While it is a commonly known theory that the so-called Big Bang -- the moment something impossibly tiny began to grow -- brought about the universe billions of years ago and is still shaping it now, what has intrigued scientists more seems to be what was there before the "explosion" when there was supposed to be nothing.
Hawking was seated next to host Neil deGrasse Tyson at the "Star Talk" show, explaining his thought on events before the Big Bang.
Hawking's theory lies upon the assumption that the universe has no boundaries. "The boundary condition of the universe ... is that it has no boundary," he told Tyson, who himself is also a physicist.
The Big Bang theory holds that the universe in retrospective can shrink to the size of an extremely small "subatomic ball" known as the singularity. According to Hawking, the laws of physics and time cease to function inside that tiny particle of heat and energy.
In other words, the ordinary real time as we know now shrinks infinitely as the universe becomes ever smaller but never reaches a definable starting point.
During the show, Hawking argued that before the Big Bang real ordinary time was replaced by imaginary time and was in a bent form. "It was always reaching closer to nothing but didn't become nothing."
To help people better understand the abstract and confusing state, the world-celebrated physicist drew an analogy between the distorted time with Ancient Greek philosopher Euclid's theory of space-time, a closed surface without end.
Hawking further took Earth as an example. He said: "One can regard imaginary and real time beginning at the South Pole ... There is nothing south of the South Pole, so there was nothing around before the Big Bang."
"There was never a Big Bang that produced something from nothing. It just seemed that way from mankind's perspective," Hawking said, hinting that a lot of what we believe is derived from a human-centric perspective, which might limit the scope of human knowledge of the world.