interesting geek discussions about useless stuff

if you seen the Aardvark'd movie, you'll remember the long segment about proving whether its possible to jump to a ledge of the neighboring building. a pretty useless discussion. but, the cool thing was that it was a geek discussion. the interns used physics, took objective measurements, debated, argued, and used more geeky stuff. all in the name of figuring out the answers to interesting problems. this is what engineers do. they think about things that are interesting, and they talk geek. they figure out ways to make things better and they do it.

the following two examples are our aardvark'd useless geek discussions:

streetlights
i got to thinking about something that has been on my mind for a long long time. its something that i haven't figured out how to figure out. i finally talked to some people about it. here is the basic question:

how many streetlights does honolulu have? and what does it cost to power them?

(haha. i'm not lying. these are the kind of things that i wonder about.) the basic idea is that we all talk about energy savings. for example, the tv commercials that talk about CFLs light bulbs. so, its kind of an obvious question to wonder about the efficiency of the street lights. i mean, there are probably tens of thousands of street lights in honolulu. and in my opinion, a lot of the lights seem very wasteful. for example, the light outside of my house - do we really need that light? why does it _need_ to be there? i actually, just went outside of my house and counted 15 lights in my direct view up and down my street. all these lights are pretty closely bunched, all within a 100 yard square area (my best guess). thats a lot. and while i was outside, i saw no cars and no people walking around. yet the lights were on and shining brightly.

so, i brought this up to a couple of my engineers. we did some searching and talking. we found these resources:

Power of a Streetlight

Initial Rated Light Output of Various Lamps

through some additional searches, we found that honolulu uses high-pressure sodium lights. we also found the wattage and lumens for that light. the interesting thing is in the second link:

A typical suburb in the U.S.A. has 3000-4000 streetlights, costing the taxpayers of that town more than half a million dollars a year in electricity costs alone.

wow! that is a lot of money. i can only imagine how many streetlights we have in honolulu. it could be tens of thousands. i plan to do more research to find the specifics. i want to find out how many lights there are and how much it really costs.

my fellow engineers brought up very good points:

lights are a good thing. it helps keep away bad people - because people can see them

we should look into some urban planning resources to find out how they figure out these things.

even 5 million dollars isn't a lot of money in the grand scheme of things. DOT operations costs must be tens or hundreds of millions of dollars.

do lights really help prevent car accidents?

what if we just made the lights dimmer?

i'm the first to admit that this streetlight obsession is a little strange. it is interesting. but, i don't know if anything can be done about it. nor am i sure it is really a problem. it just seems to me that streetlights are very low-tech and probably inefficient if their main purpose is to help people see while driving at night. for example, when it rains and the pavement is wet; streetlights actually make it harder to drive at night. at least, i think so. maybe more of the lights should be on the road. what if the lanes were slightly illuminated or glowed a little. what if cars had better headlights.

anyway, this is interesting. and it spurred an interesting conversation.

rubik's cube
i just recently finish my first rubiks cube. haha. stop laughing at me. but this accomplishment got me thinking more about the rules associated with the cube. i first started to ask people how many unique pieces are on the cube. a lot, actually almost every single person (and these are engineers), got it wrong on the first guess. i heard things like 54 and 27. those are all wrong. the answer is 26.

once we talked about that, we found that each piece was unique. then we discovered that each piece was situated in space and that each piece had rules associated with it. for example, a corner piece can only be placed in a certain side of a cube (keeping the colors situated a certain way). that is cool. rules are good.

we then had the idea of doing a virtual cube solver. the idea is similar to the robot solvers out there. but the virtual solver would help you step through the different algorithms to solve the cube. you learn the algorithms as you follow along. for example, there are fast solver algorithms and beginner algorithms.

this idea made us think about how to input the current state of the cube into the computer. we thought that taking a picture with webcam could solve the problem. a program could recognize colors. but how do we represent the sides of the cube? and how many sides of the cube do we need to take a picture of? so, we spent a while discussing how many sides do you need to look at to figure out all the pieces in the cube? take a while to think about that. i think the answer is 3 sides and a few key pieces. its a hard problem to figure out with math. we resorted to covering the sides and guessing. we need a program to figure this out. thats a cool and interesting idea.

next we thought about how many different combinations can you mix a rubiks cube into. keep in mind the rubiks cube rules and laws. obviously the answer is not 26! (factorial). instead the answer looks like (8! × 3^8−1) × (12! × 2^12−1)/2 = 43,252,003,274,489,856,000.

haha. what? we then tried to figure out why the heck that formula works. i'm not sure i totally understand the math behind it. but, all i know is that its cool.

anyway, this was interesting. it was interesting to talk through these ideas, questions, math questions, etc. its fun to work in a group to figure out an interesting idea. its fun to learn form others. this is what engineers do. these kinds of problems drive engineers to work for hours.