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Re: [APD] CO2 Experiment #2

On 09/11/2005, at 11:59 AM, Jerry Baker wrote:

> David Aiken wrote:
>> In a sterile bucket such as that used in your experiment we  don't  
>> have supersaturation with O2, and nitrogen is much more  insoluble  
>> in water than either O2 or CO2 so what basis do you have  for  
>> assuming that there's any nitrogen exchanging out? It seems to me   
>> that there's a lot of assumption going on here.
> There is some assumption, but assumption does not mean incorrect.  
> If someone tells us that they dropped something, we assume it fell  
> to the ground (or whatever horizontal surface interrupted the  
> fall). We do not need to verify that the object indeed did fall. We  
> know from prior experience and knowledge of how gravity works that  
> an object dropped will fall.

Assumption may not mean incorrect, but it also doesn't  mean correct.  
And your examples are getting tiresome. We know from past experience  
that when it rains the ground gets wet, but I can walk out into my  
yard after rain and find the grass is not wet because the marquee I  
erected for my party kept the ground dry. I can also walk out at  
another time and find the ground wet but it hasn't been raining - the  
sprinkler system has been on. Prior experience is great for telling  
us what usually happens in normal circumstances but injecting  
pressurised CO2 into water and catching bubbles isn't the normal  
situation that applied when the gas diffusion laws were discovered.  
There may be some additional laws operating that you haven't  
considered, as well as the ones you keep quoting.  You've spent a lot  
of time criticising everyone else's assumptions but you seem to be  
happy to accept your own assumptions quite unquestioned.

> Along those same lines we know that diffusion will occur at an air/ 
> water boundary where the the partial pressure of any gas is not  
> equal. We do not have to check if this is happening. What we don't  
> know is to what extent it is occurring.
>> Is the next step going to be claims that the gas collected  
>> contained x,y & z, with no testing whatsoever to determine that is  
>> the case,  simply because the assumptions have been repeated so  
>> often by then that everyone is starting to believe them?
> See above.

Precisely - unquestioned assumptions.

>> You're collecting bubbles of unknown content, and you're bubbling  
>> in  close to pure CO2. You have no evidence at this stage for what  
>> the  collected gas contains. Let's try to keep it scientific and  
>> dispense  with the assumptions. If you want to say what has been  
>> collected, get the gas analysed and tell us the results.
> There is not only evidence of what the gas contains, but good  
> scientific laws and theory behind the fact that it will contain any  
> and all of the gases that are present in the water. What is in  
> question is not what gases are present, but in what amounts.

Sorry but you're wrong. There may be good scientific theory available  
which can help us to predict what the gas will contain, but there's  
absolutely no evidence for what is actually in the test tube until  
you get it tested. The test results are your evidence. You can say  
that there should be Oxygen or Nitrogen or CO2 in there prior to  
getting the test results, or that you expect O/N/CO2, or that you  
have grounds for BELIEVING that there will be O/N/CO2, but you can't  
say that there actually is O/N/CO2 until you have some evidence of  
that.  Until you have test results all you have are good reasons,  
even very good reasons, for believing that there should be O/N/CO2 in  
there but you don't have any evidence. You have supposition. Reasons  
for belief are not evidence of actual fact. Evidence means  
verification of the fact and you haven't done any verification.

David Aiken
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