sorax123 said:I was thinking about refraction and phase velocity change, when i thought about whether the c in e=hc/lambda is always 3x10^8 or does it refer to the speed in the medium?
Thanks
The speed of light (c) is a constant value in the equation e=hc/λ and is equal to approximately 299,792,458 meters per second. This value represents the maximum speed at which any object can travel in the universe.
The speed of light (c) is directly related to energy and wavelength in the equation e=hc/λ. This means that as the energy of a photon increases, the wavelength decreases, resulting in a higher speed of light. Conversely, as the energy decreases, the wavelength increases, resulting in a slower speed of light.
The speed of light (c) is considered to be a constant because it does not change, regardless of the observer's frame of reference. This is known as the principle of relativity, which states that the laws of physics should be the same for all observers, regardless of their relative motion.
The first successful measurement of the speed of light was conducted by the Danish astronomer Ole Rømer in the late 17th century. Rømer used observations of Jupiter's moons to estimate the time it takes for light to travel from Jupiter to Earth, which he calculated to be approximately 220,000 kilometers per second. This was later refined by other scientists, leading to the current accepted value of approximately 299,792,458 meters per second.
According to Einstein's theory of relativity, nothing can travel faster than the speed of light. However, some scientists have proposed theories such as wormholes and warp drive that could potentially allow for faster-than-light travel. These theories are still highly speculative and have not been proven to be possible.