Cosmologists are agreed that the universe began with a big bang 13.7 billion years ago. People naturally want to know what caused it. A simple answer is nothing: Not because there was a mysterious state of nothing before the big bang, but because time itself began then — that is, there was no time “before” the big bang. The idea is by no means new.
In the 5th century, St Augustine of Hippo wrote that “the universe was created with time and not in time.”
Religious people often feel tricked by this logic. They envisage a miracle-working God dwelling within the stream of time for all eternity and then, for some inscrutable reason, making a universe (perhaps in a spectacular explosion) at a specific moment in history.
That was not Augustine’s God, who transcended both space and time. Nor is it the God favored by many contemporary theologians. In fact, they long ago coined a term for it — “god-of-the-gaps” — to deride the idea that when science leaves something out of account, then God should be invoked to plug the gap. The origin of life and the origin of consciousness are favorite loci for a god-of-the-gaps, but the origin of the universe is the perennial big gap.
In his new book, Stephen Hawking reiterates that there is no big gap in the scientific account of the big bang. The laws of physics can explain, he says, how a universe of space, time and matter could emerge spontaneously, without the need for God and most cosmologists agree: We do not need a god-of-the-gaps to make the big bang go bang. It can happen as part of a natural process.
A much tougher problem now looms, however. What is the source of those ingenious laws that enable a universe to pop into being from nothing?
Traditionally, scientists have supposed that the laws of physics were simply imprinted on the universe at its birth, like a maker’s mark. As to their origin, well, that was left unexplained.
In recent years, cosmologists have shifted position somewhat. If the origin of the universe was a law rather than a supernatural event, then the same laws could presumably operate to bring other universes into being. The favored view now, and the one that Hawking shares, is that there were in fact many bangs, scattered through space and time, and many universes emerging therefrom, all perfectly naturally. The entire assemblage goes by the name of the multiverse.
Our universe is just one infinitesimal component amid this vast — probably infinite — multiverse, that itself had no origin in time. According to this new cosmological theory, there was something before the big bang after all — a region of the multiverse pregnant with universe-sprouting potential.
A refinement of the multiverse scenario is that each new universe comes complete with its very own laws — or bylaws, to use the apt description of the cosmologist Martin Rees. Go to another universe and you would find different bylaws applying. An appealing feature of variegated bylaws is that they explain why our particular universe is uncannily bio-friendly; change our bylaws just a little bit and life would probably be impossible. The fact that we observe a universe “fine-tuned” for life is then no surprise: The more numerous bio-hostile universes are sterile and so go unseen.
So is that the end of the story? Can the multiverse provide a complete and closed account of all physical existence? Not quite. The multiverse comes with a lot of baggage, such as an overarching space and time to host all those bangs, a universe-generating mechanism to trigger them, physical fields to populate the universes with material stuff and a selection of forces to make things happen.
Cosmologists embrace these features by envisaging sweeping “meta-laws” that pervade the multiverse and spawn specific bylaws on a universe-by-universe basis. The meta-laws themselves remain unexplained — eternal, immutable transcendent entities that just happen to exist and must simply be accepted as given. In that respect the meta-laws have a similar status to an unexplained transcendent god.
According to folklore, the French physicist Pierre Laplace, when asked by Napoleon where God fitted into his mathematical account of the universe, replied: “I had no need of that hypothesis.”
Although cosmology has advanced enormously since the time of Laplace, the situation remains the same: There is no compelling need for a supernatural being or prime mover to start the universe off. However, when it comes to the laws that explain the big bang, we are in murkier waters.
Paul Davies is director of Arizona State University’s The Beyond Center for Fundamental Concepts in Science.
Could Asia be on the verge of a new wave of nuclear proliferation? A look back at the early history of the North Atlantic Treaty Organization (NATO), which recently celebrated its 75th anniversary, illuminates some reasons for concern in the Indo-Pacific today. US Secretary of Defense Lloyd Austin recently described NATO as “the most powerful and successful alliance in history,” but the organization’s early years were not without challenges. At its inception, the signing of the North Atlantic Treaty marked a sea change in American strategic thinking. The United States had been intent on withdrawing from Europe in the years following
My wife and I spent the week in the interior of Taiwan where Shuyuan spent her childhood. In that town there is a street that functions as an open farmer’s market. Walk along that street, as Shuyuan did yesterday, and it is next to impossible to come home empty-handed. Some mangoes that looked vaguely like others we had seen around here ended up on our table. Shuyuan told how she had bought them from a little old farmer woman from the countryside who said the mangoes were from a very old tree she had on her property. The big surprise
The issue of China’s overcapacity has drawn greater global attention recently, with US Secretary of the Treasury Janet Yellen urging Beijing to address its excess production in key industries during her visit to China last week. Meanwhile in Brussels, European Commission President Ursula von der Leyen last week said that Europe must have a tough talk with China on its perceived overcapacity and unfair trade practices. The remarks by Yellen and Von der Leyen come as China’s economy is undergoing a painful transition. Beijing is trying to steer the world’s second-largest economy out of a COVID-19 slump, the property crisis and
As former president Ma Ying-jeou (馬英九) wrapped up his visit to the People’s Republic of China, he received his share of attention. Certainly, the trip must be seen within the full context of Ma’s life, that is, his eight-year presidency, the Sunflower movement and his failed Economic Cooperation Framework Agreement, as well as his eight years as Taipei mayor with its posturing, accusations of money laundering, and ups and downs. Through all that, basic questions stand out: “What drives Ma? What is his end game?” Having observed and commented on Ma for decades, it is all ironically reminiscent of former US president Harry