If you had a time machine,, and you traveled back in time to visit the composer Beethoven and took with you a CD of his Fifth Symphony. Beethoven listens to it and writes the music down, then later his score is used to record your CD. Where does the music come from?
-as
What you're talking about is a "time paradox"
If you start thinking about the implications of this you will literally lose your mind
New knowldge of physic however showed that time is not a straight line but a round circle where past , present and future are just continuing forever, repeating themselves eternally
If that were true there wouldn't be past just a continuation of present toward the reconjunction with past
I think in the 12th century to consider the time like a straight line with past behind and future ahead is just as silly as considering the earth flat
Anyway, in such time paradox the music would not come from past or future but from the same place in the timelime, so it simply would mean that although Beethoven would compose his music by listening to the recording of it, it was anyway already in his head
Time paradox are a complicate matters, I think that if we find a way to time travel (but I think that would be impossible because of the non existence of past, present and future according to new knowledge) there would be no time paradoxes as they would be contrary to nature perfection
If humans will be able to time travel and even cause time paradox this could in turn destroy the perception of existence of even the whole solid matter
We will never time travel because it would be highly dangerous
In fact, since a lot of events orginated just by chance (like the meeting between my father and mother) by interfering with the events we could completely change the reality
For example, my mother was a nurse and met my father because he cut his arm with a broken window in the hospital hall
Let's say you could time travel and fix that window, my father would not cut his arm and he would not meet my mother, I would disappear from the world so anything I've done, and anything I've done , by turn , changed the life of other people
For example my autn was at my birthday when I was 9 years old
If I was not born, my aunt would have been at my 8th birthday and maybe she could have been killed in a car accident, this in turn would making my cousing dissapear and all their actions like when causing was admitted at college and the girl who got a lower score didn't, if my cousin was not born the girl under her would have become a medicine student and this in turn would have changed the life of other miliards of people
It's all chain, people who think they're useless should think about this
If you fix a window in the past, you destroy the whole world
Daniel