All light travels at approximately 2.99792468 *108 meters per second - an increasingly high speed so intense that it would take one-tenth of a second to travel around the world at the equator. As a result, people often question the origins of such a large speed, and in order to understand tachyons, one needs to understand the speed of light. In 1905, Einstein published a hypothesis called the Theory of Special Relativity, which states that nothing can exceed the speed of light. That speed, explained Einstein, is a fundamental constant of nature like a mole or an ampere. As objects approach higher speeds, a greater amount of energy is required to further accelerate these objects because of their constant increase in kinetic energy. Consequently, it appears as though the objects are gaining mass because it becomes harder and harder to accelerate them. Einstein calculated that at a certain speed, an object’s mass and the amount of energy required to increase its speed would approach infinite. This number was the speed of light. Now, how does light, nonetheless tachyons, obtain this colossal speed if it requires an infinite amount of energy to do it?
The answer is photons through wave-particle duality. Photons are particles with zero mass, at rest, and combine in massive amounts to form light. Because they are elementary particles, photons have qualities that are unique to not only waves, but also particles. Thus, photons do not experience friction force, and have the ability to reach uniquely high speeds. Tachyons, on the other hand, are particles that exceed the speed of light. If going beyond infinity is impossible, how do tachyons do this? Well the answer is that they don’t. There is no experiment that has contradicted special relativity, and there has been no particle known to have accelerated past the speed of light. There have been numerous instances where people have accelerated sub-atomic particles to well over ninety-nine per cent of the speed of light, but the speeds do not equal or exceed that limit. Tachyons simply exist because string theory, needs them to exist (Craig 11). Without the addition of integers greater than the speed of light, within calculations of the theory, a whole branch of string theory would be proven useless. This is the very reason why string theory is so controversial among physicists. Tachyons, as of now, are theoretical, and have not been proven to exist.