Imagine if we could freely transverse time
We can move forwards, backwards, left, right, up, and down. But imagine if we could move those three dimensions? Instead of moving within those dimensions, what if we could just pick them up and move them. We already do this, we’re doing it right now. We’re all doing it at relatively the same rate. The faster we travel through those three dimensions, the faster we move those dimensions. So if we’re just sitting still on the Earth, we’re moving those dimensions at the same speed as someone who’s walking down the street; this is because the differences are extremely negligible. Though imagine the astronauts that are rocketing through space. They’re moving the three dimensions at a somewhat faster rate than we are.
When you move those three dimensions, you are traveling through time.
Time travel is nothing more than the moving of dimensions. The real question lies in whether or not we are capable of moving those dimensions backwards. After all, time travel into the future is extremely easy. You simply have to travel extremely fast. In other words, you simply have to move very quickly through the usual three dimensions in order to notice a change in the fourth dimension. So hop on a space ship traveling close to the speed of light, travel around the the solar system, and come back and you’ll have effectively traveled forward in time. For instance, if you spent 1 hour on the space ship traveling at the speed of light, something in the order of thousands of years would have passed on Earth. Similarly, if you were able to stand on the edge of a black hole, without being crushed into an infinitesimally small point of matter, you could also experience a massively large movement of the fourth dimension.