- 20d 2h 21m
My attempts at answers inline.
Not arguing, you clearly understood the movie, I was hungover and had trouble following a lot of it:
How did they go backwards through time? Was it bc they were inverted? Why didn’t they need oxygen when Kat killed her husband at the end? How did they uninvert themselves?
They are on a ship that has a Mobile Hypercenter/Turnstile. They inverted to reposition themselves in time and then started moving forward again; you only need oxygen when you presently inverted, like The Protagonist in the Saab in the car chase. Only when you are moving against the standard flow of time, i.e. would your lungs not process regular oxygen. I assume they traveled back to the mobile Hypercenter on the ship where all of the soldiers were departing from where she was in the cube.
Was that robert Pattinson that was shot in the head at the end? If so, so he dies after they had their little goodbye at the end?
He does; that is why they have the goodbye and he convinces Ives not to kill everyone.
In the inverted/normal action sequences, the people were never really running backwards right? That was just the perspective from normal time?
What was happening when Sator was interrogating The Protagonist by threatening to shoot Kat in the room with the inverted turn stile thing?
As I understand it, IIRC fully caveat and provisos on this one, as now the movie is further away, In the fake swap, they didn't get the part, so he was threatening to shoot Kat to get the real location of the item from the Protagonist but as he was Inverted, it was playing essentially translating the speech for someone who was in their future. Basically they went back in time and had the Protagonist tell them where he was "going" to leave it after he had already left it there.
What was the whole plot with the painting about?
This was the blackmail piece Sator was using to keep Kat with him; if she left him, he would have her prosecuted for assisting the forger in defrauding her husband and she would lose Max. Getting this piece was the leverage that was key to getting her cooperation. Michael Caine and she explain this part at those first two dinners ("Brooks Bros. won't cut it" and Cheese Grater Fight.)
Also, what was the whole opening sequence about? There was an inverted round in the opera right? Who were they saving? Is that why he asked “do you like opera” to the bad guy?
It was Sator getting a piece of the algorithm "disguised" as Pu-241; there was, used by the guy with the red string, who turns out to be Neil. That is why the Protagonist used that line to get in with Sator later.
Was Robert Pattison Kat's son grown up?
That's the implication, its left ambiguous, although the red string has a coin that looks like it could be from Vietnam on it. and people have SS of Max watching the woman dive off the yacht with opened mouthed amazement on his face. I lean to think that he is but just my opinion.
When Protaganist is learning about Tenet, the bullets are shot in the stone, and he sucks them back up bc they are inverted. Didn't someone shoot them initially into the stone? So you could shoot them, then unshoot them??
As I understand it, No: The items may have their Entropy reverse forever but the impact on the world isn't seen for that long into "the future". At some point, as they describe it in the movie, (When they are first looking at the bullets in the Research Center, he describes the effect as "pissing in the wind") at some point the inversion effect will come into being and objects will be affected. Such as when they got close the Hallway fight again taking Kat back to other Turnstile/Hypercenter at the Oslo Airport and the Protagonist's arm started the bleed where he had stabbed himself in the first run through. So, close in our time to the bullet being fired, the impact will appear on the wall, and then the shoot will "catch" the inverted bullet.
Another example is the mirror on the BMW in the Tallinn scene where they are trying to get the "241" with the large vehicles. There is a shot of the BMWs mirror being cracked for no reason, because in a few minutes, (I think The Protagonist's Inverted Saab) will crash into them. Reading about the movie, it is described as the "Throwing a tennis ball into a strong wind": the point at which the tennis ball turns around and starts the go with the wind, that is when the effects of inverted objects will show up in the normal flow of time. Bullet holes will appear, people will pop into or out of view, etc. In the Research Center at the start of the movie again, you see them "pick up" inverted objects, but then they show the video played backwards and it looks like they are being dropped. It's very much like Inception and our limited perspective on the timestream.
You can't unshoot a shot bullet because events don't "unhappen" and you can't change causality in Tenet; you can't bring people back from the dead, etc. Mirrors still break, All that is changing is the flow of entropy i.e. time. Now, from a philosophical point some will say this (a 100% deterministic POV unchangeable timeline breaks freewill but not from the perspective that what you are going to do has already happened in the sense that all times are happening simultaneously and we are only limited by our 3D/linear flow of time perspective. Knowing what we are going to choose doesn't limit our choices, it only makes us predictable assuming an unknowable future.
Also, the scene on the boat where Kat is sitting, and you see the pole behind her move right to left and back multiple times, why was it so rapidly reversing time?
I didn't notice this at all; I got nothing. I will need to either wait for another viewing or find a copy sooner that video release, which someone said is December? ugh.
I also need to check the yacht dates in my answer earlier, because despite my memory of them they don't make sense in the context of the movie. Formatted for readability and I like intrinsic's use of Bold better than my highlighting inline answers.