have a thermometer, after several attempts, Aegon concluded that temperatures above 50 degrees Celsius could cause this stuff to spontaneously combust.
Besides being extremely easy to ignite and spontaneously combust, its surface tension is also very low, giving it the property of quickly wetting and penetrating the gaps of whatever it touches. This characteristic, for a flammable liquid, is an almost terrifying and fatal extra trait.
Good stuff. I look forward to seeing it ignited among a swarm of wights.
...
Aegon waited for a Pyromancer, negotiated with him, and invited him to the North to serve the Night's Watch... but was refused.
There was nothing he could do. As soon as serving the Night's Watch was mentioned, everyone immediately had a lot of negative associations, and this notion was even more deeply rooted in the minds of older people. No matter how he explained, the other party wouldn't budge an inch, and the matter was finally dropped—but Aegon wasn't discouraged. He was just a small Night's Watch officer now; it was impossible for everything to go smoothly. But after some time, when the Night's Watch Industry develops and a solid community of interest is formed with nobles in King's Landing and even the Crownlands, the terrifying power generated by the combination of money and power will emerge. By then, he will find the alchemists again and give them an 'offer they can't refuse' through coercion and inducement.
The first investment was finalized, and the future seemed bright. But just as Aegon was full of anticipation for the future, a sudden piece of news rattled him. During a routine 'emotional exchange'—that is, pumping for information—with his young apprentice, he heard the latest bombshell news from the girl.
...
Earl Jon Royce of Runestone, Lady Anya Waynwood of Ironoaks, Earl Gerold Hunter of Longbow Hall, and a series of other important nobles of the Vale have quietly formed the League of the Righteous, concentrating the most elite forces of their respective families to launch a military coup. They designed an inside-outside strategy, capturing the Blood Gate at a minimal cost, and have now completely controlled the Vale of Arryn, surrounding the Eyrie. They are besieging it without attacking, demanding that Lysa Tully, the suspect in the murder of her liege lord, hand over young Lord Robert and face trial, and that the future ruler of the Vale be jointly raised and educated by these families!
The declaration signed by this alliance in Runestone has already been sent to King's Landing. Arya learned of this from her Father's conversations with his advisors, and then, without any guard, told Aegon, making him the second person in King's Landing, after the power core, to know about this explosive news.
***
Damn, that's bold, truly bold. He's indeed Waymar Royce's hot-headed father; when he causes trouble, he's absolutely ruthless, starting with a grand gesture!
Aegon initially spread the rumors just to bring down Littlefinger, but rumors, once released, are like opening Pandora's box. Now, this demon has completely escaped its creator's control, running out of King's Landing to wreak havoc in the Vale. The Vale, which had held its ground and not participated in the War of the Five Kings, its strength completely undiminished by the end of the war, has now become the first place to descend into chaos?
Emotionally, Aegon was gloating about that crazy woman Lysa being besieged in the Eyrie. But now he is playing the money game: raising funds through financial means, and then starting a business based on advanced technology. And this game, no matter how isolated and inconvenient the world is, is closely related to everyone and affected by everything happening in the world every moment. Will this internal conflict in the Vale have a shocking impact on his business venture?
—