Graham's number is a gigantic natural number that was defined by a man named Ronald Graham, a mathematician credited by the American Mathematical Society as being "one of the principal architects of the rapid development worldwide of discrete mathematics in recent years".

Graham was solving a problem in an area of mathematics called Ramsey theory. He proved that the answer to his problem was smaller than Graham's number.

*Ronald Graham juggling a four ball fountain (1986)*

HERE ARE 5 UNUSUAL AND FASCINATING FACTS ABOUT GRAHAM'S NUMBER:

**1. Guinness Book Of World Records**

The number was published in the 1980 Guinness Book of World Records after the popular science writer Martin Gardner described it in the "Mathematical Games" section of Scientific American in November 1977 as "a bound so vast that it holds the record for the largest number ever used in a serious mathematical proof."

**2. At The Time Of Its Creation...**

Graham's number was the largest specific positive integer ever to have been used in a published mathematical proof at the time of its introduction.

**3. Close Enough To Infinity**

Many scientists describe it to be probably "close enough" to infinity!

**4. Your Head Would Collapse Into a Black Hole?!**

The basis of this mind-bending theory is that only so much information can be stored within a finite space, according to the laws of physics.

**5. The Mind-Boggling Up-Arrows...**

- In order to be able to write Graham's number down, we have to use Knuth's up-arrow notation in which a sequence of numbers are used to define the following ones
- When we reach the 64th number, it will be Graham's mind-boggling number
- However, what's stunning is that this process of up-arrows extends to a scale that could fill up the universe and beyond.

*Conclusion: Don't try to memorize Graham's number at home folks ... this number could do some serious harm! :)*