Nov 27, 2009

Ultimate Garden Path

Im a plant loving guy, so when bored I think about my future fantasy garden in much the same way young girls plan out their weddings by age 7. Being a math guy, Im interested in seeing how I can make this garden as badass as possible. Life's just one giant nonlinear programming problem for maximizing awesome.

Now when I go to a garden, I try to find a path through it that covers as much of it as possible without needlessly repeating parts of the path (as eularian as possible). This helps me see as much of the garden as possible. Sometimes this isnt possible. U of Illinois's Allerton park is a arranged mostly in a line and in no fun to walk through. To see it all and get back to your car, you have to walk through the entire park twice. Dead ends are espcially annoying, my ideal garden wont have those.

Gardens that have even degree intersections are easy to find a path for. Its just a mathematical fact, so Ill use odd degree intersections. 5 paths convering to one spot seems a bit too much so ill keep it to 3 paths for all intersections. After much thought, I came up with the diagram below:



Each one of the circles is a modular unit that i can tack on as i please. This is my ideal garden. Walkng through it leasurely wont show you the entire thing, enticing you to come back later.

Its interesting to think about how travesibility might be used in the design of public spaces, both real and virtual. Shopping centers are easy to traverse and have many even degree paths, but zoos are much harder to go through in that way. I think some games would benefit by having harder to traverse levels, They make less space feel like more and would increase the amount af playability. The real key is to not tick people off, which i think ive done in my garden plans.

Nov 15, 2009

Coopertive pragmatics and semantics in proof writing


This post has a scary title.

The cooperative principle basically states that when when people communicate, they try to be helpful by saying the strongest statement feasible.

Example: Look at the puppies to the left.

I could say "There is 1 puppy in this picture.", which translates into 2 different logical statements:

(1) There is only 1 puppy.
(2) There is at least 1 puppy.

The word one here is a quantifier over the set of puppies. Unfortunately one represents the two different quantifications shown one of which is true and one of which is false.

We tend to interpret the sentence to mean (1) because I could have just as easily said "There are two puppies". (2) is a weaker statement and just as much work to say. Thus, "There is 1 puppy in this picture." feels like a lie because its uncooperative.

It recently occurred to me that in math proofs I see this type of ambiguity all the time. I almost did it myself today and strangely I was never taught to not do this. Because the quantifier in meaning number two is essentially the existential quantifier mathematicians may be more prone to intending the second meaning even when it is not really the cooperative one. I going to start making sure I explicitly mark which of the two meanings I mean when writing proofs from now on and take it as a general rule of good proof writing.

Actually this post was just an excuse to show that picture of the two cute puppies. Arent they adorable?