Studio guest: Prof. Philipp Richter, Institute for Physics and Astrophysics University of Potsdam

"I expect there will be surprises [...]we will probably find out about a very unsecure timeline that we really don't understand so far. When was the first real galaxies were formed. How do the first stars look like, and what kind of light do they produce."
DW-TV: Professor Philipp Richter, what do you do with Hubble-data?


Philipp Richter: My research field is the so-called intergalactic medium. That's far from any life. In fact, it is a very thin plasma that sits between galaxies. It's a very thin gas, and that's the material, in fact from which galaxies, stars and galaxies are forming. Basically, it's the fuel for star formation in the universe.


DW-TV: What are actually the discoveries we would not have made without Hubble?


Philipp Richter: I think one of the major discoveries where Hubble was involved is in fact the detection, that the universe is expanding in accelerating mode, that you've seen for a thing called 'dark energy.' And I think a second big breakthrough was the way Hubble could look very deep into the universe, the famous 'Hubble deep field,' that showed us galaxies at the very early beginnings when galaxies were forming, so basically the babies of the galaxies. And so we now are able to see how galaxies are evolving through time.


DW-TV: Just one word about this 'dark energy,' Albert Einstein was already talking about it. Do you think they'll ever find what it is?


Philipp Richter: "I think it takes the combined effort from physics and astrophysics to think beyond the borders that we actually have in our heads. The current physics. And yes, I think in future generations we will know what 'dark energy' is and 'dark matter' is.


DW-TV: Now we know that Hubble gets very close to the 'big bang' to the beginning of our universe and James Webb may get back even further back into the history of our universe. What's so interesting about that time?


Philipp Richter: It's basically the time that the galaxies and the first stars were born. So we basically look back in our childhood, how everything began. And so when the first stars are formed then galaxies looked very different than they are today. And then, they assembled by the accretion of material from the intergalactic medium, for example. And, so then after time galaxies evolved, and now they look like as they look like. But as usual we want to find out how everything began.


DW-TV: And how come James Webb can look back even back further in history?


Philipp Richter: The problem is ... it's not a problem. The fact is that the universe is expanding, is that signals that come from the very beginning are red shifted, that means that signals that are emitted in a certain region, in the wave length region of the light, is now visible in a completely different region. And therefore we need a telescope that is in space, an infrared telescope to bring us that information so we can now understand what is going on.


DW-TV: What surprises do you expect up there?


Philipp Richter: Yes, I expect there will be surprises, but of course if I could predict them that would make things, of course, easier. No, in fact we will probably find out about a very unsecure timeline that we really don't understand so far. When was the first real galaxies were formed. How do the first stars look like, and what kind of light do they produce. And I think with the James Webb telescope we will learn much more about these early stages of the universe.


Interview: Ingolf Baur