I personally enjoy the paradoxes regarding time travel and omnipotence.
here's a whole list of them (in case you missed that link
List of paradoxes - Wikipedia, the free encyclopedia
Me too. they make for a spirited argument. An odd one because nobody has traveled to the future as far as we can tell, so it is all conjecture. Someone smart once said if time travel to the future were possible, we would have met these people from the future by now. Who's to say.
I do know if you visit the Great Pyramids and you stand next to the largest objects, time passes more slowly for you than those milliing abut. The great mass of the object affects the passage of time.
If you travel near the speed of light in a craft heading away from Earth, and you keep traveling for six months; turn around and return to Earth, many years will have passed on earth. For you it was only six months, but for those you left behind, perhaps several hundred years will have passed.
Or so they say.
Time travel is possible. We are all traveling into the future as we speak.