According to our current understanding of physics, it is not possible for an object with mass, such as a human, to travel at the speed of light. As an object with mass accelerates towards the speed of light, its energy and momentum increase, and it would require an infinite amount of energy to reach the speed of light. This is due to the mass-energy equivalence principle described by Einstein's theory of relativity.
However, we can explore the effects of traveling near the speed of light as predicted by the theory of special relativity. One of the fundamental principles of special relativity is that time dilation occurs as an object moves relative to an observer. Time dilation means that as an object's velocity increases, time appears to pass more slowly for that object compared to a stationary observer.
So, if we imagine a hypothetical scenario where an object could travel at a significant fraction of the speed of light (but not reaching it), time dilation effects would be observed. From the perspective of an observer on Earth, the clocks on the moving object would appear to run slower relative to their own clocks. This effect is known as time dilation.
However, it's important to note that time dilation is a relative effect. From the perspective of the moving object, it experiences time passing normally, and it is the clocks on Earth that would appear to run slower.
In summary, if an object were able to travel at speeds approaching the speed of light, time dilation effects would occur. The object's clocks would appear to run slower relative to observers on Earth, and observers on Earth would perceive time passing more slowly for the moving object.