A more circular and closer version of the previously is seen on many Neolithic rock carvings. The meaning of this ideogram has eluded researchers, but things have now changed. On rock carvings in Scandinavia one often finds signs which look like a strange type of boats or sleighs with short vertical lines on them.
Together with them a lot of small, round signs. A breakthrough to understanding of these strange ideograms seems to have been made in 1991. An archaeologist got the idea that the small, round signs on those rock carvings could be signs for stars in the sky. Thanks to a PC program he found that the rock carvings were documentations of the configurations of the visible planets and the brightest of the fixed stars at times of total solar eclipses. Thus the sign might mean the eclipsed sun.
An other variation consists in two spirals interconnected , made up not by lines but by rows of dots. This symbol has been found engraved on an amulet of mammoth tooth which is 24,000 years old, and thus must have been engraved by Cro-Magnon mammoth hunters. The sign , often used to denote the sun, is at the center of the amulet, with two on each side of it. During the Bronze Age it was a structure used for decorations of artefacts of all types. In ancient Greece it was common on vases and amphoras, and often signified water or the sea. A final variation on the same theme is found on rock engravings from the Bronze Age in Sweden.