Google Doodle For Boole 200
Written by Mike James
Monday, 02 November 2015

You might have guessed that Google would celebrate the 200th birthday of George Boole, the man who invented the logic that computers and programmers use, with a Doodle. This one is Boolean logic and a complete lesson in itself.

Mathematician and logician George Boole was born on November 2, 1815. Events to mark his bicentenary have been organised by University College Cork, Ireland where he was its first Professor of Mathematics in 1849. These include Boole2School - lessons in logic for school children in 30 countries.

Google has joined in the celebrations with an appropriate doodle that is well worth seeing. At first the new doodle looks like a mess of colors with no particular pattern but look more closely - this is Boolean logic in action:

Notice that under each of the letters is a logical expression. Start with the one under the G which reads x AND y. This is a simple Boolean expression and it is only true is x is true and y is true. Now look at the two circles where the Google g should be. Notice that it is cycling though showing all combinations of x and y. When either letter is showing then it is taken as true in the evaluation of all of the Boolean expressions in the doodle.

So when you see both x and y on display x is true and y is true and this means x AND y is true and so G has its usual blue color.

The rule is x and y are true if they are on display. All of the Boolean expressions are evaluated using the current state of x and y and if true the letter above shows in the usual color - if false the letter shows as a grey.

Now you should be able to see the pattern even if you are new to Boolean logic. For example, the first o only shows when x XOR y is true. The XOR logical operator is only true if exactly one of x or y is true. That is its "truth table" is:

 x y x XOR y F F F F T T T F T T T F

You can find out about truth tables and the importance of Boolean logic in Introduction to Boolean Logic.

George Boole 200

Who was George Boole

The Genius of George Boole

Boole2School

#### Related Articles

Celebrate the 200th Birthday of George Boole With Logic

The Greeks, George Boole and Prolog

Introduction to Boolean Logic

 IBM's Call For Code 2020 Winner - Agrolly16/10/2020IBM this week awarded the 2020 Call for Code grand prize of \$200,000 to the creators of an app that helps small farmers threatened by climate change decide what to plant and w [ ... ] + Full Story Pi Compute Module 4 - Time to Take Industrial Pi Seriously20/10/2020It's been a long wait, but at last the Raspberry Pi Compute Module 4 is available and it's quite a departure from earlier compute modules. Is this enough to get the Pi a place at the serious IoT table [ ... ] + Full Story More News