In March 2018, just days before his passing, legendary physicist Stephen Hawking completed what would become his final contribution to science. The paper, co-authored with his longtime collaborator Thomas Hertog, was titled “A Smooth Exit from Eternal Inflation” and was later published in the Journal of High Energy Physics. This remarkable work reflected Hawking’s enduring curiosity about the origins of the universe and his unyielding quest to uncover its deepest mysteries.
The paper delved into the long-debated concept of eternal inflation, a theory suggesting that after the Big Bang, space didn’t stop expanding. Instead, it continued to inflate in some regions, creating an infinite number of “pocket universes” — what many refer to as the multiverse. Each of these universes might have its own unique laws of physics, existing far beyond what we can currently observe.
However, Hawking and Hertog challenged some aspects of the traditional eternal inflation model. They proposed a new way to describe how our universe could have emerged from this chaotic, infinite process in a “smooth exit.” More importantly, they suggested that there might be detectable traces of these other universes in the cosmic microwave background (CMB) — the faint radiation left over from the Big Bang. If proven, this idea could provide the first real scientific evidence for the multiverse, transforming what was once pure speculation into testable science.
Hawking’s final work stands as a testament to his brilliance and imagination. Even in his last days, he continued to push the boundaries of human understanding, daring to ask questions few would even attempt. The idea that our universe could be just one of many doesn’t diminish our significance; rather, it fills our existence with awe and humility. Through this final paper, Stephen Hawking left the world not just answers, but a powerful reminder — that curiosity is the true engine of discovery.
Sources: Journal of High Energy Physics, BBC, Scientific American