Wave, even the light is a wave

And the waves had the mechanicals ones and the electromagnetics ones, and is the mechanicals ones the sound and the wave that you see when you throw a rock in the water, could be in a swimming pool, the mechanical wave need matter to propagate, the sound need matter to propagate, in the air is the molecules of air, so if you had a chamber in a vacuum the sound  would not exists inside no matter if you are hitting iron, the sound travels faster in the matter than in the air, so the Indians put the ear in the iron of the train rail to predict the coming of the train with some time advantage, when you hit an iron had an invisible wave that travel to the iron, so the first telegraph was an iron rail, that was hit in one city and, came to other city, probably the telegraph ‘of sound wave in the iron was under the sand the trajectory, so telegraph is old, is probably prehistoric, and was like Morse code, but probably not so sophisticate without letters, an secret communication, that the only to know is the ones in the ends of the rail, the sound  wave is mechanical but you don’t see. Are the electromagnetic waves the light, the radio wave, and all the lights even the dangerous are electromagnetic waves the radiations are electromagnetic waves, the light could be a radiation or an ray, ray and wave is the two sides of the same coin or the light is being a wave or a ray, electromagnetic waves travel in where is not the matter but had some that cross the matter maybe because the matter had microscopes spaces, the problem with the lead (the story of the superman and the kryptonite in the lead box) is because the atoms are very close of each other and the atoms of lead  are small, between small balls had less space of the big balls, so to a wave pass had to be  of small length could even had a big distance (λ). Rute Bezerra de Menezes Gondim