ishmaelcat
Registered
OK folks, here's a real puzzle I'm hoping someone knows the answer to:
First, the background (don't get excited yet, this isn't the puzzle) -- Let's say I haven't been diving for several days. Now I take my dive computer (Cressi Sub Archimedes II) up in a commercial airliner. At cruising altitude, the cabin is pressurized to what is equivalent to about 8000 feet above sea level. My Cressi shows two little mountains to tell me I'm at altitude; it also show 4 pixels on the N2 loading graph.
This all makes sense, because I started at sea level with my blood saturated at 1 atm, and now I'm in a lower ambient pressure environment, so I'm now supersaturated and off-gassing. As a matter of fact, on a long flight you can watch the saturation level on the N2 graph go down -- just like after a dive -- to 3 and then 2 pixels and so on. This all makes sense too.
What doesn't seem to make sense to me is that when the plane lands, at sea level, the computer still shows 1 pixel of N2 and about 2 or 3 hours (I forget exactly how much) time until total desaturation. And that pixel remains until those 2 or 3 hours have passed. It seems to me that any tissue in my actual body at this point should be picking up more N2, not offgassing, no matter which "compartment" it is. Strangely, just to add another oddity, the Cressi also seems to "understand" after landing that I haven't really been diving, as the "No Fly" icon does NOT appear.
So what's the explanation? And if you're going to say it's a glitch, what I want to know is, how you think the computer's algorithms arrived at this particular glitch. Onthe other hand, if it's intentional, what's the rationale.
Finally I'd be curious to know if other people had brought their computers with them on a fight and noticed the same thing -- especially if you have a Suunto or Oceanic or something else that has different innards than mine (i.e. not a Nitek Duo or Tusa whatever it is).
I've been wondering about this for over a year; any insight would be appreciated.
First, the background (don't get excited yet, this isn't the puzzle) -- Let's say I haven't been diving for several days. Now I take my dive computer (Cressi Sub Archimedes II) up in a commercial airliner. At cruising altitude, the cabin is pressurized to what is equivalent to about 8000 feet above sea level. My Cressi shows two little mountains to tell me I'm at altitude; it also show 4 pixels on the N2 loading graph.
This all makes sense, because I started at sea level with my blood saturated at 1 atm, and now I'm in a lower ambient pressure environment, so I'm now supersaturated and off-gassing. As a matter of fact, on a long flight you can watch the saturation level on the N2 graph go down -- just like after a dive -- to 3 and then 2 pixels and so on. This all makes sense too.
What doesn't seem to make sense to me is that when the plane lands, at sea level, the computer still shows 1 pixel of N2 and about 2 or 3 hours (I forget exactly how much) time until total desaturation. And that pixel remains until those 2 or 3 hours have passed. It seems to me that any tissue in my actual body at this point should be picking up more N2, not offgassing, no matter which "compartment" it is. Strangely, just to add another oddity, the Cressi also seems to "understand" after landing that I haven't really been diving, as the "No Fly" icon does NOT appear.
So what's the explanation? And if you're going to say it's a glitch, what I want to know is, how you think the computer's algorithms arrived at this particular glitch. Onthe other hand, if it's intentional, what's the rationale.
Finally I'd be curious to know if other people had brought their computers with them on a fight and noticed the same thing -- especially if you have a Suunto or Oceanic or something else that has different innards than mine (i.e. not a Nitek Duo or Tusa whatever it is).
I've been wondering about this for over a year; any insight would be appreciated.