A random and fun way to quantify are numbers to describe a person's "distance" from another (famous) person. Connections are usually in collaborations or other interactions, and each step in distance has the value of 1. It is a modern variety of genealogy, although it is lateral rather than tree-like. One example is Morphy number, the distance a chess player have to the famous chess master Paul Morphy. The distance is measured in real life games between players, starting from Morphy (number zero). Surprising, (as Morphy died in 1884) there is a bunch of players alive today who have the low Morphy number of 3, that is, they played against ("met") a person (2) who met a person (1) who met Morphy (0) in a match. I do not know if any of the number 3s are active, but if you played against one of them, you would get Morphy number 4. It is a number less about skill or accomplishment, more a fun way to trace games history, not influence/culture/genes/property/etc (said Captain Obvious).
The real fun uselessness is to combine two such totally unrelated numbers, such as the Erdős–Bacon number . It is mathematical unproblematic to add two number to arrive at a third number
a + b = c , but since the sum really does not say anything, this is rather
a + b = a + b . The only thing it really says it is that you've published some math/science and you appeared in a film. Maybe a little "brag". No, I am not envious, but it would still be fun to have such a number. Which I do not. Furthermore, I do not think Bacon's agent hates it.
After this silliness, this post needs some really useful mathematics:
When Noah had stranded the Ark on Mount Ararat he told all the animals to go forth and multiply. All the animals left (in pairs obviously).
Noah thought all were gone, but just off the boat he found two snakes.
He repeated his injunction:
"Go forth and multiply!"
The snakes did not move.
Noah repeated in his most booming voice:
"Go forth and multiply!"
The snakes looked up at him and said:
"We can't multiply. We are adders."
I heard this joke on a podcast. I checked it online and it sometimes come with a more nerdish second math joke. But, imho, it doesn't cut it as a good 2-punchline joke, which is rather rare. The above is sufficiently and simply bad. "Bad" rhymes with "Dad" which rhymes with "joke".
P.S. As Paul Erdős was a very renowned, productive and collaborative mathematician, the Erdős number seems to say something, even if thousands of people have a low number. It says something about me: "Infinity". 😉
P.S. 2 I have inscius number zero! Ignorance ahoy!