Elizabeth Benham on the Metric System and Measurement

the late 1700s, let's set the stage. We have many countries that are operating with different measurement systems, and sometimes even amongst cities. That was very frustrating, not only for trade and commerce, but for science and communication. So really, the metric system emerged out of this common goal. We need something that is universal. We need something that is simple. We need something that is based on nature, not royal artifacts. So that was really the premise that set it all in motion. Hi, welcome to the Science Fair Podcast. I'm your host, Susan Keatley. I'm a PhD chemist, writer, and I love talking to scientists. On the Science Fair Podcast, I aim to bring you conversations with scientists doing fascinating, cutting-edge work on all kinds of interesting phenomena, ranging from physics to chemistry to biology, and even the nature of science itself. In this third season of the podcast, every other week, two episodes will come out. On Mondays, there will be a shorter, 10-minute episode, linking the scientists' research to what's happening in the classroom, and then on Thursday, the full-length interview. So come along and tune in for some Science Fair. Our guest today is Elizabeth Benham, who is joining us from the National Institute of Standards and Technology, also known as NIST, and that is in Gathersburg, Maryland. Elizabeth is a physical scientist and leader of the NIST metric program. In this role, she serves as the National Advocate for the International System of Units, known as the SI in the United States. And as the NIST website states, the metric program supports businesses, officials, educators, and the public, in understanding and applying the SI across commerce, education, and daily life. And in Elizabeth's words, she is inspired to improve science communication and literacy through the SI, which is truly the global language of science. It's a standardized way of making measurements that the global community agrees upon. Our timing could also not be better as this episode will air during metric week in the United States, which is October 5th through 11th this year. So Elizabeth, welcome to the show. (upbeat music) - Hello Susan, it's wonderful to be joining you today. - So Elizabeth, I'd love to start by asking what led you to a career in metrology, which is the science of measurement? If I was to ask any of my colleagues, I would probably get as many answers as I have colleagues, because there is really no one pathway to entering into this field. And instead of what do you think, a direct path from point A to point B, it's really more of a journey. And I think students should feel free to know that that is the case. You're going to build skills, knowledge, gain experience through everything that takes you to a career. So I'll share a little bit about my journey. I started, I think, being aware of measurements when I was 16 years old. I just gotten my first car, my keys, my driver's license, like, whoa, I've got to have a way to pay for fuel for this bad boy, right? And so I need a real job. So my very first job was at a fabric store. And my role in that job was kind of twofold. I would cut fabric or notions, elastic ribbon for customers. And then I would work as a cashier to charge them for that amount of product that they were buying. So at an early age, I started to recognize why measurements are important in trading commerce. From both the customer's perspective, I need a certain amount of fabric or ribbon, whatever, for a project, versus the business owners perspective where they really wanted an accurate measurement. So they weren't giving away product. So what would happen in a typical scenario is someone to bring a bolt of fabric up. And I would say, I need a certain amount. Let's say it was, I need a yard and a quarter. So, or a yard and one eighth. So very quickly, I had to learn about fractions and mate doing this mental math and estimation, all very important skills. But not only that, I had to translate those fractions into decimal fractions. Because when you're working at the cash register, that's what you would type in are the decimal fractions. So let's say a one yard and an eighth is 1.125. You're constantly doing this mental math. You really, I found that I built up this set of estimation skills. I could see on a bolt of fabric how much I thought was still there. So, and I also learned techniques. And one of those is to help straight, can I cut? Very straight. Because a customer needs a certain amount of fabric. And if you kind of veer undercutting, they might not have enough to lay out their pattern to make the garment they're sewing. On the other hand, if you veer too much and give them too much extra, that's a loss to the business. So being able to make measurements, make estimations, and then if you made an error in that mental math translation, and a customer gets overcharged, well, you're going to have an unhappy customer. So making measurements, seeing that importance to trade and commerce is something I learned very early. And I really enjoyed doing that kind of work. In fact, I did it quite a ways through college. And I would also reflect on another experience that I had. This was later when I was an undergraduate. And I was taking a class in pharmaceuticals. And basically, that's working in a laboratory and compounding medicine. So it could be making a tablet, a cough medicine, or something like that. And kind of first off, what they present you with are all of these units you have never heard of. What is a gill? What is a minimum? What is a dream? What is a grain? You know, these are very old fashioned, what I would call customary or non-SI, non-national system of units, measurements. And it's sort of like, initially, it's trial by fire. What are all these all units? All of these converting between them. And then you're like, when you think, stop the madness, we start using the metric system. Yay! Grams. Kilograms. Milligrams. You know, leaders. Milliliters. Microleaders. It's like, oh, you know, chef kiss. Like everything that you need is there for you. And so, like, sort of, I remember that, you know, again, a very pivotal part in my education. And then my first role as a metrologist. I started as a measurement scientist in Oklahoma at the Department of Agriculture, Food and Forestry's Bureau of Standards. So which was in the way, it's a Measures Department. And I worked with a wonderful team of other scientists that mentored me. And I really didn't understand until that point truly how much a state's economy depends on measurements. And even in our laboratory, we're really focused on kind of a very narrow scope, mass, length, volume, a little bit of thermometry. So, you know, the core of things of buying and selling, you need these measurements. And I learned so much about the companies that operated and the needs of customers, how to run a laboratory so that we could have confidence that the measurements going out the door were trustworthy. They were accurate. And that we didn't always know how someone would use them, but we knew we were giving them the information they needed. And oftentimes, that was on a calibration certificate where we're communicating the findings of our measurements using units and symbols that are from the SI. And so, take an example in Oklahoma. You might think. You might hear that little twang in my voice. It just comes out sometimes. But we're in the smack dab in the middle of the country. You think agriculture. You think oil and gas. Things that come out-- but we had such an amazing example of industry. There were manufacturers of car tires. They're using metrology, measurement science. We had pharmaceutical companies that are making supplements and vitamins. We had companies that were manufacturing gypsum board or plywood, baby diapers. I mean, the gamut, besides aeronautics and other higher tech fields. So I really learned with that, working with so many customers, how important measurements are for our economy. And then when I came to NIST-- and Susan, it's been almost 20 years. I was able to bring that local state level public service in government to my experience here at NIST. When we're here at NIST, the National Institute of Standards and Technology, we are part of the US Department of Commerce. So here, it weights some measures. Our bread and butter is trading commerce, making sure that transactions are fair for both the buyer and the sellers. That is such a wonderful story. Thank you for telling that. And I love the visual of Oklahoma and all of these different industries with their very unique measurement needs. I love the mention of those specific units in your class, especially the dram. I think that's maybe the only one I've heard of. But it reminded me a little bit of my mother, who knew all of the conversions, quartz, pint, gallons, ounces. I think she even knew for dry weight how many grams were in an ounce. She just knew this from cooking. She also did a lot of sewing. She was much older. She was born in 1934. I think that generation-- they were very aware of measurements and weights in a different way. I remember learning that the metric system came out of the French Revolution. And finding that fascinating. And I actually was reading a book. It's called Beyond Measure by James Vincent. And he quotes a historian, Eric Hobb's bomb, who said, in some way, the metric units are the most lasting and universal consequence of the French Revolution. Can you talk to us a little bit? How did the metric system come to be and why? And what did it look like at first? As you mentioned, the late 1700s, let's set the stage. We have many countries that are operating with different measurement systems. And sometimes, even amongst cities, that was very frustrating, not only for trade and commerce, but for science and communication. And in those early days, some of the first units that were important again for trade and commerce were buying and selling things by length. So the meter was very important. And one of the initial ways they were defined were by these prototype artifacts. So a platinum bar with two marks on it and the distance between those two marks by definition was a meter. Another unit that was important was for mass, the kilogram. Again, early definition was one liter of water at four degrees Celsius. But the way we actually realized that the definition was tied to another physical item, a cylinder of platinum meridian metal. Both of these were housed in France. They could be damaged. They can change over time. So it was a good starting place. And one of the things I love about the International System of Units is that it has changed with us over time as measurement challenges presented themselves, as technology improved, as we've gone through multiple paradigm shifts with the industrial revolution. So that kind of history of it all. And what is always driving us forward. And one example of that, I think, is you can say prefixes. So to back up, I'll talk about the way that we can increase or decrease the magnitude of a quantity. We do that with prefixes. When the metric system was initiated through the treaty of the meter, we only had eight prefixes. As hard to believe through the 1960s, '70s, '80s, '90s, I think we gained 14 more. Wow. And in 2022, we gained four more prefixes. Why? Our technology was improving. We needed to measure larger and smaller measurements. So here in 2022, I just love that we keep improving the SI. We have these four new prefixes. I will try to get this right. Rano and Quetta, for the very large quantities, 10 to the power of 27 and 10 to the power of 30. And on the lower scale, Ronto at 10 to the minus 27 and Quetta 10 to the minus 30. So with striving that today, well, big data, really large numbers, AI. So we, as a scientific community, anticipate these needs. And so we can expand the SI and refine our definitions and how it works based on the technical challenges that we're experiencing. And I really do love that. It's just one of-- I think the benefits of the international system of units. I did not know about these new prefixes. That is super cool. My son loves to say he's going to do something so fast. He'll do it in an auto second. But I'm going to have to break the news to him that we have a smaller prefix now. Absolutely. He's eight in loves that he knows what an auto second is. But he's about to learn more tonight. Right. And so just to go through-- so there are seven measures. What do you call them? Seven units in the metric system? So seven is an important number. And when I learned the metric system, the SI, I really didn't learn in this way, because there are really just a couple of important elements to the way this system is organized. So now, we have seven fundamental constants, which we call the defining constants. Right. We have seven base units. And that is the second, the meter, the kilogram, the ampere, the Kelvin, the mole, and the candela. So by using technical methods and procedures to derive these seven base units, we can then mathematically derive more units. We have some units with special names, like the jewel, the Newton, so forth. You also have units that don't have special names. Let's say, like, for length, we have area, a square meter. For volume, we might have a cubic decimeter. And we might have a special name for that one called a liter and so forth. So that is a system. It's a coherent system. We can describe just about any measurement quantity that we need. And we can use our SI prefixes to increase or decrease the magnitude using the power of 10. When I say to a student, yes, it might seem challenging some of these units. But you need to be familiar with the whole system. You need to be proficient. But you really need to know what you need to know when you need to know it. So you can start with small bits and apply it to your, let's say, your everyday life. In 2018, the actual cylindrical kilogram was done away with and replaced by a definition that is based on these constants. So that was the last-- was that the last physical object that was sort of part of the older representation? So in 2018, and then implemented in 2019, we had this fantastic occurrence called the redefinition of the SI. And so interestingly, at that time, four of the seven base units got new definitions. based on what's called a meson-practique, a fundamental, a practical method of deriving these seven-based units, using those defining constants that are, you know, based on physics, they're the same anywhere on the planet Earth or in the universe. And we can use those and through scientific techniques to derive our units. And so that was the-- those four, let me try to remember, Kilogram, Ampere, Kelvin, and the Mole. So, most famous, as you mentioned, the Kilogram, right? That physical artifact, that cylinder of platinum oridium metal, that was-- you know, like anything, it could be scratched, it could be damaged, it could be dropped. So, moving this huge paradigm shift from these physical objects to these measurements based on physics and these defining constants was a game changer. And that allowed, you know, what we're seeing happening today is allowing measurement scientists from not only like the NMI level, the National Measurement Institute, like here we are at NIST, but down into industry to other calibration laboratories. So, truly, measurement system for all people for all time. That's where we're at today. So, when I started, you know, I learned a principle of a balance, right? One of those pans in your balance would have a known mass. Let's say it's a Kilogram. And on the other balance, you would have an unknown mass. That would be in a calibration lab. That would be your customers weight their mass standard. And by gravitational force, you would compare those. And you could add little bits if there was-- and kind of determine very small differences between the known and the unknown. So, essentially, that's what we do today on mass comparators or scales. So, in 2018, 2019, with the redefinition that all change. Now, we're comparing mechanical power, again, gravity, but using this instrument called a kibble balance and comparing that to electrical power. And using Pallink's constant, one of those fundamental constants of nature, to calculate that math. Now, the physicist at NIST have developed a fabulous video that explains this better than I ever could. And I will definitely share that with you, Susan. You can share that with students to get into the nitty gritty of the physics of it. So, a cool thing, too, if you were to visit NIST and see the kibble balance experiment that kind of led to it all, it is in a huge-- a laboratory, quite large. It would tower above you. I love this working at NIST. The collaboration of our researchers with the US Army and US industry to take that huge kibble balance experimental concept and make it smaller, more affordable, to move that to the marketplace. So, they've had this first tabletop kibble balance, very small. So, you could measure or realize smaller quantities, let's say, it doesn't have to be a kilogram. It could be 100 grams. It could be 10 grams. But it's on a tabletop. It becomes affordable. And in the very near future, other industry calibration labs will be able to purchase this type of instrument and have very small uncertainties. It's just really exciting time to be alive and to be a measurement scientist. That is really cool. So, the idea is a lot of the older balances and scales are kind of still based on that solid metal kilogram, ultimately. But now we're all transitioning to this different kind of scale or different kind of balance called the kibble. And that's using current or in a magnetic field. Yes. Yes. And measuring the current and the voltage. Yeah. And interesting, like at the very top echelon of what we call traceability, the international system of units is sort of an unbroken chain of measurements. When you first realize the unit, in this case, the kilogram, we would have a very small uncertainty, little bit of air just because of the process that we're using, that measurement technique. And then we're calibrating an unknown standard. That is used in subsequent measurement comparisons. And that may use a traditional mass comparator and later on down as scale. So, where we go from the NMI or a calibration laboratory to a scale in a measurement or manufacturing facility or a grocery store where you're buying your bananas and apples. So, that infrastructure doesn't necessarily have to change. But all along that chain, we have improved that measurement uncertainty. And-- That's interesting. OK. --we still need to choose measurement devices that are fit for purpose. Is this the best equipment for the job? Do I need a kibble balance on a manufacturer floor with a lot of vibration and uncontrolled environmental factors that is changing the volume of my kilogram as it increases or decreases, depending on the temperature, probably not. It's not fit for purpose. So, but it's, again, this is a major paradigm shift of thinking of the way of how we get measurements into the marketplace for again trade and commerce, health, quality of life, all those things. Yeah. That's really interesting. And so, you know, even no matter what kind of skill you're using because of this chain, they're all going to be more accurate as the original definition is more accurate. And we can trust that measurement when we have that S-I traceability in place. Yes. I notice-- so I will definitely link to the video about the kibble balance. And I also notice there was a video showing how to build one out of the LEGO, which I will link to as well. Very cool. So I would love to ask you to tell us a little bit more about the metric program and all the different things you do. Every day is different. We are a very public facing program. We work with a variety of stakeholders. That could be a parent, a teacher, an educator. That could be someone from the government. That could be someone from industry, a small business person. It could be anybody. And I love that. So we're in a unique position here at NIST because we have so many subject matter experts. And I would say back to my education journey for students, building your network, meeting people, and being able to develop-- you don't always have the answers. And I'll be the first to admit that I don't. But you know, I might not know a guy or a gal who can connect you. And that's-- so like your professional network is incredibly important. And being, again, customer service oriented. So we provide a lot of technical guidance and professional development training. We publish lesson plans for educators, technical guidance for manufacturers of devices, equipment, products, and services. We help solve problems. We work with supporters of metrication and like the US Metric Association. And people are out there advocating for changes. So I love that. We make resources that educators can use in the classroom. One of those-- I'll show you here-- is the NIST metric ruler. This is approximate ruler. It's included in our free SI teacher kit. Every educator in the US can request one of these per year. And they'll get a classroom set of these rulers. So they're about 30 centimeters, great for experiments that you might be doing. And so it's resources like this classroom activities. We have a card game called the SI units card deck, where you can practice those relationships between the fundamental constants, the seven base units, the drive units, and even your prefixes. So I like the gamification of learning. It's always fun to be competitive. And practice makes perfect. Really applying your knowledge is really how you grow. And another one, building your skills. We have a new activity called the metric estimation game. So it works around the basic units we use every day, mass, length, volume. So it gives students a chance. to build their proficiency, their confidence, and making these measurements that kind of impact our everyday life at a kind of a human scale, so to speak. What are some misconceptions about the metric system that students might run into or even the general public might have? Susan, that's a great question. One of the primary metric myths that's floating around out there is that the US does not use the metric system. And I will say that is not true. It may not be mandatory, but we have been metric since 1866. That's when it was legally allowed to be used in the United States. And interestingly, yeah, 1866. Think about where we were. Post Civil War. The legislator that said we need to adopt the metric system was actually a US representative from the state of Iowa. The act was actually named after this legislator, the Cassanne act. And they were very concerned that of trade about trade and commerce and exporting grain and products from the heartland internationally, so exports. So very early on when the treaty of the meter was being formed, you know, the US decided to be a signatory to this. And here we are 2025, 150 years later. So the US, it has this long legacy of using metric measurements, but it's often been hidden from the public. And analogy I often use is the iceberg. Everyone's seen the movie Titanic. You're looking off in the ocean, you're like, whoa, what's that little bit of ice floating there? No warning warning warning. The most of the ice is below the surface, right? So here, let's compare that to being a consumer perhaps in the United States. You may see products being bought or sold using gallons or feet or inches or a temperature being described in degree Fahrenheit. But below the waters level where we have the bulk of the infrastructure in this country, the traceability to the SI, the processes and procedures and techniques that are used by US industry to manufacture products. That's highly based on the SI, of course, depending on the industry sector. We have some that are more rooted in legacy measurements versus others. Like if you take, and I, one thing I love about the SI2, what we see really driving this is a change in technology. Let's say early 2000s, we had a hydrogen energy and alternative fuel coming into the marketplace. Well, guess what? When you buy hydrogen, you're by it by the kilogram and you're dispensing it into your vehicle at a certain pressure measured in pascals. At the other end of the continuum, you may have some legacy measures and some kind of everywhere in between on this continuum. But as we advance, we see more and more adoption. So, you know, don't judge a book by its cover. There's a little secret there, a little tantalizing to bet we're using the SI more than we think. That is super interesting. With medicines, they're usually in milligrams or micrograms. When people do distance runs, they're often 5Ks, 10Ks. So, I do feel like it comes up even at our consumer level of life. Increasingly, that is true. And I appreciate you bringing up something about our everyday life, because I've really been highly focused on STEM applications in our conversation today, science, technology, engineering, and mathematics. But really, measurements impact us just as everyday people, everyday citizens. And, you know, someday you may a student out there and be like, I'm not going to go into STEM. I may be going into the technical trades. Well, guess what? You're going to need to know about measurements. You will be a consumer of health care. You're going to need to know about measurements to advocate for yourself and your family. Likewise, you may become an entrepreneur or a decision maker in some industry sector. And you're going to need to know about measurements. So, I'll just use a scenario. Let's say we're entering cold and flu season, right? Unfortunately, and you wake up and you're not feeling well. You wake up your parents and we stumble downstairs to the kitchen. And one of your parents pulls out the drawer and they are like, oh, I remember something about teaspoons or tablespoons and they're, oh, what is that? What is the abbreviation? TSP? Tee, what is that? And they're like, oh, something like, should I use, you know, just a spoon? And a really cool thing, I think, to remember a little bit of a iteration. Spoons are for stirring, but milligrams are for medicine. So this kind of goes back to this skill you need, just as an everyday citizen, as a measurement scientist, choosing the right tool for the job. So a spoon out of your drawer is not going to cut it. These are not made to be measuring devices. They might be too big or too little. You can ask your pharmacist if a measurement device does not come with your over-the-counter medicine for a proper dosage dispensing device. So with your cough medicine, it might look a little something like this. Yes, it says 10 milliliters. One line, very simple. I just have to, you know, I'm groggy, you know, pour in 10 milliliters. I am good to go. You know, I know I'm getting just the right amount. I'm not over-pretentially overdosing, risking a health consequence, a negative health consequence, or under-dosing that I'm not going to get better in time because I'm not getting the right amount to be effective. Even for small children, you know, a little device like that, getting medicine in a baby's mouth is like an Olympic event sometimes. And you can really get the right amount because, you know, infants and elderly people are very sensitive to medicine and it's important that they get the right amount. So I think, you know, that's an everyday measurement that we can all identify. And why it's important to us to be confident in making measurements using the SI. Yeah, I love that you say spoons are for stirring. I do, you know, when you think about the random, if you looked at a neighborhood, all the different teaspoons they have on the drawer, yeah, I'm sure that, you know, getting it to be a perfect teaspoon was not part of the design of common tableware. It's also interesting when you think about volume. Something that's cool about the SI is that let's say let's take a cubic decimeter. And I'll start with my metric ruler. 10 centimeters is a decimeter. So imagine you had a cube that's 10 centimeters by 10 centimeters by 10 centimeters cubic decimeter. We have that special name called a leader. So it's important to be able to kind of visualize that. But you could take one one thousandths of that as a special name is called a milliliter. So, you know, here I have a 500 milliliter bottle of water and I know that, you know, kind of I can visualize what that quantity is. So in the metric system, the SI, I can measure volume of solids, liquids, gases with, you know, my cubic units. However, compare and contrast that, how frustrating it. I was talking about gills and minems and drums and all that a while back. But also, it's like there's in the non SI units, US customer units, we have a dry system of volume. We have a fluid system of volume and we have these other historic units like special things for certain products like firewood, like a cord. You know, oh my gosh, right. Yes. I have heard of a cord. Yes. Yes. So it's like, you know, again, chef kiss to the metric system for making it easy and simple and like it just is everything you really need. I want to talk a little bit about science literacy and the SI. How does the SI help with science literacy? One of the most important facets of science literacy, I believe, is communication. Effective communication where we can also prevent miscommunication. Like, are we on the same page? So we're talking about health care. Do I understand the measurement units from my physician? Is that being translated and communicated effectively to my pharmacist? And then to me in the dosing. So there are all of these changes and anytime you have this, you know, exchange, there's an opportunity for an error miscommunication. And so we have to mitigate that risk. When I'm And my career as a measurement scientist, my role was to perform calibrations and provide them to my customer in a very clear and concise way. And as a researcher in a university or an organization like NIST, you would need to communicate your measurement results, maybe even your science fair, right? Two, other researchers, the beauty of the SI is that we have a standard style and rules that help describe every aspect of this communication and writing. Where we use, for example, the same unit symbols in any language. I could be speaking French, I could be speaking Japanese or English, and we would use the same unit symbol for the second and all of those. We may have different words if we're writing a sentence and talking in our native languages. But when it comes to communicating, I mean, that puts us on the same page instantly versus abbreviations for non-SLA units. Wow, there's a plethora of those. And because they are kind of based on language, it's really an opportunity to introduce a communication error. So, I think that's really one of the strengths of the SI and why it has been adopted, you know, everywhere. Yeah. And I think that people take for granted the gift of standardization. I think in certain medical fields, you know, the way people would interpret pictures of cells or tissues would often be very different hospital to hospital, country to country. And I know right now there's a lot of work being done on the microbiome, which is kind of the idea of all of these microorganisms all over our body. And there's a huge worldwide effort to standardize some of the data collection and interpretation, because there's a lot of disagreement. But I think maybe people just assume that when in certain fields of science, everyone kind of agrees on the results, and it's not true. But the metric system is this wonderful system where everybody pretty much agrees what a kilogram is or what a meter is and how we take those basic measurements. So, as you glean from our name, National Institute of Standards and Technology, standards are very important. They allow us to get on the same page and agree on a technique or a design specification so that we do have this common playing field. Whether, for example, let's say I am a customer and I am going to laboratory A and I get a measurement result and I know that they're following nationally or international standards for a technique or a procedure, a method. And I go to another laboratory and they are following the same procedures that I have and working within a accredited laboratory structure of a quality management system that I know I can trust those measurements and that they are going to be equivalent and that I can use them in my business, in my measurement process, in my research and have confidence in those measurements. So, standards are essential. Yeah. And we're lucky that we have such an effective global system. As we wrap up, you had mentioned some tips you had for students and teachers, but I would love to talk more about them now. What have you found most useful to help students really internalize the metric system and help teachers achieve that goal in the classroom? That's a great question, Susan, and I will share with you a blog that I wrote a few years ago, the top 10 teaching tips for the SI. And I think one of those is to build your estimation skills. I noticed a recent podcast that you had was on the scientific method. Having estimation skills are very essential when you're doing the scientific method, being able to make an estimate at the beginning of the process, you're making a, you're developing your hypothesis. What do I anticipate or expect to get out of this when I get my data, my measurement results? And so kind of having a ballpark of what that's going to be in a quantity that you're dealing with is very important. Being able to know, am I close or am I way out and left field? So that kind of understanding a quantity and being able to relate to it. And of course, practice makes perfect. We will, you know, learning the SI or any measurement system or a technique. At first, it might be a little rough, but as you practice, as you apply, you're going to be, aha, I'm getting this. And it becomes easier, you become more confident. And it becomes fun. And I would say one of my other top tips is make it fun. This is not a mathematical exercises. This is getting your hands dirty, getting some measurement tools, a ruler, a scale, you know, some some volume measurements and experimenting and making measurements and figuring out how it's done. I, one of the challenges I think for a student and hopefully the students that are listening to the program are thinking about their science fair. We're getting ready to go into science fair season this autumn. And let's take, let's say an idea, I have an idea that I'm going to use volume for my science fair project research. So I go into my mentor, my teacher and I ask, what kind of volume glassware do we need? Do I have? So in the scenario, let's say the teacher says, yes, I have 1000 milliliters, graduated cylinder, I have 500 milliliters, graduated cylinder, I have a 100 milliliters graduated cylinder. So we're down to a baker. So I have four measurement instruments that I can choose from. What's going to be the one that's best for the job, especially if I am measuring a quantity of around 1000 milliliters or one liter. So kind of working that out, if on all glassware, and this is plastic, but you will have, is it too delivered to contain what is the conventional temperature you should be using that, typically 20 degrees C. But if I was to measure my quantity with this and deliver it one drop, I have delivered let's say 1000 milliliters. If I move over to my 500 milliliter graduated cylinder, I have to do two drops. I have just and I've done it twice. So if there was any kind of error here, I have doubled it by that. It accumulates and there's a mathematical way we can calculate uncertainty. Let's take, I keep going. I've got 100 milliliters. That's 10 drops, one little bit of error. If I was only measuring 90, well, maybe this is the best tool for the job. And then these are level, I can read them in this case. I have really practices by technique. But then I have the choice of a beaker. Yeah, it says 1000 milliliters too, but why is this a bad idea? Take a look at the diameter there. Your your meniscus reading, you're really going to end it, you know, it is very hard to see where that is level. And so you have maybe introducing an error. So it's these kind of small, small choices you make as a science fair, participant, you're going to need to be able to explain this. What were your measurement techniques? What are the strengths and the weaknesses with the experimental design that I chose? So when you're defending that when the judges are coming by, it's a great opportunity to dive into those measurements. And I will say for a really cool thing that's out there, nationally, statewide and even in local communities, the US metric association has an award for students for science fair, for the best use of the metric system in their science fair. So that's available on their web page. And they have this really cool guide, a bit of a checklist, so to speak, where you can say, what are the common mistakes observed in science fairs? So this just figuring out what those are when you're communicating measurement quantities can really elevate your work. And another cool thing that I will just mention while I'm on the topic, the US metric association has an award program that's available for high school seniors out there. And it is for promoting the SI. And guess what? It's like $2500, I think, for first place. And that's, I think there's also a second place. So there's really a lot of resources, not just from NIST, but but others out there for students. And I reflect back again my early days in high school when I, you know, do a science fair. It is so fun. You will meet a lot of cool kids. You will make friends for life and you will be able to build skills, you know, public speaking and working through problems, doing data analysis, critical thinking, problem solving, all that good stuff that's going to serve you well, whether you become, you know, a STEM professional go into a technical field or just be, you know, just your average citizen. Yeah, yeah, and it's important in both. Well, I love that demonstration. It really makes you think about error and number of times you do something and how a small error can propagate. And if you want to get a really good result in your science fair project, you probably want to minimize the error as much as you can. Yes, and practicing your technique, like it comes down to, you know, that technique of reading a meniscus, you think that is very basic, but you do that over and over again, you're going to get better. And so you're going to minimize that kind of process issue. Just one last question. This is the question I ask everyone, which is what advice, what general advice do you have for students who are interested in science? Gain experience wherever you can. One of the experiences that we have here at NIST that I would recommend students from across the United States to apply for is our summer undergraduate research fellowship. Surf for short. It is an experience we come for about 12 weeks during the summer work full time at one of our campuses like here with me in Gatheresburg, Maryland. And really work supporting the research with scientists, engineers, and get an insight to what it is to be like working on a team, having constraints, deliverables, and also a little bit of what it's like to work in public service for, you know, your country and for your economy. And other programs that we have include the PREP, Program PREP, Professional Research Experience Program. And that is a program, it's not just limited to the summer months. It is in cooperation with a group of universities around the country that with NIST. And you work part time with a researcher. It's often working on smaller projects maybe for longer times. If you're going to school 15 hours a week, you're taking a full load. 12, 15 hours, part time is perfect. And so I currently have a student from a local community college working with me, Montgomery College. And she's amazing, her name is Yoon. And surprisingly enough, Yoon is not a STEM major. She's a communication major. I also have worked with students that have an education background. So it's really a nice blend of STEM and and many other kind of degrees. But I'd say the majority of NIST internships, yes, are very high. And so I'm probably like the outlier. But you know, that's great. And for your teachers listening, another program that NIST has is called the Summer Institute for Middle School Science Teachers. Oh wow. Have you heard of that one, Susan? No, that sounds amazing. It is two weeks here at NIST learning about the innovative research that's going on in our laboratories. And how that's being transferred out into the marketplace where students will benefit from that because their teachers are going to bring home real live current examples of measurement science and how that's going to impact them in their studies. It is an amazing program. I've been doing it since I think it started in like 2007-ish and it's amazing. So please apply and those are all offered by our International Academic Affairs Office. That's amazing. Those are such great programs. Wow. Thank you for sharing those and I will find links for those and post them as well. Wonderful. Well, Elizabeth, thank you so much for coming on the show. Thank you, Susan. It's been a pleasure. That was Elizabeth Venom from the National Institute of Standards and Technology. Talking with us about the metric system, measurement, and all kinds of opportunities for students to learn more about the metric system via awards from the metric association or internships at NIST. Listeners, please consider filling out a survey so we can continue to bring you great content. You can find a link to the survey in the show notes of this podcast and you can also find it on the Instagram page the account is @ScienceFairPodcast. Thank you for tuning in to today's episode of Science Fair. Please rate and review the episode on the podcast app of your choice. 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