Q. How long is the Marriage License valid?A. A Marriage License is valid for 60 days, beginning the day after it is issued. Members of the armed forces who can prove they are on active duty at the time of applying for the Marriage License can obtain a Marriage License valid for 180 days.
Lesson Summary. UV light is one type of electromagnetic wave. Other electromagnetic waves include radio waves, microwaves, visible light, and X-rays. UV light is used by humans to produce vitamin D, but overexposure to UV light can damage DNA and cause painful sunburns, cataracts, and skin cancer.
The UV spectrum thus has effects both beneficial and harmful to human health. Near-UV radiation is visible to some insects, mammals, and birds. Small birds have a fourth color receptor for ultraviolet rays; this gives birds true UV vision. Reindeer use near-UV radiation to see polar bears, who are poorly visible in regular light because they blend in with the snow.