UNM Connections; 302; Physics

Hello and welcome to UNM Connections. I'm Valerie Santiannis. Fundamental physics can be described as the study of nature for the sake of pure knowledge. UNM Professor Rob Duncan's experimentation with the fundamental physics of superconductivity and superfluids has earned his project a spot on the International Space Station and a ride to the station courtesy of NASA. Now Duncan, his fellow professors and a select group of graduate students are working together to get the project off the ground. Now, find out more about Duncan's work and other UNM firsts. Next, on UNM Connections. I'm like everybody to blow up a balloon and tie it off and then pass it back towards the front of the lecture hall, okay?

By the time you have the blown up and passed back to the front of the lecture hall, I'll have some assistance ready to take them and feed them into our mystery apparatus over here. I think we've probably got 180 balloons in here. Okay. Any hypothesis how we're doing this? Yes? Okay. And? What's that? I think it's liquid nitrogen. Good hypothesis. Any other hypotheses? Yes? Uh-huh. Something sucks the air out of the balloons, uh-huh. Any other hypotheses? So we've heard one that the air is removed from the balloons by some apparatus once it gets in there. Must do it slowly. You don't hear them pop, but there's possibility. The other is that since it says cryogenics on the side, there's liquid nitrogen in there and that's causing the balloons actually to, uh, kind of freeze out and collapse. Well, since we have to conclude pretty quickly, let me say that actually that hypothesis is correct.

This thing has about 40 liters of liquid nitrogen in it. Now the liquid nitrogen causes the, uh, the error in your breath, by the way your hypothesis was a very valid one, but I'm kind of racing ahead here. But it causes the error in your breath to freeze out, it causes a nitrogen in your breath, which is 80% of your breath, to collapse in the liquid as well. The liquid's a thousand times more dense than, than the gas at room temperature. So the compression ratio is about a factor of a thousand. So I could put about a thousand times this volume into this apparatus. But what I have to do is wait a while because it takes some time for the heat to exchange between the balloon and the liquid nitrogen. Now, what I'm going to do is I'm going to do the experiment, okay? I'm just going to take the thing and just mash it apart, just to open it up and throw it across the front of the lecture hall. Now when I do so, when I do so, it'll be kind of dramatic, okay? Look for a couple things. First of all, these balloons were hand-picked because they'll re-inflate as they start to warm up again.

And secondly, the liquid nitrogen that's led these things to collapse will be like on a red hot griddle as they roll across this 300 Kelvin floor. Liquid nitrogen is at 77 Kelvin's. This is 300 Kelvin's. Liquid nitrogen is 331 below zero Fahrenheit, okay? So what you'll see is the liquid nitrogen just racing all over, picking up dirt as it goes, because it's like just skipping across the floor like it was spent on a hot griddle. But let's take a look at it then and see how it goes. Just have to make sure we get this last one collapsed well. But actually, I'm just going to do this, yeah. By the way, I'm using cold gloves. Don't try this at home. You know, you don't want your right hand to resemble the warmth that the dermatologist just dealt with. Okay, so now, let's do this. Now notice, as the balloons warm up, how they re-inflate.

And notice also, the little cloud we made on the floor, if you can look down, you'll see on the floor that there's a liquid nitrogen that remains. It's just skirting around on the floor, boiling off. But now, as these balloons re-inflate, as these balloons re-inflate, as they warm up, and the only thing that limits this is how fast the heat can transfer. Well, a lot of times the rubber gets a little bit more brittle. So as these things start to warm up, they'll probably go boom, boom, boom, boom, boom. But see, it's kind of the fate of rubber after it gets cold like this. But that was a good hypothesis.

Sure, it was as well. It just happens, in this case, the mystery apparatus was freezing all the balloons down. And now that they have heat again, they can re-inflate. Well, thanks for contributing a lecture and see you on Wednesday. Joining us in the studio now is Dr. Rob Duncan. Welcome to the show, Rob. Well, thank you very much. Thank you for having us here. That was a great piece of video. It looks like just a great way to show your students what you're working on. But before we talk about that, can you tell us who are your assistants? Well, yes. Working with me primarily at the physics department in critical dynamics microgravity is two research professors. One is Steve Boyd and the other is Alex Babkin. And you'll see some footage of them as we go on in the show as they work with us on the inserts for our experiment on the station. What were you doing with that? Why were you showing the students that bit of fun there? Oh, yes.

We were doing this primarily as the opening day introduction to physics. And a lot of times, students come to a physics class and they're a little apprehensive. They think of physics as a bunch of facts or a bunch of apparatus that they have to memorize. And they're a little apprehensive as they start physics with calculus. So what I try to emphasize is science and physics is a process. It's a process of discovery. You have to propose a hypothesis and then do tests to see whether that hypothesis is correct. So when I think students see science as what it is, a process, they tend to couple in more and they enjoy it more. Now, your specialty is fundamental physics. Tell us about that. What is that all about? Yes, fundamental physics. Personally, I'm an experimentalist. But those of us that work in fundamental physics don't really have any specific application in mind. What we've done is we've identified some aspect of nature that we don't understand yet. And we're trying, through again, the scientific method to understand how nature works essentially. So in fundamental physics, we're going for new knowledge.

We really don't know where the knowledge is going to lead. But history has shown us that knowledge always leads to new technologies to an improvement in our quality of life. So what are you focusing on these days? Right now, what we're doing is getting ready to fly the experiment that we'll talk about here on the International Space Station. We're scheduled to fly in the year 2005. And right now, the science in terms of the ground-based science has been completed. We started in about 1992. And we're now entering the phase where we engineer this to actually go into space. So in addition to fundamental physics, there's always a lot of fundamental engineering that's associated with getting the experiment on orbit. Unfortunately, NASA and the Jet Propulsion Laboratory are working with us closely on the fundamental engineering. We're also assisted by Sandia National Labs and efforts from Stanford University and from here at UNM as well. What is your hypothesis or what is your experiment? Yes.

The experiment is really very simple to describe. It's just a can, a little cylindrical can, that contains liquid helium. And helium, like any other material, if you get it cold enough, will form a liquid. But helium has to be cooled down much more to a much lower temperature than any other material. It has to be cooled to about 450 below zero Fahrenheit. And when you get that cold, liquid gas becomes a liquid. And then if you cool down about another five degrees Fahrenheit, that liquid becomes what we call superfluid. And the superfluid is very unusual. It behaves like a single quantum mechanical entity. It's an example of where quantum mechanics, which usually only is important on the tiny atomic scale, becomes important on the whole container size. In this case, the entire container of liquid helium. So what you are doing with this experiment is seeing how liquid helium, as a superfluid, will behave in space. Exactly. And the reason why we go to space is that right now our experiments on Earth are so well controlled that the only thing that limits us in understanding how the liquid goes from

a random liquid to a quantum mechanical liquid or a quantum fluid, as we call it, is Earth's gravity itself. Because the weight of the liquid causes us to get imperfections or inhomogeneities across the liquid column that limit our ability to study it on Earth. So the only way to go further in our understanding of this process of the superfluid transition, as we call it, is to actually go into space. You and several of your colleagues are working on this experiment, and we have some video to look at that will show us some of what you are doing. So let's take a look at that now. Welcome to the critical dynamics of microgravity, ground-based laboratory here at the University of New Mexico. This is where we have developed the prototype apparatus that will be almost identical to the apparatus that will fly on the International Space Station in the year 2005. What we do here is we take this apparatus and cool it down to near the lowest temperature

you can possibly achieve. We cool it down to 455 below zero Fahrenheit. Now, 459 below zero Fahrenheit is the coldest you can ever go. So we are just about four degrees above the absolute lowest temperature you can ever achieve. To do that, what we do is we take this probe and we take it and place it inside this apparatus which is called a doer, which means one serious thermos. This is a really good thermos bottle where we can put liquid helium on the inside at 455 below zero Fahrenheit and have the rest of the room unaffected completely. You wouldn't even know to look at it that it was that cold inside. And so once we're cold, once we have the apparatus cold, then we use the flight electronics that you see here and these flight electronics or these electronics that we use to make the measurements of the liquid helium properties are often far more sensitive than any other measurement electronics you can buy commercially.

That's why we've had to engineer and build much of this electronics ourselves following designs at low temperature physicists throughout the world of use for the last few decades. What you see here is the probe we use to make the measurements. Up here we're at room temperature and as we go from room temperature down, good and colder and colder and colder until way down here we're at 455 degrees below zero Fahrenheit near the coldest temperatures achievable. What you see here is the apparatus that will be at 455 below zero Fahrenheit and this apparatus is a vacuum can and inside the vacuum can is the actual hardware that we'll be using on the International Space Station. This is the prototype model we'll be building the flight hardware shortly but it'll look identical to this. And what we see here is that this gold-plated section is the actual apparatus that will fly on the space station. The rest of the apparatus above it supports it. But one of the interesting things you see are different levels of thermal isolation and

this tube actually is a refrigerator that allows us to go from 455 below zero Fahrenheit down to 458 below zero Fahrenheit. This is a little refrigerator. Now as Stephen Alex drop off the first radiation shield we see that it looks kind of like a Russian doll. What do we find inside but another radiation shield? And the reason for this is this apparatus is the most carefully controlled heat transport apparatus if it's kind ever developed in physics anywhere in the world. This apparatus is able to measure temperatures with a precision of one-tenth of one billionth of a degree which has not been achieved in any other thermal conduction experiment ever before. Now that we lowered the second radiation shield we see the heart and soul of the apparatus. This ring that you see is what we call the cooling stage which is used to extract heat in a very controlled manner from the cell and the cell is right here. Now this is so precise that we can extract heat in increments of a pico watt.

Now a pico watt is one one hundredth of one trillionth of the power output of a white bulb in your living room. So these are just unprecedented levels of experimental control that have been achieved for the first time in this apparatus for the International Space Station experiment. In this experiment the liquid helium is contained in this little can that you see here. And we measure the temperature with the thermometers which are these little tubes that stick up from each of the little wings on the cell. And these thermometers are used again with these devices, these very sensitive magnetometers called squids or superconducting quantum interference devices to measure the temperature as tiny as a temperature change as tiny as one-tenth of one billionth of a degree. And so that's the most sensitive temperature measurement yet applied to such an experiment. Now I would guess that getting your experiment on the International Space Station is quite

an honor. It's certainly taken a dedicated effort by a number of people. I'd say that Professor John Leepa from Stanford University flew to other fundamental physics experiments on liquid helium ahead of us. We flew land to point experiment in 1992 and the confined helium experiment in 1997. Both of those flew on the space shuttle. And so if learned from Stanford very closely, certainly John Leepa has provided us with a lot of assistance. So whereas I'd say certainly the group feels very honored to have the opportunity to fly in this capacity. We see it as being possible because of the extensive dedication and hard work of many people that have come before us, not only in other universities, but also in our own research group that have gone on to other research positions. So there had to be some experimentation with liquid helium in space before you could get to the point you're at now? Yes, exactly. In fact, around the mid-1980s, people really didn't know how liquid helium would behave

in space because, of course, once you're in free fall around the Earth and Earth orbit, the liquid in vapor will not stay separated as they will on Earth. So just developing a cryogenic engineering system that could control this liquid in vapor floating around in all directions was a real challenge. You've seen astronauts drinking tang on orbit where it's just a blob that they catch in their mouth. I mean, in a sense, the liquid helium now at 455 below zero Fahrenheit is a similar free-flying blob just in its own vapor. So it's a trick. And you actually brought us some footage of some of those experiments in, well, I'm sorry, what do you call that? Oh, yes. The actual platform we'll see in just a moment is the KC-135, which is basically like a 707 jet, and it's called the vomit comet among people that work with it all the time. Because all it does is just fly like a dolphin through the air, except taking huge 15,000

foot excursions between its maximum and its minimum and its maximum. And when it's actually coming down, when it's flying down, everybody appears to be weightless. Because when you're actually on orbit around the Earth, it's like you're continuously falling to the Earth, but the Earth is falling out of your way at the same rate you're falling down to the Earth. So in a sense, a good way to think of orbiting the Earth is being in continuous free-fall. Okay. And these people in this experiment are free-falling in the jet. Okay. Well, let's take a look at what they're doing. Let's see. In this case, you can see they've just started to die of the aircraft down, and everyone feels effectively weightless. And I might mention the fellow who's upside down there in the background in the green jumpsuit is Dave Elliott, who was the experiment engineer, the project engineer, on this experiment critical dynamics and microgravity. These footage, though, were taken prior to our experiment in the first days of the program when they were trying to understand fundamentally how they could control a incredibly precise

liquid helium experiment in the actual weightless environment. So for a while, you'll see them go again shortly. For a while, they're actually weightless as the jet is nose-diving back down. So here you can see they're effectively weightless. Again, Dave Elliott in the foreground now is kind of going up and down, and I think they are conducting an experiment. It looks like they're having a lot of fun, but they're also in the background with computer automation running the experiment itself. Okay, and we can see that the card in the back is where the liquid helium is contained. Exactly. Precisely. That's where the liquid helium is, and the card also contains the rack behind the card contains the control electronics to take the data and flight. Well, that really does look like fun. Probably the most fun you can have doing science. I think so. I think they're having a great time from what they can tell from that. That looks great. Now, there are, UNM is one of the first public universities that is getting a spot on this International Space Station, but I understand that it's also the first public university

that's been asked to build some of the hardware that will be carried up there. Yes, this is true. This is true in our fundamental physics discipline in NASA, Stanford University, a private university, has built flight hardware in the past as well, and again, we've learned from them and from others in this area. We're just now establishing clean room and flight hardware fabrication facilities here at the University of New Mexico that meet NASA's strict requirements for fabrication of the flight systems. Since the ride is so incredibly expensive, NASA appropriately asks us to take incredible precaution when we actually make the flight hardware systems. Making of cost, how much will this experiment ultimately cost? This is kind of a difficult thing to estimate, but I believe the critical dynamics in microgravity part, our specific scientific study will probably cost somewhere around $10 million. But then again, the facility that we'll load into and we'll take us up onto the space

station is probably about a $40 to $50 million public investment. But the nice thing is that facility will return and take two more scientists up probably around the year 2007-2008. So the nice thing about the facility is it's reusable and it allows a great deal of fundamental physics to be done for a single moderately sized fixed investment. In addition, the facilities that you will build at UNM to do this, I imagine will be something that can be used in future by students. Well, yes, absolutely. In fact, quite often, the flight prototypes that we've been building have led to very exciting new discoveries in fundamental physics, which we've published here just based on the groundwork so far. And in fact, we have to progress through that process until the only limit to our experiment is the weight of the liquid helium. Until we get there, it's hard to justify actually flying on Earth orbit. But a scientific review board towards the end of 1999 reviewed our experiment and concluded

that we have reached that point now where the last limitation is that of the weight of the helium. So now we're ready to go onto orbit. I would imagine that a program like this is extremely beneficial to students who have the opportunity to work with you. Oh, I agree completely because in addition to delving into some of the most current questions in quantum mechanics and macroscopic quantum phenomena, we call it on the scientific side, we have to really develop to a much greater level our measurement technology. So I don't think it's possible to do fundamental physics without doing fundamental engineering first. So the students also get an opportunity to learn how to stabilize measurements better, how to analyze data, how to look for trends that people have really not explored before. So we certainly have a number of students involved and both the undergraduate and graduate level and we encourage student involvement all the way through. I just might mention there's another program called NASA Pursue at UNM that's funded

through a different area within NASA headquarters. But that's primarily focused on the educational advantage and educational outreach capabilities of NASA to students. And of course, we encourage any student that's curious to work with us. We especially want to be sure that we take the advantage of being able to try to encourage students that have not really been represented in the sciences that much before to take an opportunity to really explore science. So we're always looking for the minority and underrepresented student outreach. And so that's also a very important part of NASA Pursue too. That's great. I'm sure that that experience looks terrific on a resume. Your students must go on to get some very good jobs. Yes, I must say all the experiments that have been involved in our research group have gone on to excellent jobs, either on completing their PhD or as postdoctoral students have gone on to permanent staff positions that have been very nice. In fact, I have one student now, Ray Nelson, who joined my group after having been an assistant

professor at West Point at the Military Academy. And I'm completing his PhD. He'll return to become a full professor at West Point. So I jokingly say Ray is my first ten-year graduate student because he already has this very nice position at West Point lined out. He's a Lieutenant Colonel in the Army. Well, that's great. We talked about fundamental physics and that it is the pursuit of knowledge for knowledge is sake. And while that certainly seems like an ideal thing to have in a university, which after all is a place of learning, I have to ask you, what do you see as the benefits of the work you're doing now? Will there be a practical application for what you're doing now? I believe so. The interesting thing about fundamental physics is it's always done in fundamental science in general. It's always done just for the sake of knowledge.

But we've always seen that knowledge is incredibly powerful. So in very short time, that knowledge gets translated into new engineered systems to new developments that improve our general quality of life. And I think that's a really important aspect of this. And in addition, as we push the envelope and improving our fundamental measurement capability and our engineered systems for space flight and this sort of thing, as we do that, we're pushing ourselves harder and harder to achieve new things that will have technical spin-offs in a number of areas. So really we kind of benefit both ways. But I think another thing to always stress is that when you take a curious person and train their mind to use a scientific method, the benefit of that to society is profound. So that's another great benefit of the fundamental physics program, too. Can you give us an example of something that has come out of fundamental physics that has been a benefit to the world? Oh sure. In fact, most of the things we take for granted today started as being just curiosities in fundamental physics.

One thing that I think is really striking and people point to this sometime is Benjamin Franklin, of course, one of the fathers of the United States and very involved in the first congresses of the United States and first postmaster general and ambassador in European countries. He had many, many chores, but he always took time to study electricity because it fascinated him. He pursued it because it was fascinating. It was fundamental. Nobody really understood it. And he got a lot of criticism for having spent all his time on this silly little pursuit of trying to understand electricity, which back in the 1790s and 1780s, people thought would never be useful for anything. And of course, it's critical to our lives today. And it seems like in every age you have people that think we know everything we need to know, they're always wrong. We always will benefit greatly from what we learn today. Well Rob, thank you for bringing us a little bit more knowledge today. And thank you. Thank you for joining us on UNM Connections. Join us next time.