More Good Habits

So after another extended absence from my blog, I have decided to start back up again. This is part of my plan to get refocused and back on track. I'm going to start working out consistently again, if only because of a challenge to be carried out at Christmas. I'm also going to change my diet for real this time.

I'm also making sure I keep in line when it comes to my schoolwork. I'm rapidly approaching graduation and need to pull together a complete package of academics and extracurriculars to make myself marketable.

So, I'm back, and need to be harassed if I disappear again.

-Zach

Friends don't let friends dive air

Yesterday night I finally completed my Recreational Nitrox class. This allows me to get fills and use Nitrox mixes of up to 40% oxygen when I go diving. I figured since maybe one person that reads my blog is a diver I would explain the basic principles behind this and gas management in general.

When you first get certified as an open water diver, almost everyone learns while on compressed air. This consists of 21% oxygen, 78% nitrogen, and <1% other stuff (argon, CO2, hydrogen, etc.). We are taught to dive within what are called No-Decompression Limits (NDL). This name is in fact misleading, as all dives are decompression dives to some extent. The point of the NDL is that you can ascend safely to the surface without mandatory decompression stops with minimum risk of decompression sickness (DCS), more commonly known as the Bends.

The basic premise behind DCS is a law of physics called Henry's Law. Henry's Law states that as the partial pressure of a gas increases, it's solubility in liquid, in this case blood, increases proportionately. This becomes an issue with nitrogen as you spend time at depth and the amount of nitrogen absorbed into your tissue increases. As you ascend, the pressure decreases again and the nitrogen comes out of solution. When diving within NDL and ascending slowly, less than about 15 feet/min, the size of the bubbles coming out of solution are sufficiently small to usually avoid causing any problems. However, beyond NDL or with too rapid an ascent, larger bubbles can collect in joints, under the skin, or worst case scenario, in the brain, subsequently causing the symptoms of DCS.

Where Enriched Air Nitrox (Nitrox) comes in is increasing these no-decompression limits. With a higher percentage of oxygen in the mix, there is also less nitrogen. The lower nitrogen content of the mix means there is a lower partial pressure at depth, and slower absorption into the tissue. Therefore you can spend more time down with the same effect, or the same amount of time down with less effect from nitrogen than if you were on air. Non-harmful effects of nitrogen include narcosis, which is similar to mild anaesthesia at depth, as well as a nitrogen "hangover" afterwards.

Contrary to what many people think, Nitrox does not allow you to dive deeper. It is actually classified as a mid-level gas, most useful from around 60 feet down to around 110 feet based on what mix you use. Beyond those limits you actually run the risk of oxygen toxicity. This is caused when the partial pressure of oxygen in the mix exceeds around 1.6 atmospheres, or 1.6 times the pressure exerted by air at sea level. Oxygen at high enough pressures is actually extremely dangerous and can even cause convulsions. For this reason, when diving Nitrox, you must be aware of the maximum operating depth of your mix. This is a concern not often covered with air, because the MOD of that is around 190 feet, well beyond the scope of recreational diving. However, when used with care and proper planning, Nitrox can make for a very enjoyable and safe dive.

Just remember, friends don't let friends dive air.

-Z

You can't just drop back and punt it

With regards to how much of our dynamics and differential equations classes it appears my classmates and I retained, this is an oft used quote by my vibrations professor. I bring this up mostly because this class is probably the best engineering class I have ever taken. To this point it is also the hardest engineering class I have ever taken.

Why? Is the material so much different from other classes I've taken? No, it's actually quite similar to other classes I've taken. It is mainly modeling systems, developing a differential equation, then setting up the equation so it is solvable, at least within reasonable approximation. By my count I've had three courses directly dealing with these subjects, not to mention the math classes leading up to them.

Perhaps I'm too overloaded this semester? No, actually this is the easiest semester of my college career scheduling wise. I intentionally set up my schedule to give myself a solid footing at a new school so I can push through to the finish. I knew I had labor intensive classes this semester, so in addition to working out a favorable class schedule, I am also not working this semester.

Well then why is it so hard, you ask? It is mainly because of this professor. No, not because he doesn't know what he's talking about. He knows it inside and out and I am extremely impressed. Nor is it a language barrier similar to a couple I have encountered in the past. Rather it is his teaching style. It is markedly different from every other teacher I have had thus far in my engineering career. It is taking quite a bit of getting used to, but I do believe if more professors taught using the methods of Dr. Anil Rao, the world would be better for it.

The fundamental difference comes in the distinction between getting an answer and getting a solution. Engineering students are taught, pretty much from the start of elementary school, that they need to get the same answer that is in the back of the book. I myself have done this many times where I'm not quite sure what is going on in a problem, but if I plug the given information into enough different given equations, eventually I'm going to get the answer I'm supposed to. But what does that answer tell me? Absolutely nothing. Could I explain to somebody why I got that answer and why what I did was right? What a preposterous idea. If given another problem could I identify similarities and use that knowledge to help me instead of doing the whole stupid plug and chug process again? Don't I wish. Therein lies the fatal flaw in the way most engineering classes are taught.

What Dr. Rao requires of us is to take every step, from step zero to step seven hundred and work it out in gory detail, every time. But doesn't that take more time? Naturally, but when I get a solution at the end, I know it is right, I know why it is right, and I can show you every step I did to prove it is right rather than basing it on a sheet full of equations the teacher gave us from the book. After doing several of these problems you also get another revelation: all of these problems are the same. But surely that can't be true! It is true and don't call me Shirley. You model the system making appropriate assumptions and simplifications, justifying each of them. This includes defining reference systems that not only describe the system well, but omigosh, they make the math and subsequently your life much easier. You decide which law you are going to use to describe what you need to, lately it has been Euler's Laws for rigid body motion (that's what she said), then derive all the information needed to solve it. Drop it into a differential equation and solve. Poof, done.

I know, that sounded exceedingly complicated and probably made a couple of the liberal arts majors want to cry, it really isn't as bad as it sounds, and can really be quite interesting. Each time I walk out of that class, it feels like information overload, but I know as I process it all, it is going to help me be a better engineer, rather than having to figure that out down the road when my mentor tells me I have no justification whatsoever in my thesis and not to come back until I can explain what I did instead of hiding it in a bunch of technical jargon.

It kind of goes back to "If you didn't have time to do it right the first time, how on earth are you going to find time to do it again to fix it?" It's all about thoroughness. Do it right, it works out. That's one of the nice things about engineering. I wish more stuff was like that.

So goodnight y'all. Fait des beaux reves.

-Z

A picture is worth a thousand words

What makes a great picture? What makes a picture not only catch the eye, but also have an impact on the soul? When does a picture tell a story instead of just recording an event? These are really questions that can be debated ad nauseum, but as a general rule, a picture can't be great before it is good. This aspect I can comment on.

When someone looks at one of my pictures and says, "Wow, those are good! You must have an awesome camera." I want to punch them. You wouldn't associate a painting with how good the brushes are, or the taste of a meal with how good the pots and pans are. Why would you do the same thing with photography? It is true, it is easier to take good photographs when you are using better equipment. But, it is also true that you could hand me a $50,000 Hasselblad and hand Ansel Adams a $200 point and shoot and he would outshoot me any day of the week, and he's dead!

There is still a large amount of skill involved in taking a good picture. Advances in technology have brought up the baseline so it is easier for more people to take passable pictures without thinking about it. This also means that to distinguish themselves, the top echelon of photographers also has to improve to justify getting paid for their work. Occasionally someone with a point and shoot will take an awesome picture under good shooting conditions. The separation comes when a photographer is contracted to take many good pictures on a specific day no matter what the shooting conditions. The consistency and ability to perform no matter what is where the skill and training come in, with a little help from equipment.

The basis of all photography really goes back to an understanding of light. Light is like sound for a musician. Light is like ingredients to a cook. Light is like words to a poet. Without an understanding of how it works, it is impossible to use it to its full potential. The hardest thing to wrap your mind around is the quality of light. It is not an absolute scale, nor is it even a one-dimensional scale. It deals with many aspects of light, such as intensity, direction, contrast, color, variability, and consistency. Some of these qualities are more important than others and where in that scale you want to be depends on the type of shooting you are doing. What may be ideal light conditions for a senior portrait of a teenage girl may yield a flat, uninteresting shot of a racecar on the track. Even within the same type of shooting, portraits for example, the desired qualities may change. The lighting setup for the lead singer of a heavy metal band would probably make a middle-aged soccer mom want to cry.

There isn't really one cohesive idea that runs through this post. Actually, it's a rather scattered collection of thoughts loosely connected by a camera, but it gives me something to do in between classes that breaks up the studying. For those that know me well, you probably followed this post like one of our conversations, all over the place, but you got the general idea. For those of you that don't think like me, I'm quite sorry and if you need me to clarify I am more than happy to do that too. Hope everybody has a great day. Au revoir.

-Z