This title explains the collaboration of Stephen Hawking and myself in formulating the ultimate theory of the universe and the insights it offers about the beginning of existence and time.

The late physicist Stephen Hawking first asked me to work with him to develop a “new quantum theory of the big bang” in 1998. What began as a PhD project developed over 20 years into an intense collaboration that only ended with his death. March 14, 2018.

The mystery at the center of our research throughout this period has been how the Big Bang could have created conditions perfectly suitable for life. Our answer is Published in a new bookOn the Origin of Time: Stephen Hawking’s Final Theory.

Questions about the ultimate origin of the universe, or cosmos, push physics out of its comfort zone. However, this was exactly where Hawking loved to venture. The possibility – or hope – of cracking the mystery of cosmological design drove much of Hawking’s research in cosmology. His motto was to “boldly go where Star Trek fears to tread”, as was his screensaver.

Our joint scientific pursuit means we are inevitably closer. Being around him, no one could be swayed by his determination and optimism that we can tackle perplexing questions. It made me feel as if we were writing the story of our creation, which we did to a degree.

In the old days it was believed that the apparent design of the universe means that there must be a designer – a deity. Today, scientists refer instead to the laws of physics. These laws have a number of amazing life-generating properties. Take the amount of matter and energy in the universe, the exact ratios of forces, or the number of spatial dimensions.

Physicists Discover That if you slightly modify these properties, they make the universe lifeless. It almost seems as if the universe is a fix — even one big overhaul.

But where do the laws of physics come from? From Albert Einstein to Hawking in his earlier work, most twentieth-century physicists regarded the mathematical relations that underlie physical laws as eternal truths. In this view, the apparent design of the universe is a matter of mathematical necessity. The universe is the case because nature had no choice.

At the turn of the 21st century, a different interpretation emerged. Perhaps we live in a multiverse, an enormous space-generating hodgepodge of universes, each with its own type of Big Bang and physics. It would make sense, statistically, for a few of these universes to be friendly to life.

However, these multiverse musings soon fell into a maelstrom of paradoxes and a lack of verifiable predictions.

Turn cosmology upside down

Can we do better? Yes, Hawking and I discovered, but only by abandoning the notion inherent in multiverse cosmology, that our physical theories can take on the view of God, as if they stand outside the entire universe.

It’s an obvious and seemingly tautological point: a cosmological theory must explain the fact that we exist within the universe. Hawking told me, “We are not angels who see the universe from the outside.” Our theories are never separated from us.

We set out to rethink cosmology from an observer’s perspective. This required adopting the strange rules of quantum mechanics, which govern the world of tiny particles and atoms.

According to quantum mechanics, particles can exist in several possible locations at the same time – a property called superposition. Only when a particle is observed does it (randomly) choose a specific location. Quantum mechanics also includes random jumps and fluctuations, such as particles appearing from empty space and disappearing again.

Therefore, in the quantum universe, the concrete past and future emerge from the mists of possibility by means of a continuous process of observation. Such quantitative observations need not be made by humans. The environment or even a single particle can “notice”.

Countless such acts of quantum observation continually transform what could happen into what happens, thus forcefully pulling the universe into existence. And once something is noticed, all other possibilities become irrelevant.

We discovered that when looking at the early stages of the universe through a quantum lens, there is a deeper level of evolution in which even the laws of physics change and evolve, coinciding with the universe being formed. Moreover, this meta-evolution has a Darwinian flavor.

Variation enters because random quantum jumps cause frequent trips from what is likely. Selection comes in because some of these excursions can be amplified and frozen, thanks to quantum monitoring. The interaction of these two competing forces—variation and selection—in the primordial universe produced a branching tree of physical laws.

The result is a deep review of the basics of cosmology. Cosmologists typically start by postulating the initial laws and conditions that existed at the moment of the Big Bang, and then look at how today’s universe evolved from them. But we suggest that these laws are themselves the result of evolution.

Dimensions, forces, and types of particles shifted and varied in the hot Big Bang furnace—somewhat similar to how biological species appeared billions of years later—and acquired their functional form over time.

Furthermore, the randomness involved means that the outcome of this evolution—the specific set of physical laws that make our universe what it is—It can only be understood later.

In a sense, the early universe was a superposition of an enormous number of possible worlds. But we look at the universe today at a time when there are humans, galaxies and planets. This means that we see the history that led to our evolution.

We note the parameters with “lucky values”. But we are wrong in assuming that they have always been designed one way or another.

problem with time

The core of our hypothesis is that, stepping back in time, the evolution toward more simplicity and less structure continues all the way through. In the end, even time, and with it physical laws, fade away.

This view is particularly confirmed by the holographic form of our theory. the “The principle of holographyIn Physics he predicts that just as a hologram appears to have three dimensions when in reality it is encoded in only two dimensions, the evolution of the entire universe is similarly encoded on an abstract, timeless surface.

Hawking and I see time and causation as “emergent qualities”, which have no prior existence but arise from interactions between countless quantum particles. It’s a bit like how temperature appears from many atoms moving collectively, even though no single atom has a temperature.

One ventures back in time by zooming out and taking a blurrier look at the hologram. However, eventually one loses all of the information encoded in the hologram. This will be the origin of time – the Big Bang.

For nearly a century, we have studied the origin of the universe against a stable background of immutable laws of nature. But our theory reads the history of the universe from the inside and as a history that includes, in its early stages, the genealogy of physical laws. It is not the laws in themselves but their transformative capacity that have the final word.

Future cosmological observations may find evidence of this. For example, careful observations of gravitational waves—ripples in the fabric of space-time—may reveal signs of some of the early branches of the universe. If spotted, Hawking’s cosmic finale may be his greatest scientific legacy.

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