For millennia, humans have gazed up at the stars and asked: How did it all start? And more fascinatingly, what existed before it all started? When it comes to questions such as these—large, bold, and cosmically enigmatic—few minds are as well-equipped to offer an opinion as Stephen Hawking's.
Hawking, the iconic theoretical physicist and cosmologist, spent most of his life seeking to understand how the universe began. Perhaps the most intriguing of the things he suggested was this: the mystery of what came before the Big Bang might actually not make any sense at all. Hawking's theory held that there wasn't a "before."
Time Itself Had a Beginning
During a 2018 interview with astrophysicist Neil deGrasse Tyson on the show StarTalk, Stephen Hawking described his view of the universe's creation in his signature mind-bending manner. He employed an idea called imaginary time, borrowed from the realm of quantum mechanics.
Here's the idea in a nutshell, boiled down: Think of the universe as a ball. Like a globe, there is no boundary and no beginning—you can circle and circle, but there is no corner you can point to and say, "this is where it starts." Hawking claimed that time acts in the same way when we zoom way out to the start of the universe.
"The universe's boundary condition," he explained, "is that it has no boundary." That is, the universe didn't begin at some point in time like a movie begins when you press "play." Rather, time itself is believed to have begun with the Big Bang. Prior to that, time simply didn't exist in any useful sense.
Imaginary Time: A Novel Perspective on the Cosmos
Hawking applied imaginary time (a mathematical construct with dimensions perpendicular to normal time) to characterize the early cosmos. According to this scheme, the universe was bounded but had no edges—similar to the surface of the Earth, but with four dimensions. Imaginary time smoothly evolved into real time in the earliest moments, as the universe came into being and began to grow.
In plain words: inquiring what came before the Big Bang is somewhat akin to asking what is north of the North Pole. It's a query that presupposes the presence of direction that does not exist.
The Big Bang Isn't a "Bang" At All
Another misapprehension that Hawking attempted to dispel was the very name Big Bang. It wasn't a bang in the classical sense—not an explosion within space, but an expansion of space. There was no "outside" of the universe to expand into, and no "before" to expand from.
As quantum theory and general relativity (two of the pillars of modern physics) tell us, space and time themselves are intertwined. So when we refer to the origin of the universe, we're not only referring to the origin of matter or energy, but to the origin of space-time itself.
A Humbling Thought
Hawking's view is at once humbling and profound. It challenges us to redefine what it means for something to come into existence. If time did not exist prior to the Big Bang, then the universe does not require a cause in the classical sense. It merely is, and has always been—beginning, at least, with the emergence of time itself.
Of course, it is only one explanation, albeit from one of the greatest scientific minds ever. As our knowledge of quantum physics and cosmology advances, so will our theories regarding the origins of the universe.
But for the time being, Hawking's response to what existed prior to the Big Bang is both elegant and profoundly philosophical: there was no "before"—because time itself came into being in that cosmic instant.
And that, in the man's own words, could be the final
boundary condition: no boundary at all.
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