The speed of light (c) is a characteristic of electromagnetic (EM) radiation, but it does not imply that all components of the electromagnetic spectrum are classified as light. Light is specifically defined as EM radiation within the visible spectrum, approximately 400-700 nm. While all EM radiation propagates at the speed of light, the term "light" should be used with caution to avoid confusion regarding its definition. Additionally, gravitational waves also travel at the speed of light, although they are not classified as electromagnetic waves.
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No. Light is EM radiation with a wavelength in a particular range (about 400-700nm). There's no difference between light and other EM radiation apart from the wavelength (and frequency), but light is by definition only the stuff we can see with our eyes.finney said:
I think qualifying the particular range of the spectrum as "visible light" instead of just "light", is more descriptive of what one is talking about. As we know, all EM radiation propagates at the speed of light. Calling the visible component just "light" might make one wonder why this particular range of the spectrum is singled out and whether radiation in the other ranges does not propagate at the same speed. It seems that this is the gist of OP's question. Indeed if one googles "EM spectrum/images", one gets variants of this with "visible" instead of "light" in the visible range.Ibix said:
Maybe. I'm still not sure. Perhaps the OP will add some clarity.kuruman said:
As others have said, your question is not clear but as I interpret it, no, the speed of light does not imply what you think it implies. it IS true that the entire EM spectrum is "light" in its most general sense ** and it is true that it all travels at c, but it is NOT true that the speed "c" implies the spectrum, it is a characteristic of the spectrum.finney said:
It may be worth noting that gravitational waves travel at the speed of light in a vacuum (c) but they are not electromagnetic waves.finney said:
A better name would be "the limiting speed of relativity", because the essence of relativity is that there is a limiting speed. That electromagnetic waves in vacuo have this speed of propagation is an empirical fact, i.e., that the em. field is precisely massless. The current upper limit of this "photon mass" is ##10^{-18} \text{eV}##.Hornbein said: