It’s time for another series. This time we’ll be talking about famous female astronomers. Starting with: Vera Rubin, who first identified the fact that galaxies rotate too quickly to hold themselves together, anticipating the discovery of dark matter.
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Fraser Cain: Astronomy Cast Episode 357, Vera Ruben. Welcome to Astronomy Cast, our weekly facts based journey through the Cosmos where we help you understand not only what we know but how we know what we know. My name is Fraser Cain, the Publisher of Universe Today and with me is Dr. Pamela Gay, Professor at Southern Illinois University Edwardsville and the Director of CosmoQuest.
Hey, Pamela. How are you doing?
Pamela Gay: I am doing well. And this is going to be one of those episodes where the lag is highly variable. I feel like we’re part of one of those theoretical papers where the speed of light changes throughout the history of the universe because we keep going from zero lag to like a second of lag and back to zero. So we are clearly caught in the land of timey wimey.
Fraser Cain: Timey wimey, that time is relative and one day in Edwardsville is seven years on Vancouver Island.
Pamela Gay: Yeah. I think it’s more like a couple minutes of difference, but yeah.
Fraser Cain: Did you know – interesting fun fact – that you can be off by about 30,000 years in the universe in time based on all the motion and speed and relativity?
Pamela Gay: What is off by 30,000 years?
Fraser Cain: In other words, if you’ve been moving really, really quickly – like not like in the [inaudible] [00:01:53] Black Hole but different parts of the universe as they’ve been expanding, give or take about 30,000 years in terms of relativity from each other.
Pamela Gay: That’s kind of cool.
Fraser Cain: Isn’t that cool? Yeah.
Pamela Gay: Yeah.
Fraser Cain: So it’s time to do another series, and this time we’re gonna be talking about famous female astronomers, modern famous female astronomers, starting with Vera Ruben who first identified the fact that galaxies rotate too quickly to hold themselves together anticipating the discovery of dark matter.
So this is really cool. So we’ve got – what, we’ve got five or six astronomers.
Pamela Gay: So far, more may be added to the list. That’s just where we’ve gotten to at this stage.
Fraser Cain: Yeah. Yeah. And I think – have we not – apart from Carolyn Herschel, have we talked about any female astronomers?
Pamela Gay: No. And the thing is we’ve had this hard and fast rule up until now of only discussing women who – not women – only discussing human beings who had spacecraft named after them.
Fraser Cain: Yeah.
Pamela Gay: This is why we haven’t discussed Carl Sagan is the guy has no spacecraft named after him.
Fraser Cain: We’re breaking these rules now.
Pamela Gay: We’re gonna currently break these rules, and the reason we’re doing this is because people don’t know that there’s like modern excellence in astronomy. And so, like the recent Cosmo series didn’t highlight living people all that well. Astronomy textbooks always highlight the women at Harvard before any of us were born. And there’s all of these amazing women and with everything going on with Gamergate, everything going on in the science communications community bringing to light how rarely women’s work receives accolades.
It was like, well, expletive, these women are never gonna get spacecraft named after them. So let’s just talk about them anyways.
Fraser Cain: Well, right, but I think it’s great to talk about some of the modern people. I mean, there’s some people in here who you may not have heard of, but I think we’re gonna be wrapping up this first set with Carolyn Porka who is one of the most influential Planetary Astronomers out there and responsible for the Cassini Missions imaging.
Pamela Gay: Yes.
Fraser Cain: So she’s a force and definitely stands toe to toe with any modern astronomers out there. And so, I like this idea of covering modern astronomers. So I love the idea of focusing on some of the women and I love the idea of looking at some modern astronomers. So I’m fine for us to throw our rules out now that we’ve sorta caught up with all the astronomers who have missions named after them and start talking about people who either living or dead, but especially those people who are making a difference right now. So I think it’s great.
Pamela Gay: And at the time that we came up with the list they were all still alive. And despite my recent ability to partner with things that don’t stay alive, I’m hoping they’ll stay alive.
Fraser Cain: Right. Yeah. Some of them are pretty old, so okay, well; let’s talk about today’s topic, then, Vera Ruben. And this is a huge one.
Pamela Gay: Yes. And this is the story of one of those women who has just consistently done kick ass amazing ahead of her time research that everyone sort of went, “Meh, no, can’t be right. Can’t be right. Meh, Vera sucks.” And then a few years later, like, “Oh, crap. She was right.” And this keeps happening to this poor woman. She does amazing and awesome science. Everyone makes fun of it. Some dude recreates it and it’s proven true. And that sucks.
Fraser Cain: So, well, let’s – so I think before we go – I think normally we go into their history first. But I’d like to know just from like what is the big contribution? If you are trying to think about a field of astrophysics about astronomy that we talk about, what is the big contribution, the biggest contribution that Vera Ruben has, the one that you should really remember?
Pamela Gay: She has two that are tied because she’s just that awesome. The first one is that clusters of galaxies aren’t just this happenstance grouping that is all spreading apart as the universe expands, but rather, galaxies and clusters are all orbiting a central point to that cluster of galaxies. She was the first person to figure this out, to figure out that clusters do have this center that things are flying around.
Fraser Cain: Okay. So hold on. So where Hubble looked out and saw all these galaxies flying away from us – and they are flying away from us and the further away they are, the faster they’re moving. But they’re also in these big structures that are rotating and interacting and such.
Pamela Gay: Right.
Fraser Cain: Okay.
Pamela Gay: So if you look around the sky and you grab like 20 random galaxies that are near enough to get good spectroscopy of, which is kinda where Vesta Slifer who took the data that Hubble originally used did, those groups of galaxies, they’re just gonna be randomly moving away from us at rates that depend on how far away from us they are.
But if you do entire systematic catalogs, you’re gonna find clusters within that catalog of galaxies that are all moving away from us at the same collective rate but within that group they’re going to have orbital rotations that spread them out as another woman that we’re gonna talk about later, Margaret Geller, figured out. But Vera Ruben was the first one to start figuring out that galaxies orbit about a central point.
Fraser Cain: Cool. Okay. That’s one.
Pamela Gay: Okay.
Fraser Cain: What’s the second one?
Pamela Gay: That galaxies have dark matter.
Fraser Cain: That dark matter is a thing.
Pamela Gay: It was hinted at earlier by Zwike, but Zwike is someone who falls into the if you are too nasty of a person people don’t like to listen to you so they don’t listen to your science either. And so –
Fraser Cain: So he had some personality problems too?
Pamela Gay: Yeah. Well, Vera didn’t have personality problems. She’s actually by all accounts like the sweetest nicest human being ever.
Fraser Cain: No, Zwike?
Pamela Gay: Zwike had personality problems.
Fraser Cain: Yeah. Yeah.
Pamela Gay: But she came along and while doing research to study galaxy rotation curves, she was partnered up with a rotationist, Ford, and so she was using all of this brand instrumentation. She was looking at the rate at which stars orbit galaxies as a function of the distance. And I realized, well, this doesn’t fit with what you’d expect given Newtonian physics if we can see all of the stuff that has matter.
So the idea was when you look at galaxies all of the light coming from stars is focused in the center and tapers out as you move out, and you would expect if your orbit is determined by how much mass is inside of your orbit and your distance from that center of mass, that as you get further and further away from this centrally concentrated mass, your orbit’s gonna slow down. That’s what you’d think. That’s what matches Newtonian physics if you make the assumption that all the stuff that has mass also is happily giving off light of some sort.
And she was the first person to figure out that that is seriously not the case. And over time, people started to figure out, well, there’s hydrogen gas, but there’s not enough of this not glowing hydrogen gas to make up the difference. There’s this other dark stuff that we can’t really make out but there’s not enough of it, like dark molecular clouds and stuff. And in the end, it came down to there’s stuff in these galaxies that is dark that we’re gonna call dark matter that is driving the rotation curves of galaxies.
Fraser Cain: And so, if they didn’t have the dark matter, wouldn’t these galaxies be kinda tearing themselves apart?
Pamela Gay: Because of the measured velocities that she found. The stars in some cases were orbiting at what should have been escape velocities so that instead of continuing to spiral around the galaxy, you’re looking at a snapshot of a star that’s getting ready to move in a straight line or just arc and not stay associated with that galaxy. So yeah, those galaxies were totally filled with associated high moving stars. And that mean that there was a whole lot of stuff that was at a entirely different nonexistent luminosity.
Fraser Cain: Right. And it would be like – I’m trying to think of a good analogy. Right? It would be like watching a – I don’t know, say, a star going around a black hole or a star whipping around this – yeah, around this black hole. And like man, that star should really be flying off into space. Oh, turns out it’s a super massive black hole, not a regular massive black hole. Right? That’s the trick because you can’t really cut – you can’t see the difference between the super massive black hole and the regular black hole that just – they’re not there.
Pamela Gay: Well, they’re kind of in different locations, but yeah, that’s a different issue.
Fraser Cain: Yeah. Yeah. But it’s the effect of the gravity. Right? So okay, great. So now those are the two things to hold in your mind, that galaxies are collecting into these gigantic structures and orbiting a common center of gravity. And dark matter itself is out there. So let’s go back then and let’s talk about Ruben’s history. So where did she go to school?
Pamela Gay: She’s someone who just threw out her entire life, always liked astronomy. And she started out as many young women of her age did. She went to Vassar. She got an excellent education. After going to Vassar, she was hoping to go Ivy League as one who’s brilliant hopes to do. In her case, she was hoping to go to Princeton, but Princeton didn’t exactly allow women at the time.
So since the doors to the education she wanted were literally closed to her because she was a female, she instead went on to get her Master’s degree at Cornell University, which is still a completely awesome university. It’s not Princeton. So she went on. She got her Master’s degree at Cornell. She went on to do doctoral work at Georgetown University, did excellent work the entire time.
It was while she was a graduate student working on her dissertation that she figured out about galaxies clumping together and figured out about them rotating around a central point. But despite the fact that her dissertation work was really a pivotal moment for extragalactic astronomy, people kind of just discredited what she did. She ended up going on to get a job at Montgomery Community College, or rather, Montgomery County Junior College. It wasn’t even a community college.
While she was there, she didn’t want to walk away from research. Let’s face it. When you’re a woman who’s been fighting as long and as hard to do research as she has, it’s kinda hard to just step away, so you find ways to do research. So she got a position as a research assistant, not even a research associate, a research assistant at Georgetown University.
Fraser Cain: And how is Georgetown known for its astronomy?
Pamela Gay: It’s okay. It’s not great. You don’t generally hear about cutting edge research that is pivoting the way our field thinks coming out of Georgetown. You get good astronomers there. You get solid astronomers there. But it’s not some place that you expect someone doing pivotal work to end up with the lowest possible title that you can give someone doing research.
So while she was there she continued trying to do research. She was eventually hired on as an assistant professor in 1962. It took her some time. And at that point she needed to use bigger and better telescopes to keep doing her work. And she ended up becoming the very first woman authorized to use Palomar Telescope.
So here she had to jump through hurdles of women weren’t even allowed to get time on Palomar. And at this point she’s an assistant professor at a perfectly reasonable university doing breakthrough research. And they’re like, “But you’re a girl. You can’t use this scope. Oh, I guess we’ll change the rules.” And –
Fraser Cain: So they changed the rules about who can use the Palomar Observatory to –
Pamela Gay: Yes.
Fraser Cain: – to allow her to do her work?
Pamela Gay: Yes. Yes. How gracious of them. Sorry for the sarcasm dripping through.
Fraser Cain: Yeah. Yeah. No. I think we need to prepare everyone that there is gonna be mountains of sarcasm dripping through this entire episode and probably the entire series. Because this is gonna be a theme that is gonna definitely run through a lot of it.
And fortunately, all those problems are over now, he says, being more sarcastic. But I don’t want to poke that to – that bees nest yet.
Pamela Gay: Yeah.
Fraser Cain: So let’s keep rolling. So okay, so she got access to the – now, where’s Palomar located?
Pamela Gay: It’s outside of Las Angeles.
Fraser Cain: Right. Okay.
Pamela Gay: So it at the time was probably if not the best one of the best telescopes that she could have access to in the United States. Amazing facility, great telescope, and with it she continued to do awesome work. This is where she started working with Kent Ford. She actually went on to get a position at Carnegie Institute of Washington where she was able to continue focusing more and more on research. She didn’t have to split her time quite so much.
And she’s still at Carnegie, actually. She’s there as a senior fellow so she never ended up with that golden ticket of being a tenured professor, but a senior fellow at Carnegie, still an extremely prestigious position.
Fraser Cain: And it’s fairly famous for its astronomy, like I know a lot of the –
Pamela Gay: It is. It is a top institution. So she was over time finally able to get her work acknowledged for the excellence that it was. But it did take time. Her work with Kent Ford on galactic rotation curves is now something that we make part of pretty much every freshman astronomy course at a university that has even the smallest of radio telescopes. We make them replicate the research in the radio.
Fraser Cain: That’s cool.
Pamela Gay: Yeah. It took a long time to get people to accept that this was just the way things are. But –
Fraser Cain: Yeah. But that’s amazing. That’s really awesome to me that you guys still do – that you’ll have your students replicate that data using the instruments that you have available, using radio and stuff.
Pamela Gay: Right.
Fraser Cain: That’s just so cool.
Pamela Gay: So she went out and she looked at stars, at luminous matter, and did this for galaxy after galaxy after galaxy. With our students, we just have them look at our own galaxy and look at the clouds of gas out at the outer edges of the galaxy. And so, it’s a much simpler project, but it’s getting at the heart of what she did. And so, starting in the 1970s people finally 20 years after she’d started all of this started to recognize all of her work as being as influential as it is.
And over the years she has gone on to have amazing students. Sandy Faber, who we’re gonna talk about later in the series, was one of her graduate students. She went on to receive notable awards, but there are several people that are like why didn’t she get a Nobel Prize? Because one of the big criteria for getting the Nobel Prize is doing work that observationally demonstrates that something exists. And she did the observations that demonstrated that dark matter exists in galaxies.
Fraser Cain: And we just saw just a couple of years ago, right, the award of dark energy?
Pamela Gay: Right.
Fraser Cain: Of the Nobel Prize for dark energy, which again, we don’t know what dark energy is. We probably know even less about dark energy than we know about dark matter. And yet, a Nobel Prize was awarded for its discovery but not its identification.
Pamela Gay: Right. And so, going down the list of awards, like one of the most disturbing ones for me was she is the gold medal of the Royal Astronomical Society and she was the second woman to get it. And the one before her to get it was Caroline Herschel in 1828.
Fraser Cain: Right. So like 150 years earlier.
Pamela Gay: Right. And there’s all sorts of examples throughout our history of being the first woman, the second woman, the third woman to get these long-term awards. And she did some of the most amazing work. She deserves every single one of the awards, but the fact that there’s so few women’s names on these lists was really brought home to me looking up her history. Because it would be nice to think you didn’t have to do work worthy of a Nobel Prize that no one bothers to give you in order to be one of the only names on a list of awards that don’t usually go to people deserving the Nobel Prizes.
Fraser Cain: Right. So there you are.
Pamela Gay: Yeah.
Fraser Cain: I mean, I think that – I mean, this is gonna be the theme. And I just need to warn people in advance. The theme is gonna be – or that what we’re gonna hear again and again and again is legitimate high quality astronomy work unrecognized, kind of pushed – kind of had to be proven beyond a shadow of a doubt before the naysayers started to sort of accept the validity of it.
Pamela Gay: Yeah.
Fraser Cain: And not so much with some of the more – like as I said, Carolyn Porka and stuff, I don’t think anyone is gonna say that Carolyn Porka wasn’t doing great science.
Pamela Gay: No. And –
Fraser Cain: And she would kill them if they did.
Pamela Gay: Yes.
Fraser Cain: So –
Pamela Gay: And that’s the big difference between Vera Ruben and a lot of women that we’re going to discuss is Vera is someone who has simply done absolutely amazing work with a reputation for being the sweetest, nicest human being on the planet.
Every picture I’ve found of her she’s either has this expression of complete absorbed in what she’s doing in a positive way, not with the I’m completely observed in what I’m doing and look like I’m going to scowl, but just this I’m focused and absorbed and joyful. Or she has this sweet smile, just there’s this pleasantness that comes out of her where one of her most frequent quotes that I’m trying to find on this page – I can’t find it so I’m just gonna paraphrase it – is, “Fame is fleeting. Science is forever.” That’s a paraphrase of what she wrote. But that’s just such an amazing concept.
And she was invited to go back to one of her alma maters, University of California Berkeley, and gave a graduation address there. And one of the things that she said – and I think this – I’m gonna be very controversial and say I like this quote better than Carl Sagan’s version of this quote. She said, “You drank the milk. The carbon atom entered your bloodstream and traveled to your brain, displaced a carbon atom and took part in the thought process permitting you to pass your final exam. So without that single carbon atom made in some star billions of years ago, you might have failed to receive your diploma today. See how lucky you have been?”
I just love how she gives it so much more of a picture. And it’s really worth looking up the graduation address she gave. Most of it is on the website, Brainpickings.org. And we will link to it in the show notes. It’s just chock full of amazing things.
She also goes on to chide the students in the audience who are going to go on to teach science to make sure that they didn’t focus all of their efforts on the students who were going to be scientists because, as she put it, we need senators who have studied physics and representatives who understand ecology. To her, it’s always been as important to teach the non-scientists to be knowledgeable as it is to teach those who are going to go on and follow in our footsteps and become the next generation of scientists.
Fraser Cain: So we talked about her big discoveries, her big impacts, on Astronomy on the galaxy rotation problem, dark matter, the work with Ford. What other kinds of projects did she work on? I mean, such a long career.
Pamela Gay: Right. Her entire career has continued to be focused on the study of large scale structure of the universe and galaxies and galaxies within clusters. So this is a field that even though I can say quite flippantly, scores of years ago she’s the one who figured out that there’s this universal galaxy rotation curve. That work is still going on. That work is still being refined. Galaxy cluster information, that’s still work that’s being refined. So these aren’t solved questions. They are questions where she discovered the question exists.
Fraser Cain: Yeah. That’s funny. That classic quote, right? That’s a little weird. It’s unusual.
Pamela Gay: Exactly.
Fraser Cain: Right. Yeah. And so, where – I mean, where are we – what is the current state of the art in that? What are the big still kind of unsolved questions in this idea of this galaxy movement?
Pamela Gay: I think right now with the galaxy movement we are still trying to figure out are we certain there isn’t an extra term to gravity that we need to take into consideration? And beyond saying we know there’s a direct matter particle, end of statement. We know there’s a particle. We don’t know if there isn’t also a extra term to gravity.
Fraser Cain: Oh, sorry. When you say an extra term, do you mean sort of like this MOND idea, right, that –
Pamela Gay: Yeah, Modified Newtonian Dynamics that –
Fraser Cain: – right, that over long distances maybe gravity acts differently than it does in the close –
Pamela Gay: You need to add an extra term to GMM over R squared. So we do know for certain, though, that there is a particle form to dark matter, that it is most likely non-baryonic, which means that it doesn’t like to interact with stuff the same way neutrinos don’t like to interact with stuff and that it doesn’t interact via the electromagnetic force. So it’s gonna have absolutely nothing to do with light other than bending it with its own gravity.
Now, there are arguments and literature over whether this is a weekly interacting mass of particle or something else. There are hints that maybe we have, maybe we haven’t found it in large particle accelerators. But I think that if CERN gets another good season of running we’re gonna start to be able to get theories either eliminated or confirmed for the lowest weight most reachable of these weekly interacting mass of particles. So there is hope there.
There are people working very hard using these underground neutrino detectors that can also perhaps be used to look for interactions with some of these stray particles that don’t want to interact with the electromagnetic force. And as we look further and further back with James Webb coming in our future, one of the lasting questions is how did these galaxy clusters evolve? Many of them have these massive central galaxies called CD Galaxies that are structurally something very different from your normal run of the mill elliptical.
When did they form? Was this a group of a bunch of galaxies that flowed together? Was this a matter of over densities in the dark matter that drew in not just a massive galaxy but drew in all of the stuff that would fragment into galaxies? Or was it both? So we’re still trying to sort out the not just top-down bottom-up theory of galaxy formation, which we’re now pretty sure is mostly fragments coming together to form bigger and bigger, except in some cases of ellipticals.
It’s that except that is fascinating, but we’re still trying to figure this out for clusters as well. Was it all local group like things coming together to form bigger and bigger clusters? Or did you occasionally start with the super massive clusters as well?
Fraser Cain: Well, and here we are 50, 60 years after this discovery, these initial discoveries were made. And still, we haven’t completely nailed down all these questions. It’s amazing how long this process takes, even with the modern tools. I mean, they’ve dug up half of France and Switzerland to make a gigantic, super collider and –
Pamela Gay: If only it was half of France and Switzerland, then we might have solved this already.
Fraser Cain: Half of France and Switzerland, yeah. Yeah. That’s all it took. And we still haven’t quite got to the bottom of these. We found the Higgs Boson but not the rest of it. So yeah, I think it’s great. Okay. Cool. Well, thank you very much, Pamela.
Pamela Gay: Thank you.
Fraser Cain: I look forward to next week.
Pamela Gay: Thank you.
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