According to the theory of relativity, as postulated by Albert Einstein, it is not possible for an object with mass to reach or exceed the speed of light in a vacuum. The theory predicts that as an object with mass approaches the speed of light, its relativistic mass increases, requiring more and more energy to continue accelerating. As the object approaches the speed of light, its mass would effectively become infinite, requiring an infinite amount of energy to reach the speed of light.
Now, let's consider a hypothetical scenario where we assume we could reach the speed of light. In this scenario, if an object with mass were somehow accelerated to the speed of light, it would experience significant consequences due to relativistic effects.
Time dilation: As an object approaches the speed of light, time dilation occurs. From the perspective of the object, time would appear to slow down relative to an observer at rest. This means that for the object traveling at the speed of light, time effectively stops. However, from the perspective of an outside observer, time for the object would still be passing.
Length contraction: Another effect is length contraction, where the length of the object in the direction of motion appears to shrink from the perspective of an outside observer. As the object approaches the speed of light, its length would contract to zero in the direction of motion, at least according to the equations of relativity.
Mass increase: The relativistic mass of the object would increase as it approaches the speed of light. This means that more and more energy would be required to accelerate the object, and as mentioned earlier, an infinite amount of energy would be needed to reach the speed of light.
Regarding the effects on the human body, it is difficult to predict with certainty because we do not have direct empirical evidence for objects traveling at the speed of light. However, based on the relativistic effects described above, it is likely that the human body would not be able to withstand the enormous forces and energy requirements associated with approaching the speed of light. The intense acceleration and the resulting energy would likely have catastrophic effects on the body's physical structure.
In summary, reaching or exceeding the speed of light is currently considered impossible for objects with mass according to our current understanding of physics. Even in hypothetical scenarios, the relativistic effects would have profound consequences, making it highly unlikely for human bodies or any material object to survive such conditions.