The One Who Knocks and Others
Can you either copy and paste your previous answers or link me to them for the following questions for the OP?
- What just happened?(Synopsis of the ending)
Oh boy. This one could take a bit. Long post ahead.
Using her ability to see through 'all the doors' (all realities) Liz bring Booker through a tear back to a 'focal' point that symbolizes/acts as a funnel for all possible outcomes based on the 'choice' of baptism acceptance or denial, since that is the spot which leads to Comstock's origination and Liz destroying the world.
Liz then guides Booker to realize that he is Comstock (in an alternate dimension), and says that in order to kill Comstock, she must kill the Booker who exists before the choice is made, for as long as a choice is present, some universe will end with Booker picking baptism and eventually becoming Comstock.
She then kills him before the choice can be made, and as Booker dies, since Liz can no longer be alive (possibly due to the grandfather paradox), she disappears as the screen fades to black.
This leads to several possible 'conclusions' that can be drawn based on the post-credits scene. Either the paradox ending, such as the One who Knocks and I believe, or the belief that the loop is still continuing somehow are the main ones that have been discussed in the thread.
A pair of scientists who are alternate realities of the same person. In one universe, female Lutece (who is native to Comstock's reality) discovers quantum tearing, and during her experimentation, discovers that a male alternate reality of her is doing the same experiments. In order to gain funding necessary to evolve her machine to bring her brother to her universe, she invites Comstock to look at her device. Through the tear machine, he receives his 'vision' of Columbia, and thus triggers the events of Bioshock Infinite.
- Where did Elizabeth get her powers?
The game heavily hints that this occurs because Liz's pinky is cut off as she is taken by Comstock, remaining in one reality while her body is in an alternate universe. Alternatively, it could be the cut itself that causes the powers to manifest.
- Why does killing Booker at baptism stop all versions of Comstock?
Killing Booker before he can ever make a choice stops the Comstock as we know of him from ever happening, since he can only arise from Booker being given the choice to accept baptism or not.
An unkown big-daddy esque man/machine hybrid designed by Fink after viewing tears (probably of Rapture) to protect Elizabeth from anyone deigning to harm/take her away, mainly Booker as foreseen by Comstock.
No. Symbolically, Booker stands as a parallel for Jack while Comstock has similar ties to Andrew Ryan. The Bathysphere scene does not have any conclusive evidence. It is possible that there is a common ancestor among them somewhere, but has no real significance.
- Why didn't Booker save Old Elizabeth
Saving Old Elizabeth would have meant nothing, as New York was already being bombarded. To save Old Elizabeth, Old Elizabeth sends Booker back to before the torture happened in order to stop herself from existing. She does so because in her reality, and others that she has seen, Booker always dies to Songbird. She gives Booker a note to Liz containing the control song C-A-G-E to keep this from happening.
Anna is Booker's daughter before she is taken by Comstock, and raised under the name of Elizabeth.
- What happens when you get knocked out and are in a black and white office?
Debatable, but it is at the very least signifying Booker's subconscious slowly placing together his fractured memories, which happened upon his entering a reality with a Booker with such disparate memories compared to his own (I.E. Comstock).
It could theoretically also signify that those 'knock-outs' due to cutscenes are in fact deaths, and when you wake up, another Booker has actually reached that point, where the previous Booker died, similar to how you can reach a similar scene in-game when Liz is not around. The latter is much more seemingly evident of death though, as it features no plot exposition, while the cutscenes do have memories present.
- What is the significance of the 123 flipped coins that land on heads?
It means that the Lutece's have observed 122 Bookers passing through to that point in Columbia, and have observed that no matter how Booker calls/flips it, the coin always falls on heads. It signifies a universal constant, something tying the universes together in that regard.
- Why is Comstock so much older than you if him and Booker are the same age?
He ages due to the repeated exposure to the tear machine, similar to how he and others have cancer/tumors. This is stated in a voxophone by female Lutece.
- Booker and Comstock are the same age! How do we know that?
They are the same age because they are the same person. Comstock experienced the same battle at Wounded Knee that Booker did.
- What year did Booker give Anna to Comstock?
1893. Says so on the calendar in the cutscene when male Lutece comes to take her.
- How long has it been since Booker gave Anna to Comstock before he enters Columbia?
19 years or so, since the events of Infinite take place in 1912.
- What is the relevance of the Bird and the Cage choice?
Nothing, it's a false dichotomy of choice similar to the way Bioshock 1's narrative plays out. Later on, there could be ties into how a minor 'cosmetic' choice helps allow the player to see that by offering this choice, whatever you pick, there is another universe where "Booker" (the player) picked the other option.
- Who is dead in the Lighthouse?
Lighthouse keeper, told by Comstock to kill Booker when he arrives. Killed by the Luteces to avoid that from happening, as evidenced by a picture of the lighthouse in their lab with a caption stating "the only obstacle".
- What is the connection between Rapture and Columbia and the characters of both?
As Liz says in the ending, there is always a man and a lighthouse. This symbolizes the similar thematic/narrative elements found in both games.
- Why does Bookers nose bleed?
Nosebleed occur as the body of an alternate reality of someone is transferred to another world, and experiences memory overload of his/her alternate personality native to that universe. The memories are disjointed and not easily thought of, and the brain, experiencing this overload whenever a new memory appears/returns to the surface of the brain to the non-native version, which leads to nosebleeds.
Booker's wife is never actually named, but it is suggested she died in childbirth of Anna. It is theorized that Lady Comstock is in fact the alternate reality's version of Booker's wife, since it would touch upon themes of consistency in the different worlds, but is never clearly stated.
Those are the quick and dirty responses, more fleshed out ones have been answered to pretty much all those questions at some point.