Visualize Invisible Electric Potential in 3D! An Amazing Science Craft Using a Lunchbox Lid
I’m Ken Kuwako, your science trainer. For me, every day is an experiment.
The world of electricity is invisible to the naked eye, but have you ever wondered what it would look like if we could actually see it? In physics class, we learn about the concept of electric potential, but it’s often hard to wrap your head around it just by looking at flat diagrams in a textbook. Today, I want to share a groundbreaking way to visualize this invisible map of electrical force using a very unexpected everyday item.
Could a Lunch Box Lid Be a Window into Science? The Amazing 3D Potential Model
To create this 3D model of electric potential, I used—believe it or not—plastic lunch box lids. You know those clear lids you see at convenience stores or supermarkets? By stacking them, we can represent height. You can often find just the lids for sale at home improvement stores.
The process is simple: I drew equipotential lines (lines connecting points of the same electrical “height”) on each transparent lid. Because these lids are clear and designed to stack perfectly, they make an excellent teaching tool that allows you to observe a complex 3D structure just by piling them up.
Sharpening Your Intuition with Precision
Even though this is a DIY project, I didn’t compromise on scientific accuracy. I used a software called Grapher to calculate and generate the precise patterns for the equipotential surfaces. Just as contour lines on a map reveal the shape of a mountain, accurately drawing these lines makes the peaks and valleys of electric potential vividly clear.
Imagine a Ball Rolling Down an Electrical Mountain
For this demonstration, I recreated the scenario of two positive charges placed near each other. You can think of this as a landscape with two large hills sitting side-by-side. Physics exam questions often ask things like, “What happens if you place a test charge near the center of two charges and give it a tiny nudge?” With this model, the answer becomes intuitive.
If you nudge it slightly along the x-axis, it will rock back and forth in the valley between the two hills, mimicking simple harmonic motion. However, if you nudge it along the y-axis, it will pick up speed and slide down the mountain, moving further away. When you can visualize these surfaces in 3D, you start to feel the physical phenomena rather than just solving equations.
The World of Negative Charge: Thinking in Reverse
The coolest part about this model is that you can represent entirely different phenomena just by flipping it over.
If you turn the mountain created by a positive charge upside down, it becomes a deep pit or valley created by a negative charge.
This is a single negative charge—it looks like a bottomless hole!
Flip the whole stack back over, and you have a towering mountain of positive charge reaching for the sky.
With a little creativity, even ordinary materials can be transformed into powerful tools for explaining complex physics. Why not try looking at the objects around you through the lens of science?
Inquiries and Requests
Let’s bring the wonder and excitement of science closer to home! I’ve put together various fun experiments and tips that you can try yourself. Feel free to explore more!
My book based on these science tips is now available. Click here for details.
To learn more about me (Ken Kuwako), click here.
For work inquiries (writing, speaking engagements, science workshops, TV supervision, appearances, etc.), please contact me here.
– Get the latest updates on X (formerly Twitter)!
Check out my experiment videos on the Science Material Channel!
７月のイチオシ実験！
夏でプシュッと爽やか実験！
テレビ番組監修・イベント等のお知らせ
-
時速２００ｋｍで走るランボルギーニが、長さ１２ｍのテーブルクロスを一瞬で引き抜く——そんな常識破りの実験が、ふたたびテレビの世界で大きな話題になりました。しかも今回は「視聴者が選ぶワクワク実験ランキング」で、なんと堂々の第１位を獲得したのです。Tverでまだ見ることができるのでぜひご覧ください。
- 7月18日（土） 教員向け実験講習会「ナリカカサイエンスアカデミー」の講師をします。お会いしましょう。
- 12月26日（土） ナリカサイエンスアカデミー（教員向け実験講習会）開催
書籍のお知らせ
- ７月16日発売 『高校入試 分解問題集 理科』（学研）…難しい問題も小さな問題に分解することで、問題を解くことができます。そんな分解の技術が身につくように深く関わりを持って作りました。
- 『大人のための高校物理復習帳』（講談社）…一般向けに日常の物理について公式を元に紐解きました。特設サイトでは実験を多数紹介しています。※増刷がかかり６刷となりました（2026/02/01）
- 『きめる!共通テスト 物理基礎 改訂版』（学研）… 高校物理の参考書です。イラストを多くしてイメージが持てるように描きました。授業についていけない、物理が苦手、そんな生徒におすすめです。特設サイトはこちら。
各種SNS（更新情報をお届け！）
【日本語】X(Twitter)／instagram／Facebook 【英語】BlueSky／Threads
Explore
- 楽しい実験…お子さんと一緒に夢中になれるイチオシの科学実験を多数紹介しています。また、高校物理の理解を深めるための動画教材も用意しました。
- 理科の教材… 理科教師をバックアップ！授業の質を高め、準備を効率化するための選りすぐりの教材を紹介しています。
- Youtube…科学実験等の動画を配信しています。
- 科学ラジオ …科学トピックをほぼ毎日配信中！AI技術を駆使して作成した「耳で楽しむ科学」をお届けします。
- 講演 …全国各地で実験講習会・サイエンスショー等を行っています。
- About …「科学のネタ帳」のコンセプトや、運営者である桑子研のプロフィール・想いをまとめています。
- お問い合わせ …実験教室のご依頼、執筆・講演の相談、科学監修等はこちらのフォームからお寄せください。
- Why Doesn’t Your Stomach Digest Itself? What a 170-Year-Old Accident Revealed (Video: “The Marvel of Human Digestion”)
- How Buildings Fight Back Against Earthquakes: From Liquefaction to Sloshing Dampers, Fully Explained [Miraikan]
- See the Invisible: The Mysterious Phase Shift Hiding in Coils
- Punches Aren’t Damage: Understanding Becquerels and Sieverts Through Boxing
- Pour Water and a Cube Appears! The CMY Water Cube That Reveals the Magic of Color Subtraction
- The Mysterious Device That Makes Styrofoam Float in Midair — Visualizing Sound Waves with a Kundt’s Tube
- The Switch Is Off, But It Won’t Stop! Capturing the Mystery of Coil Oscillations with a Sensor (EasySense V-Hub)
- Eddy Currents Launch Metal Rings Into the Air — The Electromagnetic Magic of Tsukuba Expo Center
- Caught in the Lab: Does Current Actually Hesitate? A Coil’s 0.0005-Second Story
