Which events drastically altered/affected the course of history? Why? Was it for the better or worse?
I think this thread will run best if we keep it related to humanity; as such not a discussion of the alteration of the continents, and evolution etc.. But the discourse of human history.
I say this because the interesting discussion will be on how these things altered societies; and who were instrumental in this; and who/what developed from this?

I'll start with... The Black Death; destroying a huge proportion of the world population, which reorganised society, promoted cleanliness and required scientific though to survive ended the Dark Ages; and as such, restarted decent human development.
(Controversial right?)

Nagasaki?

Extrapolate as to why this over other WWII events? Why not Hiroshima? Results etc..
Extrapolation!!!!

because if hiroshima were the only bomb, we probably still would've had to invade japan and that changes all kinds of things? nagasaki made the japanese tap, so to speak.

i see you're trying to manage and improve your new thread, but i thought my answer might be obvious.

the use of atomic/nuclear weapons has obviously "altered/affected" the last 60 years. in my mind, nagasaki meant more than hiroshima because they obviously were the only two times humans have used that power, but nagasaki probably ended the war with japan w/o the US invading and lots (lots) more people dying and who knows what happening afterward...

I agree that the use of nuclear weapons changed the course of human history profoundley, but the first one had already been dropped, and the war was already won by then, was just a case of how long it took for Japan to surrender, and how many lives it would take on both sides to achieve that outcome. My shout would go to the moment Hitler crossed the Soviet border. In one stroke Germany went from having a deal to split up the whole of Europe to fighting an unwinnable war on two fronts, and then 6 months later f****** it up even further by declaring war on the US the day after Pearl Harbour.

The Ottoman Empire opting for Germany over Britain during WW1. It was finally balanced and Britain was probably favorite but messed it up.

The Ottoman empire was a large but declining power but imagine if they had backed Britain instead. None of the middle east countries we are so familiar with would exist, the ottoman empire which was a mature entity would have had all the oil instead of a few sheiks and there would have been a powerful mature muslim state in the modern world.

more fancifully but plausibly imo - WW1 would probably have been much shorter which would have been so much better for Germany that probably no Hitler/Stalin or WW2.

What would have happened had not Gavrilo Princip stumbled upon the Austrian-Hungarian throne successor and shot him in 1914? Would the world have been set on fire or not? If not, there wouldn't have been any WW1, maybe no Russian revolution, no WW2 or Iron Curtin.

But on the other hand, maybe something even worse would have happened? A nuclear war,for example, when the possibility for that came?

Guess the Gavrilo incident had great impact.

I don't think we should look at trigger events like that, the world was ready to erupt and would almost certainly have done so anyway. The trigger is incidental.

Yes, but the trigger in itself was quite massive in this case. I have seen some views, that a world war wasn't sure to happen, at least at that time. There were some misunderstandings, depending on bad communications between the countries, and so on.

But by large, you may be right.

Perhaps, but it's not as though the decision to side with the Central Powers was arbitrary or 50/50. Ottoman interests at the time were rather incompatible with British, and especially Russian interests. Siding with Germany and the Austro-Hungarian Empire was almost a necessity at that point, if they were to get involved at all (now, whether they could have stayed out of the war altogether is a separate question, because Churchill, Curzon, and the other imperialists in the British government started licking their chops as soon as the prospect of Middle Eastern territory was raised).

Its a fair point that the choice was probably more between Germany and neutrality. It was finely balanced though with only Enver Bay and a few others determined to make an alliance with Germany happen (some may say they conspired) and their position in power was fragile to say the least. Even in power they had to act in secret.

That was despite a determined effort by the Germans to ally themsleves with turkey (or control the turkish military might be more accurate) and a wilful neglect by the British no doubt due to ambition as you say and a great dose of arrogance/incompetence.

The Crimea. It began England's long decline.

the big bang

Mind blown beyond belief. Big question; how did it change the course of history?
imho without big bang the universe would be a lot smaller, and our society might not even exist

Constantine I embracing christianity had a huge impact on the course of history, as well as Muhammad's sudden urge at age of 40 to preach islam (he was illiterate too).
If both events were for the better or for worse for humanity I can't tell, the jury is still out imo.

The first **** sapiens making children.

The existence of Jesus was one of the top events altering the course of history in the past 2,000 years. The same can be said for Muhammad and other martyrs.

Here we are today and those two religions combined compose half the worlds population.

Not sure this qualifies as an event, but the Louisianna Purchase always looks like a pretty big deal to me.

Without it, maybe there is no US-Mexican war, no arguments about which new states will be 'free' or 'slave', possibly no US Civil War.

And when you get to the 20th Century, the USA is 1/3 its size, Mexico is huge (Texas may or may not be an independent nation but Mexico includes California, Arizona, Utah, Nevada, New Mexico), and there is a big French speaking country in between them.

Does Mexico battle Japan for supremacy in the Pacific in WW2?

Thats more specific to our country and the past couple hundred years.

I think the question pertains more to events that span generations and thousands of years.

Is significant yes, but it does not really pertain to changing the course of history significantly (especially world history) for the rest of time.

Where is the proof Jesus existed??

Physical proof, none that I know of. I am not a biblical scholar, but I would certainly not denote the fact that Jesus existed... That is a pretty tough one to passover (no pun intended) on any right minded individual.

There is a story of him when he was very young like 8 years old or so He was visiting Israel (I think) and there he gets separated from Mary and Joseph for 3 days. When they finally find him he is discussing theology with the high Rabbi's in the city's most significant temple (and they were impressed with Jesus's thorough knowledge for his very young age and inexperience).

Oddly enough there is then a gap in the record until Jesus is in his 30's and starts becoming the miracle making son of god that he is now thought to have been by many. His existence is so thoroughly documented only during his 30's though. He died at 33. I do find it odd that there is a large gap in the record of his life. From that story of his young age experience in the Temple until middle adulthood, and then it is well documented. Maybe he was just living a simple existence for that time as a woodworker or a Shepard enjoying his physical being on this beautiful earth.

Hard physical proof? I do not really know of any. First hand accounts by many of his existence and miracles are what we know as the reason why he is so widely considered holy.

Fair enough and with out turning this into a debate on theology there are writings on Jesus early years left out of the bible which do not paint a very pretty picture of the son of god. He is portrayed as a vengeful brat to put it mildly.

Jesus was provoked and said unto him, "Thou shalt not finish thy course." And immediately he fell down and died.

-- Infancy Gospel of Thomas 4:1
or Jesus the dragon tamer

And, lo, suddenly there came forth from the cave many dragons; and when the children saw them, they cried out in great terror. Then Jesus went down from the bosom of His mother, and stood on His feet before the dragons; and they adored Jesus, and thereafter retired.

-- The Gospel of Pseudo-Matthew, Chapter 18
there are many more of these but whom ever decides these things did not want the worlds most famous fictional person's childhood brought into it because from what I have read he was an *******!

Some less obvious events that changed a lot without actually changing anything:
http://en.wikipedia.org/wiki/Siege_of_Vienna
Stopped Ottoman expansion in Europe for good and was the beginning of the end...

http://en.wikipedia.org/wiki/Russo-Japanese_War

The embarrassing string of defeats inflamed the Russian people's dissatisfaction with their inefficient and corrupt Tsarist government, and proved a major cause of the Russian Revolution of 1905...and that paved the way for Lenin in 1917...and about 80 years of fun times in the world.

http://en.wikipedia.org/wiki/Battle_of_Tours

http://en.wikipedia.org/wiki/Polish%..._War#Aftermath

Also if successfully, it would have probably make Germany its next target and that Hitler dude would have been fighting for a different cause with different set of allies.

Really??? That changed the course of history??? It didn't even really changed the outcome of the war.

If Ottomans would have sited with Brits then Russia would have, without a doubt, sited with Germans and that most likely would have stopped the war in its tracks before it even started.