How Impossible Meats Might Save the Earth

Season 1 • Episode 15

People talk about greenhouse-gas emissions from cars, planes, and factories, but one source out-pollutes them all: Cows. Raising meat animals like cows generates more methane than the entire fossil-fuel industry. So Pat Brown left his job as a Stanford biochemistry professor to dedicate his life to fixing the problem. He vowed to create perfect meat replicas using only plant ingredients. His Impossible Burger is already a megahit—but can he be serious about replacing all beef, pork, chicken, and fish by 2035?  

Guest: Pat Brown, CEO and founder, Impossible Foods.

Episode transcript


People talk about greenhouse-gas emissions from cars, planes, and factories, but one source out-pollutes them all: Cows. They belch out more methane than the entire fossil-fuel industry. So Pat Brown left his job as a Stanford biochemistry professor to dedicate his life to fixing the problem. He vowed to create perfect meat replicas using only plant ingredients. His Impossible Burger is already a megahit—but can he be serious about replacing all beef, pork, chicken, and fish by 2035? 

Guest: Pat Brown, CEO and founder, Impossible Foods.


The goal of Impossible Foods, Inc. is to replace beef, pork, chicken, fish, and steak with foods that look, cook, taste, and smell just as good or better—but don’t involve raising or slaughtering any animals. Pat Brown founded the company not to become the next billionaire—but because livestock are a disaster for the climate.

Pat We are not going to save ourselves from catastrophic climate change without replacing animals in the food system. It’s just—you can’t get there from here. 

I’m David Pogue, and this is “Unsung Science.”


Season 1, Episode 15: “How Impossible Meats Might Save the Earth.” 

This is the last episode of “Unsung Science” season 1, and at this point, I haven’t yet heard if there’ll be a second season. As soon as I find out, I’ll let you know on Twitter and, of course, at 

But for now…thank you. You, dear listener, have made this project a thrilling ride. I’ve loved reading your reviews, emails, tweets, and feedback—and finding out that you are just as fascinated by the backstories of great achievements as I am.

Anyway, today’s show is about one man’s relentless battle against beef. 

Now, before you meet him, I’d just like to acknowledge how absurd that mission must seem. I mean, beef is America. Beef is a staple—if you’re a typical American, you eat 55 pounds of it a year. If you go to a picnic or a cookout, you don’t even ask if beef is on the menu. Of course it is. So the first question for my guest, then, is:

David So what’s wrong with beef? 

Pat I could spend an entire hour going down the list because /there’s, you know, probably 10 things, any one of which is reason enough to replace it. 

This is Pat Brown. As our story begins in 2009, he was a biochemistry professor at Stanford. Well, a biochemistry professor taking an 18-month sabbatical to contemplate the rest of his life. How he, as a single person, could do the most good for the world.

And the answer was: Replace meat.

Pat In general, the use of animals in food technology is by far the most destructive technology on Earth. And cattle are the biggest part of the problem, OK? The—from a climate perspective, this is something I really want to get into, if you—if you’re up for it. 

Meat production in general is responsible for about 30 percent of—33 percent of global water consumption in the U.S. There was a recent study that reported that more than half of the water that flows out of the Colorado River watershed is, is used—is consumed by cattle, basically. Not drunk by cattle, but, but used to raise cattle. It’s incredibly water-intensive. 

More important from a climate and biodiversity standpoint, it’s incredibly land-intensive. Animal agriculture occupies about 49 percent of the area of the continental U.S., OK, almost half. Look it up. 

I did look it up. It’s true. Half of the United States land area is dedicated to raising meat. Globally, we have turned over one third of all the non-frozen land on the planet to cattle grazing. I’ll give that a few seconds to sink in.

ticking SFX, concluded with a “Mooo!”

See, to make more land for cows, we generally tear down trees. 

David And this is why they’re—this is why they’re burning down the rainforest?

Pat It’s happening in real time. Absolutely, absolutely. 

But Brown’s beef with beef isn’t just about how many resources cows require. The biggest problem—is their burps.

Cows are ruminant mammals, which means that microorganisms in their stomachs digest their food, breaking it down into the nutrients they need, and the nasty greenhouse gases they don’t. (Buffalo, deer, elk, giraffes, and camels are also ruminants, but they’re not nearly as much of a problem, because we don’t generally raise them to eat them. You can’t go to McDonald’s and order a McGiraffe.) 

Anyway. Those gases gotta come out of the cow somehow. You hear people say that cow farts are the problem, which is hilarious but not accurate. 95% of it is burps: as much as five gallons of gas an hour per cow. If you burped five gallons an hour, you’d be asked to leave the restaurant—or the relationship.

Half of the burped gases is methane, which is awful, awful stuff, many times worse than carbon dioxide. Our red-meat creatures belch up more methane than the entire fossil-fuel industry. 

If cattle were a country, they’d be the third biggest greenhouse-gas polluter on the planet, right behind China and the United States. Put it all together, and meat animals pump out more greenhouse gases than cars, trucks, trains, buses, ships, airplanes and rockets combined. 

Pat A single cow isn’t a problem. But 1.7 billion cows covering the planet is a problem, OK? 

David 1.7 billion?! 

Pat That’s, that’s the number. It’s verifiable that the, the total biomass of cows on Earth today exceeds by more than a factor of 10 the total combined biomass of every remaining mammal, bird, reptile and amphibian left on Earth, OK? Basically, we’ve replaced nature with cows, I think, is a simple way of summing it up. 

Now, you will note that in this huge list of reasons that beef is a problem, we haven’t even brought up the grisly subject of…how cows become burgers.

I considered playing a little sound clip here of a cow being slaughtered. But you know… kids listen to this podcast, too. If they had a clear picture of how beef is made—they’d never eat a hamburger again, and they’d also never sleep again. So if you’re interested in knowing how abattoirs work—that’s the fancy word for slaughterhouses—off you go to YouTube. 

David You ask your audiences, “Of all the reasons you love beef, raise your hand if ‘because it comes from the carcass of a slaughtered animal’ is one of the reasons.” Nobody raises their hand. 

Pat You know, people love meat in spite of the way it’s made. And they try very hard not to know where their meat comes from, because it’s just so unpleasant. 

Every abattoir on Earth, no matter how modern it is, is a horror show. 

I mean, we all kind of know that deep down. But who’s got the nerve and the self-confidence to say, “Meat animals are a disaster, so let’s fix it?”

Pat This is the most urgent and important problem to solve in the world. Full stop. OK? 

  We are not going to save ourselves from catastrophic climate change without replacing animals in the food system. It’s just—you can’t get there from here. /But what stands in the way is satisfying the demand for this particular kind of food that, that incentivizes people to cover the planet with cows. 

The more he researched animal agriculture, the more upsetting it seemed. And before long, well, it was good-bye, Stanford—hello, Impossible Foods, which he founded in 2011. Its modest goal was to create food that looks, tastes, smells, and handles like meat—but is made of plants—using science.

Pat When I started the company, we put together an awesome R&D team. 

  These are not people who came from the food industry. I mean, in the food industry, you know, the innovation of the year is a new flavor of Fruit Loops. we do have people from the food industry who are very good at what they do, but for fundamental innovation, that just does not happen at General Mills. 

And so I hired people who would otherwise have gone into academia, the biomedical industry, pharmaceutical industry, or whatever, who are basic scientists. 

Three years in, we had something like 80 R&D scientists and like three businesspeople, OK? We were—we were purely an R&D operation devoted to the task of understanding how meat works, and, and figuring out what—you know, what ingredients that we can source from—effectively from the plant world or produced by fermentation are required to recreate that entire experience. 

David You seem to have come into the problem saying, “These problems are solvable.” And they were! I just—I just don’t know how you knew. 

Pat I think a lot of scientists, if they had chosen to look at this problem, would have come to the same conclusion, OK? This is, this is a hard problem, but it’s easier than a lot of biomedical research problems that you might want to study. 

(cont’d) Once you ask the question, it’s answerable, OK? And the fact that we were able to find the answer basically says nobody had asked the question, OK? 

David Inside the labs, what is the process? What does it look like? Is it, is it people in lab coats with beakers? Is it, is it more like a kitchen? 

Pat We have more than 200 people in our R&D team. So we have a basic R&D lab that is building the knowledge that helps us understand, you know, what are the flavors and mechanical properties that we need to create, and our op– and are sort of optimizing. It’s the analytical part. 

There’s the, you know, there’s the figuring out the—where we can source the raw materials that—to precisely match the properties that we need for those ingredients. Then there is the engineering aspect of, of how we turn this into a scalable process and product. 

and then there’s the sensory testing and cooking. We’re iterating on all our project—products, like literally, multiple times a day. We adjust this, we adjust that, we have—we do analytical comparisons. But we also have sensory testers who are giving us feedback on whether it’s going in the right direction or not. So there is a kitchen aspect to it. 

I mean, when we were trying to make ground beef, one of our early taste tests, one of the tasters described the prototype as tasting like rancid polenta, OK? And this is great, I love it, because, because that’s how it is in science, you know. Like, you, you do it, you get better and better and better by iterating and understanding what—OK, this is, this is the next thing we need to solve. 

After five years of this taste testing and iteration, finally, in 2016, the company was ready to ship its first product, the Impossible Burger.

The Impossible Burger is not a veggie burger, which wouldn’t fool anyone. It’s not tofu. It’s not that crumbly black bean stuff. Impossible Burgers look, cook, feel, smell, and taste astonishingly close to ground beef. Here’s a chef guy on YouTube realizing that for himself:

Guy: It looks like meat, it feels like meat, and it tastes like meat.

As you cook them, these patties even bleed the way raw beef does. 

Guy This is what’s so crazy about these burgers. They’re actually bleeding there. Time to flip…And then the browning is insane. It looks just like an actual burger.

In a bun, with condiments, they’re nearly impossible to distinguish from a really great dead-cow burger. 

Guy Best burger I’ve ever had. Just the perfect combination. Doesn’t taste 100% like ground beef, but it’s very close, but it has its own feel, and to be honest, I actually like the taste of it. The science behind this,  it creates an incredibly flavorful product that really just holds up and tastes meaty. 

And yet—they are not meaty. They are meatless. The dominant ingredient is soy protein. And therefore, environmentally, they’re home runs. 

Pat Our current ground beef product—uses 1/25th the land area. It uses 1/8th the water. It uses less than a twelfth the, the fertilizer and agrochemicals that, that go into making a pound of beef. 

Overall, according to the package, producing an Impossible Burger spews out 89% fewer greenhouse-gas emissions than raising a cow burger. 

By the way—a little moment of disclaimer here—I have zero connection to this company. I don’t own any stock, I’d never met Pat Brown until I harangued his PR team for this interview, and they didn’t pay anything to be the subject of this episode. 

OK, OK, you got me. After the interview was over, they shipped me one box of their Impossible chicken nuggets. Clearly, trying to buy me off.

Anyway, back to the Impossible Burgers. They give you about the same amount of protein, iron, fat, and calories as beef, and no cholesterol, hormones, or antibiotics. They do contain much more sodium than beef. 

David What I don’t understand about your trajectory is that you had this idea: “Oh, I’ll invent a plant-based beef patty that, you know, tastes as good and has the same texture, smell, color, cooking characteristics.” And then you did it! I mean, there have been many people who tried to make tasty plant burgers before you. I don’t understand what gave you the—the confidence to think that you, this one guy, would pull it off. 

Pat Well, first of all, I think what we set out to do was not to make a delicious plant-based burger. It was to build a technology platform that could replace livestock in the food system, OK? That’s a very, very different—. 

David So even bigger! 

Pat It’s kind of hard to explain, but, but sometimes with scientific problems, it’s easier to solve a bigger problem than a smaller problem. And the—in this case, what you have to do is think about what is the essential value proposition of, of livestock as a technology? 

And basically, what they do is they, they convert cheap, abundant plant biomass into these nutrient-dense foods with a very specific kind of deliciousness that people are very habituated to, and—and have learned to love. 

And when you frame it that way, and you say, the job here is not, “I’m going to create this little one-off product,” but to replace that technology, then you have to step back and understand, “OK, how, in—you know, in actionable sort of biochemical terms, does it produce foods that have these attributes that people love, OK?” 

And, and a lot of the way that works, in terms of meat texture and flavor—it’s pretty similar across species and—and different, you know, form factors of meat, and so forth. 

Basically all the animals they’re, they’re—if you looked at their tissues under a microscope or even under an electron microscope, you’d have a hard time telling, telling one species from another, OK? 

And so, we sort of set out at the beginning basically saying that, “we’re not going to just start slapping a bunch of greens together and mixing flavors in and hoping for luck. We’re going to understand how meat works as a biochemical system, OK?” 

David Are you saying that there is no point during that four or five year development period when you wondered if you would get there? 

Pat No. No, I mean, I’ve never doubted our success. I went into this basically saying, look, it’s on us. 

When the Impossible Burger was first introduced, the company could make only small batches, so you could only get them at a few high-end restaurants. They weren’t available in grocery stores until 2019, which is also when Burger King started offering the Impossible Whopper. 

David I mean, beef is something that a beef-eater knows intimately. And you have to nail the looks, the texture, the flavor, the smell, how it cooks, how it handles.

Pat We knew that we could not just use conventional food science the way, you know, people in the past have tried to make meat replacements. We had to approach it as a hard scientific problem, a hard but solvable scientific problem, OK? 

You can break down the problem into solvable pieces.

For example, how do you make a plant-derived burger get that slightly crisp exterior when you sear it? Well, they discovered that potato protein can deliver that effect. 

What about the sizzle of melting fat in the pan? Little flecks of semidried coconut oil could simulate that, because it melts at about the same temperature as cow fat.

Pat A lot of the kind of fatty mouthfeel that people get from animal fat is—sort of depends on the fact that it has a relatively flat melting profile that is, centered around your body temperature. 

One meaty characteristic at a time—those were Pat Brown’s solvable pieces.

Pat The hard part is deliciousness. Nutrition, cost—those are, those are a piece of cake. And, and, it’s, it’s producing the constellation of sensory properties that, that matter to consumers. And it’s a constellation, but it’s finite, OK?  The hard part is deliciousness.

So how do you solve a problem like deliciousness? What plant-based ingredient can give you the delicious flavor of beef? It was clear that there would be no Impossible Burger until the company could find a solution.

Pat What is it that makes meat taste categorically different from anything in the plant world? If you give someone who, who is a meat eater some morsel of food and asked them to identify it on flavor alone, even just from the aroma, they could pretty much consistently do it, irrespective of what kind of meat it is. 

Incredibly, he discovered the answer. Feeling sufficiently teased? Then stay tuned, because after the ads, I’ll tell you about it.


OK, enough ads! Welcome back.

Before the break, I was telling you about how Pat Brown’s army of scientists created the Impossible Burger, one characteristic at a time. And I was hinting at this one miracle ingredient that, almost singlehandedly, provides the color, the flavor, and the deliciousness of beef. It’s the ingredient that made Pat Brown’s dream a reality. 

And that one incredible ingredient turned out to be—love.

Music…a crowd “Awwww” 

No, I’m totally kidding. It’s a molecule called heme.

Pat (cont’d) A lot of the flavor— there’s more to it, but 90 percent of it plus, is that—is that animal tissues contain this molecule, an abundant amount of this molecule, heme. 

That’s H – E- M- E. Otherwise known as, the molecule that built Impossible Foods. If I worked at the company, I’d have made a T-shirt for Pat Brown to wear that says “Heme-Man.” Get it?

Here’s the company’s principal scientist, Rachel Fraser, in a company video.

Rachel We were the first to discover that heme is what makes meat taste like meat. It’s highly abundant in animal tissue. And if you were to eat meat raw, that bloody flavor that you get, that’s also heme. And when you cook meat, all the different flavors and aromas that you get, that is catalyzed by heme as well.

Heme is not some exotic chemical. It’s around.

Pat Heme is required for every cell on Earth. It’s required for life on Earth. And it does a whole bunch of different things. It’s what carries oxygen in your blood. It’s what stores oxygen in your muscle tissue. And it’s also one of the best catalysts in nature. 

So the enzymes in your body that metabolize caffeine use heme as sort of the catalytic element, and the enzymes in your body that make estrogen, estrogen, and testosterone also used heme as a catalytic element. 

Animals need much more heme, because they use it as an oxygen transport and binding storage system, in a way. And, and so that’s why meat is red or pink. And you know, that’s why your lips are pink and your skin is, you know, rosy and all that sort of stuff, because you have so much heme, OK? In meat, it’s heme—that gives meat its color, which is something that people value in meat.  

So if you basically took a drop of, of a heme protein and put it into a bowl of vegetable broth, it would basically smell and taste like beef broth, OK? It’s, it’s, it’s—that’s kind of the switch between plants and animals. 

And that’s why there’s such a huge difference between cooking vegetables—and cooking meaty, meaty, meat.

Pat When you cook broccoli, basically, it gets warmer and mushier and maybe caramelizes a bit, but nothing magical happens. When you cook meat, you basically unlock an explosion of chemistry, right? You get this explosion of aroma and flavor that—it completely transforms in its flavor profile, producing much more intense and new flavors in that process. 

Heme made the Impossible Burger possible. Pat Brown’s army of scientists had done it—they’d managed to create a burger that really tasted amazing. 

The Impossible Burger was an instant hit. So was its arch rival, the Beyond Burger. 

Today, they’re both selling incredibly well, in stores and restaurants—especially since the start of the pandemic, when virus outbreaks tore through the meat industry, sickening and killing workers, closing meatpacking plants, raising prices. 

Overall, sales of plant-based meats and milks exploded 27% last year alone. We’re now buying 7 billion dollars’ worth of plant-based meats a year—a number that’s supposed to more than triple in the next two years. 

No wonder Nestlé, Tyson, ConAgra, Kellogg, Hormel, and Kroger have all introduced their own meatless burgers, or will shortly. 

David Elon Musk is famous for saying, ‘I don’t care if Tesla goes out of business, the whole point is to jump start electric cars—as long as electric cars takes over, I don’t care what happens to us.’ Are you in that vein? Like, as long as we stop harvesting animals for meat, I don’t care about my company in particular?

Pat I have a responsibility to the people of my company and so forth who have been busting their butts to help us get, you know, to succeed in our mission. And so, I do care if my company goes under. 

But on the other hand, if other people are coming into the same, you know, technology, and, and doing things better than we do, well, they deserve their success, and, you know, I’m not interested in competing with them. I seriously am not interested in competing with them from a mission standpoint. 

I mean, at some point, I think we’re going to want to be, you know, collaborating with a lot of, of other companies and people and so forth to, to, to accelerate this mission right now. 

Now, it probably comes as very little surprise to learn that the meat industry hates, hates, hates the idea of plant-based meats. Despises their popularity. Meat makers have gone to the remarkably expensive extreme of running a Superbowl ad in 2020 to try to turn people off of plant-based meat like Impossible Burgers. The ad is set at a school spelling bee.  

Judge Spell propylene glycol. 

Kid What’s that?

Judge Propylene glycol. It’s a chemical used in antifreeze and synthetic meats. 

Kid P…O…

Narr You might need a PhD to understand what’s in synthetic meat.

Just how nasty is that ad? Well, for one thing, it contains a triple scoop of misinformation. Propylene glycol is FDA certified as safe for use in food; it’s in thousands of baked goods, prepared foods, candies, frostings, sauces, dressings, and so on. It is not antifreeze of the type that you’d put in your car; that’s ethylene glycol.

And here’s the kicker: there’s no propylene glycol in the Impossible Burger or the Beyond burger!

Pat Brown was not about to get kicked around by the dead-animal lobby. Impossible Foods made an ad of its own, a parody of the spelling-bee ad—and he himself played the role of the judge.

Pat And the first word is… Poop. There’s lots of poop in the places where pigs and cows and chickens are killed and chopped to bits to make meat. And there’s poop in the ground beef we make from cows.

The meat lobby also hammers hard on the fact that Impossible Burgers are made from ingredients that have been processed. Extracted from plants, fermented, mixed, and so on. 

Also, the company needed some way to get enough heme to make its meats in the quantities we demand. So it trained yeast to make that heme. They insert DNA from soy heme into the yeast, which then ferments, much the way we ferment yeast to make beer.

And that, my friends, is a form of—genetic modification! 

(Horror-movie chord and crowd gasp)

We’re not gonna have time for a whole big thing on genetically modified food. But here’s a crash course: We’ve been genetically modifying crops for hundreds of thousands of years. When we selectively breed crops to get bigger bananas or juicer apples or whatever, that is super slow, crude genetic modification. The newer kind, where we make tiny tweaks by directly editing a crop’s genes, has been deemed safe by the FDA, the American Medical Association, the National Academy of Sciences, and the World Health Organization. Today, 90% of all soy and corn in the U.S. are genetically modified varieties. You’ve been eating ‘em for decades.

Still, I had to ask Pat Brown about this “processed food” business.

David It sounds like you’ve manipulated individual factors, and ingredients, and the way you prepare them. And we’ve been taught over the last 40 years that ‘processed’ is a bad word in food. Do you get any reluctance from people saying, “Oh, it’s so processed?” 

Pat Yeah, that comes up a lot. It’s like one of these terms that is used as a pejorative, and there have been—I think the meat industry is really pouring the fuel on that, putting out ads in The Wall Street Journal saying, “Oh, plant-based meats  are processed, blah blah, blah blah.” 

First of all, I think someone should look at their process some time, which they won’t let you do. And look at what goes into their products, including fecal bacteria. 

Kid Poop. P-O-O-P. Poop.

Pat (cont’d) But setting that aside, every food is processed.

If you make a loaf of sourdough bread, right? You know, you don’t just take a pile of wheat and, and there’s your loaf of bread. There’s a whole history of figuring out all the things you have to do to make that great. 

Separating the wheat from the chaff, you know? And you have to, you have to grind it. You have to mix it with, you know, yeast and —and cultures to get it to rise. You have to knead it. You have to apply shear stress and mechanical stress to it to get the dough to have the, you know, the elastic texture. Then you have to bake it, and then maybe you put olive oil on it. 

Well, wait. If even the healthiest kinds of foods are processed—like, chopped, mixed, heated, dried, and fermented—then where do we get this idea that processing our food is bad? Brown says processing the ingredients—and substituting cheap and grossingredients—are two different things.

Pat (cont’d): The big food industry has done a tremendous disservice to consumers and to society. It’s about minimizing their costs and, and maximizing their profits at the expense of the consumers’ health, OK?  taking, you know, addictive and cheap ingredients like sugar and fats and salt and stuff like that, and creating foods that have essentially no valuable nutrients in them, and have more or less a purely negative health impact, in service of the business, and with no regard for consumers, OK? That’s, that’s, that kind of processed food. That’s a Twinkie. 

Processed foods like Twinkies, and, junk food, Pepsi Cola, are completely irrelevant to what we’re doing. We’re incredibly conscientious about health. We have to make a product that’s healthier than what it replaces in order to win in the market.

David You also must have to think about culture and psychology. In other words, meat is more than tasty and filling and protein. It’s also, you know, the American way, it’s embedded in our history, and our Fourth of Julys, and so on. I mean, is there—is that a challenge to you?

Pat It’s not a challenge. These kinds of culture, cultural traditions are less sticky than people think. I mean, you could have said, “horses are embedded in, in American tradition,” you know, 150 years ago, and they were even more personal than, than a cow, because pretty much every household had a horse.  

But actually, it turned out that what mostly mattered to people was it got them from point A to point B, and not that it had four legs and a tail. And, and that became obvious as soon as a better technology came along, and did a better job of serving what consumers valued from, from that horse. 

Here’s another interesting factoid that I just dug up recently, but I find it amusing. That the most popular meat in the U.S. a little over 100 years ago was mutton, OK? 

David What!?

Pat Good luck finding mutton in any supermarket now. These things are not as sticky as people think. 

For those of you who weren’t doing the shopping in 1910, mutton is the meat of adult sheep.

Pat (cont’d) You don’t have to change any of those traditions, right? You just go to the grocery store, you buy your ground beef or steak or whatever. It doesn’t happen to be made from an animal, and you just go right about your business. 

About the only real drawback Pat will concede is that Impossible Burgers still cost more than beef burgers. The company has been steadily bringing the price down—by 15% in 2020, and by another 20% in 2021—but at this moment, Impossible Burgers at Walmart cost $5 for two six-ounce patties. That comes out to $10 a pound, about twice as pricey as 80% lean ground beef from the same store.

David How close are we to the price now? 

Pat In some ways, we’re almost already there, OK? 

All the costs that underlie the cost of beef in a supermarket are lower for us at scale. 

So we need less plant crops. We need less labor managing the plant crops, no labor managing the animals. And our production process is way more labor-efficient than a slaughterhouse, which basically has to take this very badly-designed starting material to turn into meat. Because it’s unstandardized, and, and you need a bunch of, you know, exploited, low-paid workers with large knives to turn it into a product that someone will buy. And we design the whole thing. So we, we can design it to be simple and automatable. 

If it weren’t for the fact that we have the inefficiencies of small scale—like, you know, we have to ship, small, small shipments of our products to 30,000 grocery stores. We don’t have the, mature distribution system of the existing industry, for example. 

Right now, you know, we’re still a very small startup, and we’re pouring money into growing our supply chain and our production stuff. We’re building it from scratch, as opposed to basically living off the legacy that the incumbent industry has. And yet, we’re getting very close to the crossing point, in terms of costs. 

I’d say within a few years, max, I mean, maybe three years. It won’t be long at all.  (cont’d) It’s going to be a very interesting point when we have products that, that are outperforming, they’re healthier, they’re, they’re delicious, and they’re cheaper.

Already, this little startup has other products. 

Pat The chicken nuggets—have you tried the chicken nuggets? 

David Are they out there? 

Pat They they’re out there, and they, in our tests, were preferred by 75 percent of consumers over the bestselling animal-based chicken nuggets. America’s Test Kitchen compared them to a bunch of other nuggets, including nuggets made from chicken. And they not only were the winner, but they describe them as tasting more like chicken than the chicken nuggets. 

Wait, what!? That can’t be right! How could anything taste more like chicken than CHICKEN!?

I found the America’s Test Kitchen article. It says, and I quote, “The Impossible nuggets were moist and plump. They were also surprisingly flavorful and tasted more like chicken than the other nuggets.” 

They’re also selling Impossible sausage, meatballs, and pork. 

But in some ways, I couldn’t help wondering: Why go to such great lengths to simulate meats we already know? Isn’t that sort of conceding defeat? Isn’t that saying, “Well, we can’t possibly get you to eat healthy and sustainable food, so we’ll create something that tastes as close as possible to the unhealthy and unsustainable stuff?”

Pat We could have said, “no, we’re not going to make anything that tastes like any of those animals, but we’ll make something that tastes like an animal you’ve never experienced before,” or whatever. And that would be a lot—that would be fun and interesting from a kind of artistic perspective, you might say, or even that scientific perspective. 

But we have a mission here, and, and it is to remove the economic incentive that keeps this industry basically driving us toward environmental catastrophe. And, and that’s why we are strategically focusing on specific products that are the economic pillars of the business of each of those livestock species. 

Yes, Pat Brown has a mission—a whopping big one: To replace animals with food technology by 2035. He’s said that so many times, it almost comes out as one big word—

Pat We replace animals with food technology by 2035. 

That mission statement might sound like someone biting off more than he can chew. But it’s never wise to bet against Pat Brown. He never had a moment of doubt the he’d master the burger, and then the sausage, and then the chicken—so why should we doubt that he can go all the way by 2035? He doesn’t.

Pat I’m 100 percent confident we’ll achieve it. 

The Man Who Stopped the Spammers

Season 1 • Episode 14

By the year 2000, the internet was already becoming a cesspool. The bad guys used software bots to sign up for millions of fake email accounts—for sending out spam. 

PhD student Luis Von Ahn stopped them. He invented the CAPTCHA, that website login test where you have to decipher the distorted image of a word. Or you have to find the traffic lights or fire hydrants in a grid of nine blurry photos. 

Those tests help to keep down the volume of spam, spyware, and misinformation; they advance the clarity of digitized books and the intelligence of self-driving cars; and, by the way, they made a handsome profit. 

The only problem: We HATE those tests! 

Guest: Luis Von Ahn, co-inventor of CAPTCHA, co-inventor and CEO of Duolingo.

Episode transcript

Captcha Script


By the year 2000, the internet was already becoming a cesspool. The bad guys used software bots to sign up for millions of fake email accounts—for sending out spam.

PhD student Luis Von Ahn stopped them. He invented the CAPTCHA, that website login test where you have to decipher the distorted image of a word. Or you have to find the traffic lights or fire hydrants in a grid of nine blurry photos. 

Those tests help to keep down the volume of spam, spyware, and misinformation; they advance the clarity of digitized books and the intelligence of self-driving cars; and, by the way, they made a handsome profit.

The only problem: We HATE those tests!

Guest: Luis Von Ahn, co-inventor of CAPTCHA, co-inventor and CEO of Duolingo. 


By the year 2000, the internet was already becoming a cesspool. Software bots were signing up for millions of fake email accounts—for sending out spam.

Luis Von Ahn stopped them. He invented the CAPTCHA, that website login test where you have to decipher the distorted image of a word. Or you have to find the traffic lights in a grid of nine blurry photos.

The only problem: We hate that test.

LUIS: I would be at a party, and people would ask me what I did,   And I would tell them that I helped invent that thing, and people would tell me, “Oh, I hate you.”

I’m David Pogue, and this is “Unsung Science.”

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Season 1, Episode 14: The Man Who Stopped the Spammers.


In his 43 years on this earth so far, Luis Von Ahn has had three ingenious, innovative, world-changing ideas. I guarantee that you’ve encountered his second one. Probably hundreds of times, actually.

Most of us have zero world-changing ideas. Occasionally, somebody has one. But three times?

His first idea came to him in Guatemala, where he grew up. 

LUIS: I wanted to start a gym, where instead of charging people to—to show up,  let people just show up for free. we were going to connect all the machines up to kind of the power grid, and we were going to use what—you know, the kinetic energy that people did or had whenever they were, you know, exercising, to generate power. And I thought we could make a lot of money from that. 

Now, you will note that I did not say that all three of his world-changing ideas actually succeeded in changing the world. 

Luis: I thought I was the first person to have this idea. Turns out, this is a very old idea. It also turns out it doesn’t work. 

That’s right: The pedal-power gym idea flopped.

LUIS: (cont’d) It turns out, this is, this is not a good idea for many reasons. The biggest one of which is that humans are just not very good at creating energy.


LUIS: You just, just don’t make a lot of money from this. There’s another reason why that doesn’t work a lot. Turns out gyms   make most of their money from people who don’t show up. 

David:  Of course. 

Luis: Here, you kind of need people to show up. 

To be fair, he was pretty new at the game when he had this first idea. 

David: And how old were you at this point? 

Luis: Twelve years old, eleven years old. 

Things started going better six years later, when he came to the United States to attend Duke University. As the year 2000 dawned, Luis was at Carnegie Mellon, in his first year of working toward a PhD in computer science. And one fateful day, he went to a talk by an Israeli computer scientist named Udi Manber, who at this point was the chief scientist at Yahoo.

Luis: By the way, in the year 2000, Yahoo was the biggest name, you know, biggest tech company. In other words, like the Google of today. And you know,   and he was giving a talk about ten problems that they didn’t know how to solve inside, inside the company. 

And one of those ten problems that the greatest minds at Yahoo could not solve—was automated software spambots signing up for free Yahoo Mail accounts by the millions.

LUIS: (cont’d)   Yahoo gave out free e-mail accounts. And  there were people who wanted to send spam from Yahoo accounts, but each Yahoo account only allowed—only allowed you to send like 500 messages a day. If you wanted to send millions of emails, spam emails per day, then what these people did is they wrote programs to obtain millions of Yahoo accounts every day. And they didn’t know how to solve that problem, how to stop that. 

So I started talking about it with a person who had just become my Ph.D. adviser. His name was Manuel Blum, or is Manuel Blum. He is still, most definitely still alive. 

And, you know, we started thinking—and this is where this idea of a CAPTCHA came up.

The idea was this: Any time you tried to sign up for a Yahoo Mail account, you’d encounter a little puzzle. Something easy for a person to solve, but hard for a spambot.

LUIS: (con’td)   the way to stop these spammers was to have a test that can distinguish between whether you’re a human or a computer. If you are human, then presumably you can’t get millions of email accounts because you get bored. Whereas if you’re a computer, you can get a million. 

And so if the only entities that we we’re giving email accounts to were humans, then that would stop the spam. 

CAPTCHA, the name he gave his online mini puzzle, stands for ‘Completely Automated Public Turing tests to tell Computers and Humans Apart.’ More or less.

Not sure if you’ve heard of the Turing test, but it’s incredibly famous among computer scientists. It’s this experiment proposed by British mathematician and computer scientist Alan Turing, who’s known as the father of artificial intelligence. There was actually a movie about him called “The Imitation Game,” where Benedict Cumberbatch played Alan Turing.

Clip from the movie: ”Do you want to play?…”

Anyway, the Turing test is intended to set a standard for determining if a computer has achieved true artificial intelligence. 

Luis: When can we tell that   a computer is actually intelligent?   This is kind of like a philosophical test that said, like, “look, we’re going to have a human judge ask questions  to two entities. One is the computer, one is the human.”

The computer and the human are hidden behind two curtains; the judge can’t see them. The judge types in questions, and looks at the text of the responses. If it’s impossible to tell which answer came from a person and which from the computer, the computer has passed the Turing test.

Luis: The judge can just ask whatever questions they want. And if we really can’t distinguish, then we’ll say that computer is really intelligent.

To this day, we have not made a computer that can actually pass the Turing test successfully. It’s just—it’s just too hard.

The funny thing is, if you really think about it, the Captcha problem is the opposite of the Turing test. The Turing test is successful if the judge can’t tell the difference between a person and a machine. The whole point of Luis Von Ahn’s project was to create a test that can tell the difference.

There’s another difference between the two tests, too.

Luis: (con’t)   here’s the key. In this case, the judge was a human. In our case for the CAPTCHA, what we needed to do is we needed the judge to be a computer, because we need—we need the computer to determine whether it’s talking to a human or computer, which is, which is much harder, in some sense, at least for to grade it.   

So, so I think the hardest thing was just coming up with this general idea that, like, “OK, what we need is a test that can distinguish humans from computers, but that computers need to be able to grade.”

Then after that, we started coming up with, like, “OK, what are things the computers are not very good at?” 

In the year 2000, the answer was obvious: Computers are not very good at identifying what’s in pictures. 

Luis: We quickly honed in on images, and just doing images of text, images of flowers, images of stuff. And then, and then after a while, the images of text were the ones that seemed like the best idea. 

And then I just went and developed a program that, that distorted random text. And, and that was the first version of a CAPTCHA. 

That’s right: The test they came up with presents you with the image of a typed word—but the letters are all, like, twisted, bent, and distorted, as though the typist were severely drunk and typing on Saran wrap. You are supposed to interpret what that word is, and type it into a box on the website. 

SFX: computer keyboard typing

Actually, computers in the early 2000s were pretty good at OCR—that’s optical character recognition, meaning looking at a picture of text and figuring out what the letters are. But the added challenge of the twisty distortion really threw those OCR programs off the track.

David And behind the scenes, I mean, what is it? I mean, there’s got to be some, I don’t know, SQL database or massive bank of little images. I mean—

Luis Actually, there was no database at first.  we would just write a program that, what it would do is it would place—it would pick some, first, random characters. We’d put them on an image, then it would distort them, and then we would save that image. And then we just had a couple million of those saved, not even in a SQL database, just they were there. So saved as files. 

It worked brilliantly. The spambots didn’t have a chance.

At the time, Von Ahn had no idea if his invention would be of any commercial use. But one guy, he knew would be interested: Udi Manber, that Yahoo chief scientist, who’d given the talk that started this whole affair. 

Luis (cont’d)   We sent them an email saying, “Hey, we think we can solve your problem.” And he said, “Oh, that seems like it solves the problem.” And then, in fact, pretty soon after that, it was being used by Yahoo, and then basically, every website started using it, and there was just, you know, millions of websites out there were using it. 


Well, how wonderful! Luis Von Ahn’s ingenuity 1, spammers zero. Internet saved!

Luis: [00:06:03] And, you know, at first I was very proud of myself, because, OK, look at the impact that my, my work has had. You know, basically, we stopped spam, it’s being used by a lot of people. 

There was only one problem: 

Music abruptly stops

People hated his invention.

TEDx Talk clip

LUIS: 0:00 How many of you had to fill out a web form where you’ve been asked to read a distorted sequence of characters like this? How many of you found it really really annoying?

OK, outstanding. So I invented that. (laughter)

That’s how he introduces himself in a 2011 TEDx talk at Carnegie Mellon.

Luis: I would be at a party, and people would ask me what I did,   And I would tell them that I helped invent that thing, and people would tell me, “Oh, I hate you.” 

That’s right: The inventor of Captcha is fully aware that people hate the thing.

LUIS: I say either— “well, I’m sorry.” Or,, “I find it annoying too.”  

You heard it right here, folks: Even he finds them annoying!

In fact, Luis can tell you exactly how much of your time they waste.

Luis: I did a little back of the envelope calculation. At the time, about 200 million times a day, somebody typed one of these CAPTCHAs.   200 million times, times ten seconds, which is how long it takes to type one of these—you, humanity as a whole was wasting about 500,000 hours every day typing these annoying CAPTCHAs.

David  Great.

Luis So I started feeling bad about that. And that’s when I started thinking, “OK, can we do something good with that time?” 

See, the thing is kind of similar to the, the gym idea. Can we get millions of people to do something during that time that is actually valuable? 

I’ll give you a hint: We’re only at the halfway point of this story. After the break, we’ll tell you what he came up with to make those half a million hours every day useful to humanity.


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Welcome back!

By 2005, Luis Von Ahn’s invention, the Captcha test, was a huge hit. It reduced the world’s scumbag spammers to blubbering losers. No longer could they bombard websites with phony signups, for the purpose of pursuing their pathetic spammy schemes.

Unfortunately, he had achieved this success by transferring the burden onto us. Treating us as though we were guilty until proven innocent. Now we were the ones being challenged. We were losing ten seconds per website, typing in those stupid distorted letters. 

Now, to be fair, history is full of examples like that, where the actions of a few selfish, greedy idiots wind up inconveniencing billions of innocent people for the rest of our lives. Some dirtbag tries to put poison into drugstore Tylenol bottles, and now the rest of us are stuck with frustrating, plastic-wasteful bottle lids. Some delinquent tries to blow up a plane with a shoe bomb, and now we all have to walk through the TSA scanners in our socks.

Luis felt bad that his hacker blockade wasted everyone’s time, but at least he could do something about it.

Luis: So that’s very valuable time. So can we use it for something? And then we, we you know, I ended up coming up with this idea, that while you were typing a CAPTCHA, you could be helping digitize books. And here’s kind of how that works. 

So at the time, the year, maybe 2005, 2006, there were a lot of projects trying to digitize all of the world’s books, where, where, you know, the way that worked is you start with a physical book, and you want to put it on the Internet. And the way you do that is you basically take a digital photograph of every page of the book. 

Now, these are pictures of text. The next step in the process is that the computer needs to decipher what’s the text in there. 

In other words, computers had to perform—c’mon, you know this term!—OCR. Optical character recognition.

Luis: (cont’d) And unfortunately for books that are older, where maybe the ink has faded, computers could not recognize many of the words. 

At the time, computers couldn’t recognize about 30 percent of the words.   So the thought, the idea was, let’s take all those words that the computers could not recognize while —while books are being digitized, and let’s get people to read them for us while they’re typing a CAPTCHA.   what we started giving people were these words that the computer was not able to digitize, and or, to recognize. 

So, yeah—all this time, you thought you were typing random words. In fact, you were helping companies digitize old books and articles. And, by the way, helping Luis’s little company make money.

Luis The idea is we made a CAPTCHA, a system, a whole system that would help your website be protected against spam. So, and we gave that away for free, on, for example, Facebook use our CAPTCHA, and we give it away for free. But always with the caveat—that if they are going to do that, then we can see the answers that users are typing so that we help to digitize something. 

And the way we made money is by charging people who needed digitization stuff. 

For example, The New York Times was our client. The New York Times had this old archive of old editions of The New York Times from 130 years of New York Times or something like that, from the, from the 1800s. And they, they needed this to help digitize their whole archive.  

they were sending us all the scans they had scanned already, and we were sending them—we were taking all the words that computer could not recognize, and we were getting, you know, through the CAPTCHAs, people who are, for example, signing up for Facebook or Twitter or a lot of websites where you use CAPTCHA, they were helping us to digitize The New York Times. And we would make money from The New York Times. 

(moved from earlier)  It became very successful. And then Google bought it to help their Book Digitization whole project.  

The new system, called reCAPTCHA, became an even bigger hit. Here’s how he described the aftermath in his TEDx talk:

TEDx Talk clip

LUIS: So every time you buy tickets on Ticketmaster, you help to digitize a book. Facebook: Every time you add a friend , you help to digitize a book. Twitter and about 350,000 other sites are all using reCAPTCHA. And the number of sites that are using reCAPTCHA is so high that the number of words we’re digitizing per day is really really large. It’s about 100 million a day, which is the equivalent of about two and a half million books a year. And this is all being done one word at a time by just people typing CAPTCHAs on the Internet.


David: There are some people who are a little nervous about Google being the owner of one of the most widely used CAPTCHA systems. I’m sure you’ve been asked about that. 

Luis: Yeah, there are people who are nervous about that. I mean, I understand. I think, you know, this is these are very, very tricky questions.  I mean, personally, I, I think the privacy fight is over. I mean, I, I I’ve given up on my privacy against large companies a while ago. 

David: Wow. 

Luis: And not only that, I also think—  after having been inside Google, I saw with how much respect they treat user data, because they know that they are—you know, they know that, that they are a few scandals away from being in deep trouble. So they take it with— with a lot of care, I think. 

David: And we should point out that Google has said, “we do not use data collected   for advertising purposes.”

Luis: Yeah, that’s the case. And so I, and I actually believe them.   

Now, remember: Luis said that the hard part was finding a test that was too hard for a computer to pass, but easy enough for a computer to judge whether the test had been passed. That’s been bugging me.

David: If the computer chooses a word that’s so distorted that it itself cannot do the OCR, then how does it know if we’re right? 

Luis Yeah, that’s a great question.  when we try to digitize books, this is what we do. We, we take a word that the computer does not know— We actually pair it with another word for which the computer does know the answer. And we actually give people both words, and we say, “please type both.” And we don’t tell them which one’s which, we just say, “hey, please type both.” 

If they typed the word for which we know the answer, they type that one correctly, we assume that there are human, and we also get some confidence that they type the other word correctly. And then, and then what we do is, okay, so now we have a guess for what that other word is. We give it to like 10 other different people and we see if they type the same thing, and if they all type the same thing, we get with very high accuracy what that word really is. And that works. 

One hallmark of the reCAPTCHA system, in other words, is that you have to type in two words. 

Luis There’s sometimes also funny words that, um, funny combinations that happen, especially because we are showing two words at a time. 

DAVID: Oh boy. 

LUIS: I mean, there’s been all kinds of really funny examples, where it’s just like a website of a church, that’s says like, ‘Bad Christians.’ And it’s just—but these are just two randomly chosen words.  

David : So we shouldn’t infer any evil on your part? 

Luis: No, they’re random.

Now, a lot has happened since 2000, when Captcha came along, and since 2006, when you started unsuspectingly helping Google and the New York Times digitize their old pages. 

Luis: You know, early on in the first version of the CAPTCHA, computers were pretty bad at recognizing distorted text, so they didn’t have to be that distorted.   But over time, computers got better and better. And in fact, by now, computers are, in many cases, about as good as humans. 

Because of that, we have to make them harder and harder. 

David: A lot of times, the puzzles are so hard that even the human can’t pass the challenge.   I’m sure you’ve been sent screenshots of words that are so munged no one can tell what it is. 

Luis: Yes. That happens. I mean, it’s rare that that happens. 

And that’s why the CAPTCHA itself, in true arms-race fashion, has evolved.

Luis: (cont’d) So what has happened is that for the more secure things, the CAPTCHAs have moved away from these distorted characters.  And what is being used now are these—the puzzles are now things like, you see a bunch of pictures, and you have to click the ones that contain a stop sign— 

David: Right, the traffic lights, the fire hydrants.

Luis: Yeah.  It’s exactly the same idea as reCAPTCHA,  except we’re not this time, we’re not trying to digitize books. This, a lot of times, comes from things like all the—all the mapping cars, or the self-driving cars. Basically, these are cars that are driving around that are capturing images of the whole world that are trying to figure out what’s around them.  sometimes they cannot recognize what’s in an image.   So it’s a similar case. It takes things—like, “is this is stop sign? I’m not sure. Okay, send it to human.” And then when you, when you get it, and you click on the stop sign, you’re actually helping either the self-driving car or the mapping software or whatever know that there is actually a stop sign, stop sign right here. 

David: Oh. So we’re still doing good for the world as we do this. 

Luis: Still doing good for the world. 

David: Or for a company. 

Luis: Or for a company. Just maybe not digitizing—or for a company, but maybe not digitizing books.   but it’s a similar idea, it’s a thing that a computer cannot do.   

David: You just solved a mystery for hundreds of millions of people—why it’s always traffic lights and fire hydrants we’re supposed to choose, and not bananas and puppies or…. 

Luis: It has to do with both self-driving cars and also mapping software. 

OK. So now we kind of get why we have to put up with these challenges. Or we did 20 years ago! But really? Nothing better has come along since?

David: Are we sure that there’s nothing less annoying that we could do to thwart these spammers? 

Luis: Yes, there is.   by now, it did become a lot less annoying. I don’t know if you’ve seen that of late, where, you know, there’s a thing that says reCAPTCHA. We’re just trying to figure out whether you are human, and they just ask you to click somewhere.   just, ‘click on this box’—that, that is much less annoying. 

David: Sometimes, you don’t see anything except, ‘I’m not a robot.’

Luis:  Yeah, yeah, yeah. I’m not a robot.  

This is something that is, that that is done by Google. This actually comes from the original team.   This is the company that they bought from me.  

When you get that one, that means that in this particular case, probably means Google, has figured out that—yeah, you know what? We know you, because you’ve been around since 2016 in this computer, and you have a lot of Gmail emails, and you’ve done a lot of Google search queries. You’re a normal person, you’re not a spammer. 

So they just do a little thing that just tries to double, double check that, that I can move the mouse or whatever.   So, so one thing that has changed from the year 2005 to now is that there are companies like Google or like Facebook that, for the majority of people on the Internet, they kind of know who you are.   

If you have a fresh computer that you’ve never used before,   then you would have to do that annoying CAPTCHA. But for most of us,   you are unlikely to have to type this as much as you were back in, say, the year 2005.  It has become a lot better, you know, probably a little bit at the cost of your privacy.  

OK, but wait a minute. We now know that computers eventually got too smart for the distorted-text-reading Turing test. Won’t they eventually get good enough to identify a few stupid stop signs in a photo grid?

Luis: It is, it’s a cat and mouse game. Now probably there’s a bunch of people working on making better recognition of stop signs or something like that.   eventually—  eventually computers are going to be able to do everything humans can. And so at some point, there won’t be a test that can distinguish humans from computers. 

David: Well, wait a minute. Does that mean the end of the Internet? I mean, what happens is that—if there’s no sort of Turing test that works anymore?

Luis :  I don’t think it’s the end of the internet, particularly because, like I said,  more and more, these companies are going to know more and more about you. And I just don’t think there will be a humongous problem. 

David: Okay, well,  whatever the endgame is, why can’t we do that today?  since we know it’s an arms race, since we know that eventually we’ll lose it to A.I. and computers, why can’t we jump to whatever will follow it now?  

Luis: I’ll tell you why.  this, by the way, is like 95 percent of the way there. I mean, really, for most of us, Facebook knows who we are. And Google knows who we are, so it’s 95 percent of the way there. The reason it’s not a hundred percent of the way there is because there are some people who really care about privacy. And, you know, there’s, there’s always going to be a kind of a way to browse privately. So, for example, there’s Chrome has private browsing. There’s all this stuff when people care about privacy. 

  I mean, there’s, there’s a tradeoff here, right?  

David: Well, the irony is that it seems like most of the websites that present me with a CAPTCHA, I’m trying to get to in order to supply my name and address, like signing up for something. 

Luis: Yes, it’s funny. 

David: Why do I need privacy when the whole purpose is to supply my information? 

Luis: Yeah, that’s funny.  

Now, I mentioned at the beginning that Luis has had three world-changing ideas. You’ve heard about the gym membership that powers the grid, and you now know about Captcha. 

But what about his third creation? It’s Duolingo, the language-training app. At this moment, it has half a billion registered users, learning 40 different languages, all for free. 

Audio clip of DuoLingo in action.

And from the beginning, you could see the fingerprints of Luis Von Ahn, master of crowdsourcing, all over it.

Luis:   In early Duolingo, as you were learning a language on Duolingo, you’re actually helping us to translate stuff that computers could not translate.  

In fact, CNN was a client, so CNN would send us their news in English. We would then give it to people  who were Spanish speakers who are learning English. And we would say, “Hey, you want to practice your English? Help us translate this CNN article into your native language of Spanish.” And so they would do it, and they would be learning English, and then we would get that translation, and then we would send it back to CNN and they would pay us for the translation. That was the very first version of Duolingo. 

It turned out that,   Just like the gym, it ends up being that you just —just can’t make much money from this.  

And so we decided, “OK,   just go, go to a business model where we   actually give you ads.” And the way we make money is by showing you ads. 

The dude just keeps doing that! He keeps coming up with ideas that make the world a better place, thwart the bad guys, and make a lot of money! It’s really a shame he gave up that electrical-grid gym thing.

David:  Are there ever things that come to you in the shower that might be your —your big third act? I mean, honestly, to, to have the impact you’ve had, twice, is astonishing, but it makes me think there’s something in you that just has great ideas that can go really wide. 

Luis: You know, as time passes, I am a lot more interested in  literacy and teaching people how to read.  I think with a computer, we should be able to teach the whole world how to read, significantly better than humans can teach you how to read. 

You know, the U.S. is, the U.S. is fine. Most, most adults in the U.S. know how to read. But   many countries in the world, there’s a significant fraction of people who don’t know how to read. In fact, there’s about a billion adults in the world that are illiterate. And I think we can—I think we can make a big dent with, you know, with a system to teach people how to read. So we’re working on that. 

In the meantime, now you know why you have to encounter those infernal website challenges, you know how they came about, and you now consider them a necessary evil. Well, maybe you do.

David:  Just for people who are like, “I don’t know what it is, I just don’t like doing it, I can’t even tell what’s a freaking traffic light.” Let’s just lay out what would happen if all of these challenges went away tomorrow. What would happen to the Internet? 

Luis: Most likely, you would get a lot more spam in either your email spam, or you’d get a more kind of random Facebook followers that are not real people.   these fake accounts can start boosting up bad political messages.  There would be probably more fake news. They would probably be, you know, more spam.  

David: Right. And from spam, phishing and spyware and…. 

Luis: Yeah, more spyware—the web would be a less safe place. 

David: All right. So when you do explain this to someone at the proverbial party, are they generally satisfied with the— the notion that—

Luis: Yeah, I think most people, I think most people realize that it’s like, you know, these things are kind of like a— like a key. Nobody, nobody likes—it’s not like I love opening my door with the key. It’s kind of annoying. But it’s there, and I understand it just makes, it makes my house safer. In this case, it kind of just makes the whole Internet safer.   eh–kinda gotta do it.

Thanks for listening to this second-to-last episode of the season. If you have any interest in a second season, please spread the word! Subscribe to this podcast. Leave a review on Apple podcasts, or a rating on Spotify. 

UNSUNG SCIENCE with David Pogue is presented by Simon & Schuster and CBS News, and produced by PRX Productions. The Executive Producers for Simon & Schuster are Richard Rhorer and Chris Lynch.  

The PRX production team is Jocelyn Gonzales, Morgan Flannery, Pedro Rafael Rosado and Ian Fox, project manager. Jesi Nelson composed the Unsung Science theme music, and Kristina Rebelo fact-checked my script. 

At, you can listen to every episode ever made, and read complete transcripts. For more of my stuff, visit or follow me on Twitter, @pogue. Thanks for listening!