Around 13.5 billion years ago, energy, time, matter and space had come to be known as the phenomenon of the Big Bang. The theory of the fundamental features of the universe is referred to as physics. Around 30,000 years when these features had appeared, energy along with matter had started the coalescing into various complex structures referred to as the atoms. These then combined themselves into bigger molecules. The theory of atoms along with molecules as well as its interaction is referred to as the chemistry. Some 3.8 billion years before, on some planet known as the Earth, several molecules had combined to result in some large and well-defined structures known as the organisms. The theory of the organisms is referred to as biology.Around 70,000 years before, the organisms which belonged to the group homo sapiens had started forming even larger and elaborative structures known as the cultures. The development of these cultures is known as history.