Unsurpassable pace, immutable reference of the universe.
The speed of light is the ultimate speed limit, even if we tend to perceive speed as a relative concept. For example, you are sitting here reading this text, and you might think you are still. But a friend of yours sitting in a train could say the opposite: for them, you do have a speed! However, no matter who or where you are: in vacuum, light always travels at the same speed. This simple and intriguing fact has tremendous repercussions for the evolution of our universe.
The explanation that the mass of an object increases as it approaches the speed of light is a rather common misconception.
How is this possible?