Zodiac celestial coordinate system, or more specifically an ecliptic coordinate system, which takes the ecliptic as the origin of latitude and the Sun's position at vernal equinox as the origin of longitude. The English word ' derives from ', the Latinized form of the Ancient Greek "zōidiakòs kýklos" (), meaning "cycle or circle of little animals". "Zōidion" () is the diminutive of "zōion" (, "animal"). The name reflects the prominence of animals (and mythological hybrids) among the twelve signs. The zodiac was in use by the Roman era, based on concepts inherited by Hellenistic astronomy from Babylonian astronomy of the Chaldean
Name-letter effect to a significant degree. The effect was also found when only looking at letters in family names, as well as only first name letters. The name-letter effect emerged as very significant in all languages when only initials were considered. There was a probability of 0.46 that initial letters were chosen amongst the top-six letters. Further analysis revealed that the overall name-letter effect is not simply due to initials: when excluding initials a name-letter effect was still found across all languages. Nuttin analyzed the data to see if there was a national-letter effect, but failed to find one. Norwegians did not