Another Tables vs. Computers Thread

[LSDeep]

Again, what principles am I not teaching? How does a letter group better represent Nitrogen loading over a picture of a bubble? Tables are not a diving panacea. Using them is purely mechanical and does little to promote the understanding of deco theory.

I might also add that if not learning to use tables is a sign of being lazy, then knowing HOW to use these tables and not using them is the HEIGHT of laziness.

ROFL, i love the last conclusion - have to remember that one!!! as for the rest, its the never ending story of table vs. "go with technology advances" hardliners.

learning to use tables differs in no way from learning how to use your computer properly. both dont give you an understanding of the underlaying principles and science (as far as you can talk about that). the statement in an earlier post that no computer this days relies on table models is just outragous bs.!! they might rely on modified models or even new models (there are none that come to my mind you cant trace back to haldane and friends) but there was no revolutionary outragous new concept to make computers work. i would say that 90% of certified divers that use tables couldnt explain were this numbers are coming from and why they are on this slate / screen or whatever. so whats the big difference???? everybody going to get involved in more diving at whichever level he wants will surely start to show an interest at one point or another to get to the roots and find appropriate courses or reading material to fill his needs.

and as for our hardcore table supporters and believers that we need to know everything to the creationpoint (and thats not sarcastic or a joke) could you explain the rgbm model and underlaying science to me please - beside my personal experience that it will bend you on serious tech dives (not only me, but a bunch of other people also). it got adopted fast (also into print and plastic tables) and used widely. i guess it might be reasonably safe within rec limits, sofar i still miss the serious proof for that also. abyss software basically went down with it as a good factor and even the scientist / should we say inventor? of it seems to be very tightlipped about actual analysis of the prob with his model and the resulting probs for way more known and "famous" ppl in diving than little me.

basically it is pretty scary that we dive on models somebody "figured out" with sheeps and others later based on experimental diving with actual divers and derive the least bend level minus one as save limits. after that there is very little serious research known to me, just derivated mathematical models with variations based on more bend s cases and more math with more theoretical tissues. i might be wrong and somebody has an actual example of a lately scientificly researched and developed table.

as was discussed to the puking point, even the computerbased easy nitrox course by sdi still covers the basics for the student to get an understanding (as much as in any other course) of the proposed and believed true principles to go from there to the actual understanding of their main tool (actually sdi requires them to dive with it, so its nothing you have with your logbook for alibi reasons), the computer.

i personally think it is good to know both and the behinds (jeez i should, actually teaching it) but i still fail to see the livesaving benefit for my students. i am actually much more at ease to know they have a halfway idiotproof tool that will do all the calcs for them as long as they dial their mix in than having students that might dive 12 mth after i certified them with tables again and try with half remembered table use info to plan a dive and bend or kill themself.

thats purely for rec courses, if i teach tech i expect a bit more .

 

[Kevrumbo]

Quoted from another thread:

Ignoring issues of reliability, just considering understanding of decompression, why do so many people repeatedly say that learning to use the deco tables in OW is preferable to learning to use a computer?

Because starting out with Tables --particularly NAUI RGBM Recreational Tables-- is much easier to follow for the Basic/Beginning Open Water Student. The convenience of Computers and the understanding the Deco Theory behind it all, ideally should further motivate learning and practice for the novice diver. . .
http://70.84.188.178/showpost.php?p=132221&postcount=5
http://www.rgbmdiving.com/

 

[LSDeep]

Because starting out with Tables --particularly NAUI RGBM Recreational Tables-- is much easier to follow for the Basic/Beginning Open Water Student. The convenience of Computers and the understanding the Deco Theory behind it all, ideally should further motivate learning and practice for the novice diver. . .
http://70.84.188.178/showpost.php?p=132221&postcount=5
http://www.rgbmdiving.com/

now as an "answer" for your first link let me give you this one in return:

http://www.inspired-training.com/RGBM Really Good Bends Model.htm

as for the second one (i only understand half of it completly to be truthful) i can just quote my dad (who is a scientist with various degrees at the dr and prof level) "... interesting thesis that still requires proof to become a theory........". i am not trying to claim that they are not on to something, but where is the rocksolid proof of it - people get bend (even with considered safe oldfashioned tables).

also, have a good look at the material delivered at this site! as the discussion is ongoing about the student having to understand and get a grip on the underlaying (call it) system and theory and math, i would like to see how you incorporate all this information in a beginners nitrox course to make sure students have a deep understanding of the "basics" behind your tables !

 

[DivesWithTurtles]

... the statement in an earlier post that no computer this days relies on table models is just outragous bs.!!
...

What are "table models"? What was "outrageous bs.!!"?

I've read of mechanistic models, empirical (probabilistic) models, and (most widely used) mathematical models. I've never read of "table models". Results of these models may be only lists (tables) in the case of empirical models, or they may be algorithms. Algorithms are used to calculate tables or are implemented in slide rules (the Wheel), dive planning software, or real-time dive computers.

There used to be dive computers that had lists (tables) saved in them as data and did real-time look-ups on those tables. Those may be called "table-based computers". They are obsolete. All dive computers currently on the market use algorithms to calculate deco status in real-time. None do table look-ups.

This is a reflection of what I've read and understand. I am not a thoroughly educated student of this stuff. I could be wrong. Please correct me if I am wrong, and if you know what you are talking about.

 

[LSDeep]

table models = deco models like haldane, buehlmann, rgbm etc in terms of the actual "science" / theory behind your table numbers.
outragous bs = outragous bull $h!t in context with computers are not based on actual deco theories.

 

[LSDeep]

as for mathematical models, yes your deco tables (or ndl tables) are a mathematical model of a thesis that needs serious proof to become a solid theory. so please excuse my sloppy term for mathematical decompression model (i refuse still to call it theory, since a theory is usually something thats scientificly proven)

 

[DivesWithTurtles]

Because starting out with Tables --particularly NAUI RGBM Recreational Tables-- is much easier to follow for the Basic/Beginning Open Water Student. ...

Good answer to the original question.
But I disagree. Learning to use tables is difficult for many (most?) OW students. That is why so much classroom time is spent on them.
I'm not familiar with how to use the new NAUI tables. They may be much easier. I'll check 'em out as soon as I can.

...the understanding the Deco Theory behind it all, ideally should further motivate learning and practice for the novice diver.

Complete agreement here. But very few are so motivated. (I was, as are so many that are also motivated to read ScubaBoard.) And I don't think that really affects their ability to dive safely.

 

[LSDeep]

What are "table models"? What was "outrageous bs.!!"?

I've read of mechanistic models, empirical (probabilistic) models, and (most widely used) mathematical models. I've never read of "table models". Results of these models may be only lists (tables) in the case of empirical models, or they may be algorithms. Algorithms are used to calculate tables or are implemented in slide rules (the Wheel), dive planning software, or real-time dive computers.

There used to be dive computers that had lists (tables) saved in them as data and did real-time look-ups on those tables. Those may be called "table-based computers". They are obsolete. All dive computers currently on the market use algorithms to calculate deco status in real-time. None do table look-ups.

This is a reflection of what I've read and understand. I am not a thoroughly educated student of this stuff. I could be wrong. Please correct me if I am wrong, and if you know what you are talking about.

good (i am not the super scientist either - if so i would poss be at MIT or some place simular), as far as i am concerned the whole deco thesis is a math model of body functions actually based since ages on algorithms to calculate them. they might produce "lists" like the tables or are more complexely calculated by a computer "on the fly". yep, the first computers basically worked down lists and gave you infos, todays computers basically do the same, they calculate based on math models and algorithms in a usually more complex manner due to technology advances. but they still work on (my sloppy term again) table models or math models and their underlaying algorithms. so, to claim that computers dont use this kind of math and algorithms is outragous ignorant bs. it might be based on more complex models or modified models, but it still works based on that and not a can of spam mixed into milk to get numbers .

 

[Charlie99]

No computers currently on the market are based on tables. There haven't been any table based computers since the early 90s.

the statement in an earlier post that no computer this days relies on table models is just outragous bs.!!

That's NOT what DivesWithTurtles said. There were some very early generation computers that were simply table lookup devices. Once you understand what he meant, the statement is in no way outrageous.

-----------------

Dive computers are not based upon tables. Tables are not based upon dive computers. Both are based upon the models.

There are models. Dive computers implement those models. If you are in compliance with the dive computer calculations, then you are in compliance with the model.

Dive tables are a simplified representation of those models, and if you dive in compliance with those tables, then you will be within the limits of the model.

The converse is NOT true. Since the dive tables are a simplified representation of the model, one can be within the model limits, but outside the table limits. Multilevel dives are a common, everyday example of where a dive within model limits can be well outside the limits of a square profile table.

 

[DivesWithTurtles]

... (my sloppy term again) table models... is outragous ignorant bs.

You're right, LS. "Table models" is your sloppy term. It borders on outrageous ignorant bs.

See how I twisted what you said into something you didn't say? Kinda like you've twisted something I said into "computers don't use this kind of math and algorithms".