= Faster-than-light implies time travel
\Image[https://raw.githubusercontent.com/cirosantilli/media/master/Faster_than_light_implies_time_travel_diagram.svg]
{title=<Spacetime diagram> illustrating how <faster-than-light> travel implies time travel}
{description=Legend an explanation are https://physics.stackexchange.com/questions/13001/does-superluminal-travel-imply-travelling-back-in-time/615079\#615079[shown in this answer].}
Bibliography:
* https://physics.stackexchange.com/questions/13001/does-superluminal-travel-imply-travelling-back-in-time/615079\#615079
* https://physics.stackexchange.com/questions/574395/why-would-ftl-imply-time-travel
* https://physics.stackexchange.com/questions/516767/how-does-a-tachyonic-antitelephone-work
* https://www.physicsmatt.com/blog/2016/8/25/why-ftl-implies-time-travel shows the <causality> violation on a <Spacetime diagram>