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 line 18 the use of the sorrowful sounds of the monkeys are a reminder to the wife of her own sorrows. Lines 19-21. These lines are centered on the river merchants absence. In line 20 the phrase by the gate implies she has returned to the gate and is a memory of when/where he left. Lines 22-25. In line 22 the river merchants wife is again reminded of her sorrow by the falling leaves of autumn and by the paired butterflies who are turning yellow and changing with the season. she says the butterflies hurt her because they make her realize she is growing old too but not with her husband.