Time is a relative thing. It is never fixed as we all are in a relative motion with respect to moving sun, stars, galaxies and all.
How does time get slow down when we approach the speed of light as mentioned in Time Dilation ? So next what happens when we travel at the speed of light? Time must stop forever, isn’t it..? That is youth forever. We never get aged when we travel at the speed of light.
So next what, when the speed is further increased..? Can we go back in time..? Will there be a new timeline..? What happens to my thoughts then…can I have a working brain then..? It implies that time is not moving in one direction. If so, it could be multi directional/ dimensional.
Ahh !.. The more you ponder, the more strange the notion of time travel appears…