Speedster (fiction)

A speedster is a superhero whose powers primarily relate to superspeed. Primary abilities shared by all speedsters include running at speeds far in excess of human capability (to varying degrees) and resistance to the sideffects (air resistance, inability to breathe, dynamic shock resulting from contact with objects at high speed, etc.) that result from such velocity. In almost all cases, speedsters are able to physically attack opponents by striking them while at high speed to impart huge amounts of kinetic energy without suffering harm, although this has on rare occasion been lampshaded by characters discovering that they cannot do this and suffering severe injury from the attempt. A variety of other powers have been attributed to speedsters depending on the story, the origin of the power, and the established continuity and rules of a given universe.

The use of speedsters in non fiction requires artistic license due to the laws of physics that would prohibit such abilities. Moving at the speed of sound, for example, would create sonic booms that are usually not heard in such stories. An enormous amount of energy would be required to achieve such speeds, and as some speedsters can actually move close to or at the speed of light, this would cause them to gain near-infinite mass, according to the laws of relativity.

For example, the Official Handbook of the Marvel Universe states that the character Nova maintains speeds which can be considered "modest," especially when carrying a passenger. The Handbook also concedes that a solid object moving in the Earth’s atmosphere at one times the speed of several times faster than the speed of sound which would wreak havoc on the planet and that moving at such speeds would prohibit Northstar from breathing, while the generated wind/friction would ravage his body. On the other hand, the Handbook states that the character quicksilver was born with adaptations that make higher speeds possible, such as enhanced cardiovascular, respiratory, musculature, and digestive systems, a more efficient metabolism, better lubricated joints, tendons with the tensile strength of spring steel, unidentified bone composition that can withstand the dynamic shock of his touching the ground at speeds over 100 miles an hour, and a brain that can process information fast enough for him to react to his surroundings at high speed.

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Wikipedia