A Conversation With Jonas Mureika

Jonas Mureika is a theoretical physicist and professor in the Frank R. Seaver College of Science and Engineering. He studies quantum gravity, black holes and cosmology. Mureika is a KITP Scholar at the Kavli Institute for Theoretical Physics at UCSB until 2024. We asked him about the new James Webb Space Telescope, his research on quantum gravity and funding of cosmology and astronomy research. Mureika was interviewed by Editor Joseph Wakelee-Lynch.

What are the capabilities of the James Webb Space Telescope, and how will it change the way we study the universe?

The James Webb Telescope is the most powerful optical telescope that we have to date. Its predecessor is the Hubble Telescope that was launched more than 30 years ago. The James Webb allows us to peer deeper into the universe than we ever have before. It can resolve objects that are almost 13 billion light years away. So, essentially, we’re seeing light from 13 billion years ago, when the universe was young. Its scientific capabilities are such that we can learn a lot about what the structure of the early universe looked like, what we call initial conditions — what kind of objects were there. We can put that data up against our theories about the formation of the universe, to see if we’re on the right track. The telescope can also be used to study things nearby: planetary systems, atmospheres. We can also turn it toward exoplanets.

If we can see objects from 13 billion years ago, then we don’t see how those objects developed afterward. But it is it possible to combine what we learn from that early period with what we know about nearby systems and galaxies to extrapolate how things must have changed in the billions of years that followed?

What the James Webb Telescope provides us is what we call initial conditions — what things were like then. We have models that tell us how the universe has evolved since then. If we tweak the initial parameters, we can ask whether that matches with what we have observed from light from the more recent past. And we have seen the recent past through the Hubble telescope, other space-based observatories and ground-based observatories. By doing that we can better cement some theories that have held up to scrutiny and toss others out that might not have.

Is your work entirely computational or conceptual? Is any of it observational?

It didn’t used to be, especially with black holes, because we have had very little observational data about black holes. That changed in 2015 and 2016 when LIGO, the Laser Interferometer Gravitational Wave Observatory, had their first detections of colliding black holes. That changed everything about the field of theoretical gravitational physics. For the first time, we had a window to see these objects behaving as we suspect they do. It gave us a new test bed to study general relativity and gravitation. Since that time, there have been about 90 collisions that have been observed between black holes and between black holes and neutron stars. That has given us a new window to study the universe, we study it gravitationally now. We see gravitation, basically. From my point of view, that’s the closest I get to being an observational astronomer, through the LIGO data.

Will the Webb Telescope be of any use to you in your work?

I’m not an observational astronomer, so not so much. But in the sense of giving more information about the early universe — post-Big Bang — the conditions that prevailed, and how did we get the structures that exist today, that’s of interest to me.

Why have you chosen to do a great deal of research on black holes as opposed to other phenomenon of the universe?

Black holes are ubiquitous objects that we think are mysterious. They are, and they aren’t. We understand the basic mathematics about them, but we don’t understand anything about what’s inside a black hole, and we don’t understand what happens when you get to the quantum level with gravity. Stephen Hawking, in the 1970s, told us that black holes evaporate, they’re not eternal objects that don’t change. There is always stuff coming off them, they’re evaporating just as an ice cube would on a hot day. When they boil down to almost nothing, that’s when quantum gravity kicks in. The mathematics that come to us from Hawking tell us that things will get very wonky when they begin to disappear. So, that’s why I think black holes are the key to understanding quantum gravity. That’s what makes them so fascinating.

Disease research receives large amounts of private funding. Are private contributions to research in astronomy as crucial as government funds?

It used to be that this work was largely funded by government agencies like the National Science Foundation and the Department of Energy. That has shifted in the past few decades, with more private foundations chipping in — for example, the Kavli Foundation, the Gordon and Betty Moore Foundation, the Simons Foundation. The Kavli Foundation funds research institutes around the world, including the Kavli Institute for Theoretical Physics in Santa Barbara. I’m a Kavli Scholar. That’s a three-year appointment that allows me to go there to do research. The Simons Foundation funds the Flatiron Institute in New York. Maximiliano Isi ’14, my former research student, went from LMU, to Caltech, to MIT, and he’s now at the Flatiron Institute. He works on the LIGO project, the Laser Interferometer Gravitational-Wave Observatory.

How old were you when you first demonstrated a strong interest in the universe, as opposed to playing soccer, learning the violin or becoming a priest or minister?

I can pinpoint that exactly. I was in eighth grade at the age of 13 or so. One night I turned on a PBS documentary called, appropriately enough, “Creation of the Universe.” I was incredibly captivated by it. The show talked about the quest for an all-encompassing theory of where the universe came from, why the universe exists. It talked about grand unification, which is the idea that gravity, electrostatics and nuclear forces are all part of the same single, unified force that existed at the beginning of the universe. I credit that show with sending me on this path of inquiry, curiosity and discovery.

Much of your work involves the study of gravity. Is gravity the key to understanding the foundation of the universe, from an atom to the composition of galaxies to black holes themselves?

Yes, absolutely. Gravitation, in a way, is the structure of the universe. If we can understand how gravity works from the very tiniest scales to the very largest scales, then we will understand the universe itself. I study quantum gravity, which is gravity as it works at the smallest scale possible. We really don’t understand that. Einstein’s theory of general relativity tells us very well how objects behave in larger scales in the universe. Newton tells us how things behave in the solar system around the Earth. But when we dial the microscope down to very tiny levels, those theories fail, and they fail spectacularly in certain ways. We really are still trying to find that Holy Grail of physics, which is understanding quantum gravity.

Do you think we’ll come to understand quantum gravity in your lifetime?

That’s a good question, and there are as many answers as there are opinions. We’re on the road, but we’re at a point where the compass is spinning, so to speak. There are several avenues to take. I think it will happen when the next paradigm breakthrough occurs. Whether that will be in 10 years, 50 years, 100 years is really hard to say. Right now we’re just chugging along.

I’m not trying to surprise you with a veiled religious question here, but how do you explain the origin of our universe? 

I don’t have the information to explain it. However, as a physicist, we expect certain rules to be in place. Physics is a science that runs by mathematical formulations and mechanism. The models we have for the universe today — how it has evolved into what we see in our telescopes — are mathematical models that start somewhere. They start, we believe, at this thing we call the Big Bang. What caused that we don’t know. There are a lot of competing ideas. One of which is something just caused it to start, we don’t know what. Another is that we are in a particular cycle of what’s called the cyclic universe that expands, then contracts, expands, then contracts. There must’ve been a start to that at some point, but we think we’re not the start of it; that happened some time earlier. There are some more kooky ideas: Maybe we’re all holograms in a simulation. Was there something that started the universe? I can’t answer that. I don’t have the evidence to point either way. That’s one of the open mysteries that when we get an understanding of quantum gravity will, hopefully, help us to figure out certain details of what happened at the beginning.