Under a Gibbous Moon

Archive for March 27th, 2010

Judges can’t do math

by on Mar.27, 2010, under Science

At least in Ohio. James Barnes received a ticket for ticket for going 84 in a 65 zone along interstate 75. His speed was not acquired by either laser or radar but by calculations made by an Ohio State Highway Patrol airplane (yes, there’s a great use of taxpayer money). In short:

The pilot testified that in Barnes’ case, on the day in question, he first observed a white vehicle, later determined to be driven by Barnes, halfway through the first marked quarter-mile section. As this vehicle entered the second quarter-mile section, meaning the moment the front bumper/grill portion of the white vehicle met the second white epoxy mat, he began timing the vehicle with his two stop watches. At the end of the second section, the pilot noted that 10.68 seconds had elapsed, giving him a speed of 84 miles per hour. He also timed the vehicle through the third and fourth quarters, ascertaining the elapsed time at 10.66 seconds and 11.61 seconds, respectively, giving him speeds of eighty-four miles per hour for the third quarter and seventy-seven miles per hour for the fourth quarter.

The pilot also claims there were no other white vehicles along that stretch of interstate at that time, a claim I find dubious, if not ludicrous.

Barnes, though, thought he was lucky because his employer tracked his whereabouts and speed via GPS, just to make sure that he was being a good boy. Barnes pulled the company logs which showed him going 50 mph. Unfortunately, since GPS is such a new and untested technology (first GPS satellite launched in 1978 and fully operational by 1995) the judge rejected this evidence.

Barnes testified that his speed was detected through his Verizon Wireless cellular phone. He testified that his employer utilizes a GPS program to detect the location and speed of its employees when traveling through their cellular phones and that this program actually sends alerts to his employer if one of its employees is speeding. As previously noted, he submitted downloaded documents regarding his speed and location when the troopers stopped him on March 17, 2009. These documents reflected a rate of speed of 50 miles per hour at the time the troopers purported that he was traveling at 84 miles per hour. However, Barnes did not have an independent recollection of his speed at that time. In addition, Barnes testified that the GPS provided the average of his speed over a two-minute time frame. In other words, the GPS did not give his specific speed at a specific time, but an average speed over two minutes.

The judges complaint is, that since Barnes GPS report didn’t give instantaneous speed, it doesn’t count. My favorite part of this is the judges lack of mathematics. Barnes GPS gave an average speed over a time period of two minutes (120 seconds). It is also given that, according to Barnes GPS, he never exceeded the posted speed limit, otherwise he would have been flagged by his employer.

According to the police airplane, we can account for 32.95 seconds of that time. Now we must assume that Barnes GPS speed covers at least part of the time that the ticket was issued for, otherwise it would have simply been thrown out for being irrelevant.

First we’ll look at a best case scenario for the defendant. This assumes that the 32.95 seconds that he was timed by the pilot fit within a full two minutes of his GPS average time. This leaves 87.05 seconds unaccounted for. The average sample time of the pilot is just a hair under 11 seconds giving us 11 roughly equal time samples.

The average speed for three time samples is 81.67 mph ( (84 + 84 +77) /3 ). Now the article says he was charged with 84 in a 65 but we’ll run with the average. The GPS states that in a 120 second period, Barnes averaged 50 mph.

Given 11 samples, a value of 550 must be obtained to average 50 ( SUM(data) / 11 = 50 therefore SUM(data) must equal 550). For the known time samples we have 84 + 84 + 77 = 245. Subtract 245 from 550 and you are left with 305. The SUM(unknown) must equal 305 in order to make a 50 mph average.

The fun part about this, is the higher we speed we make any of the given unknown points, the lower the rest must go to make up the average. The best possible solution, then, is to simply give the average of the remaining data points (305 / 9 = 33.89). So yes, in order for him to be going 81.67 mph for 32.95 seconds he would have to have been averaging 33.89 mph either before or after (or both) the sample period.

Next, for the worst case scenario. That is were only a single sample period falls within Barnes 120 second average. We’ll take the lowest, 77 mph for 11.61 seconds. Whether we round up to 12 time periods or down to 11 time periods, the difference is almost identical so I’ll round up since it gives Barnes as having a faster average.

12 time periods must equal 600 ( SUM(data) / 12 = 50). 600 – 77 = 523. Since we only had one sample this time, we  are left with 11 unknown points. Given that for each high data point another data point must be reduced to total to our remaining 523, we take the average and arrive at 523 / 11 = 47.55. So, once again, whether before, after, or both, Barnes was averaging 47.55 mph.

In the first scenario, for the pilot to have been correct, Barnes was going only 41.5% of the speed he was alleged to have been going out side of the sample period and 58.2% in the second scenario.

In either case, he apparently suddenly increased his speed rather radically increased his speed for a very brief period of time (32.95 seconds), was “clocked” by an aerial observer, and then returned to a slower speed.

Math calls bullshit.

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No sale without a test drive

by on Mar.27, 2010, under Technology

Brooke Crother, over at CNet, puts forth the theory that one of the reason that the Nexus One has failed to sell is that it is nearly impossible to get your hands on a demo model.

With this, I am in total agreement. I never do business with any cell phone store or kiosk that does not have actual working cell phones that test out.

The same goes for any electronics, from mp3 players to computers. These things are very expensive and yet there are still places that put out plastic shells on the shelves and say that that is enough for you to decide if you want to buy it.

That’s like going into a car dealership and the dealer showing you the manufacturer’s brochure on the car and asking you to make a decision.

While not as expensive as a car (mostly) consumer electronics are still a major purchase decision, and one that I would like to make after I have at least had the opportunity to fiddle with the buttons, check the ergonomics, and otherwise “kick the tires”.

I know there are people who will buy anything, no matter what it is(see Laser Disc) but I, personally, prefer to actually be able to see, touch, and use the products I intend to purchase. At least when they cost several hundreds of dollars.

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Cars dicks drive

by on Mar.27, 2010, under Rant

I commute a bit over two hundred miles a week to work. While I know that is not a lot compared to some people, it does put me on the highway for five or six hours each week.

In that time I have noticed a that how rude or reckless a driver’s behavior is is roughly correlated to the car that they drive. While this listing is unscientific and based solely upon my own personal experiences, I believe that these observations can be borne out upon whatever highway you happen to frequent.

In approximate order of offensiveness:

  1. BMW
  2. Audi
  3. Honda
  4. Volkswagen
  5. Toyota
  6. Chevy
  7. Jeep
  8. Dodge
  9. Cadillac
  10. Ford

There is some wiggle room as to placement, particularly near the bottom of the list. The top of the list is pretty set with BMW being ahead by a mile. While most vehicle makes, the model makes a huge difference but almost every BMW driver I have interacted with on the road can be classified as a dick.

I think Ford hits the bottom of the list simply because there are not many of them sold out here and so there are fewer opportunities to be dicks.

Honda, Volkswagen, and Toyota are split evenly between their large SUVs (or only in Volkswagen’s case) and their compact cars (with all the teenagers who drive them thinking they are Vin Deisel from The Fast and the Furious).

Of course, within any given make, the more expensive the vehicle, the more likely they are to be a dick, i.e. the driver’s of the Corvette are more apt to being dicks than driver’s of the Malibu.

And finally, it seems that in order to qualify for purchasing an Escalade, you must be a dick.

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