A while back I used to author a webcomic called Prof. Paradox. I stopped doing it because, well, it just got to be to much like work. It wasn't fun to do towards the end, which is why I started to do it in the first place.

Yesterday I decided to redirect all the traffic from the old site to this new one. When I checked my traffic stats, I noticed that I had gotten a bunch of hits off of people searching for "Water Gas Electric Puzzle" on search engines. This was a puzzle I had talked about on the old site. I started feeling bad for all those confused people looking for the solution to that puzzle, and coming here to find me blathering on about cooking. So I've dusted off the old images I used and created some new ones. Without any further delay, here is the puzzle, solutions, and my explanation of why I like this puzzle so much.
You are the manager of a construction site. You have three houses built, and need to hook up three different utilities to them. The utilities are water, electric and gas. You need to run the utilities to the houses through lines, but you can't cross the lines. Most people start by drawing three dots representing the houses and three dots representing the utilities, and then trying to make all the appropriate connections. I have made some nifty pictures for you, so you can follow along without having to get up from your computer and searching for some paper and a sharpened pencil with an eraser (a rare item in my house). Consider this first image for a moment before moving on.
Once you get started on this puzzle, you may notice "loops" forming. This image shows one of those loops. These loops are unavoidable, and the reason this puzzle is so hard. anything in side these loops are unaccesable to anything outside of the loop. At this early stage in the solution, however, nothing is blocked. Not even the red house, because it's on the border of this loop.
Here is the final water and electric connections to the green house. If you're paying attention you'll realize that this can't be the solution because the red house is now completely contained within the loops, while the gas utility is completely outside the loops, meaning you can't make the connection between them. You might, at this point, try erasing the line going from the water to the green house, and redirect it around top instead. While this will free the red house, it would trap the blue house. This situation is also unavoidable.

So what's the solution? The truth is this puzzle doesn't have a solution. It's unsolvable. Isn't that awesome?

I'm sure, at this point, you're calling me a rat bastard. Just give me a moment to explain.

While this puzzle doesn't have a solution, we can still learn some pretty cool stuff from it. Not the least of which, is the fact that some problems just don't have solutions. No matter how much they look like they do. Sometimes retreat is the best strategy. I agonized over this puzzle for days when I first learned about it. Even then I didn't fully understand it until I came back to it as an adult years later.
There are other cool thing you can learn from the puzzle, though. Consider this picture I drew. You see a rough blob that is supposed be some imaginary continent. Next to it is a stick figure. The stick figure is a representation of the continent. Each of the nodes represent the countries, while each line represent the countries bordering each other. You'll notice that countries B and E can't touch each other, because coutries A and F are touching. This is easiest to see by looking at the stick figure, because you can see that you can't cross the lines(by drawing straight lines, anyway). Starting to sound and look familiar? Also you'll notice that country A is completely surrounded by other countries
When coloring a map people like to have the countries all different colors, so each individual country is easily discernable from the others. There are only so many significantly different colors, however. Also a map with every color on it would just be an eyesore. So how do we color a map? Let's start with country A and color it yellow. Move on to country B. Now, country B borders country A, so we can't make them the same color. Let's make country B red. Moving on to country C, we notice it can't be yellow or red because of it's neighbors, so let's color it blue. we can continue going around country A in this fashion until we come to the last country, country F.
You can see that we can't color country F with any of the previously used colors. because it borders countries that use all of those colors. Let's color this one green. Now it seems we'll have to endlessly continue on this way just using new colors when we need to. However looking at the picture, we see that country A is now completely surrounded by different colored countries, meaning that no matter where an aditional country was located, we could color that country yellow.
Here you see that adding additional countries doesn't complicate things at all. What it boils down to is that a single colored country can always be surrounded by three additional colors, and then you start re-using that single color to surround the next country. Pretty cool stuff if you're into logic problems and puzzles. There are lots more puzzles out there based in what's called graph theory. If you'd like to learn more about this, go Google graph theory.
Oh, and if you just can't accept that this puzzle doesn't have a solution, I guess you could just do this and cheat, ruining the beauty of this puzzle.

You damn dirty cheater.

Logic rules!

Just thought I'd stop by and say 'hi'... I've added you to my blogroll thing too.

Hey! I'm glad you made it over to see the new site. I'll add ya on to my links section.