One is the visible spectrum, as mentioned above, and the other is the radio spectrum. However, not all of the radio spectrum is useable for space communication. The available window spans from about 30 MHz to 30 GHz, although these are not absolute end frequencies.
Isaiah 43:2 (BBE) When you go through the waters, I will be with you; and through the rivers, they will not go over you: when you go through the fire, you will not be burned; and the flame will have no power over you.saiah 43:2 (CJB) When you pass through water, I will be with you; when you pass through rivers, they will not overwhelm you; when you walk through fire, you will not be scorched-the flame will not burn you.
In the mornin' you go gunnin' for the man who stole your water. And you fire 'til he is done in but they catch you at the border. And the mourners are all signin' as they drag you by your feet. But the hangman isn't hangin' and they put you on the street, yeah. You go back, Jack, do it again, wheel turnin' 'round and 'round. You go back, Jack, do it again.