A View from the Back of the Envelope top

If you can't explain it
to a nine year old...
Deep understanding
For children
Rough Draft
On the quality of one's understanding

If you can't explain it to a nine-year-old,
then you don't deeply understand it yourself.


"I am sorry for the length of my letter,
but I had not the time to write a short one."
[Blaise Pascal [1]]

By analogy,
"I am sorry this explaination is so long / detailed / messy / difficult,
but I didn't understand it well enough to give a short / fundamental / clear one."

Writing a short, concise, pithy, tight, crisp letter is difficult. It requires a crystal clear idea of what you want to say. The greater your uncertainty, the greater the letter's length and cruftiness. The harder it is for another to read and understand. Making something effortless takes hard work.

Creating a good simple explanation requires a deep understanding of what you want to describe. It requires you generalize. That detail be abstracted, removed, or aggregated away. That you know the thing's aspects, and know their relative importances. That you "grok" what is really fundamentally going on.

It may sometimes not be possible to create an interesting explanation. Perhaps in some areas indescribable subtlety is all there is. But even there, with effort, it may atleast be possible to describably capture the essence of the subtlety.

A View from the Back of the Envelope
Comments encouraged. - Mitchell N Charity <mcharity@lcs.mit.edu>

[1] Pascal quote. Cite found here. Blaise Pascal (1623-62), French scientist, philosopher. Lettres Provinciales, Letter 16 (1657). Also quoted as I have only made this [letter] longer because I have not had the time to make it shorter.

 Reframe argument.  Rewrite.
  Separate out quality of description from real-time aspects.
  Emphasis on judgement, not creation or existence.
  Better, not judgement but self testing / discovery / learning & growth.
  Failing to make fundamental point.  That accessible explanation is possible.
  Ah well, next draft.
 Needs an example.  On own page.
  Perhaps link in / elaborate Schrodinger stuff. [have draft elab]
 Comment on selection of nine year old.  "nine year-old"?

 1997.Jul.27  First draft.  Based on notes in `deep understanding'.
              Began draft of example.