What is the history behind blowing candles?

It is said that the custom of placing candles on a birthday was started by early Greeks who used to place candles on the cake that they offered to Artemis - the Goddess of Moon. Lit candles made their round shape cake glow like the moon. Scholars also say that the custom of placing candles originated because people believed that Gods lived in the skies. They thought that lit candle helped to send signals and prayers to the god so that they could be answered more effectively. The other belief that people held was when a person makes a wish while blowing out the votive candle a signal or message was received by the god and the prayers would be answered.