But Why: A Podcast for Curious Kids
Episode: Do Atoms Never Touch?
Release Date: April 18, 2025
Host: Jane Lindholm
Guest: Ben Still, Teacher, Scientist, and Author

Introduction

In this captivating episode of But Why: A Podcast for Curious Kids, host Jane Lindholm delves into the microscopic world of atoms with expert guest Ben Still. Titled "Do Atoms Never Touch?", the episode explores fundamental questions about the building blocks of our universe, all prompted by curious young minds.

Meet the Expert: Ben Still

Ben Still, a high school physics teacher and passionate particle physicist, brings his expertise to the show. Author of Particle Physics, Brick by Brick and The Secret Life of the Periodic Table, Ben provides insightful explanations tailored for young listeners. As he puts it at [02:07], “I very much enjoy talking about physics and science in general to anyone that will listen to me.”

Understanding Atoms

Jane introduces the topic by explaining that atoms are the smallest units of matter, too tiny to see even with a microscope. Ben elaborates, “[...] everything around us is made up of atoms being made of atoms ourselves. [...] we have built the idea that there are these subdivisions of things in our universe, and an atom is one of those subdivisions” ([02:58]).

Composition of Atoms

Kids Noah and Ari pose fundamental questions about why everything is made of atoms and why atoms are so small. Ben responds by comparing atoms to LEGO bricks, emphasizing that “[...] if you want to create something complex, it's going to require each of those building blocks to be really small” ([06:52]). He further breaks down atomic structure:

• Protons, Neutrons, and Electrons: Atoms consist of a nucleus containing protons (positively charged) and neutrons (neutral), surrounded by electrons (negatively charged) ([09:13]).

• Quarks: Delving deeper, Ben explains that protons themselves are made of quarks, highlighting the complexity beneath the atomic level ([11:22]).

Scale and Immensity of Atoms

Oliver’s curiosity about the number of atoms in the world leads Ben to an astonishing fact: “If we think about the mass of the Earth, we can make an estimate, and you get to something around 10 to the 50 atoms” ([14:16]). Jane reinforces the immensity by comparing it to “75 elephants or a million school buses,” emphasizing that all these are composed of billions and billions of atoms ([14:56]).

Properties and Interactions of Atoms

Addressing why atoms don’t touch despite being the building blocks of everything, Ben explains the role of electromagnetic forces and the quantum mechanical exclusion principle. He states, “[...] atoms are points in space, but they're always going to repel one another through the force of electromagnetism” ([23:08]). Additionally, the exclusion principle ensures that no two particles can occupy the same space simultaneously ([24:29]).

Visualization and Detection

Elizabeth’s question about visualizing atoms prompts Ben to discuss advanced tools like the tunneling electron microscope. He mentions, “The way that we see atoms is not in the way that we see, but we look at atoms through the interactions that they have with other particles and other atoms” ([15:37]). Through such technologies, scientists can image the spherical shapes of atoms and understand their interactions ([17:55]).

Atoms and Color

Emily’s curiosity about how atoms get color leads to an exploration of electron excitation. Ben explains, “Atoms themselves don't have color, but they do emit colored light” ([25:31]). When electrons jump between energy levels, they emit unique wavelengths of light, a principle utilized in spectroscopy to identify elements ([26:48]).

Origin of Atoms

Luke’s final question touches on the origin of atoms. Ben recounts the Big Bang theory, stating, “All the matter in the universe [...] can be traced back to something called the Big Bang” ([27:29]). He describes how the extreme heat of the early universe led to the formation of the first atoms, primarily hydrogen and helium, with heavier elements forming in stars over billions of years ([27:55]).

Conclusion

Ben wraps up the discussion by marveling at the simplicity and elegance of atomic theory: “[...] there's only a handful of things that make up pretty much everything in the universe around us, and I think that that is quite, quite amazing” ([28:43]). Jane encourages listeners to stay curious and explore further through provided resources and upcoming episodes.

Notable Quotes:

• Ben Still [02:58]: “Why everything is made of atoms isn't really a question that I would say science is able to answer, because essentially, we just find ourselves in a universe with atoms being made of atoms ourselves.”

• Ben Still [06:52]: “[...] if you want to create something complex, it's going to require each of those building blocks to be really small.”

• Ben Still [11:22]: “Protons are actually made of three smaller particles, which are called quarks.”

• Ben Still [23:08]: “Atoms are points in space, but they're always going to repel one another through the force of electromagnetism.”

• Ben Still [25:31]: “Atoms themselves don't have color, but they do emit colored light.”

• Ben Still [28:43]: “[...] there's only a handful of things that make up pretty much everything in the universe around us, and I think that that is quite, quite amazing.”

This episode of But Why masterfully breaks down the intricate world of atoms, addressing complex scientific concepts in an accessible and engaging manner for young listeners. Through thoughtful questions and expert explanations, children gain a deeper understanding of the very fabric that composes our universe.