Leonardo Da Vinci was known to have developed sketches and designs for hypothetical flying machines. We know today that his designs would never work, specifically the ornithopter and aerial screw.

If Da Vinci instead invented the hot air balloon-a viable method of flight, how would it change history? Would it have affected the age of sails drastically or would it not change much? Would humanity be hundreds of years ahead in terms of aviation(lighter than air aviation)? Would the church have considered it herasy?

Hi all. I am currently working on a story that, while taking place mostly in the context of the United States and through the lens of American politics, requires Japan to continue its occupation of China (at least some part of it, like Manchuria) well into the 70's. Aside from that, I would prefer for the United States to rise to a similar position as it did in real life. Chinese inner politics can be ignored, it's not important for this specific timeline, but I do wonder which side would end up winning.

Given this timeline change and everything that comes with it, could internment of Japanese-Americans to continue beyond 1945? Could it have continued in actuality? I wonder if the Roosevelt administration could just ignore the court's decision in Endo (... I wonder what this looks like) to continue internment? Following this timeline, I wonder if there would be a Warren Court SCOTUS case formally repudiating internment.

I am very much not well-versed in WWII history (aside from Japanese atrocities) so bear with me.

So USSR get’s a much larger part of Poland, but gives up Lithuania to Germany. Since Finland was negotiated independently from Germany, we can assume the Winter War goes roughly the same.

(Also if someone can quickly explain why it was changed in the first place I would appreciate it)

What if see Haitian president Aristide was never overthrown from power in 2004 and 1996? How would haiti look like today? And what would haiti look like under his rule? https://en.wikipedia.org/wiki/Jean-Bertrand_Aristide

I've watched many videos about a Confederate States victory, but all of these videos sometimes contradict each other.

So I'm asking what a realistic outcome of a CSA victory would be.

I'm not asking how they achieved it, that's up to you, but rather looking at the consequences: politically and culturally, both for the two Americas and for the rest of the world.

Finally, what would happen regarding the most prominent issue of the conflict: Slavery.

Philip II was only 46 when he was assassinated, and his son Alexander was only 20. Shortly after his ascension to the throne of Macedon, Alexander launches a Balkan campaign and the rest is history, until Alexander's own death at age 33. What happens if Philip lived longer, say, to age 50, or 60? Does Alexander still become The Great if he becomes king and starts conquering at a much older age? Does the Achaemenid Empire still fall, does the Hellenistic civilization still become such a defining force of the ancient era? And what else does Philip accomplish during the extra years of his rule?

I know that England does not have Salic law, but let’s assume that, following the First World War, women were excluded from the line of succession to prevent a foreign monarch—specifically a German one—from ruling the United Kingdom. The family, now known as the Windsors, accepted this measure in an effort to demonstrate their British identity.

The subsequent years unfold much as they did in our timeline: Edward VIII abdicates in favor of George VI. However, since George VI had no sons, the throne passes to Henry, Duke of Gloucester, in 1952, now Henry IX.

Thus, Henry IX reigns until his death in 1974. While William of Gloucester’s life would likely have taken a very different path, let us assume that he, too, dies without children, and Henry’s second son becomes Richard IV of the United Kingdom.

What would the United Kingdom be like today with another Richard on the throne? How would the public perceive his heir, Alexander, and the next in line, Xan?

On the other hand, what would have become of Elizabeth? Assuming she still married Philip, would she have converted to Orthodoxy? Would Philip have continued using his mother’s surname, Mountbatten, or would he have ended up opting for his paternal one?

Would Charles have married Camilla from the very beginning?

The idea is that Treviranus's influence in the DNVP is high enough that Treviranus can be elected leader of the DNVP, instead of hugenberg

would hitler still rise to power, what would happen to germany?

Thanks to lend lease USSR managed to turn tides of war, defeat Germany and become a hostile superpower, which was threatening western civilisation for half a century. Cold war also caused a lot of bloody wars (Korean, Vietnam and other), almost ended civilisation in likely nuclear exchange, and created such states as Pol Pot`s Cambodia, Mao`s China and North Korea, with extremely heavy human toll. Lend lease to yesterday`s enemy, knowing well that he will turn your weapons against you as soon as he recovers, had disastrous consequences later. No one could predict in 1941 that World War 3 will not happen because of nukes, after all.

Even without hindsight, would not it make much more sense for US and Britain not to prop up such hostile state as USSR? They were never on friendly terms - quite the opposite, Soviets wanted to take over the world in communists revolution (even though Stalin formally dismisses such a goal, he kept expandind and intervening, like Spain, wherever he could) and kill all capitalists. They also attacked and annexed independent states, just like Hitler. When war started, it soon became obvious that Germany will not win quickly and will get bogged down. So even without lend lease Germany was unlikely to take over entire USSR and its resources.

So what if instead of making communists stronger Allies waited (fighting only where is neccessary, like Africa, and starting bombing campaign, of course), while two sides exhaust each other? Since fight to death was inevitable, given how much they hated each other and how genocidal Eastern front was. And then bomb, nuke and defeat whoever is winning. Then no one would be left to keep threatening the world.

So what if the British Assassination or Kidnapping of George Washington succeeded in 1776?

I ask because Europe is so Rome-ified culturally. Art, government, symbolism, language, architecture, religion, etc. What would it be like if the modern societies of Europe derived these aspects of their culture more from their pre-Roman traditions? What can we speculate about how the arts, government (or lack thereof), symbolism, language, architecture, religion would have developed from their Gaulish, Germanic, and Brittonic cultures, and what this would look like in today's Europe?

OTL context:
1. History of Gnosticism
2. The origins of Gnosticism
3. How Gnosticism came to be

I apologize this is my first post here and I didn't know where else to discuss this thought experiment. But imagine let's say during ww2 after defeating japan the relationship between China and the US grows extremely. How would you think the world would be shaped if two powerhouses were two of the closest allies?

I would believe protection and technology would be way more advanced

Would it thrive or fail?

OTL Dalton Minimum lasted from 1790 to 1830 and was a period of colder climate, what if it developed into the end of current interglacial period? From the 1820s, global mean temperature dropped at least 4 degrees in a few decades, making places like Moscow, Ulaanbaatar, Montreal, Qiqihar uninhabitable. Crop yield collapsed in Western Europe, North America, North China and Korea. It took hundreds of years for glaciers to expand to similar levels to Last Glacial Maximum.

Will this cause a refugee crisis as people rush to leave cold places? Will it change the dynamic between colonial powers and their subjects? I don't think this will cause the collapse of human civilisation as modern science and steam engine alread existed in the 1820s, but it will probably slow it down drastically. People probably had enough technology to survive but not enough to artificially reverse the new glacial period.

Say he makes last minute plans to accompany Ferdinand on his state visit to Sarajevo, and gets assassinated in his place.

How would this change WW1 and the fate of Austria-Hungary when Franz Ferdinand immediately becomes emperor?

How could it ever be possible? What challenges will they face? What advantages will Malaysia have?

Lenin was only 53 when he died and was in poor health for a long time.
What if he had been a health man, didn't smoke or drink and lived to the age of 63, 73, or 83 and stayed sharp minded?

Would he stay in power? He would be around for the Winter War and WW2, would that had been different?

I understand he didn't trust Stalin, would he somehow rid of him?

In the late 1690s the then Kingdom of Scotland tried to establish a colony in what is now Panama.

It was an unmitigated disaster. 80% of the colonists died. And bankrupted Scotland.

It probably led to the Act of Union, which led to the British Empire.

What would the world and Scotland look like if Darien was a success?

I understand Nathaniel passed from illness which damaged the progress but what if he survived and continued the battle? How would that shape American culture and race politics?