The work is at least 30,000 years older than the earliest previously known abstract and figurative drawings. What is a symbol ... Tribology is the science of friction and wear.

Scientists use symbols to represent the different components in a circuit. Symbols are simplified drawings. We use symbols because they are easier to draw and they act as a universal language ...

Blombos Cave drawing with ochre pencil on silcrete stone ... But trying to understand what the ancient symbols meant may be an inscrutable puzzle. “There, I think we’re stumped,” Henshilwood ...