According to our current understanding of physics, it is impossible for an object with mass to travel at the speed of light in a vacuum. This is because as an object with mass approaches the speed of light, its energy requirements and relativistic mass increase infinitely, making it impossible to accelerate further.
However, if we assume a hypothetical scenario where you could travel at the speed of light, several consequences would arise based on the theory of special relativity:
Time dilation: Time would appear to slow down for you relative to someone who is not traveling at such a high speed. This means that while only a short time would pass for you, a significant amount of time would elapse for those who are not moving at such high speeds. This phenomenon is described by the time dilation equation of special relativity.
Length contraction: Objects in the direction of your motion would appear shortened from your perspective. This effect, known as length contraction, means that distances along the direction of your travel would appear compressed.
Infinite mass and energy: As mentioned earlier, an object with mass cannot actually reach or exceed the speed of light. As you approach the speed of light, your mass and energy requirements would approach infinity, making it impossible to achieve or surpass this speed.
Relativistic effects: The laws of physics, as we currently understand them, would behave differently at such high speeds. Concepts like simultaneity and the order of events may become distorted. Additionally, the relativistic effects would impact how you perceive the world and how the world perceives you.
It's important to note that these are theoretical consequences based on our current understanding of physics. Since we haven't observed anything with mass traveling at the speed of light, it's challenging to predict with certainty what would happen in such a scenario.