What makes a particular light wave (red) shorter than other light waves (e.g violet)?
Whether or not the light being emitted is moving towards (violet) or away (red) can affect this. The amount of energy being put into the light also affects this.
Red is actually a relatively long wavelength if you compare it to violet. The wavelength of an electromagnetic wave is determined by it's frequency(Think of the equation c = fλ). Also, the shorter the wavelength is, the more energetic the wave is.
wavelength is the distance between two peaks of a waveform. saying it's the speed over the frequency doesn't really explain what it is, it only puts it into other vague terms. What your question seems to be asking is, if light is a wave, it's a wave in what? Water waves are in water and sound waves are in air or solid matter. What does light wave in? Answer is nobody knows. It just seems in some ways to act like a wave acts. A wave in something.
Light is traveling at the speed of light, 300,000 km/sec. Speed pf light = frequency X wavelength. wavelength is the distance from crest to crest or trough to trough , of the wave and it is dependent on the frequency, how many times it vibrates per second. violet is shorter than red.
