i think it's theoretically possible to view all of history. like watching it on a screen and controlling a flying observer camera that you can go anywhere with. the revolution in technology that could allow such a thing would be a forwards time machine.
you cant go back in time because it would change the present and be a paradox, but i think you CAN go forwards in time. imagine a time capsule or dino bones, thats the same thing as teleporting an object from the past way into the future. it can greatly affect the future world, as the discovery of fossil fuels very suddenly affected humanity.
you can jump forwards in time, and suddenly the future is affected by your presence.
so essentially, the time machine is a one way trip into the future, you cant ever come back.
now hear me out: i dont know HOW, but i have a feeling such an invention would come out around the same time as (and have a lot of scientific overlap with) a process of extrapolating past events based on current conditions. like analyzing a dent in a wall and knowing with 100% accuracy the qualities of the object that hit it and its velocity, and based on that what other thing launched it and how, etc.
BUT!!! (this is very important) again i dont know HOW, but this technique would NOT enable you to predict the future based on current circumstances. for the SAME or very similarly connected reasons that time travel backwards is impossible.
so the whole secrets of evolution, anthropology, language, who cheated on who, who killed who, which imprisoned persons are innocent or guilty, what everyone ate for dinner last night and indeed!!!!! what everyone did a just millisecond ago (allowing for full realtime exposure of literally everybodys actions at every moment, viewable by anybody). it will be a world where there are no secrets, no surprises, no concept of individual or self.
the only way to get out of the organism of humanity would be to use the time machine and go into the future, because then nobody would be able to view you anymore. but they can view you when you make the attempt, and they will stop you before you can do it. this would be analogous to a cell in a body attacking the others and then the immune system goes and kills it. humanity would kill you for trying to use the time machine. and if EVERYBODY used the time machine at once thats the only way it COULD be used, which would be the extinction of humanity.