Friday, September 26, 2008

If a tree falls in the yard and hits the only one there, does it make a sound?

On Sunday, September 14, 2008, a branch fell from a tree and injured me. Here is the story as I remember it.

The tractor just wouldn't start. Apparently, I had flooded it badly enough that it was refusing to turn over. Resigned to having to use the push mower on the entire yard, I left mom's house and began the short walk back home. I'm not sure what I was listening to on my phone's MP3 player, but "The Empire Strikes Back" is a likely candidate as I had just acquired a bunch of Star Wars MP3's. I looked at the clock on my phone. It was about 12:30 PM.

...and then I had this horrible dream. It was dark. I was crawling on my hands and knees. There was a great weight on my back and I was trying to crawl out from under it. I fell onto my chest, then struggled back to my hands and knees and kept creeping forward.

...and then I was in my car - riding in the passanger seat. My wife was driving. "What's going on?" I asked, "Why am I riding? Where are we going?"
"Good God!", she laughed, "for the eighth time, a tree fell and hit you in the head. I'm taking you to the immediate care center to have you checked out."
"What's so funny?"
"You asked me that like eight times already!"

...and then I got out of the car, walked into a building, sat down, got back up then walked back to the car - strange.

...and then my wife was helping me out of my jeans and into a hospital gown. I was in a hospital room. There was a nurse there with a wheelchair saying something about x-rays. I sat in the chair. It was lumpy and uncomfortable. She whisked me through the hospital, dodging people, racing around corners. I thought I was going to be sick.
They got me up out of the wheelchair and began to x-ray my back. I was having trouble seeing and hearing. I tried to tell the aid, but I'm not sure if she heard me. "Everything is fuzzy," I said/thought, " and I am hearing this buzzing in my ears. I think you need to hurry up. I don't think I can stand up much longer."

...and I was back in the hospital room, on the bed. A different woman was taking my blood pressure. "60 over 40" she said. "That's pretty low."
"Doesn't blood pressure usually go up when someone is in a lot of pain?" I heard my wife ask from across the room.
"Usually," the woman answered, "but sometimes it goes down." Alarm bells were going off in my head. Maybe I had seen too many medical shows, but this seemed wrong. Was I going into shock?
The woman (I don't know if she was a doctor or a nurse), hooked my up to an IV, and gave me something for the pain - morphine. (Morphine is a wonderful thing. I can see why people get addicted to it.)

Sometime after that is when I came out of my mental funk. I noticed a clock on the wall. It was 4:30. My wife was sitting in the room with me, talking on her cell phone.
"They gave him an IV,", she was telling someone. "Then they are gong to try the x-rays again. They want to do a CT scan, but they are on emergency power and that machine won't work. They have a tech coming in to fix it." After more small talk, she hung up.
"Ok," I asked. "What happened?" She rolled her eyes at me. "It's ok, I'm better. I remember things now. Tell me what happened."
"You were out mowing and it looks like a tree limb fell on you. We don't really know. I was inside when you called on your cellphone and asked for our daughter to come outside and help you, I thought you wanted her to pull weeds or something. She got you up and into the house. You were babbling and you kept asking for your glasses. Also, the umbrella pulled the glass out of the table, so I sent our daughter outside to try to wind down the umbrella. She said she was going to put on a jacket and a helmet first - smart girl! While she was out there, the glass shattered. She didn't get hurt, but there's glass all over the patio. She's at mom's house now."
"Anyway, I brought you to an immediate care center first, but they said they would want to do a CT scan and that they don't have one. They recommended I take you to the emergency room. On the way, our daughter called and said that the big tree in the front yard came down, but it didn't look like it hit the house. And, the power is out at home. Our daughter and your sister went back later and found your glasses, they are pretty bent up."
"When we got here, the hospital lost power. They are on emergency power and can't run the CT scan until they get a tech to come in and repair it. "

I was very sleepy. The morphine kept the edge off the pain, but my back really hurt as did my left ankle and my left knee.

Soon after, another nurse came in (with the same lumpy wheelchair) and carted me off for another round of x-rays. I made it through this time without passing out and soon found myself back in the hospital bed attached to my beloved morphine drip. Because the hospital was on emergency power, the TV in the room didn't work. My wife and I just stared at each other. Little did I know this was a sign of things to come.

Around 6:30 PM, they got the CT scan machine working again so I took another trip in the same lumpy wheelchair. I was back in my room soon after. I sent my wife off to get some dinner for herself and asked her to bring back my prescription sunglasses that I knew were in my car. I'd rather see clearly in the dark than have everything be blurry.

While she was gone, yet another doctor came in to talk to me. He said that the x-rays and CT scan were all normal so there didn't appear to be any permanent damage, though I had suffered what he called a level 3 concussion. Unfortunately, here was a lot of bruising on my back and that it would be painful for quite some time. I told him that he would have to repeat all this information for my wife because between the head injury and the morphine, I was likely to forget a lot of the details.

My wife returned and, we gathered our things and went home.

Our yard was a disaster. The big maple in the front was down and it took lots of limbs from a pine tree when it went. The maple was about 70 feet tall and over three feet in diameter at the base. On top of that, another tree split and half of it fell across the driveway and blocked in the other car. Limbs, leaves and pine needles were everywhere. It was a giant mess - and I couldn't do anything to it.

The power was out. The power stayed out for eight days. The only thing worse than being stuck home on the couch and not being able to move, is to be stuck home on the couch not being able to move and not being able to watch TV either. I spent a lot of time on the couch, on my back, listening to the radio of my mp3 player. I mostly listened to NPR. If you check your calendar, you'll see that was the big financial collapse started - news not well designed to cheer up an injured person.

My daughter was awesome. She's only ten years old but she really pulled through in a big way that week. My wife has a bad knee and walks with a cane. That left my daughter as the most physically capable person in the house. She ran errands around the house, walked dogs (we have three), pick up things and never complained. (Well, that's not true. She did complain some, but not nearly as much as she had a right to). School was out that week. So it was like summer vacation for her - except that all her friends were in daycare (working parents) and with no electricity, she couldn't play on the computer or play the Wii or even watch TV, and her parents kept giving her jobs to do. Oh, and she had to go to bed at 8:00 PM, cuz that's when it got dark!
She was awesome.

I was up and around in a day or two. I get a little better each day, but I'm still far from 100%. Most of the debris in my yard has been cleaned up. My knee still hurts, but I'm walking close to a normal speed. My back hurts around the level of my shoulder blades. I'm still taking LOTS of Ibuprofen. A few days after the accident, I had a bruise on my back that ran from my waste line almost to my shoulder blades.

At this point it looks like I'm going to recover fully - eventually.

Wednesday, September 10, 2008

Of 21 and Monty Hall

Recently, I saw the movie "21" (with Kevin Spacey and a bunch of young actors I didn't recognize). Early in the movie, there is a Kevin Spacey talks about the classic Monty Hall - a problem that almost everyone gets wrong. It goes like this.

Imagine you are playing the classic TV game show "Let's Make a Deal." You have three doors to pick from. Behind one door is a brand new car. Behind each of the other doors is a goat. Monty let's you pick a door. Not knowing where the car is, you pick a door at random, say door #1. Monty (who knows where the car is) opens door #3, revealing a goat.
He then gives you the option of either keeping your pick or choosing door #2 instead. What should you do? If are like me (and almost everyone else), you would think "It doesn't matter. The car could be behind either door so changing my mind doesn't improve my chances." And like me, you would be wrong. You should ALWAYS choose the other door.

The answer defies common sense. It is completely counter intuitive. It is also correct.

When I saw that scene, I got it wrong as well, but I was so convinced that I was right that I went to the all-knowing Wikipedia for the answer. They have their own explanation as well as few examples to try and explain it. In trying to understand it as well as explain it to some of my friends (who were equally unbelieving), I came up with my own example that, I think, better explains what is going on.

Let's use the same game but with something more familiar. Imagine you are playing a game with three cards - an Ace of Spades, a 2 of Hearts and a 2 of Diamonds. The dealer deals one card face down to you and then deals the other two cards face down to himself. He looks at his two cards and flips over one of them, always a red 2. (The rules state that he must do this.) Then he gives you the option of keeping your card or switching with his remaining down card. What should you do?

Keep in mind that before the cards were dealt:
  • the chances of the dealer getting the Ace were 2 in 3 because he gets 2 of the 3 cards
  • the chances of you getting the Ace were 1 in 3
  • the chances of you getting a 2 were 2 in 3
  • the chances of the dealer getting a 2 were 3 in 3 (there is only 1 ace and since he gets two cards, the other card must be a 2)
Before he flips his card, you already know that one of his cards is going to be a 2. Therefore, when he shows you a 2, it CHANGES NOTHING. The chances of his other card being the Ace ARE STILL 2 IN 3.

So, do you want to change cards now? I thought you would.

If you don't believe that explanation, here's another more rigorous (read "anal retentive") way to prove it. The surest way to explain something in statistics is to list every possible outcome and compare the number of outcomes that succeed vs the number of outcomes that fail. That's not as scary as it sounds. That's exactly what you do when you flip a coin. Think about it.

Here is every possible outcome.

Scenario 1:
Dealer gets an Ace and a 2.
You get a 2.
Dealer flips his 2.
You trade and get his Ace.
You win.

Scenario 2:
Dealer gets a 2 and an Ace.
You get a 2.
Dealer flips his 2.
You trade and get his Ace.
You win.

Scenario 3:
Dealer gets a 2 and a 2.
You get an Ace.
Dealer flips one of his 2's.
You trade and get his other 2.
You lose.

There are only 3 possible scenarios. In 2 of them you win. In 1 of them you lose. It can't be much clearer than that.