# Definition:Googol

## Definition

A **googol** is defined to be $10^{100}$.

## Also see

## Historical Note

The **googol** was apparently invented by a schoolchild writing $1$ followed by $100$ zeroes on a blackboard:

- $10000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000$

In discussing the **googol**, Edward Kasner and James Newman point out that the number of grains of sand on Coney Island is approximately $10^{20}$.

It is also estimated that the number of raindrops falling on New York, for example, during the course of a century, is far less than a googol.

The total number of particles in the visible universe, even, has been estimated as between $10^{80}$ and $10^{87}$, again still far less than a googol.

Numbers of this size are really only needed in the field of combinatorics, as was presciently suggested by Kasner and Newman.

## Linguistic Note

The word **googol** was coined by 9-year-old **Milton Sirotta**, nephew of American mathematician Edward Kasner.

Beware the mis-spelling **google**, which is the name of an internet search engine.

## Sources

- 1940: Edward Kasner and James Newman:
*Mathematics and the Imagination* - 1962: Clifton Fadiman:
*The Mathematical Magpie*: Introduction - 1986: David Wells:
*Curious and Interesting Numbers*... (previous) ... (next): $10^{51}$ - 1986: David Wells:
*Curious and Interesting Numbers*... (previous) ... (next): $10^{100}$ - 1997: David Wells:
*Curious and Interesting Numbers*(2nd ed.) ... (previous) ... (next): $10^{51}$ - 1997: David Wells:
*Curious and Interesting Numbers*(2nd ed.) ... (previous) ... (next): $10^{100}$ - 2008: David Nelson:
*The Penguin Dictionary of Mathematics*(4th ed.) ... (previous) ... (next): Entry:**googol** - 2014: Christopher Clapham and James Nicholson:
*The Concise Oxford Dictionary of Mathematics*(5th ed.) ... (previous) ... (next): Entry:**googol**