In the grand body of the universe and even our own solar system the speed of light is incredibly slow on the cosmic scale. Why does it have this speed limit ? It is theoretically possible to go faster than light ? Or is light just the fastest thing we have observed thus far ?
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You ask: *why is does light only travel 300,000 km/sec ? Why does it have this speed limit?*
The speed of light in a vacuum, commonly referred to as “c,” can be derived from fundamental constants of nature. Specifically it can be derived from the vacuum permittivity (ε₀) and the vacuum permeability (μ₀) according to:
c = 1 / √(ε₀ * μ₀)
where ε₀ is the vacuum permittivity, which represents the electric constant and describes how electric fields interact with matter in a vacuum and μ₀ is the vacuum permeability, which represents the magnetic constant and describes how magnetic fields interact with matter in a vacuum. The values of ε₀ and μ₀ are defined constants, and their product is exactly known. So, c, in a vacuum is also a precisely defined constant. The point: the speed of light can be derived from fundamental constants and its value is integrally related to the fabric of the universe. So, the speed of light is what it is for sort of the same reason that π is π and *e* is *e.*
Your follow up question: *Is it theoretically possible to go faster than light ?*
No, because as a the velocity of a mass approaches *c,* it’s mass also increases as described by the equations of special relativity, approaching infinite mass as its velocity approached *c*. It would require an infinite amount of energy to continue accelerating, an impossibility.
The implication is only massless objects, like waves and photons, can travel at *c*, the speed of light.
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