According to the theory of special relativity proposed by Albert Einstein, as an object approaches the speed of light, time dilation occurs. This means that time appears to pass slower for the moving object relative to an observer at rest. However, it is important to note that the theory of special relativity states that objects with mass cannot reach or exceed the speed of light in a vacuum.
As an object with mass accelerates toward the speed of light, its perceived time dilation becomes more significant. For example, if you were on a spaceship traveling at a significant fraction of the speed of light, observers on Earth would perceive time passing more slowly for you compared to themselves. This effect is due to the relative motion between the two reference frames.
However, from your perspective on the spaceship, time would appear to pass normally, while you would observe time dilation for the stationary objects around you. This phenomenon is known as the "twin paradox," where one twin stays on Earth while the other travels at high speeds, and upon their reunion, the traveling twin will have aged less.
It's important to note that the concept of an object with mass reaching the speed of light is purely hypothetical, as it would require an infinite amount of energy. As an object approaches the speed of light, its mass would also increase, making it harder to accelerate further.
In summary, if you were somehow able to travel at the speed of light, time would appear to stand still for you. However, achieving this speed is currently considered impossible for objects with mass, according to our current understanding of physics.