Instant Genius - How safety engineers test everyday products to destruction

Episode Date: October 1, 2026

Whenever we buy a new product or use a service, we simply expect it to work as advertised, usually without giving much thought to how it came to being in the first place. However, behind the scenes, every piece of technology we use, be it a toaster, a lawnmower or even the aeroplane we travel in when we head off on our holidays, has gone through a rigorous series of tests to ensure its safety and efficacy. This often-overlooked aspect of our everyday existence is carried out by test engineers. In this episode we’re joined by tech journalist and author Alex Davies to talk about his latest book, How to Keep a Plane in the Sky – Tales from the Wild, Unseen World of Test Engineering. He tells us how engineers design the products we rely on to perform well beyond any expected limits of use, how they build in safeguards to account for almost every eventuality and the great lengths they go to to account for human unpredictability. Take your curiosity further with a subscription to BBC Science Focus magazine. Every issue is packed with fascinating insights into the science behind everyday life, the latest breakthroughs and expert analysis, delivered straight to your door. Receive an extra £5 when you subscribe using the code SF5OFF, (minimum spend £20, see full terms and conditions on our website). https://www.ourmediashop.com/bbc-science-focus-magazine-pod30 Learn more about your ad choices. Visit podcastchoices.com/adchoices

New from Nespresso. Blend wellness into your coffee routine with a coffee plus range, infused with functional benefits. Choose the coffee you love with added B vitamins, like coffee plus B12 to help support immune function, and coffee plus B6 to keep your day moving. Or go with the flow and choose ginseng delight. Our new double espresso with ginseng extract. Whatever lies ahead, don't change your morning. Let your morning change you.

Discover Coffee Plus on Nispresso.com. from the studio that brought you WandaVision. I was an Avenger, but I'm not a hero anymore. On October 14th, the Vision returns for the final chapter of the groundbreaking trilogy. That family wasn't real. You sure about that? I had a father called Vision. How is this possible?

Don't miss the two-episode premiere of Marvel Television's Vision Quest. Nothing bonds a family together quite like Mortal Jeopardy. Streaming October 14th. Only on Disney Plus. Hello and welcome to Instant Genius, a bite-sized master class in podcast form. Every Monday and Friday you'll hear world-leading scientists and experts talking about the most fascinating ideas in science and technology today. I'm Jason Goodyear, commissioning editor of BBC Science Focus.

Whenever we buy a new product or user service, we simply expect it to work as advertised, usually without giving much thought to how it came to being in the first place. However, behind the scenes, every piece of technology we use, be it a toaster, a lawnmower, or even the aeroplanes we travel in when we head off on our holidays. It's been through a rigorous series of tests to ensure their safety and efficacy. This often overlooked aspect of our everyday existence is carried out by test engineers. In this episode, we're joined by tech journalist and author Alex Davies to talk about his latest book, How to Keep a Plain in the Sky.

Tales from the wild unseen world of test engineering. He tells us how engineers design the products we rely on to perform well beyond any expected limits of use, how they build in safeguards to account for almost every eventuality and the great lengths they go to to account for human unpredictability. So welcome to the podcast. Thanks so much for joining us. Yeah, thanks for having me. So today we're talking about your new book,

how to keep a plane in the sky. Tales from the wild, unseen world of test engineering. So we're kind of, you know, we're surrounded by technologies of various kinds that we use every day and we just sort of expect them to work. And when they don't, we get sort of really annoyed by them, don't we? But all of these sort of products and services that we use, hopefully, anyway, go through a rigorous process before they get in our hands.

And so this is the job of the test engineer. Yeah, the test engineer is in a world that's really big on founders and inventors. I think that test engineers are the unsung heroes of our technological age, and they're doing the work that takes something from, I have this idea to, you can buy this thing and be reasonably assured it's going to work the way you want it to work, and it's not going to hurt you. And they're the ones creating this unseen layer that underpins just about everything you buy, everything you use, every vehicle you ride in. Yeah, it is one of those things that you don't really think about.

So you talk earlier in the book about a sort of step-by-step process that can sort of, you know, is an overview of summing up the way that test engineers work. So to kick us off, can you just briefly take us through that? Sure. So test engineering, or any product test, takes about five steps. The first step is observe and imagine. This is where you think about what might actually happen to the thing I'm building. How are people going to use it?

How are people going to misuse it? Is it going to be really hot? Is it going to be dunked in salt water? What are all the conditions that you have to think through? Step two then is set standards. And this is where you think about what do you actually want it to survive? What do you want it to be able to handle? A rubber ducky doesn't need to withstand negative 100 centigrade temperatures without shattering,

but a Mars rover does. And so that's depending on your product, who the user is, and that's where you get things like a 10,000 mile warranty on a car, because that's the standard they've built that car to. Step three is create similarity. This is where you get into the actual nitty-gritty of the testing, where you think through how to create a test that mimics as closely as possible real-world conditions. So jet engine manufacturers, for example, they know that bird strikes are an issue,

and so they've got a cannon that shoots birds into their jet engine at 220 miles an hour. And so that's recreating those conditions. And then step four, though, is sort of the other big pole of testing along with similarity. It's something I call workability, which is you have to make sure that your test produces good data, that it's reproducible, repeatable, and practical. Right. So the other way to test the jet engine would be to fly it through a flock of birds, but that's not a reasonable way to do it.

It's not a controllable way to do it. You're not going to hit the same number of birds each time. They're going to hit different parts of the engine. And it's also expensive and dangerous compared to a cannon in a laboratory setting. And then once you've done all of that, you've got step five, which is judge the results. You have your standard. You have your test. Did the product meet the standard?

Yes or no. Yeah. So sort of that we can apply that process in, sort of different areas that you talk about in the book. So let's talk about a couple of those. So I think if somebody listening, you know, probably most people aren't aware of how this all works. But if they guessed, they'd say that oh, is this like limit testing, which is how you start the book. As the title suggests, you talk about planes in this section. And one of the things that I've seen videos of, which is pretty wild to see, is that, you know, the wing testing and

the wings really bend a lot further than you would imagine. So if anyone hasn't seen that, I recommend watching that. It's quite something to see. But, you know, thankfully as well for people who perhaps aren't too keen on flying, these tests go, as I sort of touched on there, way beyond what we'd reasonably expect the plane to experience in its working life. So what can you tell us about that? So there is a concept in engineering called the factor of safety.

And what you do with the factor? So to use the plane bending, plain wing bending example. So first of all, you want your plane wings to be flexible. Because if they were completely stiff and they hit turbulence, they'd be more at risk of snapping. You want some flex there. And that's what gives them their strength. And the way you create a factor of safety for plane wings, as our example, is that you think about what is the worst possible storm or conditions this plane might conceivably experience.

And you say, okay, in that storm, the planes would have to bend to, say, 45 degrees upward. The factor of safety then says you're going to take that as your baseline and we're going to multiply that more. So another example is, let's say, you're in an elevator, right? and it says, maximum weight of this elevator is 3,000 pounds. That's the limit it's telling you. And that's probably about as much weight as you could get in there, given how much people weigh.

But the factor of safety on that elevator is probably two or more, which means that the elevator could actually hold 6,000 pounds, even if it's telling you the limit is 3,000 pounds. And another way I like to explain this is if you're at the grocery store and they're packing your groceries and paper bags. If you just use one paper bag for your carton of milk and your bottle of wine or whatever, that's a factor of safety of one.

But if you double bag, that's a factor of safety of two. So to go back to the plain wing bending example, the factor of safety for aviation for most components is actually 1.5. And you might think, why isn't it like 10? Right. Why isn't this thing 10 times stronger than what it could possibly have to do?

And the reason is you have to be practical with these things. And if those plane wings were 10 times stronger or if every component was 10 times stronger than it needed to be, you're adding a ton of weight and you're adding a ton of expense and complexity. So for aviation, it's about 1.5, which means that if you bend the wings to the maximum degree where you think they're going to have to go, you have to go then prove that they can bend 50% further than that. It's essentially building in a big buffer of safety around what you think. And I think when you see something like max weight on a ladder

or max number of years this product will last, you can probably say like, okay, there's probably a factor of safety in here. It's a little hard to know what it is. But you can probably go a little bit beyond that without risking yourself too much. Yeah, so that's sort of in the book you talk about, I mean, two prongs that we can use when we're testing limits. So we sort of touched on them there. But how long and how strong? So can you just sort of run us through exactly what you mean by that? Yeah, when I talk about testing the limits of something, which is really, I think, the most fundamental kind of testing we do.

So when you talk about plane wings bending or how much weight an elevator can take or how much weight a bridge can take, that's what I call how strong testing. It is how much force can this thing take? Essentially, how strong is it? How long is the other way we think about limits, which is essentially how many times can you hit the space bar on your keyboard before it's going to give out? How many cycles can you do it? And one way I look at this in my book is I talk about the De Havilland Comet, which was a British jet, one of the first jet airliners built in the years after World War II. And the way that plane was going to fly higher than other passenger planes had before, and it needed to be better pressurized or pressurized to a greater extent to do that.

And so they had to run two kind of tests. They had to run the max pressurization test. If we put this much stress on the walls of the fuselage, where is it going to burst? But also they needed to think through cycles of testing, right? Because every time the plane takes off and gets to altitude, it pressurizes. And then as it comes back down to ground, it depressurizes. So you're putting cycles of stress testing on the cabin. And so a lot of products need both how strong and how long.

So sort of sticking with planes, like if we're talking about sort of, if I bet if you spoke to people saying what do, what do test engineers do? They'd probably say, well, oh, do you mean test pilots? So, you know, of course, like, if we're making something that flies, you know, some brave soul in a way has to be, or traditionally anyway, has to be the first person to fly them. So how does that work? So these days, I'm happy to say, and I'm sure test pilots, are happy to know that we have a really good knowledge of how to build a safe plane today. So by the time a test pilot is taking a new Boeing or a new Airbus up for the first time, that plane has been through hundreds and hundreds of tests and simulated hours.

But if you go back 100 years, 110 years to the early days of flight, we really didn't know that much about how to build planes. And because we didn't know that much about what actually happened to planes and the science of aerodynamics was very new, we didn't know how to properly test planes. And that's something you usually in the early days when you figured out a plane wasn't working, it's because you were crashing. It wasn't, you know, some flag in a computer system saying, actually, you know, this component isn't working as well as we thought it would. So you're going to have to rely on the five backups we've built in for it. So, for example, to talk about load testing on plane wings, how much strength can those actually take. It was done on the ground in the early days with sandbags.

You just put, you know, maybe you stand the plane up on a little stand, and then you put weight more and more weight onto the wings until they break, and you say, okay, that's about the amount of force they can take. So I guess I should stay shy of that. And that started to change kind of in the interwar years, where I'd really, you know, write about a guy named Jimmy Doolittle, who, if anyone remembers that schlucky movie Pearl Harbor from 25 years ago with Josh Hartnett and Ben Affleck and they were World War II pilots, Jimmy Doolittle in that movie was played by Alec Baldwin.

He led a group called Doolittle's Raiders, and they were the first American pilots to bomb Tokyo. But we're talking 20 years before that when Jimmy Doolittle is a pioneering pilot, And he thinks that we need a better way to actually test airplanes, a more rigorous way to test airplanes. And the only way to do that is in the sky. And so actually for his master's thesis, he's one of the first students at MIT's aeronautical engineering program. So for his master's thesis, he creates a flight regimen where he's going to take a

a Falker plane up in the sky and he's going to do barrel rolls and he's going to do dives and he's going to pull up and he rinks his plane up with accelerometers, which is not something people were doing before him. And he got to the point where he could just start to feel his wings cracking. And he looked at this accelerometer and he said, okay, that's the limit of this plane. Very brave man. Very brave man. And not many people get to say, my master's thesis is a landmark piece of aviation technology.

New from Nespresso. blend wellness into your coffee routine with the coffee plus range infused with functional benefits. Choose the coffee you love with added B vitamins, like coffee plus B12 to help support immune function, and coffee plus B6 to keep your day moving. Or go with the flow and choose ginseng delight. Our new double espresso with ginseng extract. Whatever lies ahead, don't change your morning. Let your morning change you.

Discover coffee plus on espresso.com. Hear that? it's your money calling. It wants a promotion. Elevate your savings with the Scotia high interest savings account. Always earn high regular interest rates that grow the more you save and invest. Conditions apply. Visit scotiabank.com slash hisa to learn more.

Scotia Bank. You're richer than you think. So let's move on to another category of this testing, which I find really interesting, which is foolproofing. So, you know, this word's sort of thrown around an awful lot, but what exactly do we mean in this context? Full proof testing is harder than limits testing

because that first step of the testing process, think about what's going to happen to this thing, is a lot harder when you have to think about what are people going to do to this thing? How are people going to use it? How are people going to misuse it? And at least in the American legal system, which is the legal system under which I live, tort law is very consumer-friendly.

And I think this is true in a lot of the world these days, where it is required of manufacturers to think about how someone might misuse a product and work to blunt the consequences of that misuse. And so in the U.S., we have this engineering term called foreseeable, misuse, where you as the engineer have to think about if this toaster gets really hot, is someone going to touch it? Almost certainly, right? Or it might be hot even after you've left the room and the next person comes in and uses it or you're just cleaning up the kitchen and your cleaning person touches it and could get burned. Because that's reasonably foreseeable that someone

will touch a hot toaster, you have to make a toaster that won't burn you after it's been used. So how about sort of this concept of then what used to be called user error or as he said, plain misuse. So you sort of mentioned I thought it was really funny, the extreme example of using a screwdriver to clean your ears. So I hope no one does that. But you also talk a lot about woodworkers. And personally, I'm a guitar player and I watch a lot. I'm really interested in how they're built. So I watch a lot of guitar builders on YouTube and such.

And I'm often shocked the amount of them have got sort of long beards or they're wearing dangley jewelry, you know, bracelets and necklaces, and just sort of leaning over bandsaws and lathes and things. For someone who's sort of squeamish like me, it just absolutely makes me wint. Yeah, and in the US at least, table saws cause a lot of injuries. The American population loses roughly 10 fingers a day to table saws. That's like two hands worth of fingers. So to use table saws as an example, there are product safety engineers think about foolproofing in three basic layers. And the most basic layer, the least useful one, is called worn and scorn. And this is where you just tell someone, this is a spinning blade, don't touch it.

Don't cut your finger with it. And then if you do it anyway, that's where the scorn part comes in. And they say, well, it's basically I told you so engineering. I told you not to do this. You did it anyway. You're the dummy. You lose out. You're the fool.

The better ground than that is what's called shielding the hazard, where you can't get rid of the dangerous element of a thing because a lot of things like table saws don't work if they can't cut wood. Something that can cut wood can hurt you, self-evidently. And so a lot of table saws these days come with these plastic. guards over the blades that are meant to stop you from touching them. But if you actually look at how they're used, woodworkers often find that those plastic shields stop them from using the saw

exactly the way they want to. So a lot of the time, they just pull those things off. And that's why shielding the hazard is good, but it's not the greatest level of foolproofing. The best thing you can do is remove the hazard altogether. With table saws, that's really hard, right? Because if it can't cut you, it can't cut wood. But I talked to a guy named Steve Gas, who lives in Oregon, and he created a way to remove the hazard from the table saw with an invention he called Saw Stop. And so what he did was, because he's an amateur woodworker, and by day, as a patent attorney.

So this is exactly the kind of thing he wants to do is inventive. way for a table saw not to hurt you. And he runs an electric current through the blade of the table saw. That's not quite complete. And he attaches a microprocessor to the chip and he adds a metal brake to the blade. And so what happens is if you're not paying attention or you make a mistake or for whatever reason, you touch the blade of the saw. Because you conduct electricity, you're touching it completes that electric circuit that he's set up. When it's completed, the microprocessor says, hey, this is completed, time to fire the brake.

And the brake works almost like putting a stick in your bicycle spokes. It just stops you. So it's basically this forked blade that fires into the sawblade and catches it and stops it within milliseconds. And the result is that even if you touch that saw blade, it might nick your finger, but it's not going to cause you a serious injury. And since Steve Gas created this product, he's saved hundreds, I think, or at least dozens of people from serious injuries.

Yeah, so another sort of example that you think about this is like these safety measures. It's those pill bottles that have the push-down release. It's just that when you think about that, what a great idea. So where did that come from? Yeah, so that's called the Palm Intern, and that came out of work by a Canadian pediatrician named Henry Breyo. And he in the 1950s and 60s was seeing a lot of child poisonings, kids getting into medicine bottles. And his first idea was something similar to that warn and scorn idea, which he wasn't warning people and then, you know, yelling at kids or yelling at parents, but he tried for a full decade education campaigns,

telling people, put these things out of reach, keep them where your kids can't get them. But it just didn't work. And it's not because people wanted their kids to get poisoned, but you use the bottle and you put it down and you don't think about it. So all of these reasons that it's very similar to the reason people get hurt with table saws, which is just, you know, your attention wanders for just a second. And all of a sudden something really terrible happens. And so after all of these education campaigns totally failed, Breyo decided, well, okay, how else can we stop them?

How else can we stop little kids from getting into these things? As you know, if you have encountered a small child, they put everything in their mouth, right? And you're obviously not going to stop them from doing that. And so he sets up an engineering challenge. He just puts out word, anyone who can figure out a way to stop kids from getting into this. I'll give, you know, it's a cash prize. And the guy who wins this contest is an inventor named Peter Hedgwick.

And he had done previous safety work. Like he was one of the people who created those little light-up studs that you see in the highway that reflect your headlights and the reflective triangle that you can fold up, that you keep in the boot of your car that you can put on the roadway if you're broken down. So he puts his mind to this and he comes up with what's called the palm and turn medicine bottle, which everyone today has encountered where you have to push down on it and twist it to open it. And the trick with this is that it's not a sheer matter of strength. You could make something that's just really, really hard to untwist. But then you're causing a new problem, which is that older people or people with arthritis or people who are people who are.

with various conditions that limit their hand strength won't be able to open it. And if they can't open it, the one time someone opens it for them, they're probably just going to leave the lid on loosely, thus recreating the risk. The genius of the palm in turn is that it's an intellectual blocker, right? You have to know, I have to push down, I have to twist this, I have to pop it off. And you're counting on three-year-olds, four-year-olds, not being at the point where they can think through all of those steps. You have to do it. It's the same way we keep bears out of things. Yeah, it's really interesting. So when products are being designed, the amount of thought

that goes on behind it, it's not just what its intended use is, but you have to go through all the iterations of how it may be used or found that could cause harm or damage. And that's where the real testing comes in. So if someone invents a new kind of child-resistant package, the way we test it is we give it to a panel of three, four, and five-year-olds. And actually, the way it works in the U.S. is those kids are sat down in pairs together as if they were siblings and they're, you know, wandering around their house. And someone, an adult in front of them doesn't describe how they're opening it, but opens it in front of them the way a parent might naturally do in front of their kid.

and then it's given to the kid for five or ten minutes and to see if they can open it. And the way you have to, what's really revealing about these tests is that you see all of the way a kid is naturally going to do this. They're going to chew on it. They're going to bang it. They're going to twist it.

And as the product engineer, you have to think through all of those things. And we do the same thing with bear-resistant products, coolers and trash cans in national parks and bear canisters, which are the thing you're supposed to put your food in if you're in the back country. And the way those are tested is there's a bear sanctuary outside of Yellowstone National Park in Montana in the U.S. And when a manufacturer has a new supposedly bear resistant product, they fill it with fish and honey and chips and all the things bears like and they give it to a bear who lives at this sanctuary and who's familiar with human food. And

If the bear can't open it within an hour, it's certified as bear. Okay. When I sell my business, I want the best tax and investment advice. I want to help my kids, and I want to give back to the community. Ooh, then it's the vacation of a lifetime. I wonder if my head of office has a forever setting. An IG Private Wealth Advisor creates the clarity you need with plans that harmonize your business, your family, and your dreams.

Get financial advice that puts you at the center. Find your advisor at IGPrivatewealth.com. You're resistant. That's quite interesting based on what we were saying earlier about the 1.5. So surely these bears, I was going to say something terrible then, I'll say it anyway, are smarter than the average bear because they've approached a lot of these problems before. So that's a sort of extra level of testing. I mean, I'm not an animal behaviorist.

or anything, but I think so. Yes, and so this is where you get into the sticky work of testing, which is that there's, I talked about those two ideas of make your test really similar to the real world and make it workable in a laboratory setting to give you reliable data. If you really think about those things, those are inherently opposed to one another. Because the more similar it is to the real world, the more random. it is, and the more it's usable in a laboratory, the less random it is. And the bears are a really good example of that, in that the bears living in this sanctuary,

are in this sanctuary because they've had encounters with humans. They are what we call problem bears, where they're used to human food, they're used to opening these things, and so you might think, like, sure, like, they're more motivated to get human food than maybe a bear in the woods would be who's never seen people before and smells it, but once they're stymied a little bit, they might give up after five minutes instead of an hour. But on the other hand, the thing you're doing by only using a panel of, I think it's something like eight to 16 bears or so live in the sanctuary at any given time, and most products are only tested by one or two bears.

You're only testing with one bear in one moment. And so that bear might not think of something that a bear in the wild might think of. And indeed, there was a famous bear in the Adirondack Mountains called Yellow Yellow, who was a wild bear. And she, it seems, was smarter than the average bear because she encountered campers with certified bear resistant products that she figured out how to open. And so bears in a sanctuary is the best thing we've got.

It's as similar as we can get to the real world in a setting where we can see what's actually happening, where we can film it, where we can fairly compare different products. But still, there's always going to be a gap between the test you run and the real world in which the product actually has to live. So let's move on to another thing then. So, you know, nothing lasts forever. And, you know, things do get worn out over time and use. And you call this in the book Disintegration. So this also comes into several different categories, you know, which, you know, you might not think about. So can you tell us about that and give us some examples of that, please?

Sure. So disintegration testing is testing with the knowledge in mind that at some point your product will fail. Your car will crash. Your plane will have a hard landing. A fire is going to break out in your building. And how do you build things and test them? to limit the destruction that comes with that breakdown. Here I talk a lot about how cars are crash tested.

And the way you build for disintegration, there are a couple of ways you fight back against breakdown. One is with redundancy. So, for example, when you send a rover to Mars, you don't put just one computer in that thing. You put two at least because you know one might break down. And so you want to have a backup to go to. So, for example, planes have multiple engines, most of them.

Some planes have four engines. Some planes have two. And that's another move toward redundancy because even on a Boeing 747, any one of those jets had enough thrust to keep that plane in the sky. Maybe not to fly all the way to its destination, but to give the pilot enough control to safely land. That's a form of redundancy. A weakness of redundancy, though, is that the kind of thing that might take out one system is liable to take out the backups, too. And this happened with 747s, for example, you could see all four jets taken out by birds or by volcanic ash, for example, when that Icelandic.

volcano erupted and put all this ash in and we had to stop all these flights. That's because even if you had 10 jet engines on your plane, they're all subjected to the same conditions, which is that ash in the air. And so the kind of thing that's going to take out one jet is going to take out two. And there's a way to design against that, which is to have redundancies that work in different ways than the primary system. So one example is sailors on a ship might have a GPS system, but if that breaks down, they can use the stars. And if it's cloudy out, well, maybe they have at least got a compass and a map and can figure out their speed.

And so just because one system breaks down, your backup might work differently. And that's a way of making redundancy work better. But let's say we have to accept that your thing is going to break. Something is going to happen to it. That's where I talk about engineered weakness, built-in weakness to a product, and you make it so that if your car is going to crash, you want to absorb the energy of that crash in such a way that it moves it away from the thing you actually want to protect, which are the people inside the vehicle. And so if you took your car entirely apart, you might see along the railings of the car, which are the main structural bits, you might see these little dimples along them, which are the aluminum or steel equivalent of folding a crease in a paper so you can tear it cleanly, which is what you're actually doing, what that crease is you're weakening the fibers of the paper. So when you go to tear the paper, that's where the tear. is happening, is along the weak point. So you're building in weakness in such a way that

when the car does hit a tree or another car, that's where the breakage is happening and that's where the force gets absorbed. And so it's not happening inside the cabin instead. So we've covered an awful lot there. Obviously, there's a lot more in the book. But how about some of the ways that we can apply this knowledge in our everyday lives? Is there any way that we can sort of be sure or at least reasonably sure that we're buying the most reliable versions of whatever it is we're buying and that we're using them properly. So I think there's a lot to learn from knowing about the world of testing. And I don't expect you to, and I don't expect myself when I buy a new bear resistant

container to go find a grizzly bear and give it to him to test for me, you kind of have to on what the testers are doing. But I think that by going inside this world and seeing how people work and understanding the tenets of testing and also the tensions within that world, how standards are negotiated and how the workability of a test is a trade-off from the similarity of the test, that when you see a warranty or when you see a rating, when you see this bear canister has been certified as bear resistant by the interagency grizzly bear committee of the United States, that you're better prepared to ask questions about that. You're better prepared to understand that testing at its heart is a very human process. The standards we test to and the

ways we test to them are negotiated by people. They're not laid down by on high. And when I talk about a bear-resistant product as being tested for one hour by a bear, you can ask the question, well, why one hour? Why not five hours? Right? If you're sleeping overnight in a campground and a bear sneaks off, he might have more than an hour to get into your food. Or you might have, you know, you could have been looser and said half an hour. And just thinking through and being able to think through how those compromises are made, I think is valuable knowledge in a world where technology has more and more prominence in a world where trust in institutions is eroding

in a world where AI is running amok and where the climate crisis is hitting infrastructure with more and more force, more and more frequently. And so understanding the thinking that went into these products, I think, is valuable. Thank you for listening to this episode of Instant Genius, brought you from the team behind BBC Science Focus. That was Alex Davies.

To discover more about the topics we've just discussed, check out his book, How to Keep a Plain in the Sky, Tales from the Wild, Unseen World of Test Engineering. If you liked why you just heard, then please do consider subscribing to Instant Genius on your preferred podcast platform. If you'd like to see our guests and hosts in person, then why not check out our YouTube channel, at Science Focus. If you've enjoyed this podcast, why not take your curiosity a step further with BBC Science Focus? magazine. Receive an extra £5 off when you subscribe using the code SF5 off.

For more details, see the show description. The current issue at BBC Science Focers magazine is out now. Pick up a copy wherever you buy your favourite magazines or download us on your app store of choice. You can also find us on Apple News or online at sciencefocus.com. This family is on the brink of civil war. series is now streaming on Paramount Plus. We are the Harrogans. Don't know them yet? And Google us.

From the underworld of Guy Ritchie. Do you want to step up the ladder? I won't comment dead. Starring Tom Hardy, Pierce Brosnan, and Helen Mirren. Do I have to do everything myself? You want to want? Hurt! Moblad.

New season is now streaming on Paramount Plus.