17/Historical Note

Historical Note on $17$

$17$ was the highest number whose square root was proved irrational by Theodorus of Cyrene.

Plutarch reports that the Pythagoreans had a horror of the number $17$.

That was because it lay half way between $16$ and $18$, which are the areas of rectangles whose areas equal their perimeters.

$17$ seems to be a popular age to write a pop song about:

At Seventeen by Janis Ian

7-Teen by The Regents

Edge of Seventeen by Stevie Nicks

to name but three.

Sources

• 1954: B.L. van der Waerden: Science Awakening

• 1986: David Wells: Curious and Interesting Numbers ... (previous) ... (next): $17$
• 1997: David Wells: Curious and Interesting Numbers (2nd ed.) ... (previous) ... (next): $17$