Happy Birthday, John Venn! Five fun facts about our favorite mathematician

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BlueLlull. BlueLeibniz. BlueEuler. If our name had been inspired by anyone else, BlueVenn just wouldn’t be the same. Sure, John Venn may not have been the first to use schematic diagrams to represent set collections and all their possible logical relations, but he was the first to popularize them.

Today is the venerable (or, should that be Venn-erable) logician, mathematician and philosopher’s 186^th birthday. Would he recognize how Venn diagrams are used in the modern world? Would he ever believe that, nearly two centuries later, he would be celebrated by Google? Or, that the same sort of diagram first used in his paper, The Logic of Chance (1866), would be used to create internet memes about Batman, interpret song lyrics, and form the basis for many, many hundreds of Buzzfeed posts? Probably not.

So, join us in celebrating one of East Yorkshire's finest exports, with this delightful collection of John Venn facts.

1. People get Venn diagrams and Eular diagrams mixed up all the time

When Venn first published his now famous diagrams, he referred to them as ‘Eulerian Circles’, named after the 18^th century Swiss mathematician, Leonhard Euler. People regularly get the two confused (even us, we must confess), and many so-called Venn diagrams are technically Euler diagrams.

There is one main difference between the two:

Venn diagram vs Euler Diagram

Venn diagrams – Show every possible logical relationship between sets, whether anything is in a set or not. Empty sets are commonly shaded.

Euler diagrams – Only sets with a relationship that exists will overlap. Shaded (empty) sets can often be completely removed.

So, while an Euler diagram can be a Venn, a Venn diagram is not a Euler. If you're really keen, you can read more about the difference here.

2. Venns are a lot older than you think

Even before Euler, mathematicians had been creating Venn-like diagrams. For example, 17^th century German polymath Gottfried Leibniz used similar logic diagrams (which appeared in works originally created in 1686). In The Logical Status of Diagrams, author Sun-Joo Shin claims that “circles used for representing classical syllogisms” (that is, processes of logic in which two general statements lead to a more particular statement) go back as far as the Middle Ages, with Mallorcan logician Ramon Llull and his 16^th century book on algebra, Ars Magna.

3. The term ‘Venn diagram’ was not used until almost half a century after John Venn created it

American philosopher Clarence Irving Lewis first coined the term ‘Venn diagram’ in his paper, A Survey of Symbolic Logic, published in 1918 - 38 years after Venn's paper, On the Diagrammatic and Mechanical Representation of Propositions and Reasonings. Incidentally, this was just five years before John Venn’s death, aged 88, in 1923

4. Venn worked with George Boole, the creator of Boolean logic

In the aforementioned paper, published in 1880, Venn's diagrams were first used to visualize and extend fellow Yorkshireman George Boole’s algebraic logic. And, as any statistician or computer programmer will tell you, Boolean logic is considered to have laid the foundations for the Information Age.

5. Venn once built a cricket bowling machine

As well as a mathematician, mountain climber, keen botanist and ordained priest (only for a while, because Venn could not maintain his philosophical beliefs as well as his religious conviction), John Venn was a bit of an inventor.

In 1909 he and his son, also called John, patented a portable machine that could bowl cricket balls. When the Australian cricket team visited Cambridge (where he was a fellow and President of Caius College) that year, it clean bowled an Australian star player four times!

So, thought you knew about Venn diagrams?! Well hopefully you now know a lot more about them and their inventor.

Happy Birthday, Dr. John Venn!