Today is Friday the 13th. Here are some things you may or may not know about the superstition that surrounds today.

The curse that surrounds Friday the 13th goes back a long time and ranges from sailors and fishermen being afraid to head out on the water to people being afraid of hearing bad news on this day for fear it would add a wrinkle to their face. In 1913, a pastor in New York named Charles Reynolds offered to marry couples for free if they dared to challenge superstitions. In France, there were citizens known as quatorziens or fourteeners who made themselves available as a 14th guest for dinner parties.

One extreme superstition is that if you eat dinner at a table set for 13, one will die within a year and throughout history, many serial killers had 13 letters in their name including: Jack the Ripper, Jeffrey Dahmer and Charles Manson.

Pope John Paul II was shot on May 13, 1981; then Vice President Richard Nixon was attacked May 13, 1958 and Winston Churchill promised to, "Wage war, by sea, land and air with all our might and strength that God can give" May 13, 1940.

Many high rises, hospitals, apartments and hotels don't have a 13th floor; airports don't have a gate 13 and airplanes don't have a 13th row. Italy doesn't have the number 13 in their lottery, and in Florence, they don't have house numbered 13 either. If there's a house between 12 and 14, the street address is 12 and a half and many cities don't have 13th Avenue or 13th Street.

By the way, the fear of the number 13 is called triskaidekaphobia. A specific fear of Friday the 13th is called paraskevidekatriaphobia.