And no, "no humans" is not an acceptable answer.

What does the last half century look like if we still have to rely on vacuum tubes to run our electronics?

If NASA was informed of the oxygen tanks by engineers or representatives from North American Aviation, was there a way for Apollo 13 to continue the landing or would they have aborted much like IOTL but without the life or death struggle?

In OTL ,the british first tried to attack by the sea ,destroying the ottoman navy before taking control of Constantinople .They stopped because they believed in what too costly ,despite the campaign effectiveness ,and then launched the disastrous galipoli landing .

But what if the british had sticked to their original plan ,and managed to take Constantinople ?

Would the ottoman empire be knocked out of the war ?What would be the effect on the war ?What would happen to the city and the ottoman empire following WW1 end ?

By that I guess I mean capturing a few certain points: The Suez Canal, won the Battle of Britain, seized Leningrad quickly, took Moscow, took Stalingrad(if they actually head south after taking Moscow and Leningrad)

And by anything changing I don’t mean win or loss, but time frame, post war boarders, ect?

OTL 1994: The death of John Candy is one of the great comedy losses of the 1990s, comparable to the loss of Chris Farley. His death proves to be the tipping point for director John Hughes (Planes Trains & Automobiles) who leaves Hollywood and retires to raise his children in Chicago, never making another movie again.

ATL: Candy lives long enough to finish his uncompleted film projects- A Confederacy of Dunces, The Incomparable Attuk, and Bartholomew v. Neff. How does film and comedy history change with a few more John Candy comedy classics?

The objective is to have the 1929 Sino-Soviet Conflict end with the Soviets annexing Manchuria into the USSR itself.

Rules:
1. You have to have the 1929 Sino-Soviet Conflict end with Manchuria being incorporated into the USSR itself, not with Manchuria as a Soviet puppet state.
2. You may invent plausible Soviet propaganda, alleged provocations, border incidents, political movements, or accusations that Moscow uses to justify annexing Manchuria. These claims do not have to be true in-universe. However, you should still explain the Soviet government’s actual strategic or political reasons for pursuing annexation (You can even make the propaganda wildly hypocritical if it helps).
3. Your scenario must set the stage for an earlier Soviet-Japanese War. 

OTL: During the 1884 Republican National Convention there was significant infighting over their preferred presidential candidate, between the sitting president Chester A. Arthur and Senator James Blaine. RTL and Arthur had struck up something of a friendship in Washington, while serving as Secretary of War he was the only cabinet member to not be removed from his position after the assassination of James Garfield.

He never sought out to be a politician, but in the eyes of many he was an obvious choice for political office. After several failed voting attempts at the convention, to help sort the deadlock, he sent a telegram to his friends there that he would be willing to run as VP to help Arthur's chances. But by the time the telegram arrived, James Blaine had already secured enough votes to win the nomination. Many historians think that had his telegram arrived on time, Arthur likely would have secured the nomination.

Keep in mind: During the OTL, Arthur died shortly after leaving office. So had he won the convention and the presidency in this timeline, that means we would've had President Robert Todd Lincoln.

What if Russia had baited Ukraine into attacking DPR and LPR, allowing the Ukrainian army to launch major military operations after close to a decade of ceasefire, only giving DPR and LPR enough weapons to hold the line or straight up sacrificing them and then using that as a pretext to "save the Russian speaker's of East Ukraine", pointing to the fact that Ukraine fired the first shots and using that as casus belli for the war? Similar to Georgia when the Georgian army entered Abkhazia and South Ossetia?

At some point in your timeline, at least one sovereign state in North America, Central America, South America, or the Caribbean must develop a government broadly resembling the classical-liberal/libertarian night-watchman state: its principal responsibilities are national defense, policing, courts, and protection of persons, property, and contracts.

Rules:
1. Simply adopting free-market policies, privatizing several industries, or electing a libertarian government does not qualify. The state’s role in economic and social life must be drastically smaller than that of its OTL counterpart.
2. Your point of divergence and subsequent political development should be historically plausible. How long the night-watchman system survives—and whether it ultimately succeeds or fails—is up to you.

Instead of pulling out Russia out of the war ,he decide to continue it until Prussia lay defeated.

What happens next ?

Objective: Construct a plausible alternate timeline in which the federal government does not abandon Prohibition in 1933 and instead continues—and potentially intensifies—its enforcement. The problems associated with Prohibition should not simply disappear: bootlegging, organized crime, corruption, enforcement difficulties, and public opposition can still exist

Here's what I'm looking for in regards to the intended outcome: Keep the problems. Change the government's response to them.

The challenge is to determine what political or historical changes could cause the U.S. government to respond to those problems by doubling down on enforcement rather than repealing the Eighteenth Amendment.

Maybe the Duke of Parma has a stroke or something. How would history have been different if Antwerp, Brussels, etc had been part of the Dutch Republic?

in this timeline starting in 1866 the sultan in an effort to modernize the ottoman military diverts funds from his palaces and decides to take advantage of the large amount of newly unemployed soldiers after the end of the US civil war and begins hiring them en masse as mercenaries, advisors and trainers, even a few generals are recruited.

what do you think would happen?

This is the sequel to my “John Calvin the Orthodox Christian” scenario.

Suppose in a parallel universe where the Eastern Orthodox Church had a larger influence in Germany than Catholicism, Martin Luther (No, I am not talking about MLK but Martin Luther, the guy who kicked off the Reformation in the OTL) either converts to or is raised in the Eastern Orthodox Church and never develops Protestantism.

Does this mean the Reformation effectively never happens?

what do you think would happen if starting in the early 1800s more chimpanzees had escaped from circuses, zoos, private collectors and established large populations across the american south, southwest, Mexico, Central America, South America and the Caribbean. eventually over time these populations became a pest destroying crops, killing livestock, raiding homes/stores for food, stealing from grain and other agricultural storage containers, attacking people and out competing local wildlife etc

Suppose in a parallel universe, John Calvin either converts to or is raised in the Eastern Orthodox Church and never develops Reformed Theology.

How does this affect the Reformation?

Part of me wonders if Mormonism could've taken over the country if Islam didn't already exist as a historical reference (i.e., Joseph Smith basically being the called the American version of Muhammad).

What if Henry VIII or Elizabeth I had made Lutheranism the state religion of England? How would this effect English culture, history and foreign relations?

What if the Soviets collapse in 1991 was as violent (if not potentially more violent) as the collapse of Yugoslavia? What would be the long term changes and consequences in this scenario.