Richard Feynman

The Great Explainer’s Enduring Legacy

May 25, 2025

On Feynman’s birth anniversary this year, I posted a brief article sharing my admiration for a man whose brilliance wasn’t just in marvelling mysteries, but making it accessible to everybody.

Known as "The Great Explainer," Richard Feynman, a Nobel Prize-winning physicist, had a rare gift: he could take the most complex ideas in physics and make them feel like a conversation with a curious friend. His approach - rooted deeply in first principles, relentless curiosity, and a refusal to accept anything on faith - transformed how we think about physics and learning.

Feynman’s genius wasn’t confined to equations and theory. It was in his humility, his playful spirit, and his insistence that true understanding comes from building knowledge from the ground up. As Freeman Dyson once noted, Feynman "refused to take anybody’s word for anything," choosing instead to rediscover physics on his own terms. This led to groundbreaking contributions, like his work in quantum mechanics and the development of Feynman diagrams, which revolutionised how we visualise particle interactions.

But what makes Feynman timeless is his ability to inspire. His famous phrase, "What I cannot create, I do not understand," found on his blackboard at the time of his passing in 1988, captures his philosophy: real understanding requires grappling with ideas until you can rebuild them yourself. This mindset resonates deeply with me, both in my work at ASML and in how I approach learning every day.

Before I moved to a new department at ASML, my first team gifted me Feynman’s Lectures on Physics, a cornerstone of scientific education. These volumes, now some of my most prized possessions, feel less like textbooks and more like an invitation to explore the universe with a guide who’s endlessly curious and refreshingly honest.

In this post, I want to dive into some of my favourite Feynman works and stories, each a window into his unique mind. From lectures that sparked my career to videos that capture his awe for the world, these moments show why Feynman remains a hero for scientists and non-scientists alike.

1. An Actor’s Perspective: Alan Alda on Feynman’s Magic

In his 2002 Caltech commencement address, actor Alan Alda shared a vivid portrait of Feynman that captures why he was so beloved. Alda, who portrayed Feynman in the play QED, described him as a man who combined intellectual rigor with a childlike sense of wonder. In the speech (available here), Alda recounts how Feynman’s curiosity was infectious, whether he was cracking safes at Los Alamos or explaining quantum electrodynamics to a room of students.

What struck me most about Alda’s reflection is how he highlighted Feynman’s authenticity. Feynman never pretended to know more than he did. If he didn’t understand something, he’d admit it - whether to a Nobel laureate or a cab driver. This humility, paired with his ability to make science feel like a shared adventure, is what made him such a powerful communicator. Alda’s speech reminds us that Feynman’s legacy isn’t just in his discoveries but in how he invited everyone to join him in asking questions.

2. “Plenty of Room at the Bottom”: The Spark for Nanotechnology

Feynman’s 1959 lecture, “Plenty of Room at the Bottom” (available here), is a visionary essay that arguably laid the foundation for nanotechnology. In it, he imagined a world where we could manipulate matter at the atomic scale, from writing the entire Encyclopaedia Britannica on the head of a pin to building tiny machines that could revolutionise medicine and computing.

Reading this lecture as a young scientist was a turning point for me. Feynman’s ability to see possibilities where others saw limitations was electrifying. His questions beautifully - “Why cannot we write the entire 24 volumes of the Encyclopaedia Britannica on the head of a pin?”. These were not just thought experiments; but a call to action.

This essay is a testament to human ingenuity and the power of asking “what if?” Whether you’re in tech, art, or any field, Feynman’s invitation to explore the “bottom” of things - literally and figuratively - will spark your imagination.

3. The Mystery of Rubber Bands: Feynman’s Playful Clarity

One of my favourite Feynman moments is his explanation of why rubber bands work, captured in this delightful video watch here. With his signature enthusiasm, Feynman breaks down the molecular mechanics of elasticity in a way that feels like a magic trick. He starts with a simple question “Why does a rubber band snap back?” and in a few short minutes, leads you through a dance of atoms and energy that’s both rigorous and joyful.

What I love about this explanation is how it embodies Feynman’s philosophy: if he couldn’t explain something in everyday terms, he didn’t believe he truly understood it. He doesn’t rely on jargon or authority; instead, he builds a mental picture so clear you feel like you’re seeing the world anew. Watching this, I’m reminded of why I fell in love with physics - it’s not just about equations but about uncovering the hidden rules that govern everyday life.

4. Orbits and Oval Paths: A Lesson in “Infinite Intelligence”

Feynman’s lecture on why planetary orbits are elliptical, beautifully reimagined by the YouTube channel Three Blue One Brown watch here, is a testament to his ability to make the complex feel elemental (but not easy). He begins with a disclaimer: “I am going to give what I will call an elementary demonstration. But elementary does not mean easy to understand. Elementary means that very little is required to know ahead of time in order to understand it, except to have an infinite amount of intelligence.”

This tongue-in-cheek remark captures Feynman’s approach perfectly. He doesn’t dumb things down; he invites you to wrestle with ideas. The lecture, animated with stunning clarity by Three Blue One Brown, walks through why orbits are oval rather than circular, using Newton’s laws and geometric reasoning. It’s a journey that requires focus - what Feynman playfully calls “infinite intelligence” - but for those who are paying close attention, rewards you with a deeper appreciation for the universe’s elegance.

For me, this lecture is a reminder that understanding doesn’t always come easily, but the effort can be worth it.

5. The Beauty of a Flower: Feynman’s Ode to Wonder

In a short but profound clip watch here, Feynman reflects on the beauty of a flower. He contrasts the artist’s appreciation of its colours and form with the scientist’s awe at its cellular structure, its evolutionary history, and the physics of its pigments. “The science,” he says, “only adds to the excitement, the mystery, and the awe of a flower.”

This moment captures Feynman’s ability to find wonder in both the simple and the complex. He didn’t see science as stripping away beauty but as revealing deeper layers of it. For him, understanding the atomic dance behind a flower’s color didn’t diminish its charm - it made it more miraculous.

This perspective has shaped how I view my work and the world. At ASML, we deal with the invisible - light, atoms, and patterns smaller than the eye can see. Yet, like Feynman, I find that the more we uncover, the more there is to marvel at. This clip is a must-watch for anyone who thinks science and beauty are at odds.

6. The Mystery of Light and Mirrors: A Question That Lingers

During my college years, a friend asked me a deceptively simple question: what’s happening at the atomic or quantum level when light reflects off a mirror? It was one of the most beautiful questions I’d ever encountered, and it sent me down a rabbit hole of exploration. Feynman’s work on quantum electrodynamics (QED), particularly his accessible book QED: The Strange Theory of Light and Matter related article here, offers a glimpse into the answer.

Feynman explains light’s reflection as a sum of probabilities, where photons take every possible path and “decide” their final trajectory through quantum interference. It’s a mind-bending concept, yet Feynman makes it feel like a detective story.

This question from college still lingers with me, a reminder of how a single curiosity can spark a lifetime of learning. Feynman’s QED lectures are a perfect starting point for anyone intrigued by the strange behaviour of light.

Why Feynman Matters Today

Feynman’s legacy isn’t just in his Nobel Prize or his contributions to physics - it’s in how he taught us to think. His insistence on first principles, his humility in the face of the unknown, and his joy in discovery are lessons for all of us, whether we are scientists, artists, or simply curious souls. In a world that often demands quick answers, Feynman reminds us to slow down, question assumptions, and build understanding from the ground up.

I encourage you to dive into these works and let Feynman’s curiosity inspire you. Whether it’s the playfulness of his rubber band explanation, the vision of “Plenty of Room at the Bottom,” or the awe of a flower’s hidden beauty, there’s something in his world for everyone.

Share your favorite Feynman moment in the comments - I’d love to hear what resonates with you!

This post was edited with the assistance of Grok 3, created by xAI.