This never made any sense to me whatsoever.
I’ve see all the physicists (Michio Kaku, Stephen Hawking, Neil DeGrasse Tyson, etc.) explain this principle but it doesn’t make sense. They say that if you were to go to the moon and back at a certain speed near the speed of light, you might return to Earth a thousand years into the future like what happened in Planet of the Apes. But if you were going at the speed of light, you would arrive at the time light takes to arrive there. Why the dip? What is being missed?
What’s described is Einstein’s theory of relativity. It states that time moves at different speeds depending on how fast things go. The faster you go, the slower you will age.
Say you go to the nearest star, which is about 4 light years way. If you go near speed of light this journey would feel like an instant to you. For anyone else on earth observing your journey, it will look like it has taken you 4 years to complete the journey. A journey that felt like an instant to you actually took many years to complete.