Richard Feynman was a physicist, an expert in quantum mechanics, a Nobel laureate. He was also a great teacher. The Feynman Lectures on Physics published as a three volume book are widely read outside of the scientific community, and the summary Six Easy Pieces is the lay person’s best chance of understanding the sub-atomic world.

Feynman also wrote about explaining and testing ideas. And a simple search on You Tube reveals him talking with brevity, and engagingly, about things that are impossible for mere mortals to understand.

The big challenge with any idea, Feynman observes, is not to fool yourself. Have you ever been in a meeting and something comes to mind and you talk about it, and the people in the room seem impressed, and you feel good, and you go home and tell your partner, but somehow that idea has evaporated, and you don’t feel quite so good any more?

I would start each of my meetings with my doctoral students by asking them “what is the core idea?” Quite naturally, they switched from pillar to post in the early days. But as the work moved towards conclusion, the explanation became not only logical, and better supported by evidence, it was also consistent. In the last months, each time they explained their work, they said more or less the same thing. 

Feynman’s test of an idea was whether he could explain it to a Martian. He approached all explanation in five steps.

1. Write the name of the idea at the top of a piece of paper. Writing it down is the big test. It takes it from ‘sounds good when you say it in a meeting’ to ‘sounds good when somebody reads the idea back to you’.

2. Explain the idea in plain language so that your neighbours can understand, and give practical, real world examples of the idea in action.

3. Show what you have written to the neighbour!

4. Use what they say to identify any:

  • weak spots in the argument
  • redundancy in the argument (the words that don’t really add much).

5. Edit, go back to step 3, Repeat.


Richard Feynman, Five Easy Pieces