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Re: [APD] Assumptions
David Aiken wrote:
> On 10/11/2005, at 8:23 AM, Jerry Baker wrote:
>> David Aiken wrote:
>>> I never challenged the principles of diffusion. You claimed to
>>> have evidence for what was in the tube and all I said was that you
>>> had no evidence for that claim. You have scientific principles
>>> which are an extremely good basis for predicting what is in there
>>> but, until you confirm that prediction by testing, you have no
>>> evidence for what is in there and, without evidence, you're
>>> making an assumption. That's something you happily criticise
>>> everyone else for.
>> The evidence is the fact that diffusion happens. It's not a matter
>> that is in dispute. To say it might not have happened in this case
>> is to question the principles of diffusion.
> Diffusion is not in question, and no one is saying that it might not
> have happened. I'm asking what actually happened. Elsewhere you said:
>> Jim Swinford wrote:
>>> The argument(differance of opinion?) is not whether there is
>>> diffusion but the rates, types and causes of diffusion.
>> That is exactly what I have been trying to say. We know there is
>> diffusion, but we do not know the extent of it.
> And that's what's being asked. Which gasses diffused and to what
> extent? Does supersaturation of one or more gasses influence the
> outcome of diffusion? I understand that Yogi Berra once said
> something like "In theory there is no difference between theory and
> practice, but in practice there is." You said that we don't know the
> extent of the diffusion so why are you so reluctant to test and find
> out exactly what is actually in there? The question is what actually
> did happen and you can't say that without an analysis of what's in
> the tube.
>>> Until you test, you aren't stating what is in the tube - you're
>>> merely predicting what will be found if you do test. You have
>>> grounds for the prediction. You don't have any evidence for what
>>> is actually in the tube since evidence for that requires testing
>>> what exactly is in the tube.
>> I would bet on penalty of death that there is *some* oxygen in the
>> tube. There's no way there isn't. What is in question is whether it
>> is something like 0.0001% or 50%.
> I won't take your bet because what is at issue is the concentrations
> - as I said above. If the oxygen content happens to be only 0.0001%,
> then for practical purposes it's irrelevant and can be ignored, to
> use one of your favourite phrases. If it happens to be 50%, that is
> way higher than the normal proportion of oxygen in air. In either
> case something unexpected would be going on. So, is something
> unexpected going on or not? I'm using those percentages since you
> raised them, so don't bother trying to prevaricate on the percentages
> here. The question is whether or not something unexpected is going on.
>>> As to me doing anything like being "intellectually dishonest" and
>>> trying "to attempt to discredit the results of a scientific
>>> investigation by representing established scientific principles as
>>> open to controversy when they aren't", your test was about
>>> dissolution rates which you were measuring by counting the bubbles
>>> required for the gas to reach a certain volume in the tube. I
>>> didn't question those results at all. I questioned a claim you
>>> made about something else - the contents of the gas collected -
>>> which you did not test. It's intellectually dishonest to claim
>>> that I was trying to discredit the results of your investigation.
>>> I accepted the only investigative results you reported. I
>>> questioned a claim that was not the subject of an investigation.
>> I did not mean that you were questioning my results. I meant that
>> you were introducing a controversy where there is none. Diffusion
>> is a fact of life. It happens without qualification wherever there
>> is a concentration gradient. A bubble of nearly pure CO2 is one
>> such place. If oxygen is present, it *will* diffuse into the
>> bubble. There is absolutely no question about that. Implying that
>> this is not the case appeared to me as though you were trying to
>> make it appear that there
>> was a genuinely valid question about whether diffusion had taken
>> place. Of that, there is no question. My apologies if that is not
>> what you intended.
> I never indicated that diffusion had not taken place but the point
> here is about intellectual dishonesty. I questioned your claims as to
> what is in the tube because that claim was not the subject of your
> investigation and no evidence for the claim was presented.
First of all, I never claimed anything about what was in the tube at the
end of the experiment other than to say there was some oxygen. There has
to be and I stand by that. I did not claim anything other than that.
> Yes, you
> did present reasons for making the claim, but not evidence that it
> was correct. You then misrepresented me by claiming I had questioned
> scientific principles - I didn't - in order to throw discredit the
> results of your investigation when I also did not question the
> results of your actual investigation. That misrepresentation is
> actually intellectual dishonesty on your part, and it is totally
> consistent with your tendency to accuse anyone who questions your
> reasoning and conclusions with questioning the laws of science and
> then ignoring the actual question which was raised.
If it makes you feel better to think that, I'm not going to stop you.
The fact is that I made no claim that the tube did not contain CO2, nor
did I claim that the contents of the tube were in any way related to my
test. Your tirade here is *EXACTLY* why I precisely delineated the scope
of the experiment before conducting it. Clearly you did not read that or
chose to disregard it.
> You're the one who has repeatedly claimed elsewhere that small
> differences are irrelevant and can be ignored in the practical world,
> but here you are saying that you don't have to do the tests because
> you know what's in the tube when the tests will also show what the
> proportions are and whether or not we can, for practical purposes,
> ignore the presence of oxygen, nitrogen, and any other components of
> dissolved air.
I said I do not have to do tests to know that there is some oxygen in
the tube. We know it's there in some amount. I also clearly stated that
this experiment was not going to test the remnants of the bubbles.
Please stop misrepresenting my statements to fit your arguments.
> We can definitely take it for granted that there are pressure
> gradients. In a live planted tank, the levels of dissolved oxygen and
> nitrogen are not in the same proportions as in air and the diffusion
> rate out of solution at the surface will vary depending on the
> dissolved concentrations. When diffusion is into a bubble of pure CO2
> - or at least as pure as it comes from a cylinder - and the water is
> or is not also supersaturated with CO2 as well, we can expect more
> variation in what happens due to the fact that the pressure gradients
> once again aren't the normal ones we would expect for the diffusion
> of dissolved gasses out of water.
CO2 is not saturated in water until over 1500 mg/L. You will never get
there in an aquarium without killing everything in it. At 30 mg/L we are
talking less than 2% of saturation. The whole point of the experiment
was to demonstrate that the rate of diffusion is not affected by small
This is the last response I am going to make to any post on this topic
that isn't directly related to the experiment as it was outlined beforehand.
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