Physics Lessons

Freebie: Hi, Fred. We got a little accident. Could you send a tow truck, please, to 618 Elm Street? Hold it. It’s the, uh, third floor, apartment 304.

Freebie and the Bean (1974)


…And the hits just keep on coming.

In Our Last Episode, I’d noted that, for the first time ever in my adult life, I’d actually made it onto a jury. The judge tried to get everything done today so we wouldn’t have to come back tomorrow, but no such luck. What that meant, was a lot of hassle at my school.

The reason it’s a hassle for school is because I’d scheduled IEP meetings for several of the students on my caseload. If I’m not there, then there’s nobody to keep things running and such, and the data entry is going to be less-than-awesome, and a few other headaches. So after they let us go for the day, around 4:15PM, I decided to head over to my school, let my principal know what was up, and do some advance prep to make it easier for the team to get stuff done, or at least into a decent place for me to finish it all off.

My school is typically a 10 minute drive from the courthouse area, but we’re talking A) downtown Baltimore, B) close to rush hour, C) within an hour of the Orioles starting a playoff game. It took me 40 minutes, no exaggeration, to cover that one-mile course. Maybe longer; it was after 5 by the time I got into the school. The principal wasn’t happy to hear the news (of course), but she was glad I’d come in to help set things up.

Around 8:00, I finally left the building and headed home. My plan was to take I-95 part of the way, adhering to the speed limit because, after all, I was still on the donut spare.

Here’s where we have to go to the map:

It's possible that when I pulled over, I considered jumping onto Russell Street.

See that road running through the middle of the picture? That’s I-395, the spur that runs between the Downtown area and I-95. The red arrow is where I hit the pothole, or more accurately, the shoddily-filled series of potholes. The orange arrow (because, Orioles) is where I stopped the car. Those arrows are no more than a couple of hundred feet apart.

So I called the Triple-A guys via an app on my phone, and they called me back in a couple of minutes. It took a little explaining to get them to understand exactly where I was, but finally he got it and said he’d be right over. Sure enough, he was there within a few minutes. That was the guy with the AAA Service vehicle; there wasn’t a lot he was going to be able to do for me; this car needed a tow. So he got the tow truck dispatched.

In the meantime, I’m working my phone to see if a friend of mine, who used to work in a garage not far from my school, would contact said garage and let them know I’m bringing my car over. No problem, he says. Then a second call to Wife, to let her know where she’s picking me up. Tow truck shows up, car gets taken to the garage without extra fees (being on that on-ramp kind of complicated the distance, so AAA showed a little mercy in that respect: as the crow flies, it was no more than a mile to the garage. Because the tow truck couldn’t just do a U-turn, it was maybe a six-mile circle we were driving in). Total time from breakdown to Wife picking me up: about an hour. All is reasonably well. Except for the whole Nearly Dying Last Night thing combined with two flats within a 25-hour span.

OK, so here’s the Physics Lesson:

If you look at that orange arrow, you’ll see that my car was situated almost exactly between Orioles Park at Camden Yards (at the top of the picture) and M&T Bank Stadium, where the Ravens play. I’m also on an elevated highway, maybe 30-40 feet up over Russell Street. The Orioles were playing the Detroit Tigers tonight in the first game of the Division series, and the Orioles were doing quite the fine job this evening (final score: 12—3). So while I was waiting for the AAA guy, I turned on the car’s radio and tuned in the game. Then, just for the giggles, I opened my car window to see if I could hear the sounds from the stadium. Turns out I could, but I was hearing the stadium AFTER I heard it on the radio! The ball would get hit, the crowd would roar on the radio, and right after that I’d hear their hollering through the car window. How could this wizardry be?

Here’s how:

I estimate the distance between the stadium and my car to be roughly 400 feet. That means it takes, at 1,122 feet/second, about 1/3-second for a sound from the stadium to reach the car. However, when the sound hits the announcer’s microphone, it’s speed-of-light almost the rest of the way. Into the mic, through the wire, to the transmitter (five miles away), out through the radio waves and into my car’s radio (five miles back), where it’s converted back to sound for the last two feet. But it’s all happening at 186,282 MILES/second.

It’s the same reason you see the fireworks before you hear them. Physics, boy.