Nitrox Class Without Tables or Math...OK?

[Charlie99]

I once heard the analogy made that, "You don't need to understand the workings of an internal combustion engine to know how to drive, so you really don't need to understand the physics of gasses under pressure to know how to dive." However, not knowing what a carb and spark plugs do will probably not kill you. Failing to understand MOD's and PPO can. I can see where agencies are moving away from requiring dives, but I can't see how they can teach Nitrox without tables or math.

Very few divers have gone to the trouble of using the basic exponential equations to derive and generate the dive tables. They just take the NDL table at face value. In a very real sense, the table of %EAN vs MOD is not anything different. It's pretty simple. Once you know your FO2, look up your MOD. No equation needed. Using Netdoc's techniques of letting the computer calculate MOD just replaces the paper table with an electronic calculator. No big deal in my view.

For many people the equations are self evident (or at least the simplified equations that assume ideal gas law and linear superposition of the multiple gas components). That does not mean, however, that going back to the basic equations is the only suitable method of learning how to use nitrox.

At the core of a lot of this type of debate is the difference between Education and Training. Training is goal-directed education with a specific purpose in mind. The goal of dive TRAINING is to impart the knowledge and skills needed to dive. Just like I don't need to understand internal combustion engines to be able to drive a car, I can safely dive (air or nitrox) after going through a training program that may be lacking from the point of view of someone who wants an EDUCATION (development of the mind and knowledge).

Training covers the essentials. Education gives you the background and better understanding. Being educated is nice, but not necessary.

 

[Charlie99]

I seem to remember not being allowed to use a calculator in math class until AFTER I could do the math by hand.

There is a limit to the value of manual calculation. Solving cube roots and other polynomials by hand using Newton's method was part of my high school math class. It got old pretty fast. IMO, there was very little value in solving such equations by hand, nor was there much value in using log tables to solve exponential equations by hand.

 

[lamont]

There is a limit to the value of manual calculation. Solving cube roots and other polynomials by hand using Newton's method was part of my high school math class. It got old pretty fast. IMO, there was very little value in solving such equations by hand, nor was there much value in using log tables to solve exponential equations by hand.

being able to do a little quick arithmetic and estimate the answer to a physics problem to a close order was invaluable in taking tests. after crunching the numbers out the hard way to get the exact answer you had an idea of if you were in the ballpark or had done some little mistake in the middle of the problem somewhere. most of my really good upper level physics and astronomy profs were in the practice of making close order of magnitude guesses as the first step when looking at a problem, and they taught using that approach.

 

[Charlie99]

being able to do a little quick arithmetic and estimate the answer to a physics problem to a close order was invaluable in taking tests. after crunching the numbers out the hard way to get the exact answer you had an idea of if you were in the ballpark or had done some little mistake in the middle of the problem somewhere. most of my really good upper level physics and astronomy profs were in the practice of making close order of magnitude guesses as the first step when looking at a problem, and they taught using that approach.

My electrical engineering courses predated the ready availability of calculators; and getting a run on a computer involved punching cards, submitting the deck, then coming back 24 hours later to find out about your syntax error. So slide rules were the most common calculating tool. Since slide rules don't give you a decimal point, you had to do a rough calculation in your head.

In spite of that (or perhaps because of it), I very much prefer using calculators and computers than manual methods, while doing just enough of the problem in my head to make sure the computer answer makes sense.

Works for diving too.

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Rather than walking 5 miles to school every day, uphill both ways, I pefer to use the snowmobile. :banana:

 

[spacemanspiff1974]

Just finished my IANTD nitrox yesterday.

Lots of posts on this subject, but I still don't understand why anyone would take a mathless nitrox class. The math is helpful in understanding what it is you are breathing and the concept behind nitrox.

Additionally, this is basic basic math. There are some things from school that are a must in everyday life. Basic algebra is one of them. How a person gets by without knowing these things is beyond me.

 

[limeyx]

...

In spite of that (or perhaps because of it), I very much prefer using calculators and computers than manual methods, while doing just enough of the problem in my head to make sure the computer answer makes sense.

Works for diving too.
...

No it doesn't. Dont you know you have to turn your brain off as soon as you hit the water?

 

[DivesWithTurtles]

...The math is helpful in understanding what it is you are breathing and the concept behind nitrox.
...

Yes it is.

But it's not helpful at all in diving with nitrox.

Read what was said a few posts ago about training vs. education.

 

[Swan1172]

Training covers the essentials. Education gives you the background and better understanding. Being educated is nice, but not necessary.

I tend to disagree. Training gives you the ability to do something, but not necessarily the understanding of why you are doing it. This is known as "learning by rote" and is merely teaching through imitation. You can train a parrot to say words, but they in no way understand what they are saying. To them, words are just sounds. They only mean something to us, because we are educated.

Try looking at it this way. If your sixteen year-old daughter told you she was going to take a sex education course at school, you probably wouldn't give it much thought. But, what if she announced she was going to take part in some sex training at school? Would you feel the same way? Of course you wouldn't.

Dr. Suess said it the best in Hooray for Diffendoofer Day when he said, ""We've taught you that the earth is round, that red and white make pink. But most importantly of all: We've taught you how to think..."

 

[Charlie99]

I tend to disagree. Training gives you the ability to do something, but not necessarily the understanding of why you are doing it. This is known as "learning by rote" and is merely teaching through imitation. You can train a parrot to say words, but they in no way understand what they are saying. To them, words are just sounds. They only mean something to us, because we are educated. <emphasis added>

Actually, you ARE agreeing with me. The essentials of what is absolutely necessary to safely dive is a very small set of skills and knowledge. They can indeed be taught by rote. Decompression theory can be nothing more than "follow these tables". Indeed, although many people seem to think that learning how to manipulate tables is some sort of higher education, it is a simple rote, relatively non-understanding sort of operation.

While I have chosen to get a better understanding of many areas of diving, it is simply a choice I have made. Most of my further education is not truly required knowledge for safe diving.

To make the argument more specifically related to nitrox, how many of us actually understand the specific biochemical phenomena that occur when exposed to high partial pressure of O2? While I have been exposed to some buzzwords having to do with possible mechanisms for CNS toxicity, in no substantial way could I explain what specifically is happening.

OTOH, I have learned what are commonly accepted combinations of partial pressures and duration of exposure. (Which is a significant step up from what most divers do, which is just memorize a "safe ppO2", without knowing the acceptable exposure duration related to that ppO2.) Pure Rote Learning. Also very useful.

 

[Quero]

Charlie99 has it right in regard to the depth of knowledge needed for dive training.

Learning to dive Nitrox using a computer as a tool is no different from using tables. Neither approach is "mathless"; the physical gas laws and the mathematical processes they entail can and should be explained and understood, but the *calculations themselves* can be carried out in a number of ways, including pencil and paper, reference to a chart, or with the use of a computer.

Charts and tables are not "cheat sheets." They are tools like any other tool. I don't imagine that those of you who rely on the Wheel or RDP tables or V-planner type software for planning dives are doing your own pencil and paper calculations with M values, tissue compartments and gas half-lives, are you! If you use those tools does it mean you're cheating?