Lawn Theory 101

Four years in this house and I have yet to find a Hamiltonian circuit of the lawn. Curse you NP-completeness!

Explanation: In graph theory, a Hamiltonian circuit is a path that starts at a point in a graph, travels through all other points in the graph exactly once, and returns to the starting point. Determining whether such a path exists in a graph is an example of what's called an NP-complete problem, which means (among other things) that there is no known algorithm of polynomial time complexity for solving it. In other words, it's really hard.

Consider my lawn to be a collection of points, with each point connected to the points closest to it by an edge. Now it's no longer a lawn, it's a planar graph! Thus, we can apply graph theory, and the most efficient way to mow my lawn is the Hamiltonian circuit that starts (and ends) closest to my garage.

You know, for $30 a mow, you can just pay the local lawn guy to do it while you play computer games.

I really should be thinking of it as a Travelling Salesman Problem instead. In that case, I attach a weight to each of the edges in the graph (the length of the edge) and then solve for the shortest tour of the vertices. It's still an NP-complete problem, but now I not only mow each part of the lawn only once, I also travel a minimal distance in doing so. I can't solve it, but if I could it would give me a better answer.

You think about this stuff while vacuuming, too, don't you?

Yes. And mopping the floor. Mopping the floor is easier to visualize because the floor is neatly broken down in to tiles. It's more difficult, however, because you have to take into consideration that you can never stand in a place where you've already mopped.

This is why mathematicians never work as landscapers or housecleaners.

Interestingly, those jobs are often taken by immigrants who speak little or no English, and therefore have better communication skills than most math majors.

It kind of sucks the fun out of things when you make fun of yourself.

It sure does!

Can we talk about toasters now?

No.

Dyson Update

For the record, I have now used my new vacuum on carpet, tile, a bed, a futon, a couch, the kitchen table, and a labrador.

Explanation: As you may recall, the nice people at the window company bought us a new vacuum because they wrecked our old one and filled our house with glass. Sure, it works on all kinds of floors, but the other furniture is even more impressive. Because I was afraid to wipe the specks of glass off of the table (for fear of scratching the finish) I used the brush attatchment on the Dyson and sucked it clean. The bed, futon, and couch all were easy to clean because the brush attatchment has holes you can use to limit the suction and not pull your entire comforter into the vacuum. The most impressive piece of furniture I cleaned, however, was the hassock we are borrowing from our parents this week.


Emma's limited hearing ability combined with the vacuum's quiet operation convinced her that she was just being pet - something she is happy to encourage. For anyone out there with a shedding deaf labrador, this is the way to go.

Don't Say the "B" Word!

This status message is kosher for Passover.

Explanation: The internet brings with it new challenges for those who wish to keep with Jewish law. We at Jeremy's Status Message are proud to proclaim that today's message is kosher for Passover.

You may think it is quite simple to proclaim a status message as kosher for Passover, but it most certainly is not. I cannot mention bacon. Shellfish are strictly not allowed. A rabbi must examine the creation process to assure readers that the content is indeed kosher. Any animals mentioned in this status message must be killed in accordance with Jewish law. Fruits and vegetables are permitted, but must be inspected for bugs. This status message cannot contain both meat and dairy. There are so many rules, but in the end, just know that you can enjoy this message on Passover without any guilt whatsoever. So, what, are you too important to call your grandmother once in a while?

Important Update: Thanks to the good people at the window company, we are now the proud new owners of a Dyson D14 vacuum cleaner. If you felt a strong suction last night, that was me cleaning up the broken glass all over our house.

Windows 2.0

Walkin' on, walkin' on broken glass.

Source: Technically these are the lyrics to an Annie Lennox song.

Explanation: In reality, these are the lyrics to my life. The second half of our windows were installed yesterday and our installation crew was not nearly as competent as the crew that did the first half last summer. As a result, I have to wear shoes inside at all times until the new crew (we requested that yesterday's crew never set foot in our house again) finishes up today.

Why was yesterday's crew incompetent, you ask? They took out 13 windows, breaking most of them, AND DID NOT BRING A SHOP VAC. One of the crew members did a rapid cleanup job using our vacuum from the hall closet. He did not ask to use the vacuum. He did not ask to look in our closet. He just took it. To the best of my knowledge, my cheap Hoover is not designed to suck up large chunks of glass and metal. As a result, the good people at the window company are buying us the best damned vacuum we can find.* There's more, but hopefully the new improved crew, courtesy of the nice customer service gentleman who visited our house last night, will make everything right.

Did I mention that my wife stepped on a small piece of glass in the shower this morning? If you're keeping track at home (and we are) that takes the "where we found broken glass" list up to: the driveway, the kitchen, the upstairs hallway, the love seat, and the shower.

*If anyone has any suggestions on what we should get, feel free to post them. I'm guessing our new vacuum will be in the $300-$400 range. I have also considered the carpet zambonis they use at work, but it would be tough to do the steps with one.

Thoughts On Vacuuming

From the archives:

10 Things I Thought as I Vacuumed My New House For the First Time:

10) Wow, this place is bigger than my old place.
9) This is going to take forever.
8) I wonder where my employer gets those carpet zambonis from.
7) Maybe it'll be better when we actually have furniture.
6) I wonder if I can vacuum a giant VT into the center of this room.
5) I bet they make ride-on carpet zambonis, too.
4) Am I taxed by the square foot?
3) If I walk forward and then back, I can make my footprints disappear.
2) A housekeeper can't be THAT expensive.
1) THIS VACUUM SUCKS!

Explanation: I have a LOT of time to think while I'm vacuuming. This would also be how I concocted Hoover's Paradox. I should also note that now that we have furniture, vacuuming is not much more fun.

Oh, the joys of home ownership! Today's chore: raking the yard.*

*I should note that raking the yard will still be a slightly more fun activity than Monday's scheduled periodontal surgery.