Fearful and very pesimistic predictions are about catastrophes leading to the end of the world by for example fire, flood, ice or cosmic collision. These are so called "end time" prophecies and they were made by many different cultures during the last 6,000 years.
Humanity has always been fascinated by the study of predictions of the future and prophecy.
Of all prophecies, probably Biblical prophecies are the most important for people with the Christian tradition.
This one is not the Biblical prophecy, but the Maya calendar.
"Reports that the Maya calendar calls for the end of the world Dec. 21, 2012 are inaccurate, says SMU archeologist Brigitte Kovacevich, an expert on Maya culture.
The Maya used a number of different calendars, which scholars interpret in different ways. One of the calendars turns over, much like an odometer, on Dec. 21 or 23, 2012.
The last time that this odometer turned over in the Maya calendar – August 11, 3114 B.C. – it was an event of creation, not destruction. Only two monuments out of all Maya sites refer to 2012, and they use the date as a rhetorical device, not a prediction.
Other monuments predict events still thousands of years in the future.
The Maya text often cited as predicting the end of the world is the Dresden Codex that lists astronomical information of great accuracy. It is also the oldest known book from the Americas.
It's one of four remaining ancient sources attributed to the Maya culture, which flourished in the Yucatan Peninsula, Guatemala and Belize centuries before the arrival of Europeans in the Americas.
It's also one of the most important original sources of information about Maya culture.
But according to SMU archeologist, the Dresden Codex does not mention 2012. Another famous ancient text the Chilam Balam books - compilations of religious, historical, chronological, astrologers and literary types.
This work speak fundamentally of facts that will happen in the future and these dire predictions describe events for certain period endings.
However The Chilam Balam source dated to the 15th and 16th centuries, was heavily influenced by the Spanish conquest event and Western culture.
According to Kovacevich, the prophecies about 2012 are a collection of myths and legends, independent of academic scholarship, spread by television, commercial publications and digital computer networks.
Not only are they inaccurate, they exploit, misrepresent and romanticize the Maya culture, she says.