YouTube Science Star Derek Muller Confronts PFAS 'Forever Chemicals'—In His Own Blood

Scientific American

2 days ago

As the creator of Veritasium, a science education YouTube channel with 18 million subscribers, Derek Muller has spent the past 15 years exploring a counterintuitive vision for learning: Clarity numbs the mind, but confusion can crack it open. His audience has grown because of how he challenges common misconceptions about the laws of nature, and his rise has paralleled YouTube's, whose creator-focused approach has made it the world's largest streaming service by almost every measure—from content library to audience size—recently surpassing Netflix in revenue. Amid this symbiosis, Veritasium evolved—from unpolished five-minute clips of Muller quizzing people on the street to technically sophisticated science explorations with the satisfying depth of feature films. Muller himself has appeared in many roles: trickster science teacher, experimenter with a mad-scientist flair, fearless investigator in the mold of Indiana Jones. And in Veritasium's most recent video, one of the channel's longest yet, he steps forward as an advocate for one of today's most pressing health issues: the toxic 'forever chemicals' that are now being found to contaminate almost every human being, animal and ecosystem on Earth. Entitled How One Company Secretly Poisoned the Planet, the video clocks in at nearly an hour and garnered almost three million views within a day. It is not only an exposé of corporate malfeasance but also a scientific explainer of these forever chemicals (known as perfluoroalkyl and polyfluoroalkyl substances, or PFAS) and their harm to humans. It debuted on the same day that the Environmental Protection Agency announced sweeping rollbacks of PFAS safeguards, supercharging the video's impact. Leveraging his audience, resources and cinematic craft, Muller has now focused Veritasium on a crisis whose invisible poisons, as the film's finale reveals, are already circulating in his own blood.
Learning from Wrong Answers
Teaching began early for Muller. Born in Traralgon, Australia, in 1982, he relocated to Vancouver as a toddler and so excelled in school that his teachers sometimes invited him to tutor the class. 'There was a certain way in which science appeared like magic,' he recalls—invoking science-fiction giant Arthur C. Clarke's adage that any sufficiently advanced technology is indistinguishable from sorcery. He remembers ordinary school experiments—the upside-down glass that keeps a tissue dry underwater and the soda-and-Mentos fountain. But what stuck was the sense that the universe kept secrets only curiosity could unlock. 'Isn't it everything?' he says when asked why science matters. 'Isn't it obvious that it's the most important thing?'
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When Muller graduated, he was torn between pursuing filmmaking and science. He wanted to be 'uniquely useful,' he says. 'I felt like if I went into science, maybe I would be a swappable cog in some sort of machine.' But he also feared that pursuing film might have him running coffees in Los Angeles in hopes of making the right connection and getting a break. He took a full scholarship in engineering physics at Queen's University in Ontario and then decamped to Sydney, Australia, to pursue film—only to learn that the Australian Film, Television and Radio School admits just a handful of students per program each year. Lacking a portfolio, he wandered into the University of Sydney's physics department in hopes of a tutoring gig and stayed to do a doctorate on how people learn—or fail to. In classes, he noticed that students often nodded appreciatively but retained almost nothing. 'If you perform a demonstration and don't force the class to make a prediction,' he says, 'they'll learn about as much as if they never saw the demonstration at all.'
Muller's doctoral thesis compared two instructional video styles, which were viewed by undergraduates at the University of Sydney. The first featured an actor delivering a polished, textbook explanation of Newton's laws. Participants described this version as easy to follow. The second portrayed a student repeatedly stumbling over the laws while a tutor tried to set him straight. Most viewers found this depiction confusing. But when tested on the concepts, participants who called the textbook account 'clear' scored no better than they had before watching it. By contrast, those who watched the 'confusing' video improved significantly. Muller's takeaway was that learning requires friction—and that a student's first confident error may be the strongest lever a teacher can pull. 'Some level of discomfort seems to be essential,' Muller says. 'That's when learning can really take place.'
From Back-Up Plans to Veritasium
After Muller received his Ph.D., he says, he took a stable job with a tutoring company in Sydney only to realize that 'so much of my life had been about back-up plans.' As he looked for a way to merge his passions, his attention fell on YouTube. The platform, which launched in 2005 and was acquired by Google in 2006, had reversed the logic of the Web: Instead of charging creators to host videos, it was sharing advertising revenue with them and splitting the money 55–45 in the creators' favor—'a profound shift in thinking,' Muller says. In Australia comedian Natalie Tran's YouTube channel had already crossed a million subscribers, and she was pulling in a six-figure income. Whereas success in the film industry often depended on luck and connections, YouTube seemed more meritocratic to Muller. He kept tutoring 15 hours per week to pay his bills and started the channel he named Veritasium, which combines veritas, Latin for 'truth,' with the 'ium' suffix of an element to mean 'an element of truth.'
Muller uploaded his first clip under the channel name Veritasium in early 2011. His trademark became the street-corner quiz. He would ask passersby why the sky was blue or whether a heavy object would fall faster than a light one and then watch their confidence crumble as he kept questioning them. In one video, he asked people what they thought would happen to an extended Slinky when it was dropped from a roof. They guessed it would simply fall. When his slow-motion footage revealed that the bottom end of the released Slinky merely hung suspended until a compression wave arrived from above, viewers felt their intuition buckle. Millions clicked, with each view yielding pennies and each penny affirming Muller's hypothesis: discomfort correlates with learning—and with viewer engagement.
Nigel Kuan, a high school physics teacher, who met Muller while studying at the University of Sydney and later collaborated on several Veritasium videos, says Muller's emphasis on using people's misconceptions to teach science has influenced his own approach. 'I actually recommend the videos to newer teachers,' he says. One in particular, called Why Do You Make People Look Stupid?, stands out to Kuan as best representing Muller's pedagogic style. It opens with Muller arriving at a café table and saying, 'Hey, YouTube, you said you wanted to talk. What's up?' Across from him also sits Muller, wearing a white YouTube T-shirt and the type of reflective aviator glasses favored by law enforcement. 'YouTube Muller' accuses Muller of making people look stupid and shows clips in which the latter watches as individuals fumble through incorrect scientific explanations. YouTube Muller then quotes viewer comments—many laden with expletives—that called Muller 'condescending' and 'pretentious' and asks, 'Why does your face light up with glee every time you hear a misconception?' This video, it turns out, is no different from those in which Muller invites people to explain what water is or where trees get their mass. But now the fallacy to be disproved is not about science but about him: that, in his own words, he 'delights in humiliating other people.' Muller, of course, returns to his core idea: people learn better if they confront their own misconceptions.
The Rise of YouTube and Veritasium
In mid-2011, when Muller was getting his channel off the ground, YouTube was already processing 48 hours of new videos every minute and logging about three billion daily views. Soon it began organizing meetups and creator spaces in major cities and promoting thousands of fledgling teaching channels—from crash-course chemistry to Muller's experiment-driven physics. The result was a self-reinforcing marketplace where educators could earn a living and viewers could binge gravitational waves alongside gaming highlights. YouTube's 2012 decision to reward watch-time minutes over mere clicks also encouraged Muller to develop longer videos in which he layered demonstrations, expert cameos, and slow-burn narrative reveals, unspooling each episode like a mystery novel. In 2013 Veritasium cleared one million subscribers—by 2021, the number was 10 million. As for YouTube, today more than 500 hours pour onto the platform each minute. It counts 2.7 billion monthly users. And as of October 2024, its combined ad-and-subscription income had topped $50 billion in the past four quarters—comfortably ahead of any other individual streaming platform, including those owned by Amazon and Disney.
Casper Mebius, who joined Veritasiumas an intern in 2023 and now writes, directs and produces episodes, recalls his first meeting with Muller, who, 'instead of interrupting me or cutting me short, just literally let me talk through the whole thing for 40 minutes.' Mebius soon learned this wasn't unusual. Muller often patiently listens through meetings with his team. 'Then he just makes one comment, and it's like he's throwing a dart and hitting the bull's-eye,' Mebius says. In this way, Muller is still teaching—letting others lay out their predictions and take the risks necessary for learning. But at times, his emphasis on the pedagogical value of risk-taking goes further, as when he swam in shade balls (softball-size plastic spheres that float on reservoirs to block sunlight) after a manufacturer warned him not to, explored Fukushima's radioactive zone and had a bucket of pennies dumped on him from a helicopter to prove that they couldn't kill him.
Changing How We See the World
Fifteen years after its inception, Veritasium—now one of the world's most popular science channels, with 18 million subscribers and more than 3.3 billion views—has grown from a one-man passion project to a team of nearly 20 people supported by investments from Electrify Video Partners, a company that helps digital creators scale their businesses. 'Now there's a big team, with dedicated editors, writer-directors and hosts, and that lets us tackle bigger and better stories,' Mebius says. One question the members always ask is whether the story they are telling will make people 'change the way they view the world.'
How One Company Secretly Poisoned the Planet is perhaps Veritasium's boldest attempt yet to do so. Gregor Čavlović, a producer and director at Veritasium who co-wrote it with Muller, learned about PFAS while researching a previous project. The new video, which received more viewer watch hours on its first day than any other video in Veritasium's history, layers one mystery atop another: from why fridges were killing people in Chicago in 1929 to why cattle drinking from streams in West Virginia began dying in the 1990s to how the dangers of PFAS were hidden even as chemical corporations made billions. 'I think something important to note is how young and scarce research on PFAS is,' Čavlović says.
In the video, as Muller and Čavlović discuss the many ways that PFAS have infiltrated our lives—such as via nonstick cookware, waterproof clothes and stain-resistant carpets—the story becomes increasingly unsettling. It follows West Virgina farmer Wilbur Earl Tennant, who watched more than 150 of his cows slowly die, and environmental lawyer Robert Bilott, who read through 60,000 corporate documents to reveal the risks of contamination. It describes how PFAS have contaminated not just household well water but also snow in the arctic and rain on the Tibetan Plateau. And it culminates with Muller testing his own blood for the forever chemicals. Levels of one of the PFAS chemicals in his blood, he discovers, is twice the national average, and another is six times higher than the average. His combined total places him close to the limit at which U.S. science and health advisory groups recommend screenings for PFAS-related diseases. Based on the contamination levels in many U.S. water sources, Čavlović and Muller deduce that the latter could have reached those blood levels merely by drinking tap water from various sources in and around Los Angeles. This is usually the moment in Veritasium videos where Muller shows his delight in solving a mystery, but this time the look on his face is one of dismay.
The video also points out the Trump administration's threats to newly established EPA rules to limit PFAS in drinking water. 'An important point for the video was not just to inform people about how potentially harmful these chemicals are but also to tell them what academic and governmental institutions are doing to help regulate this,' Čavlović says. 'But it was by pure chance that the video was published the same day that the EPA actually decided to pull back some of these regulations.'
The Courage to Question
In an online sphere crowded with science content, Veritasium has consistently excelled for years by not dumbing down its videos to chase clicks. And Muller, as its host, is always quick to share his personal fallibility. 'The first principle is: you must not fool yourself, and you are the easiest person to fool,' he says, invoking the cautionary mantra of physicist Richard Feynman. When a concept confuses or surprises him, he lets the audience know, and these viewers become his partners on the path to discovery. He hopes his approach—relentlessly trying to figure out the truth—will 'seep into people's brains on this deep level' and encourage them to understand the world 'not as I want it to be, not as it appears to be, but as it actually is,' he says. 'That is the unvarnished truth of the channel: it's trying to promote the increase of rationality and critical thinking.'
The company he built operates nomadically, though Muller, his wife—planetary scientist Raquel Nuno—and their four children call Lisbon, Portugal, home at the moment. Parenting, he reflects, is beautifully poetic. 'You get to exist in the same interaction that you've already had as a child, but now you're on the other side of it,' he says. When his son asked why a rainbow is an arc, Muller felt the old itch to replace quick answers with deeper voyages. He created the video Why No Two People See the Same Rainbow to explain droplet geometry, refraction, optical caustics and the human penchant for stopping one level short of a true explanation. In this sense, the man accused of making people look stupid is chasing a rarer spectacle: the instant they look enlightened. And as Muller's story proves, embracing confusion can lead not only to deeper understanding but also to extraordinary outcomes and the courage to take on ever greater challenges. After all, Veritasium itself was born when Muller decided to stop playing it safe.