The photo below shows a peaceful sunset. The sun is low in the sky which are hazy, so no filter is required. A large sunspot is seen clearly and close inspection will reveal several more sunspots. The sun, like any star, is a strong source of electromagnetic radiation. The sun emits radiation in many wavelengths long ans short, and we can see only small part of it which is the visible light. In the photo you will see two more source of radiation. The power lines which are of high voltage and emit radiation in the radio wavelengths (long waves), The cellular beacon also emit radiation in the microwave range (Not as long as radio waves).
The most dangerous radiation is, however, the shortest waves, Ultra Violet, X-rays and Gamma rays, The shortest the wave, the longer the path that a particle goes along it. This makes the shortwaves much more energetic, and therefore they can harm living organism.
