Systematic Errors: Stories about failed experiments

Many factors can lead to a failed experiment -- human errors, errors in measurement, and sometimes just random errors. In this week’s episode, both of our storytellers share tales of when their experiments didn’t go as planned.

Part 1: As a new science teacher, Zeke Kossover is determined to capture the attention of his students.

Marc “Zeke” Kossover has been presenting stories as part of his physics circus shows all over the country in venues from coffee shops and music halls to the National Science Foundation and Capitol Hill. He thinks of them as magic shows, but in reverse—the secret to a magic trick is to make something simple intentionally confusing, while Zeke tries to make confusing things easy to understand. Zeke was a physics and environmental science teacher before dying and going to teacher heaven and getting a job at the Exploratorium. His main work is helping science teachers have the resources they need to be the best teachers they can be, like designing novel hands-on activities for teachers to use in their classrooms and helping new teachers find their voices in their classrooms. He believes that science education starts when students construct their own understanding of the world.

Part 2: While on a field expedition in Kenya, Evan Wilson is tasked with the seemingly impossible job of figuring out the role of dust in wearing down herbivore teeth.

Evan Wilson is an archaeologist and paleoanthropologist focused on the dawn of technology and emergence of human culture. They study the interplay between technology/culture and biology via the Stone Age archaeological record of Eastern Africa. They have done fieldwork spanning the last 3.5 million years in Kenya and Ethiopia discovering both fossils and artifacts to better understand the deep human past and our evolutionary history.

Episode Transcript

Part 1

As I was walking out of school on a Friday afternoon, I ran into one of my students. He was that kind of kid who always had his feet up on the desk, but whenever I tried to call him out, he knew the answers to all my questions.

And I overheard him talking about me as I was leaving. He said, “That guy, he's the most boring asshole I have ever had as a teacher.”

I didn't even correct his profanity. He was right. Good teachers know how to find out what kids are interested in, find ways to make sure that they can't even avoid learning. But I was not yet that teacher, even after five whole days of teaching.

Zeke Kossover shares his story at the Exploratorium in San Francisco, CA in February 2023. Photo by Exploratorium.

Teaching is the only profession where they expect you on your first day to be as good as someone who's been doing it for 20 years, so I decided I need to do something to have a better lesson on Monday morning. As I was walking out, I saw the chemical storeroom which they had given a key to to a person who had been teaching for only five days.

I opened up the door to the chemical storeroom and it was filled with many dangerous things. There was hydrochloric acid on the shelf. There was concentrated sulfuric acid. There was sodium hydroxide. There was magnesium wire, but I was thinking that those weren't necessarily the kinds of things I would do on Monday. What I've been thinking of was an activity that I had seen my high school chemistry teacher do.

He had made a substance called nitrogen triiodide which has the interesting property that when you step on it, it makes a little purple cloud of smoke along with a small explosion. It seemed a perfect way to catch the interest of my students.

So I looked around on the shelves and discovered what I remembered to be the ingredients for it, which was iodine powder and concentrated ammonia. Now, this was a long time ago, before the internet, so I couldn't really look up the recipe or the safety concerns that went along with this.

You all are laughing. You didn't have the confidence of a mediocre, white guy to go with this.

So I picked up the things that I needed for it and left to go home. I was going to practice on this Friday evening and I was going to work all weekend so I would have the perfect lesson come Monday morning.

Now, the first thing I needed to do was to mix up the iodine powder and the concentrated ammonia. So I grabbed a glass mixing bowl out of the kitchen, brought it outside. You know, it's an explosive. I brought it outside and put it in the bowl, stirred it up, put down a couple of napkins, scraped it out of the bowl in the napkins into the driveway.

I knew I needed to wait. See, the interesting property of nitrogen triiodide is that when it's wet, it's completely safe. But when it's dry, then that's when it'll explode. So I've got a wet pile of it. I need to wait a while,

I wait about an hour. I come back and poke it. Nothing happens. I wait another hour. This time, I get a stick and I poke it and nothing happens.

I go back inside to start wondering what I should be doing next because I really want to be a good science teacher. Science had opened up my eyes to the world, let me see the world as it actually is. I wanted to help impart that to my students and so I was determined to be successful, but this was not working either.

So I got around to tracking down my own high school science teacher by calling a bunch of different people who led me to other people who led me to other people and I finally got him on the phone.

And so I'm asking him lots of information about how to be a good science teacher and he's going on with me. We talk for a long time, maybe 45 minutes or so. I finally get around to ask him about what if I want to do something a little dramatic in class.

He's like, “Well, what are you thinking?”

I say, “Well, I was thinking about making nitrogen triiodide. How would you might go about that?”

And he said, “Making nitrogen triiodide? I wouldn't make that.”

I'm like, “What if I actually really want to make nitrogen triiodide, what should I do?”

He says, “Well, I wouldn't make more than a teaspoon of it.”

I'm talking a tea teaspoon here and I'm looking at a mound the size of my fist.

“What other advice could you give me?”

“Well, when you mix it up, you have to be very careful that you don't leave even a crystal of it underneath your fingernail. Because when it dries under that, it'll blow your fingernail off.”

So I get off that call and I go to the sink and I wash my hands in a way that no one since Lady Macbeth has ever done and then I look out the window. And there's a pile of nitrogen triiodide there and somebody has to deal with it. That's going to be me.

So I think I need protective gear. I decided that a winter coat might be helpful. It's squishy. Then I put on an apron and I brought home a smock, so I put that on. I have a bicycle helmet. I put that on my head. I do have safety glasses so I put those on. But remembering the fingernail issue, I got a pair of yellow rubber dishwashing gloves to put on my hands and I go out to face the nitrogen triiodide.

Remembering that when it's wet it's safe, my thought was I just need to get it wet again. So I think to myself, I could just flood the driveway. I could take the hose and put it on the driveway and just send water everywhere. But if I do that and it actually works then I'm just going to spread the nitrogen triiodide everywhere and then I'm going to have to figure out how to clean that up. So that seems like a bad idea.

Maybe if I mist the water down on top of it then that will work. Like I can get it wet faster than I can agitate it. That was my goal.

And so I take the hose on the finest mist setting. It's become evening by this point. So when the water comes out of the hose and goes up into the air, it glitters like diamonds in the streetlights and it slowly flutters down and hits the nitrogen triiodide. It doesn't go boom. Boom is the sound of explosions when you're far away. It goes crack and then that is the last thing I would hear for many hours. I could hear nothing.

I look down and there are chunks of concrete all around me and a hole the size of a bowling ball. Then I assess myself. I'm dry and that is good in all the ways.

And then I noticed something else start to happen. The lights of my neighbors start to turn on, blink, blink, blink, blink. And there they see me standing there. I'm wearing a winter coat in October. I've got an apron, a smock, a bicycle helmet, safety glasses and yellow rubber dishwashing gloves. I'm just your local mad scientist. Don't worry about me.

The interesting bit about this situation is that it actually still had only been the outside of the mound of nitrogen triiodeide that was dry and so it did in fact spread it all over the driveway. I didn't know what to do but nature would solve my problem for me. I moved my car to block the driveway so that my housemates couldn't drive home and then it started to rain. And every so often, a drop would hit a little crystal of nitrogen triiodide and it would make a little pop and a little purple cloud of smoke escaped, just like I had damn wanted to have in my class.

I didn't work on my lesson the rest of the weekend. When I came in on Monday morning, I had prepared some notes and some transparencies to use in class. When I saw my first class of the day and saw their eyes roll with another boring‑ass lecture, I decided I couldn't do that again.

So I sat down on the desk and told them the story of my weekend. For once in those five days of teaching, I had their rapt attention. At the end, they had thousands of questions, and some of them were about chemistry.

Thank you.

Part 2

So, there I was on a research compound in Northern Kenya, my left arm in a sling, my right hand two knuckles deep in a coffee mug full of goat poop searching for dust. The year was 2016. I was a sophomore in college and I was on a human evolution field school in Northern Kenya exploring things like Lucy and Homo erectus and all that jazz.

It was my first time out of the country. It was actually my first experience doing science hands‑on and it was kind of crazy. It was immersive. It was amazing experience. Set me on the path that ultimately brought me here in front of you all tonight. Great time.

It was during the paleontology portion of this field school that we had a group project. My group was tasked with investigating the role of dust in wearing down herbivore teeth accidentally. So we wanted to find out the dust that animals were accidentally consuming. How did that wear down their teeth and how could we actually search for this?

My professor, an esoteric Finnish man with a long hair and a long beard and handlebar mustache, he suggested that we do this by finding a way to separate the dust that animals are accidentally ingesting from their poop and then somehow correlate this back to the wear on their teeth naturally.

Evan Wilson shares their story at Kraine Theater in New York City, NY in March 2023. Photo by Zhen Qin.

When we asked how we might do this, he suggested that we seek out a way. We find a way to pull the dust and the poop apart. Simple enough.

When we asked further how we might do this, and, mind you, we were in a very remote setting. We did not have access to the traditional lab equipment that you might expect so we had to get creative. He did not offer much guidance at all. In fact, he giggled, smiled amusingly and rattled off a piece of poetry by Rumi the Roman about the importance of aimless ambling in the discovery of new things. Essentially, he said you'll figure it out.

We had one week. At the end of that week, we would present in front of our entire class and our professors and share our results.

Now, day one was devoted to data collection, of course. So we went to the local herders and sought out the most abundant source of feces in the area, the local goats. We spent hours chasing them down with plastic bags in hand to catch fresh poop as it fell from their anus before it hit the ground. If it hit the ground, outside dust would contaminate it.

This is actually even harder than it sounds because, as I said at the time, just the week before, I had slipped in the shower while dizzy off malaria meds and I had fractured my wrist. So, one‑handed I'm chasing these goats down, trying to catch these pellets as they fell to the floor. Needless to say, despite our best efforts, we did not acquire the sample that we needed.

So we said, “Okay. Let's seize the means of production.” And Albus, the goat, joined the team as our ace pooper. The most consistent source of uncontaminated samples in exchange for dusty vegetation. Simple enough.

Day two, we attempted our first try at separation. We actually tried to emulate the very lab equipment we were lacking. So we tried to Jerry‑rig a makeshift centrifuge. For those who don't know, it's a machine that spins things really fast. And when it spins them, they come apart. I don't know why. It doesn't matter.

So there we were with a two‑liter plastic water bottle full of Albus's best poop soup stuffed inside of a tube sock spinning it around our heads for hours in the middle of the Kenyan desert. This resulted, of course, in multiple sweatily‑handed mishaps. Bottles of poop arced left and right through the air like rockets.

Ultimately, we ended up with not‑too‑nicely separated portions of poop and dust. Instead, we were left with a concoction that could only be compared to chocolate milk, if you ignored the clumps. Needless to say, we had no dust.

Day three was upon us. Day three we attempted something very similar. We tried to take it a step back, simplify it a bit. We went for a very similar thing without the manual labor. So we just poured the dust in and tried to let it settle a bit. It didn't work. Same result, who‑who.

Day four was even worse. We got the bright idea that if we couldn't physically manipulate the dust from the poop then maybe we could chemically disintegrate the poop from the dust. So we went to the kitchen. We acquired some coffee mugs. The staff was very pleased to see us. And we went to the first aid kit and we grabbed a bottle of peroxide. And with our bare hands, we started to break the poop up into a fine paste, pour the peroxide in and left it for a few hours.

When we returned, we had spoons in hand and hoped that we could just scoop that fizzy, bubbling, lovely layer of poop sitting on the top of this peroxide just right off and then we just filter the dust through some coffee filters, of course, and then we'd have our sample. We'd all be good.

Did we find the dust? No. Did I learn what peroxide‑soaked goat poop smells like? Yes.

Day five, attempt number four, we thought, okay, disintegration. It doesn't work. What if we incinerated the poop?

So we developed what we could only call the Baked Potato method. Taking some inspiration from classic campfire cooking, we bundled some poop up in aluminum foil that we sourced from the kitchen. Once again, the staff was overjoyed to see us. And we acquired a small pit charcoal oven and we nestled our bundles in the oven, passed them off to a nighttime security guard in the hopes that he could keep an eye on it and, in the morning, after some well‑deserved rest, we'd return. We'd find the dust we so desperately sought.

I woke up at 1:00 in the morning to what I know now to be the smell of burning shit and the hacking coughs of my peers and classmates. Of course, my group and I had some inkling of what might be happening here. The dorm was veranda style after all, all open air, and I could very clearly see an acrid, thick cloud of smoke billowing in from the direction where we were cooking our poop.

To play it cool, we pull the covers over our heads and pretended to be asleep. And for the next two hours our classmates suffered.

Bright and early, we ran out to the oven and we said, “Are our worst fears realized?” Of course they were. It turns out, the aluminum that we had sourced from the kitchen was not the highest quality. You had two, thin layers of aluminum and, in between them, one very thin layer of paper so, naturally, when the temperatures reach the necessary height, holes begin to burn in all of our bundles and dozens of goat pellets just fell right onto the hot coals releasing, like a volcano, a pluming crowd of poop smoke, destroying all of our data and leaving us, once again, dustless.

We realize now on our fourth day, as all of our fellow classmates and peers were making due progress, talking about results and interpretations, extrapolating on data, we knew nothing of it. We were frustrated and we went back to the drawing board.

The next day, the sixth day… fifth? No, it was the sixth day. The sixth day, we, in fact, ran out of brainstorming ideas. We could spitball no longer and we went to our professor and we admitted all of our failures. We detailed the lengths we went.

Surprisingly, he did not seem disappointed. He seemed amused, almost as if he expected it. He told us, “That's just how science goes sometimes. You fail and then you try and try again.”

So we went to our last resort. And Albus, the good goat that he was, donated his body to science. We took his gut remains and we shipped them off to Helsinki for proper analysis in a real lab, which of course meant that we had no data. We had nothing to report on. We had no results to tell our fellow classmates, but at least science was being done.

Dinner that night was delicious nyama choma, roast goat. Our classmates only realized who was on their plate the next day during our presentation, during Albus's eulogy. So, with a healthy dose of shame and with quite a bit of regret, we presented our results to our classmates detailing the great lengths we went in the disgusting avenues we sought to try and find this dust.

If this wasn't bad enough, right before we started presenting, the founder of the program and a legendary paleoanthropologist Meave Leakey happened to walk in the room, visiting the compound on a surprise visit.

She caught our entire presentation, including the end of it where our professor dubbed us the ‘Goat‑Shit Boys’, and, very much like him, she seemed not disappointed but amused. She laughed, chuckled the entire time and when we approached her afterwards, she looked at us and said very much the same thing. “Science doesn't always work out how you plan. It doesn't always go the way you expect. You don't always get the results you want.”

Basically, she said shit happens.

Thank you.