MarkPNeyer.com

I was telling some friends of mine about a mathematical modelling competition I plan to take part in next weekend. It’s a 96 hour contest. They describe two different systems to you at 8pm on a thursday night, and you have until 8pm that monday to come up with equations describing one of the systems, model those equations using some sort of computational process, and write up a paper. It sounds pretty entertaining to me.

They mentioned a ‘day of dialogue’ on the iraq war that is happening that saturday at 9:30, and said I should go. This is probably due to an incident where I went with one of them to a viewing of an anti-wal mart movie, from which I was thrown out because I lost my temper when some dirty liberal kid kept accusing me of working for wal-mart. My friend told me that after I got thrown out, they were much more receptive to his arguments and that the net effect I had was great. I, however, felt pretty embarrassed about the whole incident and figured this Iraq thing would give me a chance to engage in political discussion without making an ass of myself. I also told them it’d be a great way to get my mind off the modelling thing, so that when I was ready to go back to thinking about it, i’d have a clear mind.

They seemed to think this was funny – that I’d ‘clear my mind’ from one intellectual activity by engaging in another. They thought that going to a bar was a good way to clear your mind. I’ve never been to a bar, so I have no data from which to draw a reasonable conclusion, but something tells me I’d just want to sit and think about the problem under consideration. I feel as if my mind will always be thinking about something, and there’s nothing I can do about that fact. What I do have some control over is the subject which is under consideration. Going to a bar wouldn’t give me anything new to think about, whereas the political debate would cause me to stop thinking about the math, allowing me a fresh perspective when i returned to it.

Are there really people who can turn their minds off? Who can just not think about something for a period of time?

The ‘dissapearing sock’ phenomena is somewhat of a cliche. It never ceases to irritate me, though, when it happens to me. I was putting my clothes away when I found an extra sock. I looked in the sock drawer and there was a match for it. Hooray! I then picked up the last shirt, and there was an unpaired sock lying underneath it. Gah!

The thing that makes sock loss noticable is the fact that you don’t have one to pair it up with when it comes time to put it back in the drawer. If you always lost socks in pairs, then eventually you’d have to get more, but this seems like a natural enough thing to me. If you run out of socks, it’s because maybe you threw some away because they got holes in them – or perhaps they undergo a spontaenous decay process. In any event, the only thing that causes me irritation is when I’ve got a sock with nothing to pair it up with.

Now for the mathematical analysis. Consider two possible cases. In case one, you’ve got an odd number of socks when you put your load in the washing machine. If we lose no socks, we’ll be mad when laundry is finished because then we’ll still have an odd number of socks and therefore one will be left without a pair. If we lose one, howerver, we’ll feel OK because all the socks will have matches. In case two, you’ve got an even number of socks. Here, if you lose one or three, you’ll be mad, but losing two or zero will leave you feeling OK. If we assume that N is large enough, then regardless of whether N is even or odd, the probability of losing one sock is the same, as it is for two or three socks. Let P1 = the probability that one sock will be lost, P2 = the probabilty that two socks will be lost, etc:

Let’s compute the possibilty of unhappiness after a given load of laundry:

If we started with an even number of socks, then the chance that we will be unhappy after doing the laundry is:
P1 + P3 + P5 …
Likewise, if we started with an odd number of socks, then the chance that we will be unhappy is:
P0 + P2 + p4 …

If we assume that there’s a 50% chance we’ll start with an even number of socks and a 50% chance that we start with an odd number of socks, then the total chance we’ll be unhappy is:
(0.5)(P1 + P3 + P5 …) + (0.5)(P0 + P2 + P4 …) = (0.5)(P0 + P1 + P2 + P3 + P4 + P5 ….)

Because P0…PN represents all possible sock losses, the the sum of P0…PN must be one.

Meaning that after every round of laundry, there’s a 50% chance of us being unhappy about a missing sock.

Maybe I’ll just buy new socks instead of washing them.

I work in IT at a medical company in west chester. A lot of the things I do are pretty boring. I fix people’s email and such when it doesn’t work for them. I contact the cell phone companies to get people mobile devices and handle issues with them. I do maintenance on computers, like wiping, reformatting and sending them out to users. These things are not very entertaining.

Some days, however, I have fun and really enjoy my job. A couple of weeks ago we had a phone that wouldn’t charge. I found that if you put it in the charger and pushed it back a bit, it would charge. I took the thing apart, removed some brass contacts, bent them a bit and put them back in. The phone worked. I was happy.

When you’re trying to get data off of a laptop, the quickest way is to remove the hard drive and hook it up to a desktop and swap the data over. It’s quick and pretty painless. The thing is, sometimes the screws holding the laptop hard drive’s cover in place (actually, more like ‘very frequently’) will get stripped at the top so you can’t remove them. In these instances, I take the hard drive assembly over to the testing lab, put it in a vice, and use a dremel to cut a groove in the top of the screw so that it’s accessible from a standard screwdriver. I’ve done that several times, and I’ve enjoyed it every time.

Today there was a phone handset lifter that wasn’t working. I took it apart, fiddled with it for a bit, and saw what the problem was – the motor had gotten caught in a single position for some reason. I manually turned the shafted coming out of the motor to move the lifter back to the ‘down’ position, and tried it out. It worked. Hooray! Fixing email programs and bugged blackberries is ultimately not as satisfying as engaging in physical combat with a broken device. Why is this?

When you fix something, you work on your mental model of how that thing works. With a mechanical thing, it’s pretty easy to form a mental model of how it works, because you can think of how all the pieces fit together. With software, though, it’s different. Software programs can be horrendously complicated. I have no idea how microsoft outlook pulls a list of contacts from active directory, but I’m pretty sure it has something to do with forbidden magics and eldritch rituals going on somewhere in our server room. So a first guess might be that it’s more entertaining to fix physical things because it’s easier for us to form models of how they operate.

But then something seems wrong with that conclusion – there have been computer problems that I fixed fairly quickly, and as a result I gained new insight into windows and its vagaries. I enjoy doing that, but it’s never as satisfying as fixing a physical thing.

Maybe it’s something about working with your hands instead of your mind ? I’m not really sure.