Length and period and frequency are all intimately connected to each other, one of them decides the other, that is the most important characteristic. Why I say? You take for example, electromagnetic wave light wave spectrum, you take typical radio waves or you
know two x ray. Radio waves, two x ray all travel at the same speed, but radio waves length and period are inverse you see. No sorry. The speed is constant there in radio waves. Only thing is that length and period, frequency and wave length actually h into lambda what they call becomes constant. If the x ray has a wave length longer, it has a smaller period etcetera, but the speed is constant. But in here the interesting part is that, this relation tells me that speed becomes a function of length, How it is so? Let us say speed C, what is this C? C is given by omega by K. By definition, what is omega by K? From this equation is equal to g by omega.
Omega by K, if you write it is g by omega. So, celerity becomes omega by K which becomes g by omega. And that also becomes root over of g by K. How it is? See, here now this relation requires lot of little discussion, I want to tell that. See, omega square is g k this is my dispersion relation.