In life, Hawking was a vocal champion of the Big Bang theory — the idea that the universe began by exploding suddenly out of an ultradense singularity smaller than an atom. From this speck emerged all the matter, energy and empty space that the universe would ever contain, and all that raw material evolved into the cosmos we perceive today by following a strict set of scientific laws. To Hawking and many like-minded scientists, the combined laws of gravity, relativity, quantum physics and a few other rules could explain everything that ever happened or ever will happen in our known universe.
“If you like, you can say the laws are the work of God, but that is more a definition of God than a proof of his existence,” Hawking wrote.
With the universe running on a scientifically guided autopilot, the only role for an all-powerful deity might be setting the initial conditions of the universe so that those laws could take shape — a divine creator who caused the Big Bang to bang, then stepped back to behold His work.
“Did God create the quantum laws that allowed the Big Bang to occur?” Hawking wrote. “I have no desire to offend anyone of faith, but I think science has a more compelling explanation than a divine creator.”
Hawking’s explanation begins with quantum mechanics, which explains how subatomic particles behave. In quantum studies, it’s common to see subatomic particles like protons and electrons seemingly appear out of nowhere, stick around for a while and then disappear again to a completely different location.
Because the universe was once the size of a subatomic particle itself, it’s plausible that it behaved similarly during the Big Bang, Hawking wrote.
“The universe itself, in all its mind-boggling vastness and complexity, could simply have popped into existence without violating the known laws of nature,” he wrote.
That still doesn’t explain away the possibility that God created that proton-size singularity, then flipped the quantum- mechanical switch that allowed it to pop. But Hawking says science has an explanation here, too. To illustrate, he points to the physics of black holes — collapsed stars that are so dense, nothing, including light, can escape their pull. Black holes, like the universe before the Big Bang, condense into a singularity. In this ultra-packed point of mass, gravity is so strong that it distorts time as well as light and space.
Simply put, in the depths of a black hole, time does not exist. Because the universe also began as a singularity, time itself could not have existed before the Big Bang. Hawking’s answer, then, to what happened before the Big Bang is, “there was no time before the Big Bang.”
“We have finally found something that doesn’t have a cause, because there was no time for a cause to exist in,” Hawking wrote. “For me this means that there is no possibility of a creator, because there is no time for a creator to have existed in.”
This argument will do little to persuade theistic believers, but that was never Hawking’s intent. As a scientist with a near-religious devotion to understanding the cosmos, Hawking sought to “know the mind of God” by learning everything he could about the self-sufficient universe around us.
While his view of the universe might render a divine creator and the laws of nature incompatible, it still leaves ample space for faith, hope, wonder and, especially, gratitude.
“We have this one life to appreciate the grand design of the universe,” Hawking concludes the first chapter of his final book, “and for that I am extremely grateful.”