As discussed in other posts, humor is a delicate thing even for rational (at least sometimes) human beings let alone for a machine intelligence the grasp. Case in point, a little joke that sneakily crept up on me all I was in a pub on a beach holiday.  It was the kind of joke that at first you likely don’t get and then the light bulb goes on after a few seconds and then the subtly of the humor hits you, much like that ‘ah-ha’ moment when you finally got the Pythagorean theorem or riding a bike or some other experiential thing.


The name of the place is Shenanigans.

Given that it is an Irish Pub, it’s hardly a surprise that the dining area would stimulate its public with various pieces of trivia and witticisms. Some of these witticisms extended beyond the usual humorous ones one would expect in a conventional bar setting and bordered on wisdom.  One in particular opened vistas of thought about language, meaning, ambiguity, and humor.The witticism in question, which really caught my attention, asked the following question:

Why does a dish towel get wet when it dries?

The obvious answer, of course, depends on an equivocation in the verb to dry.In English, the action of drying can be interpreted as two distinct and opposite sequence of events. In the first, we have the passion – that is to say, the passive event – of an object as it dries out.  In this case, the object loses any water or other such liquid that it has been carrying or holding.  An excellent example of this being the ground drying after the sun has come out after a rainfall.  The object is simply bystander as it is subjected to the drying action performed by an external entity.  In the second, we have the action – that is to say, the active performance – of the entity that performs the drying action.  In the wet ground example mentioned earlier, the sun would perform the drying.  In older language that, sadly, has fallen out of favor, the sun is the drier and the ground the ‘driee’.    

Getting back to the witticism, the humor, obviously turns on the fact that the verb ‘dry’ is ambiguous in the present tense.  Consider the two sentences:

The towel dries in the sun.

and

The towel dries the dish.

The first three words of each are identical with the same subject and verb.  The only clue that the first is the passive sense and the second the active one is the inclusion of the prepositional phrase ‘in the sun’.

At first glance, one might think that indicator is sufficient and a bit of parsing here and a bit of coding with a lookup table there and one has taught a machine to tell the difference.  Then one nips out to the pint and while drinking a pint of Guinness one realizes that the next sentence can be said with proper meaning and with equal probability of being either passive or active.

The towel dries fast.

What’s a machine to do, you may ask?  Well… if it is to pass the Turing test it might randomly make an assumption and move forward or ask for clarification.  If the machine were being really ‘clever’ it might do both.