Writing for Non-Physicists

Argh!

I, admittedly, am not a fizzisist. However, as a Mechanical Engineering graduate specializing in mechanical design, I was more in tune with it than (say) your average Civil Engineering graduate specializing in transportation. For example:

From the AASHTO, “A policy on Geometric Design of Highways and Streets (2004),” pg. 135, here is the following paragraph:*

An electronic accelerometer provides an alternative to the ball-bank indicator for use in determining advisory speeds for horizontal curves and ramps. An acclerometer is a gravity-sensitive electronic device that can measure the lateral forces and accelerations that drivers experience while traversing a highway curve (65).

In defense of the writers of this policy, I must admit that I am not the specific target audience. This policy has been written so that everyone from technician level and up can read and understand the basic ideas behind road design. However, that does not excuse sloppy physics, in my opinion.

The second sentence of that paragraph repeats the first sentence, in essence, and makes two bad statements and one falsehood. Yes, an accelerometer could sense “gravity”, but not while you’re immersed in the gravity-in-question’s reference frame. I challenge anyone to go out and buy an accelerometer and measure the earth’s gravity; Yes, an accelerometer measures acceleration, we got that; NO, an accelerometer does not measure lateral forces!

I could go deeper into the uselessness of the paragraph, regarding the industry-wide use of ball-bank indicators, and how no one really cares about the actual accleration, except as it applies to a conversion to a ball-bank reading, and how a ball-bank indicator is an acclerometer, but I won’t.

I hate to sound peevish and petty, but that paragraph really bugs me. It’s one of those “flesh it out” paragraphs that are unnecessary but placed in a report (or policy) merely to add weight. [sigh]

Again, in defense of the policy writers in question, when sticking to road design, this is an excellent manual. But the physics needs some work.

* Note Added 10:20 AM: I always have to go to the wife for my proper APA or MLA or Chicago references, so don’t kill me for the improper citation.

* Note Added 10:39 AM: Damn Typos! I’ve fixed four since publishing this.