Before the Big Bang

An interview with Martin Bojowald.

What preceded it all? Naturally, it is impossible for Martin Bojowald to provide an all-encompassing answer to this question; however, his theory goes beyond the big bang. In this interview, he explains why as a physics expert he encounters the boundaries of natural sciences again and again and why words, instead of numbers and equations, can sometimes provide more order to the world.

Mr. Bojowald, your book ‘Zurück vor den Urknall. Die ganze Geschichte des Universums [Before the big bang. A comprehensive history of the universe],’ published in 2009, put into question the theories of Einstein and Hawking.

That’s true, but I never intended to discredit their efforts or bodies of work. Instead, I wanted to more closely explore whether we could prove their theories using mathematical equations. The general consensus in teaching back then was that the big bang preceded everything else. This statement never held water because it was always missing mathematical proof that showed their theories were also consistent with the rules of math.

In your opinion, there was no big bang?

Yes, there was. It’s more a question of how we describe the big bang. I believe it’s going too far if we say that this event is the beginning of the universe. For that to be the case, we would first need the singularity. Singularity means that the physical values like density or temperature become infinite. However, new calculations from recent years indicate that there was never this infinite density. There was only a very high density. It would concentrate the entire universe with one trillion suns onto one dot. This extreme state would mean the density is so high that not even time could pass through it. It would be a timeless phase in which the collapsing and expanding forces cancel each other out. The fact that time disappears in this theory didn’t really please many of my physics colleagues, because it contradicted the general consensus in teaching up until that point, and even the theory of general relativity.

Why is the big bang important in your opinion?

The difference between infinite density and unimaginable density that I just mentioned may sound like splitting hairs, but in essence it means that the big bang describes more of a transition.

What does this transition mean?

Current models surmise that the universe has always been there. They show that it was a collapsing system that would shrink over and over again until the movement was reversed by the opposite forces. It became an expanding universe, which is the universe in which we live today. Yet, there is no linear timeline for this expansion. There are many indicators that lead us to believe that the expansion process will last forever and only the density will decrease accordingly. But we know too little to be able to make this claim conclusively. We cannot deny the possible existence of a slowing or accelerating of this process. This also applies to a reversal of the process. Then the cycle of collapsing and expanding would start over again.

So that means you cannot define a beginning after the big bang. We have to view it like a continual process that last for eternity?

It is definitely a much more agreeable approach from a mathematical perspective. The creation of something from nothing puts our previous models up against problems that we cannot resolve. And it is also difficult to imagine mathematics or theoretical physics from nothingness. We can better formulate a continual process if we use equations, even though we also are left at ground zero again and need to use simplifications that can only unsatisfactorily reflect our actual findings.

Is the search for the beginning of the universe also inextricably intertwined with the search for the meaning of life?

No, I don’t believe so. I see it as a search for the explanation of the state in which the universe is, in which it was, and in which it will be. In my research, I use cosmology as a case study for mathematical models that attempt to develop a deeper understanding of things.

What role does gravitational wave research play in developing this understanding? In August 2017, some of your colleagues were able to precisely measure the collision of two neutron stars for the first time ever and they began to speak about a new era in astronomy.

It was the first time ever that they observed and measured the existence of a ripple through space–time. It is yet another piece of evidence that upholds a theory that has existed for nearly 100 years. The gravitational waves enable us to investigate the structure and properties of objects in space. The radiation properties observed when these two neutron stars collided – which is called a kilonova – confirmed the theory that the radioactive material from this convulsion is launched throughout space. Apparently heavy chemical elements such as gold and platinum are also created in these colossal smashups. Previously their creation was unclear. These observations will open new doors for astronomy, and there will be seminal changes in store when it comes to proving and disproving the big bang theory and my work.

Why?

Because the measurement methods have been much too inaccurate to develop conclusions for the overall system up until now. We are now far more capable of observing isolated incidents and placing them into the overall context. However, we don’t have a complete picture yet.

Creating order in a seemingly chaotic system: That’s a tall order for researchers. It requires the ability to transform events into scientific models. Which is easier for you: to express these thoughts in words or numbers?

In principle, in numbers. But the ability to express assumptions in math and physics in words means that you have reflected on your own work and can observe it from the perspective of others. Of course, the limits of language can be reached quickly. Yet, on the other hand, other problems that were hiding behind numbers become evident.

If a fairy godmother were to grant you one wish for your work, what would it be?

My wish would be that my physics colleagues could confirm the purely mathematical proofs through experiments. It would elevate the significance of these proofs greatly. It would be awesome.


Mr. Bojowald, we appreciate your taking time for this interview!

Picture Credits: © Gabriela Secara