Nuclear Gets Personal with Prof. Michael Short (S1:E1)

Key Takeaways

instead of saying analyze this theoretical problem I said analyze your toenails tell me how much arsenic and gold you've got in your body all we study at MIT is the natural world and things we make out of it so everything is reducible to practice everything can be real if you put in the effort today in the podcast we're talking about ionizing radiation and nuclear engineering how do you make these things real and tangible matter is a form of energy and once that clicked everything seemed to make sense radioactive decay nuclear reactions all these things I remember that aha moment in this class that I teach as a second year student back in 2002 and it's those kind of moments that made me want to stay in it because I feel like wow I really know this field now welcome to choc radio a podcast about inspired teaching at MIT I'm your host Sarah Hansen from MIT OpenCourseWare the nuclear engineering and ionizing radiation course at MIT take students from understanding basic physics to grappling with the core concepts of Einstein's e equals mc-squared in this episode we're going to delve into how this is possible and what it takes to make a class that's not only hands-on but also capable of evolving daily my guest is one of the main people that makes this happen professor Mike short this course is all about radiation both it's its origins and its uses so this is the first course on it's intro to everything nuclear that any student at MIT would take and a lot of times for students it's their first modern physics course the physics courses that first year students take are often things that we've known for 100 to 300 years and the field of nuclear physics is still evolving we're still using nuclear radiation spectra to detect the presence of water on Mars or the moon we're still confirming our knowledge of which particles do and don't exist in Y so this is also intro to modern physics so nuclear science and radiation in particular are emotionally charged top you know you you read on the internet claims like cell phones cause cancer things like that how are you preparing students to debunk pseudoscience and to really serve the public we actually spend two weeks at the end of the class looking at studies that are false or have exaggerated claims and teaching students what to look for so the first 11 weeks of the class we teach the students the fundamentals of nuclear science and then we turn to published articles and blogs and other things in the field and we debunk myths like cell phones cause cancer due to ionizing radiation cellphones don't emit ionizing radiation we debunk myths like the tiniest little bit of irradiation can harm you when in truth we don't have the data for that but a lot of a lot of misinformation in radiation and nuclear science is incorporated into culture into our sort of collective consciousness and even in what's called the linear no-threshold model which says every little bit of radiation does harm we don't know that to be true or false and it's a good thing we don't because we would need to have exposed tens of millions of people to low levels of radiation in a controlled study which is not something I think is ethically correct to do it's also not ethically correct to say that all radiation causes harm because we don't know and I want students to both recognize false science in the field and recognize when we don't know enough information to say something confidently and be comfortable with that lack of knowledge it means there's something new to explore but it's if you don't have something to conclude don't draw a conclusion mm-hmm how does this connect to the irradiated fruit party that you have in the class what what is that yeah the last day of class we often have an irradiated fruit party where I bring in fruit that could only be brought into the US because it's irradiated so there are many fruits that are there are many different types of produce including fruits that are irradiated and it's the only known way to kill all of the insect viral and bacterial pathogens that can wreak havoc on either people or on our crops an interesting point of information Hawaii and Puerto Rico despite being part of the u.s. our agriculturally distinct in areas and you are not allowed to simply import produce from those I had an Apple confiscated from the airport Puerto Rico what I learned that to be the case however if you were radiate foods like this is why we can get a lot of pineapples from Costa Rica we've started getting mangosteens in from Thailand where I didn't know what that fruit was until a few years ago and now you can find them at H bar in Cambridge a lot of this is because we can kill the pests and it doesn't harm the food it doesn't make the food radioactive but a lot of us is to personalize the science so when students eat food that they may or may not known of been irradiated they taste good they seem safe and it's one of those things where once it's personalized it's not as scary when you learn the knowledge and then you see it for yourselves it becomes a lot more acceptable yeah learning through experience is very powerful what does it mean to you for students to develop fluency in this field it's important to be fluent in this field because a cursory knowledge of radiation science is not enough I'd say there are a lot of self-proclaimed experts I'll call them armchair PhDs who have learned a bit of genuine knowledge but then extrapolate it too far and that combined with all the things we've heard in pop culture unfortunately sometimes from celebrities spouting falsehoods about radiation or vaccines or other things that they don't understand people listen to other people and people listen to role models and folks that they look up to but it's important to be fluent and well grounded in the fundamentals so that you can sort out fact from fiction and I want every student that leaves my class to be able to recognize something that's incorrect even if it's told to them by a celebrity an expert a parent a friend anyone that they know what the reality is and it shouldn't depend on the source it comes from they should be able to tell whether it's real or not and verify if the source is genuine mm-hmm and how do you help students develop this fluency so it starts off with the fundamentals of radiation science so like any class we teach all the fundamentals from well-established theory but along the way every week we have labs and personal as like for example the first day of class I asked students to bring in their toenail clippings and they usually say that's disgusting what are we doing and I said you'll see we're gonna put them in the reactor and we irradiated air toenail clippings and because to some degree you are what you eat some of the elements which we eat and we don't want to things like arsenic or selenium or chromium some of which can be good in small amounts that and large amounts others like arsenic I'm not sure if there's a good use of it get incorporated into our toenails so we activate those toenails by putting them in the reactor they absorb neutrons and give off characteristic gamma rays giving away how many atoms of arsenic and selenium and such are incorporated into the toenails with striking precision and so we're able to tell where students come from based on analysis of their toenails we had one student who had a lot of gold in their toenails and I said I thought I asked you guys to you know clean these off remove any polish and the student said yeah I did but I live near a gold mining town and it's in the water wow that's so interesting so that's what I mean by personal is they discover things about themselves through nuclear science and the problem sets instead of saying analyze this theoretical problem I said analyze your toenails tell me how much arsenic and gold you've got in your body right right so in the course you make a point of saying that the method of instruction is often context first Theory second and then context again how does that relate to that method of instruction this is an example of that method of instruction I like to start by opening knowledge gaps rather than spouting theory at someone it doesn't usually stick if I just say here are some facts learn them it's usually in one ear out the other if they're listening at all but when you show someone something surprising they're fully engaged they're all this multi-sensory engaged they're they're listening in a lot of cases they're touching in some cases even smelling taste is the sense that we don't tend to engage in nuclear science with good reason but you can sense and feel and hear a lot of things in nuclear science like yesterday I was you know with one of my graduate students we were looking at some highly irradiated materials of a reactor and Idaho and we heard this little faint buzzing noise in the Geiger counter and if you put your ear up to the Geiger counter near the radiation source you can hear tiny electrical discharges so you could hear the detector working and then I want the student to say why is that why does why do I hear this fuzzy noise near the detector when it's working then when you explain why students tend to remember mm-hmm not too many people learn well by being lectured at but everyone learns well by opening knowledge gaps and you're effectively pulling the information in rather than us pushing it to the students something I learned from a mentor here is you can't push a string you want knowledge into a student's brain they've got to pull it you can't push it you made a choice in this iteration of the course to offer students the ability to do analytical homework or take home hands-on labs how did that work out what did that look like in practice interestingly I spent all this time making these optional labs nobody did them so the next couple of years I simply made everything mandatory the students said they love the flexibility they're really psyched that I put in all this time to do the labs but it wasn't for a grade so they didn't do it and so that's what I learned if it's not graded it's not gonna get done so I made all the labs mandatory cut out a little bit of the analytics in favor of adding context before and after the theory and retention went up grades went up on average and the course evaluations went up too so anything numerical we can get improved and in my subjective opinion so did the students knowledge of what's happening and that I get from my colleagues because I track these students as they progress through MIT through our department and my colleagues who teach further on courses the more advanced ones can tell me whether or not the students really know the fundamentals that they're depending on so far things have been getting better that it requires planning and it also requires a lot of thinking where I'll look through my syllabus and I have an empty column where the user doesn't exist in most syllabi which is what is this week's hands-on instruction and I try to make sure that's full so another example is if you want to know do you have real diamond rings when we get to reading electron spectra and carat mystic x-ray spectra I could either give them a problem from theory which is boring or I can run some standard for them where you they know what to expect or I can say that's a nice diamond ring you want to know if it's real and the student unbearably says absolutely I want to know if it's real so we have the student take the controls of the electron microscope and analyze it to see does that diamond emit zirconium x-rays because if it is it's cubic zirconia if it emits silicon x-rays it's moissanite or silicon carbide my favorite one was this day happened to fall on parents weekend so I asked the students does anybody have a diamond ring and one of the students mother said oh yeah let's check my engagement ring and her husband was just oh god what's gonna happen what's gonna happen he thinks he bought a genuine ring turned out to be real okay we had the mic can you tell us about the radioactive scavenger hunt sure I challenged the students to find the most radioactive place in Boston and each of them had to go in teams of two and pick a place that they thought would be radioactive based on what we've learned about where you find radiation so radiation a lot of it comes from space from cosmic protons that hit the atmosphere so some students thought I'll go to the top of the tallest building and I'll probably get more radiation others had read about radon underground because there are isotopes of radium and meeting radon gas and so they thought we'll go down into the subway get as low as we can go other students looked at the relative amount of radiation and different building materials like wood clay marble granite and they went to the most granite dense locations they could find or the ones with the most marble and those are the students that won there were places in Boston that have six times the normal radiation background simply because they're made out of marble or granite these include things like the state house and some fancy fountains around town did not know about the fountains but they just thought let's find giant chunks of stone and they were right [Music] the hands-on experiences that might creates for students of his course are pretty unique he told me that when he took this course as an undergraduate student at MIT it wasn't typically hands-on so I wanted to know what it's like to teach in a way that's so different from his own personal experience what does it take to create such fascinating labs and lessons without a clear model from one's own educational background its natural I teach the way that I learn because I thought back on all my experiences and I thought from which courses did I really remember a lot and these were things like hands-on blacksmithing or laboratory courses we did have a lab class where we counted a lot of radiation and I remember those labs very well and then I think back to my neutronics problem sets I remember the theory okay but I don't remember very many visual instances of that class it just kind of happened my knowledge just may be in there somewhere I don't know but I know where I was when I did most of the hands-on exercises and in the end you can make anything hands-on even neutronics that I mentioned so I what some point went skulking around places I oughtn't like around in the reactor once I got access and found an 8-foot pile of graphite that was behind a bunch of equipment it wasn't hidden it was just covered with junk and I asked what's that they just said oh that's our subcritical graphite reactor pile you know we're gonna get rid of that next year so I sounded the alarm and said it cannot get rid of this graphite pile and then our neutronics professor's been forging cored Smith said yeah you're right we can't so they spent a whole winter restoring it with a couple of students and now it's one of the central labs in my class and in their class so we've taken the most Theory heavy dry and boring class and turned it experimental because you can you're only studying the natural world right all we study at MIT is the natural world and things we make out of it so everything is reducible to practice everything can be real if you put in the ever part of what's so special about this class is the dedication that Mike and his colleagues have to constantly improving it through real-time student feedback and I don't mean fixing pieces to implement for the next semester I'm talking about next-day transformations of class procedures to accomplish this Mike created the aptly titled rants page the rant page is an anonymous simple PHP comment form that I wrote where I want students to tell me things that they want changed because I I try my best to collect in-person feedback from the students most want both one-on-one and in-class but some students don't feel comfortable telling a professor I don't like what you're doing so I give them a place to do so completely anonymously they could ended up being twenty lines of code wasn't hard and what I started getting was real-time feedback about I can't read your writing so then I know to slow it down or I really wish you wouldn't slow the class down for this one students incessant questions so I know to limit each student to a few questions if it gets to be too much and I would address them in class to say it's safe to address this because it's anonymous I have literally no way of knowing but if one person wrote it probably a lot of you are thinking it and the students responded positively to say wow it was really nice to know that we'd make a suggestion at 2:00 in the morning and then by 10:00 in the morning it would be addressed the class would change in real-time and they knew they had the power to shape their own learning [Music] with all the buzz around this course we had a ton of great questions come in from educators and students alike so we picked out some of our favorites and posed them to Mike number one what math do I need to understand this field that's a good question depends on how deeply you want to understand the field if you want to pass my class if you want to get an A in my class you don't really need much math beyond single variable calculus and even then it's not very much I think we use we have one or two lectures with integrals and a few lectures with differential equations but linear first-order things that you solve in calculus one number two when you were a student how did you deal with courses that didn't seem interesting to you but that you had to study that's a good question I have a few answers to that so for courses that didn't seem interesting that I had to study if I knew why I had to study it there was at least a practical reason to to do well for example from you it was neutronics Neutron transport is one of the things that makes nuclear engineers what they are I found it to be dry and not very real-world because I knew I was never going to be a reactor designer but I felt I would need to understand Neutron transport and power levels in order to be an effective nuclear material scientist luckily I was right for the classes which I just had to take because they were requirements and I had no reason to want to take them I got a little sneaky I ended up double majoring with material science and wrote a petition to get out of this one medical imaging class and replace it with 12 others in order to make a second major and that petition was approved so I actually did get to simply drop a departmental requirement by articulating why I wanted to study something else and not all students realize that they can do this but they can do this with a very good intellectual justification rules can be bent or broken okay number three why can't we just send nuclear waste to space we could just send nuclear waste to space and get it out of our hair it would be expensive it costs a lot of money per gram to get something off the planet someone has to agree to pay for it and what worries me most is what if one of those missions goes wrong what if you're launching a rocket full of the world's worst nuclear waste and something goes wrong at the launch and then it comes back down along with a rocket explosion then you have contaminated the planet so I personally believe in containing nuclear waste where we can see it rather than blasting it off into space and contaminating space unless we know where it's going and that nothing will go wrong as a lot of folks are worried about the dangers of radiation how are we gonna deal with nuclear waste and I don't fear nuclear waste but I've got a healthy respect for it and that whatever we do with it has to have the lowest probability of getting out and contaminating anything I think is a necessary thing to make in order to make nuclear power so if we want to make almost unlimited carbon free power we're going to make waste in the process you can't fight thermodynamics you're always going to have some waste of energy or something else but then what you do with it has to be very carefully considered and it sounds simple to blast it into space but then you have to think what could go wrong and who could I hurt if it goes wrong number four what do you think about the cultural and political idea against nuclear power to me the current cultural and political idea against nuclear power is not grounded in fact it's grounded in emotion and I've talked with a lot of folks who either know very little or very much about the physics and engineering of nuclear power but I find more often than not it's an issue designed to rally a base strangely I've never really understood this so many environmentalists are against nuclear power and I'm an environmentalist - which is why I'm for nuclear power so I find the anti-nuclear sentiment to be so strongly democratic and the pro-nuclear sentiment to be so strongly Republican neither of which is for reasons which I'm willing to accept they seem to be more about political tribalism than fact and it's interesting now that for the first time since we've had Chernobyl disasters and such more and more environmentalists are coming out in favor of nuclear power not because they're in favor of radiation and waste and such but the goal is to prevent climate change I would much sooner take a risk of something going wrong with nuclear power then definitely lose the battle to climate change everything to me comes out to minimizing risk to human life and maximizing quality of life so to me the risk of nuclear power is that if we can go all carbon free for energy we can reverse climate change if we refrain of using nuclear power for fear of the wastes getting out or the risk or the weapons then we're automatically losing the war and we're going to have an uninhabitable planet anyway and we can't get off this planet yet and then we'll go like then the same mistakes there's a good here for example I came into this department wanting to study fusion felt it wasn't ready yet so I spent a lot of my time on fission thinking this is going to be the bridge to fusion because fusion promises more carbon free power with far less radioactive voice but not none and I'm willing to accept the sum so it's not to lose the climate change battle which is already at our doorstep I do worry that many environmentalists lose sight of the real goal which is protecting the planet and to me protecting the plane that doesn't mean do no harm it means do as little harm as possible while preserving our quality of life number five while learning occasionally you'll have these moments where all of the sudden that dot suddenly connect and a previously challenging topic becomes seemingly perfectly clear to you could you share with us one of your brain blasts let's see for me it's the same one that most students get at about the one month mark in my class and that's energy is matter that equals mc-squared you see it on shirts all over MIT it's probably the one equation that everyone in America knows but not a lot of people really understand it that the conversion of into energy through ionizing radiation is the movement of energy from one form to another matter is a form of energy and once that clicked everything seemed to make sense radioactive decay nuclear reactions all these things I remember that aha moment in this class that I teach as a second-year student back in 2002 and it's those kind of moments that maybe want to stay in it today I feel like well I really know this field now if you're interested in learning more about ionizing radiation we've got all of Mike's course materials on our site you can find us at ocw.mit.edu [Music] in his OCW course page made especially for educators you can find all sorts of different instructor insights on our educator portal at ocw.mit.edu slash educator until next time I'm Sarah Hansen from MIT OpenCourseWare