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# Is it possible to travel faster than the speed of light?

Credits : Wikipedia / Argonne National Laboratory

In theory, no. Except for in certain mediums, according to the Cherenkov effect. Let us explain the differences between this effect and the theory of special relativity.

In the year 1905, the theoretical physicist Albert Einstein announced the theory of special relativity which was to make him famous. According to Einstein, nothing or nobody could move in a vacuum faster than the speed of light, this being around 300,000 kilometers per second.

In reality, it is not the speed in itself that cannot be surpassed. It is rather the energy necessary for the propulsion of the object that prevents acceleration. In fact, according to the theory of special relativity, an object moving at speed increases in mass. By reaching a speed of around 300,000 km/s, the object could also potentially infinitely acquire mass. But it would require an object to be furnished with sufficient energy, also proportional to its mass.

Therefore, nothing can move in a vacuum at a speed greater than the speed of light. But in certain mediums, it seems that it may be possible. This is what is called the Cherenkov effect, a phenomenon discovered in 1958 by the Russian physicist Pavel Cherenkov, in a study that won him the Nobel Prize for physics.

In fact, Einstein’s theory of special relativity is true for objects that move in a vacuum. The Cherenkov effect is only possible in a given medium, and it occurs when a particle moves faster than the speed of light. Thus, although it is not possible for a particle to exceed the speed of light in a vacuum, this doesn’t stop it from moving faster than light in certain mediums, such as water, for example. When this happens, an intense blue coloured light is emitted, referred to as Cherenkov rays.

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