It is called the Time Traveler's Paradox. In which a scientist creates a Time Machine and kills their younger self. So now a man who should not- can not- exist, somehow does. That is the Paradox, and Paradoxes are impossible.
2016
1984
1986
1989
1997
2000
2002
2005
2006
2019
2022
2018
1969
2014
1962
