Sun was not taken to the year 1977 by the flash because she will not be born until 1980. Perhaps existing in the past for an extended period of time requires that you to have already been born and living elsewhere at the same time.
In this scenario, flashing to times before you were born leads to nosebleeds (the nosebleeds start in 1954)and time eventually fixes itself by killing people who violate the paradox of being alive before you are born.
When the flashes stop and leave our characters in 1974, these characters have already been born (on or off island). Sawyer (born in 1969), Juliette (?), Miles (?), and Jin (1974).
The flash during the Ajira flight transports Sayid (1968), Jack (?), Kate (1977), and Hurley (1977) to 1977. It seems too coincidental that Kate and Hurley are born in 1977 or Jin was born in 1974.
Using this theory, Arron and Walt would also not have been able to return to the past because he had not been born yet. They would have likely ended up with Sun in present time. Since Sun comes along, the Island improvises and does not transport her, knowing she would die of temporal displacement in 1977, three years before she is born.
Of course I am probably wrong but that's the fun in theories isn't it? :) Theory by jcarlson34
In this scenario, flashing to times before you were born leads to nosebleeds (the nosebleeds start in 1954)and time eventually fixes itself by killing people who violate the paradox of being alive before you are born.
When the flashes stop and leave our characters in 1974, these characters have already been born (on or off island). Sawyer (born in 1969), Juliette (?), Miles (?), and Jin (1974).
The flash during the Ajira flight transports Sayid (1968), Jack (?), Kate (1977), and Hurley (1977) to 1977. It seems too coincidental that Kate and Hurley are born in 1977 or Jin was born in 1974.
Using this theory, Arron and Walt would also not have been able to return to the past because he had not been born yet. They would have likely ended up with Sun in present time. Since Sun comes along, the Island improvises and does not transport her, knowing she would die of temporal displacement in 1977, three years before she is born.
Of course I am probably wrong but that's the fun in theories isn't it? :) Theory by jcarlson34
