If an object travels at a speed which is equal to the speed of light will its mass increase? And will its weight be infinity?
We do not know what happens to a substance if it moves faster than the speed of light for the very simple reason that it can never move faster than the speed of light. The speed of light poses a fundamental limit to the speed that an object can take, relative to objects nearby it. In fact, no object with any finite rest mass can move atthe speed of light. That is why all the particles that move at the speed of light (e.g. photons) have zero rest mass. As a particle with mass approaches the speed of light, its energy increases and becomes infinite at the speed of light, which is the reason why it can never be accelerated to reach that speed. This has actually been verified by experiments, and it has been shown that nothing moves faster than the speed of light.
However, the above discussion only applies to objects on small scales in the universe -- for example, if you take a baseball or a planet or a star or a galaxy and try to accelerate these objects to the speed of light relative to objects nearby them, it is impossible to do. However, there is nothing which prevents objects that are separated by huge distances from moving relative to each other faster than the speed of light. Over these large distances, the effects of the universe's expansion become important, and the above discussion no longer applies.
We do not know what happens to a substance if it moves faster than the speed of light for the very simple reason that it can never move faster than the speed of light. The speed of light poses a fundamental limit to the speed that an object can take, relative to objects nearby it. In fact, no object with any finite rest mass can move atthe speed of light. That is why all the particles that move at the speed of light (e.g. photons) have zero rest mass. As a particle with mass approaches the speed of light, its energy increases and becomes infinite at the speed of light, which is the reason why it can never be accelerated to reach that speed. This has actually been verified by experiments, and it has been shown that nothing moves faster than the speed of light.
However, the above discussion only applies to objects on small scales in the universe -- for example, if you take a baseball or a planet or a star or a galaxy and try to accelerate these objects to the speed of light relative to objects nearby them, it is impossible to do. However, there is nothing which prevents objects that are separated by huge distances from moving relative to each other faster than the speed of light. Over these large distances, the effects of the universe's expansion become important, and the above discussion no longer applies.
