It’s a mind-boggling question that has intrigued scientists theologians, and the curious alike for centuries: What was before the Big Bang? Roughly 13.7 billion years ago, the entire universe existed as a singularity, a point smaller than a subatomic particle, according to the Big Bang theory. But what existed just before that moment?
The question predates modern cosmology by at least 1,600 years. Fourth-century theologian St. Augustine wrestled with the question of what existed before God created the universe. He concluded that the Biblical phrase “In the beginning” implied that God had made nothing previously. Moreover, Augustine argued that time and the universe had been created simultaneously.
In the early 20th century, Albert Einstein’s theory of general relativity led to similar conclusions. Mass warps time, making time run a tiny bit slower for a human on Earth’s surface than a satellite in orbit. Based on Einstein’s work, Belgian cosmologist Rev. Georges Lemaître proposed in 1927 that the universe started as a singularity and expanded through the Big Bang.
According to Einstein’s theory of relativity, time only came into being as the primordial singularity expanded toward its current size and shape. However, this is one cosmological quandary that won’t stay dead. The advent of quantum physics and a host of new theories resurrected questions about the pre-Big Bang universe.
Some astrophysicists speculate that our universe is the offspring of another, older universe. This story, they believe, is written in the cosmic microwave background (CMB), the relic radiation left over from the Big Bang.
As we continue to explore the far reaches of the universe, from the very beginning to the far future, we must constantly rethink our understanding of the cosmos. From the hot, dense state of the early universe to the cold, empty space between distant galaxies, our journey to understand the universe is far from over.