Saw a post at badscience.net which piqued my interest. Before you read it, first think about the odds of a mother having 3 children on the same day of the year. How likely (or unlikely, as the case may be) would you guess it is? Turns out it's a lot more likely than most people would think. OK, now you can click the link.

FWIW, thanks to my recently revived statistical knowledge, I did pick up that the correct odds wouldn't be 365*365*365, but rather just 365*365. That's because once the first kid is born, the chance of him being born on that day is exactly 1 (unless she's a Chinese gymnast in which case she'd be born 3 years later). Think of that the next time someone asks, "what are the chances of that happening again?". The answer is, the same as the chances that it happened in the first place (assuming the factors haven't changed, of course).

I also realized that the odds of same day births would probably be lower due to the dates of conception being non-independent. For instance, my wife and I planned to have our kids in the spring because she didn't want to be pregnant during the heat of the summer. So the range of possible days our kids could have been born is only a window of about 100 days. Would you believe they were all born inside that window? (Actually, one of them did sneak in a bit late, but within a decent margin of error).

A while back I did an energy audit in my house. Fortunately for me I do live in an area served by cheap hydroelectric and coal energy. Well, fortunately for my pocketbook anyway. Regardless, I'm ever attempting to reduce my energy needs for both personal and altruistic reasons, hence the audit.

I surveyed all the lights in my home, noted their location, type, wattage, etc. When we moved in, most of the lights were old school incandescents. Altogether they added to 2918 watts of lighting. By swapping in a few compact fluorescents I've reduced that total to 1778. That's a savings of 40%. Impressive, but not so fast. Are all those lights used the same amount? Definitely not. The garage lights are on for probably only 10 minutes per day, on average. So clearly we need to factor actual usage into the equation.

So I also estimated the average usage of each bulb. Yes it was as fun as you think. What I found is that our 2918 watts account for about 4950 watt hours of actual usage per day. After my upgrades that dropped to 3274 watt hours, for a savings of 34%. If you notice that's less than the 40% we calculated earlier you get a brownie point. Indeed some of the lights we use the most are ones that I cannot reduce any further.

Even more interesting is something I've recently come to understand as I make a concerted, although to many unquestionably bizarre, attempt at understanding statistics. Quite often a very small number of things will often account for most of your results. A good example is the US federal budget. While McCain notably complained about earmarks in bills (which may be undesirable for many reasons) they account for a very small fraction of the money spent. If you want to make any reasonable dent in the outlays your best bet is defense, social security and medicare/medicaid which account by themselves for 65% of our expenditures.

Getting back to the original point (and hopefully avoiding a political tangent), I found that just a few of the lights in the house account for the majority of the electrical usage. In fact, the two sets of fluorescent lights in the family room account for nearly 60% of the total electricity. Even if I were to upgrade the rest my bulbs to compact fluorescents, it would only decrease my current usage by another 15%. I'm pretty much bound by those two sets of lights.

The exercise was a useful one. I'm on a slow quest to analyze all the electrical usage in the house. The light bulbs were the easiest to tackle. Some time I'll move on to the appliances and computers. The latter I'm rather apprehensive about. I might rather be ignorant.

My data files:
OpenOffice.org format
CSV format

I've been following a blog for a while by Jeremy Robb. He's a Linux nerd which is how I came upon him, but turns out he's also the dad of an autistic son. He's chronicled the experience of learning to adapt to his son's condition and it's a great resource for anyone in a similar boat. His most recent post is an excellent story and would be a nice place to start from.

I'm really not sure why I'm so interested in autism. Something about it just strikes me. Maybe it's the fact that when I was in first grade my teacher thought I was autistic. Who knows, maybe I am. At this point in my life I doubt it's really worth investigating. It just really concerns me that lately so much bad information about autism has been going around, and I'd really like to get the word out so that people who are truly autistic can get the correct help and understanding.

Way back on the 2nd day of this year I signed up for a digital TV converter box coupon. Actually I visited the site at about 2am on January 1st, but apparently they hadn't launched the site yet. Just this last week, on Tuesday in fact, my coupon finally arrived. I only got one because we only have one TV and if we were to ever get another TV, it would be digital so there really wasn't any point.

We had the option of shopping at Best Buy, Radio Shack, Circuit City and Walmart. Since I've sworn to never shop at Circuit City and to never buy electronics at Walmart, that left only two options. And Radio Shack kinda gives me the willies, so really I only had the one option. That's OK though. Best Buy hasn't ticked me off yet. Well, except that every time I go in they manage to slip my purchase into a plastic bag before I can ask them to use my canvas shopping bag. Oh, well.

I was hoping to have a few choices, which is why I took along the list of approved devices, but it turned out that Best Buy only carried a single model, the Insignia NS-DXA1. That made that easy. It was $59.99, which of course dropped to $19.99 with the coupon (plus tax).

For a quick review, I'll just say that the box works just as it is supposed to. We plugged it in, it scanned the frequencies and found every available channel. I was worried that I would have to get up and reorient my antenna (a large boom secured to my chimney). I was therefore extremely relieved that it Just Worked®. There was a brief period of concern though because it didn't pick up two channels, but after reading about them on Wikipedia I discovered that they were not assigned sister digital channels for the conversion. Instead, sometime between now and February 17, 2009 they will make an instant conversion. Luckily, those are the channels we watch the least.

With my digital converter the signal quality is great. The analog channels ranged from mostly OK to mostly not so much, but all were watchable. Now they're all crystal clear. We also now get 5 extra channels, one is a weather channel from the NBC affiliate, and 4 extra channels from PBS. The latter are a real bonus because one of them shows cartoons all day. My kids love PBS Kids.

My assessment would be that the digital conversion has gone well for me. Just took way too long. But is anybody really surprised about that?

Deal or No Deal is a fun show to watch for really only one reason, at least to me. It shows me why so many people waste so much money at casinos: because they never paid any attention in math class.

I'll skip the overview and just point you to the writeup on Wikipedia if you're not familiar.

The heart of my rant is this, when the contestant gets down to a few cases left they start saying things like "33% chance that his case contains $1,000,000". But when you get down to the math of it, that just isn't so. I know that because I actually learned something in my statistics class in college. I took it twice so I should hope so!

Here's the problem, when the contestant makes his initial pick from the unmarked cases, he has a 1/30 chance that it contains $1,000,000. That should be pretty obvious, right? What people don't understand is that those odds don't change during the course of the game. When there are just three cases left, the odds that the lucky contestant's case has $1,000,000 is still 1 in 30!

I find myself hoping that the contestant opens the big money and has to settle for $500. So in that way, I do have fun watching the show. Probably not the sort of thing the person playing the game would hope for, but what do I care? But do yourself a favor and read about the Monty Hall problem until you understand how it works. You might be surprised how often it will come in handy.

And if you ever get on Deal or No Deal and want to go for broke, that's fine. It might be fun for you. Just don't expect probability to be on your side. But when you win, do remember who tried to help you. :)

The annual South by Southwest Festival is up and going. I like this conference for a couple reasons. First, it's all about the artists. You gotta love that.

But what I really love is the free music. OK, I'm a cheapskate. I'm also opposed to giving money to record labels that don't really care about their clients and instead sue their customers. I can't justify taking the music either, so it's nice when they give it away. To be honest, it's turned me on to a few bands that I would have never found any other way, such as the Eli Young Band. It's too bad they're on an RIAA label. I really considered buying some of their music.

I usually end up deleting about 1/3 of the music. Be warned that some of the lyricists have potty mouths and some of the musicians should really be working in fast food. But still, 2/3 of 738 ain't bad.

In the mail the other day, I got a letter from Wells Fargo which is where I have my checking account. That's not unusual. They try to sell me stuff pretty frequently. This one seemed pretty good on the surface, prizes just for using my check card, even up to $250,000. Wow!

Then there's the fine print. "PIN-based purchases are not eligible", it says. Think about that for a second. When you use your PIN, the transaction is handled just like with an ATM. The card issuer doesn't take a cut. But when you use the Visa network (or its peers), the merchant (the person who sells you goods) pays a percentage for the privilege of working with Visa, usually about 3% of the total cost.

So it makes complete sense that Visa and card issuers like Wells Fargo would want you to make more Visa transactions. It make them more money. But considering the low probability of me winning one of these awards, I'd rather use my PIN and save a couple bucks for my local vendor.

I heard an interesting news story on the radio today about an 87 year-old woman in New Jersey who was arrested for bringing a concealed handgun to the courthouse. She had forgotten to move it to her trunk which she normally does.

Now the whole thing could have been completely avoided if she had never purchased the handgun in the first place. She really has no business carrying around a weapon like that, but not for the reason you might be thinking. I fully support gun ownership and self defense, but this lady is more dangerous, both to herself and others. The gun was in its original box and she admits that she's never used it. Well, how do you expect to hit even the broad side of a barn, let alone a would-be assailant?

Apparently there's an annual musician's festival in Austin Texas called South by Southwest. I've never heard about it either, but this year they are offering downloads of tons of mp3s from attending musicians. When I say tons, I mean tons. We're talking 2.7 GB worth of music in 758 files.

Title: Tom Clancy's Splinter Cell
Developer: Ubisoft
Rating: T
Released: 2002
Platform: Gamecube

My lovely wife got me this game for Christmas. Her brother-in-law recommended it to us as an intense game that required a lot of thought. It sure lived up to that description. Overall I enjoyed the game quite thoroughly and would recommend it to anyone else who likes to sneak around. Bring your patience.