Michelle Thaller, assistant director for science communication at NASA’s Goddard Space Flight Center, set out to convince people at her TEDx talk on Sunday that most of what we know about the composition of the universe, is nothing — at least as far as our senses can perceive it.
According to Thaller, who specializes in the life cycles of stars, all of the matter that we are familiar with only makes up about 4 percent the universe, 3.6 percent of which is just cold gas.
“The other 96 percent is something we call ‘dark matter,’ and we don’t really know anything about it, hence the ‘dark,’” she said.
Thaller’s lecture, titled “Dark Matter: We’re Not Made of the Same Stuff the Universe Is,” featured a brief history of the study of the universe, accompanied by numerous photos of deep space gathered from her work at NASA, and inspired “ooh’s” and “ahh’s” from a mesmerized audience.
“I hope you all agree with me, but we live in an extravagant and beautiful universe,” Thaller said. “The scale of it is something that not only humbles us, but inspires us.”
According to Thaller, dark matter is so ubiquitous that it creates a web underlying everything in the universe, which accounts for some of the intricate patterns and clusters of cosmic bodies such as stars and galaxies, and may contribute to our understanding of how the universe formed.
“This is the invisible scaffolding of our universe, it makes up all the matter in the universe,” Thaller said. “Over time, all of the regular matter was attracted by the gravity of this dark matter, to this web underneath it. Things were brought together to create galaxies, and stars and planets. None of that would have started without that scaffolding of dark matter underneath.”
Q&A
Pipe Dream: What is your area of research, and what are you going to talk about today?
Michelle Thaller: I’m an astrophysicist, I work for NASA, and one of the biggest discoveries in the last couple of decades is that the universe appears to not be made of what we’re made of. We’re made of atoms: protons, neutrons, electrons, and it looks like all of that is about four percent of the universe. Everything else is a state of matter, and we don’t know what it is.
PD: So we don’t know what 96 percent of the universe is?
MT: We don’t know what 96 percent of the universe is, and that’s a problem. Any time you want to talk about how the universe began, how it’s evolving over time, or how galaxies and stars form, what are you going to say if we don’t know what 96 percent of it is up to? So, the talk is going to be a little bit of a history of how we could be that stupid. How could we say that 96 percent of the universe is in a form that we don’t even know what it is? Where do we go from here, and how do we find this?
PD: How will learning the composition of the universe, or of stars, help us better understand the tangible world that we see around us? How will this research impact our daily lives?
MT: You know, it’s a good question. Obviously right now, as usually is the case when you study cosmology, the universe as a whole, it doesn’t have a lot to do directly with us. But in a really basic sense, we actually think that this 96 percent of the dark universe was probably responsible for getting the first galaxies and the first stars to form. So point blank, we would not be here today if it were not for this dark universe. When we think about what our origins are, how life forms, there’s this mysterious contribution that’s been there since the beginning, and we’re just beginning to see it. So it doesn’t really affect exactly how your day is going to go today, you can live happily and ignore dark matter, but at it’s most basic, we think that this is responsible for all of the structure in the universe: all of the galaxies, all of the stars, all of the planets.
PD: How do you study something and gather information about something so abstract that you can’t see?
MT: It’s not even just that you can’t see it. There’s dark matter in the room with us right now, it does not even interact, it goes right through us like a ghost through a wall. We only can see this because we can measure its pull of gravity. Gravity is a force that pervades the universe and obviously holds us to the earth and all of that. This dark matter has no physical substance, but it has gravity. We can measure things orbiting around it, and we can actually measure the way that it distorts space and time. It actually creates warps and lenses in space and time, and we’re directly observing it with the Hubble Space Telescope and other large telescopes. So this is not a theory. The problem is, we see space warping, and bending, and lensing, and that’s the dark matter.
PD: String theory is a really popular theory right now. How does this work either fit into that, or dispute it?
MT: It fits in with it a lot, we hope. The question is, what is this stuff if it’s not made from the same stuff we are? A lot of people think that we may have seen evidence of a new type of particle, that there’s a new family of particles. We know about the stuff that makes atoms up. At it’s most basic we’re made of these things called quarks, these tiny little particles. So have we just discovered that there’s an entirely new set of particles out there that doesn’t really interact with our type of matter, but may have it’s own type of interactions? We’re hoping that the people at CERN, the largest collider in the world, the Large Hadron Collider, will give us some insight as to what dark matter particles may be like. We have some theories, there actually are theories in physics right now as to what these particles actually should be like, now we need to find them in the collider. It hasn’t happened yet, but we’re hoping that in the next few years there will be a dark matter particle.
PD: Where do you see the future of this research going? For people that are graduating and want to go into this field, where would you direct their studies?
MT: Everything is about to change. To give you an example, we’ve also discovered this thing called dark energy, which isn’t actually related to dark matter. We found out that the universe is not only expanding, but it’s also accelerating, its going faster and faster all the time, and that takes a lot of energy. That was only discovered about ten years ago, and we’re launching a next generation of space telescopes. For example, you’ve probably heard of Hubble.In 2018, we’ll be launching a telescope that is seven times the size of Hubble, and it will be that much more sensitive, and we’ll be able to see that much farther out into space. We’re hoping to get a much better angle on how much of this dark matter and dark energy is out there. The thing is, by the time that people in college today get to graduate school, or by the time they’re young professors, we will have already rewritten the textbooks. There is so much to learn, this is a great time to be an astronomer because we are just getting started on beginning to understand this stuff.
PD: So would you say that space research is still relevant in science today? Is it still the last frontier?
MT: We just figured this out. I mean think about it, the idea that the universe is not just expanding, but accerlating as well is just ten years old, and we don’t know what’s doing it. So, that’s a pretty big one. It’s a lot of stuff to work on; there will be no dearth of jobs for astronomers trying to figure that one out.
PD: How did you initally get into this area of research?
MT: Well I just love space. I’m one of these more general astronomers who studies everything. Dark matter especially is not my topic of research, I’m more of a specialist on the lifecycle of stars, how stars are born, live and die. The fun thing about dark matter is that a friend of mine from grad school got the Nobel Prize for it this year, and I was sort of along with him at the observatories while he was doing some of this research, and this was not the result we were expecting. I have a lot of respect for accidental discoveries. You make an observation, you think you know how it’s going to go, and it goes the opposite way and tells you something brand new about the universe. I just love anything to do with space, and the dark matter problem is a little close to home because I have a lot of friends in it.
PD: What kind of previously held theories about space and the universe have been challenged because of this new information we’re getting about dark matter?
MT: A lot of us were wondering about the end of the universe. The universe is expanding now, that’s easy to see, but is it going to expand forever? That’s a little depressing, because then everything just becomes thinner and thinner, and colder and colder and pretty soon all the stars go out and you’re left with nothing. A lot of people wondered, and I sort of hoped that this was true, that maybe the universe would eventually stop expanding and start coming together again and there would be sort of a cycle. A cycle of birth and death, it seems sort of wonderfully philosophical. Dark matter just kind of blew that away. Dark matter and dark energy suggest that not only will the universe expand forever, but it will rip apart, and some day this expansion may even rip apart matter. The very atoms that make us up may be ripped apart by this expansion. So we’re back to square one. Why is there a universe at all if it just comes into being out of nothingness and then just rips apart? Most people now suspect that there are many universes, perhaps an infinite number, so this idea of the multiverse, more than one universe, kind of helped solve that. So my ideas of a nice, clean universe that had a cycle to it, doesn’t seem to be the case.
PD: As a woman in science, what is your personal opinion about the state of affairs for women in your field?
MT: You know it’s a little bit mysterious to me. I feel very well taken care of at NASA, I feel very well respected and I work very well with my colleagues. We actually, among our scientists, have about a 25 percent rate of women at NASA, which is a little better than the academic whole. When you look at people just getting out of school, young PhD’s, they are about half women. So things are changing pretty quickly in astronomy. The thing that you always have to wonder about, is that all of the people I work with at NASA, the top three tiers of management, they’re all men. You sort of get women at the middle level, and there doesn’t seem to be a lot of penetration of women into the upper levels of management in scientific leadership. I’ve had a great time working with my male colleagues, I’ve always felt accepted, I’ve never been harassed or anything like that. The question is, why aren’t we moving up a little faster? Why aren’t we filling in the senior professorships and the senior management positions? That’s going to be hard, because that speaks to very subtle forms of discrimination, ones that people may not even mean to do. A senior male professor may look at his graduate students and be more familiar with the men, they remind him of the way he was when he was young, and it may be just a little bit harder for him to socially accept that the women may be a little different, but as good scientists. So there’s that level going on that we have a lot of work to do yet. You know 25% is good, but I did notice that I was the only woman speaker here at the TED conference, and I was a little bit upset by that. You know there’s plenty of women to talk about this stuff, so they need to look just a little bit harder.
PD: Lastly, can you tell us a little bit about your job at NASA, and what it entails?
MT: You sort of change jobs as you get older at NASA. I used to be a research astronomer. I would go to telescopes, make my discoveries and write papers. Over time, as I got to be more successful at writing grants and getting funding for the science, I started to become a manager. Right now, I’m the Assistant Director of Science at NASA in the Goddard Space Flight Center. This is the largest research space that NASA has, there are about 10,000 people there, and about 1,500 of them are astrophysicists. I’m trying to keep track, and manage and get money and approval for the work of over 1,000 scientists. So I do a lot more management these days, but it has to get done. I talk to members of congress a lot to get support for NASA. The thing that’s great about still being embedded with the scientists, is that I still get to see all of the latest results. I get to go to the seminars and read all the papers, so I get to stay current even though I’m the one pushing all of the paperwork through.