Stephen Hawking collaborator talks about when the famous physicist said it was ‘time to stop playing God’

Play transcribed audio

After completing his doctorate, Thomas Hertog – a close associate of Stephen Hawking – went on vacation on the Silk Roads.

Hertog was stuck on a bridge in northern Afghanistan when he received an email from Hawking, asking him to give up his vacation and come back to work with him.

“It was then that he realized that A brief history of time was written from the wrong perspective,” Hertog said.

Hertog did what was asked of him. The border guard in Afghanistan turned out to be a fan of Hawking and let Hertog pass after seeing the physicist’s email.

Hawking’s book, A brief history of time, reshaped scientific understanding of the universe by positioning the Big Bang as the beginning of time itself. This realization that he had the origin story wrong prompted Hawking and Hertog to work on a new model for the universe.

In his book On the origin of time: Stephen Hawking’s latest theory, Hertog explains how he and Hawking’s thinking changed. A theoretical physicist and professor at the University of London, Hertog spoke with The flow host Matt Galloway on Hawking’s incredible ways of thinking and their work together. Here is part of their conversation.

You say there was a touch of magic in Hawking. What do you mean?

When I met him, [it] was 1998. A brief history of time had already been published. He was already famous, but he no longer knew how to write equations. By then, he had developed this incredible ability to research theoretical physics…almost in his head. He had designed this visual way of manipulating shapes, forms, universes and black holes so that he could, in a way, develop his intuition without having to do these actual calculations.

And it drove a lot of us crazy, it’s true, because we were doing these calculations and he was guessing it in his head. [But] I loved it from the first second I met it in 1998. I just loved it.

You describe the practical elements of [working with Hawking] when communication became more and more difficult for him, but when we managed to overcome that, it must have been exhilarating to work with him.

We worked together for 20 years. We discovered some new ideas when he was using his computer voice in the late 90s and early 2000s. Communication was, on the whole, pretty smooth.

But this communication slowed down considerably six, seven years before his death. But… at that point, it turned out that we had developed a kind of common language and we started collaborating using a lot of non-verbal communication.

And so at the end of his life, I could kinda ask him questions [and] detect through his facial expressions several degrees of no and several degrees of yes. And so it became a very strong bond because in a way; it’s almost as if we’ve developed a kind of intimacy around cosmology.

A Brief History of Time is a bit mind-blowing in what it explains. Explain what was the essence of this theory of the universe.

In the early 1980s, Stephen proposed a scientific model which he interpreted as the creation of our universe – the creation of space, time and matter from what he called nothingness. And of course everyone asks, well, what does that mean, nothing? What preceded the Big Bang?

But it was a monumental achievement in itself, because until then the Big Bang, the true beginning of time, was considered… unsolvable by science. And Hawking comes up with a scientific model that includes the Big Bang.

But unfortunately, his model created an empty universe – a universe with no stars, no galaxies, and no life, and therefore not a very useful universe. And that’s what led him to think of a much better theory, which ultimately led to a completely different view.

What was your reaction when he said he had changed his mind?

I sort of expected that, because such fundamental shifts in the way we think about the universe, it’s this typical paradigm shift story in science. The model you’re working with isn’t working, and at some point one of the key assumptions has to go.

We were going into such a paradigm crisis, and then we broke up. And it kind of crystallized in my mind – and apparently it crystallized in his mind – that [the] hypothesis of A brief history of time had to go.

WATCH | CBC’s Bob McDonald on Hawking changing his black hole theory

One of the things he tells you is, “It’s time to stop playing God. What has changed for him?

We have built physics over many, many generations and centuries from what Stephen calls the eye of God perspective. That’s really the success of science — that we’ve been able to study the world in an objective way, as if we were outside the system we’re trying to understand.

If you’re trying to understand the habitability of our universe, the fact that we exist in the universe, obviously it’s wrong to try to look at it from the outside. And that’s what Stephen did in A Brief History of Time, and that’s why he told me [it’s] written from the wrong point of view.

It takes an incredible amount of humility for someone like Stephen Hawking to say he got the perspective wrong, doesn’t it?

Yes I am sure. I admire him for that. Stephen had an ego, sure, but his passion for understanding was greater.

What are the implications of [this new theory]do you think?

There is a lot of. We are always told the laws of physics as a kind of eternal truth. We arrive at a fundamentally evolutionary understanding of these laws. So no real basis, a bit like the laws of biology in a way, which emerged with the different layers of life. So those are the big implications.

What does it say about the role of a higher power to help explain how we are here?

We have always considered the laws of physics as immutable and eternal truths. And now I say that they are the result of an evolution, which involved many channels and a certain necessity and a random process. This model allows you to reveal the interconnectedness, not only between the different species of life, but between the physical levels of the universe.

We also say, precisely because we place this evolutionary character so centrally, that perhaps the idea that we would find an absolute answer for a final theory in physics was wrong. There may be limits to science. There is perhaps a certain finitude associated with this. And that, of course, leaves room for some mystery.

You end the book by saying that Hawking was the freest man you ever knew. What did you mean by that?

He was intellectually free. He was so ready to let go of dogma, reimagine the world, and rethink the foundations of physics. I have never met anyone like him. This feeling of freedom, despite these terribly difficult conditions… it was very special.

---

Questions and answers edited for length and clarity.