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Sep 13, 2017 · The speed of light in vacuum is constant and does not depend on characteristics of the wave (e.g. its frequency, polarization, etc). In other words, in vacuum blue and red colored light travel at the same speed c. The propagation of light in a medium involves complex interactions between the wave and the material through which it travels.
Each observer can be imagined to measure the speed using a pair of clocks at different positions along a ruler (the clocks synchronized in their own frame using the Einstein synchronization convention), measuring the time T1 on the first clock as the light wave passes it, and the time T2 on the second clock as the light passes it, and then if their ruler shows the clock to be a distance D ...
Jan 5, 2015 · The speed of light (in vacuum) is constant for every observer, independent of the movement of the light's sources. From this he was the one to drop the ether hypothesis: Before it was assumed, even by Lorentz and Poincaré, that electromagnetical waves need a mechanical medium which does the vibrating and propagating like the media for water or gas waves.
Oct 6, 2015 · $\begingroup$ The speed of light in vacuum is a defined constant just like the number of liters in a gallon, or the length of a mile expressed in meters. it's not something to be determined by experiment (which doesn't mean that you can't do an experiment to measure it's value, just like nothing would stop me from bringing my meter stick to Britain and measure the distance between two mile ...
The speed of light through vacuum is 299792458 meters per second but does it change if it would say travel through air or water? If so why and if not why? speed-of-light
The metre is the length of the path travelled by light in vacuum during a time interval of $\left (\dfrac {1}{299 792 458}\right)$ of a second. It follows that the speed of light in vacuum is exactly 299 792 458 metres per second and there is no caveat to this statement.
May 26, 2024 · In a vacuum an electromagnetic wave has the same phase and group velocities, so the speed of light in a vacuum is unambiguous. If the light is propagating through some medium this is generally not true.
Then the speed of light was measured based on that length, which turned out to be 299792458 lengths of the bar per second. This was then used to redefine the meter to the distance light in vacuum travels in 1/299792458 seconds, so that the old and new definition match as closely as possible.
And yes, Light is still the constant in vacuum. When dealing with astronomy, we often say that the interstellar space is approximated to 0 Pa (vacuum). So, we guys have astrophysically assumed that the speed of light is constant. Just minding you that, we take this vacuum into account and not the bell-jar one..!
Mar 15, 2020 · Alright but what does this have to do with the constancy of speed of light in vaccum? The fact is that $\mu_o$ and $\epsilon_o$ are independent of reference frame, and hence, the speed of light in vaccum is a fundamental constant irrespective of the reference frame in question. This was the start of Theory of Relativity as proposed by Einstein.
