Every date on one line
All the key dates from every topic, oldest first. Tap one to open its topic. Notice how the stories cross: the same names (Kettering, Leland, Edison, Goodenough) and the same problems (losing power in wires, making parts that fit) keep coming back.
Quiz me
Ten questions picked from the topics (from the filter on the Topics tab, if one is set). Each answer tells you why and which topic to read.
About these rabbit holes
Every topic is built the same way:
- The question it answers, the way you'd actually ask it ("why is a car 12 volts?"), and a short answer.
- The story: who, when and what happened, with the key dates listed.
- Why it turned out that way: the engineering, money or people reason. This is the part to remember.
- What it means today in a house, a garage, a car or on a solar battery bank.
- Word origin, where it helps a term stick.
- Myths and corrections: popular stories that are wrong or half-right.
- Rabbit holes to follow next, two check questions with the why, and sources.
How to use it (with a friend)
- Read the question out loud and each guess the answer before opening the story. Then see who was closer, and why.
- The "Why it turned out that way" box is the one to explain back to each other. If you can say it in your own words, you've got it.
- Search by any word (it searches the whole topic), or narrow to Car, Garage & shop, Power & solar, Printers & office, or House & everyday.
- A topic counts as read when you press Mark as read. Progress and quiz answers are kept in this browser only. Nothing is sent anywhere.
How accurate is it?
Dates and names come from encyclopedias (Britannica), museums (Smithsonian, The Henry Ford), university and government pages (NIST, the National Park Service, the Library of Congress), professional societies (IEEE, the American Physical Society), original patents, and the Nobel Prize site. Each topic lists its sources. Where historians disagree or a popular story can't be confirmed, the page says so instead of picking one. A separate reviewer checked every date, name and claim before the page went live.