Light does not travel in "rays" it is a wave. To be more specific it is an electromagnetic transverse wave and visible light is just a small section of the electromagnetic spectrum,

  • cosmic rays

  • gamma rays

  • x rays

  • ultraviolet

  • visible light

  • infra red

  • microwaves

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Insulin injected into humans used to come from pigs. However there were some political and health issues with this. Some peoples bodies also rejected it. It is now made by genitic engineering where the human DNA for making insulin is inserted into the plasmid of a bacteria cell. This is very tricky and is done … Read more