The Labour leadership paradox

Zeno's Paradox: Illustrating the Labour leadership contest, and why Owen Smith (left) could never beat Jeremy Corbyn (right)

In between all this ever-so-fair-minded slagging-off of the BBC, I'd just like to put in a word for the return of one of my favourite Radio 4 programmes, In Our Time. 

This week, Marcus de Sautoy & Co. gave Melvyn a fine lecture on Zeno's Paradoxes. 

This didn't tell the following Zeno-based joke though, which - for your pleasure - I'll give in two distinct versions (the first Barry Cryer's, as told to Paddy on BH; the second Jo Brand's, as told to Matt and Alex on The One Show): 

Version 1: A mathematician, a physicist and an engineer were asked to answer this question: A group of boys are at one end of a dance hall, and the same number of girls are lined up at the other end of the dance hall. Both groups then have to walk toward each other by one quarter the distance separating them every 10 seconds. In other words,  they are d apart at t = 0, they're d/2 at t = 10, d/4 at t = 20, d/8 at t = 30, and so on. When would the two groups meet in the middle of the dance hall? The mathematician said they would never really meet since the series is infinite. The physicist said they would meet when time equals infinity. The engineer said that within one minute they would be close enough for all practical purposes.

Version 2: An engineer, a mathematician, and a theoretical physicist went to a dance. Shyly they positioned themselves against a wall where they had a good view of the dance. 

  The mathematician sighed heavily and said “I wish I could go ask one of those people sitting at that table over there to dance with me, but it is impossible.”

  “Why is that?” asked the theoretical physicist.

  “If I go halfway over to the table, I will still have halfway to go” replied the Mathematician.

  “Yes” Said the engineer.

   “Then if I cover half the remaining distance I will still have a quarter of the way to go” Said the mathematician.

  “Yes” Replied the engineer.

  The mathematician continued “I can then cover half the remaining distance, but a 16th of the distance remains.”

  The theoretical physicist chimed in “Everytime you cover half the distance to the table a small but calculatable amount of distance remains.”

  “Right!” said the mathematician “So it impossible for me to go over there and ask for a dance”

  The physicist was about to commiserate with a “too bad for us” when the Engineer got up and walked over to the table.

  The physicist and the mathematician watched in amazement as the engineer asked a particularly attractive young lady to dance, proceeded to dance with her, gave her a lingering kiss, and then came back to their place on the wall.

  “How did you do that?” asked the physicist in awe.

  “Although you were correct I calculated that I would be able to get close enough for any purpose I could think of”.