Mu is Not U

Time for another blog post where I try to improve science grammar.

This is the lower case Greek letter mu: μ. This is the lower case Latin letter u: u. Latin letters are, of course, what are used in the English alphabet as well as many, many other languages. While μ and u look similar, they are different. The Greek letter mu, uppercase Μ, is closer to the Latin letter M. The Latin letter U (uppercase, or u, lowercase) is more related to the Greek letter Upsilon (uppercase Υ, lowercase υ).

So now that I got that out of the way, when it comes to science in particular, μ and u are NOT interchangeable. In the International System of Units (SI), otherwise known as the Metric system, μ is the symbol used to represent the prefix micro-. “μ” can easily be added into a document using a insert symbol compound. It is an easy procedure, and there is no need to be lazy and just use “u”. “u” does not mean micro-. It is wrong. Don’t do it.

Speaking to High School Students

I was asked to speak at The Washington Youth Summit on the Environment (WYSE) to a small group of the delegates about my career as environmental engineer/health scientist. The delegates are high school students. I’ve never done anything like this before, and I can’t remember the last time I’ve spoken to a group of high school students about anything. I was told to talk about my career and talk about specific projects on which I’ve worked. I prepared a few slides on the basics of risk assessment as that is the general field in which I work now and then quite a few slides on my dissertation and a few slides on the project I am currently working at work. I wasn’t sure what to expect. Would they be interested in this at all? Would my slides be interesting or too far over their heads? I took out what I thought were the more advanced and complicated slides and just focused on graphs and photos. I wanted to focus on the big picture.

Part of my problem with giving this presentation was, the more educated you become, the more you take for granted what other people know. At least, I have that problem. I have had so much math education including three semesters of calculus, differential equations, linear algebra, probability, statistics, and biostatistics, that I’m flabbergasted when I meet people who can’t do or understand basic algebra or understand what a square root is. Certainly, you can make an argument that this is a sign of the failure of the US education system, but people’s education level is what it is. If you want to explain something to someone, than you have to be able to explain it to them on their level. These are high school students, and I can’t expect them to know information that is not taught until college or after. Thus, I have a group of high school students that I need to talk to about the work that I do and the work I did to earn my Ph.D. I am not entirely sure how to do this. I don’t quite frankly remember what I knew in high school. I have no idea what these students know. I don’t want to bore and confuse them by talking at so high a level that they can’t understand me, but I don’t want to insult them by explaining things they already know.

I am really not sure how I did. The one thing I am fairly sure about is that I babbled and rambled a few times. I am really not the best speaker. I am not a bad speaker, but I do much better if I have a set text that I am reading or very specific things with high points written on slides. I didn’t do that for this talk because I wanted to be able to change what I was saying once I got there and started getting questions. They did ask me questions. They asked me great questions in fact. However those questions made me realize just how much I know and forget that other people don’t know. That is in no way meant to be an insult to these students. I was really impressed with them. Like I said, they asked great questions. Also, they were very polite and politely listened even when I am sure I started to ramble. I really appreciated their attentiveness, and I loved their questions.

For example, one of the first questions I got was on one of my first slides, which had the word epidemiology on it. I was asked “what is epidemiology?” This is probably where it hit me that I had no idea what they knew. It didn’t really dawn on me that some (or all) would not know what that word meant and what that science field is. Again, that is not an insult to them. If anything, I was annoyed with myself for not considering when I learned that word. I am glad I was asked the question. It gave me a chance to tell them about John Snow and the London cholera epidemic. I am fairly sure all epidemiology courses are legally required to start with a discussion on John Snow and the London cholera epidemic, so I had fun telling them about it.

I can’t remember all the questions I got, but I got quite a few. I loved this because that meant the person asking the question was listening and engaged. When I describing issues related to soil and groundwater contamination, I got a very simple question as to how these chemicals get into the soil and groundwater. I LOVED this question. I can’t describe all the reasons why I loved this question, but one is because I am an engineer, and I get frustrated when people think we build things and then no maintenance is ever needed. Bridges in the US keep falling down, and the American Society of Civil Engineers gives our infrastructure a D+ grade. One of the reasons is lack of maintenance. I got to explain to the students about maintenance and inspections and things simply not being designed or built to last forever. I also explained how decades ago, people used to just dump chemicals in the ground or water and never think of the consequences.

I also got some questions of how to find out more information on different topics and things I discussed. They wanted to know more. As I always want to know more, how could I not like these students? I hope some of them already have or are now on the internet reading more about the topics I only lightly discussed. Maybe one day I will meet them again professionally.

Kilograms Do NOT Measure Weight

I think like many engineers, one of the reasons that I liked the idea of going into engineering was the mistaken belief that a career in engineering meant working with numbers and not having to write. I have never been very good with words. I love numbers. Numbers make sense to me. Words confuse me at times. Also, the English language in general makes no logical sense to me, and I am a native English speaker. [Well, I’m a Southern, so you can go ahead and make an argument against the native English speaker part.] I can’t spell worth crap because of the aforementioned English language illogical thing. This is actually fairly common among engineers. Had my family known the warnings signs, it would have been obvious since I was about 5 years old that I was destined to be an engineer. I have always been good with numbers, and I can’t spell worth crap. Take note parents, as these are the warning signs your child may be an engineer. Also, an early love of duct tape.

I am fairly good with grammar though probably because there are more rules and less exceptions. Partially because of this and for other reasons, at my current job, I often edit other people’s documents not just for science and engineering accuracy but also for grammar, readability, and clarity. I have also been a peer reviewer for a few manuscripts submitted to scientific journals, and previously, I used to edit manuscripts that were about to be submitted to peer review journals. I keep coming across certain words and phrases that are scientifically and grammatically incorrect. There are many grammar style manuals that exist, but I have yet to come across a science grammar style manual. If one exists, I would love for someone to point me to it. So I’ve decided to start writing about some of the most common and inappropriate phrases in the hope that maybe it will stop at least one one person from using these incorrect phrases.

The most common and completely wrong phrase I see is stating that something or someone weighs a certain number of kilograms. Ironically, non-US citizens, i.e. people who live in a country where they use the metric system, are just as guilty of this phrase as US citizens who sort of have the excuse that they live in a country that refuses to stop using the completely archaic and impossible to use if you are a scientist or engineer, English imperial or US customary units. For the benefit of everyone who doesn’t understand why this is wrong, let me explain why it is.

A kilogram is a unit of mass. Mass is the amount of stuff that an object has.

To say something weighs something, you are saying it has a certain amount of weight. A weight is a specific type of force, and because it is a force, weight, like all other forces, is measured in Newtons (N) in the metric system. Weight is the amount of force on an object due to gravity. Therefore, weight is the mass (the amount of stuff) multiplied by the acceleration due to gravity. If you happen to be a person on Earth with a mass of 70 kg, then since the gravitational acceleration on Earth is 9.81 m/s2, you have a weight of 687 Newtons (N). Let’s say you happen to be an astronaut, and the Moon program gets revived, and you go to the moon. Your mass will not change. Your mass will still be 70 kg, but once you arrive at the Moon, your weight will be about 114 N because the Moon’s gravitational acceleration is 1.63 m/s2. While you are on your journey to the Moon in space, there will be no gravity, so you will have no weight. You will be weightless, hence the fun videos of astronauts floating, but you will still have the same 70 kg mass.

To review, a person or an object has a mass that can be measured in kg. A person or an object that is on any celestial body with gravity has a weight that can be measured in N. It is completely incorrect to say that a person or an object has a weight in kg. It is also confusing. Does it mean you have a mass in that number of kg? Does it mean you have a weight in that number of N, not kg? Please, don’t use kg and say weight. Mass and weight are not interchangeable. They do not mean the same thing.