Candles are a leading cause of home fires and fatalities. Soot on the walls and furnishings is unsightly, and may also be a sign of serious problems. It may also be unhealthy, as inhalation of minute particles of soot has been documented to cause health problems.
It is a popular misconception that the phenomenon of a total eclipse of the sun is a rare occurrence. Quite the contrary. Approximately once every 18 months (on average) a total solar eclipse is visible from some place on the Earthâs surface. That's two totalities for every three years.
Only those located in the path of the Moon's full shadow, its umbra, can see a total solar eclipse. The Moon's umbra travels eastward at about 1,700 km/h (1,056 mph). A total solar eclipse can last for several hours. Totality can range from a few seconds to 7.5 minutes. The longest total solar eclipse of the 21st century took place on July 22, 2009 when the totality lasted 6 minutes and 39 seconds. Total solar eclipses typically happen a little less than once a year when: