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.
1902
2018
2006
2022
1920
1963
2010
1962
2012
2013
2017
2020
1932
—
2025
1927
2019
2014
