Re: [APD] Just how accurate do we need lighting recommendations to be?

[urville <urville at peoplepc_com>]

i have mild oppositional disorder! not to make light i just thought that 
was interesting. i had no idea that exsisted. for me if everyone goes 
one way it's extremely hard for me to not go the exact opposite or 
alternate route. i can do it, but it's an internal struggle. i always go 
for the underdog for example. haha till everyone else does it.

Jerry Baker wrote:

>David Aiken wrote:
>  
>
>>On 19/09/2005, at 1:40 PM, Jerry Baker wrote:
>>Sorry, but measurement is not the basis of all empirical knowledge.  
>>There are all sorts of things we know empirically which don't rely on  
>>measurement - the sun will rise tomorrow,
>>    
>>
>
>And how do you propose to define when tomorrow is without measurements? 
>You can't define it as when the sun comes up because then you would have 
>  a logical absurdity ... that the sun will rise when the sun rises. You 
>would probably say, "the sun will rise in about 9 hours."
>
>  
>
>>sugar tastes sweeter than  
>>salt,
>>    
>>
>
>That's a measurement. Just because you didn't use a ruler to get the 
>measurement doesn't mean it isn't one. If you compared a plant and a 
>tree, you would probably say the tree is bigger. Your senses are 
>perfectly capable of measurements. In fact, all measuring devices do is 
>allow us to increase the resolution of our senses.
>
>your partner's favourite food treat, and so on. There's a huge
>  
>
>>amount of empirical knowledge that doesn't rely on measurement and  
>>the first humans certainly learnt enough to live and survive without  
>>any measuring devices.
>>    
>>
>
>You don't need a measuring device to make measurements. Devices just 
>aide our senses where we do not have the ability to resolve the detail 
>we seek. You do not need a ruler to see that a tree is taller than 
>grass, but you probably need a ruler to see that US letter-sized paper 
>is slightly wider than A4 without holding them next to each other.
>
>  
>
>>That's not to say that measurement isn't useful in many areas and  
>>absolutely essential in some. That's just saying that your claim  
>>about measurement's role in empirical knowledge is wrong.
>>    
>>
>
>No, it isn't. I think you are just thinking of measurements as always 
>being conducted with a device.
>
>  
>
>>So, let's say we pin the lighting levels down exactly. Let's say you  
>>do what you said you want to be able to do and work out what light  
>>levels will keep certain internodal lengths under 50 mm, or certain  
>>plant heights under x mm. You've done your controlled test in  
>>particular systems with or without CO2, a given fish population, and  
>>a certain feeding and fertilisation routine. I run a different tank  
>>with a different fish load, both in numbers, species and size. I use  
>>a different substrate for whatever my reason of choice is.  
>>Temperature of the tank is slightly different to satisfy my different  
>>fish choice. I feed differently and I dose different fertilisers  
>>because I live in Australia and a lot of your US products and the  
>>European products available to you aren't available here. You give me  
>>your data on what level of light I need to get those plant growth  
>>results.  Now tell me how I apply that data to my different and  
>>unique situation.
>>    
>>
>
>My whole point is that you cannot definitively say which variables 
>matter and which don't unless you do the study. I am truly surprised at 
>how much resistance there is to this idea. Maybe it is true that there 
>are too many variables to account for, but it's also possible that none 
>of those variables you listed have any measurable effect. Have you 
>tested that? If not, why postulate otherwise?
>
>  
>
>>And the real trigger for me in your post was your claim about  
>>measurement and empirical knowledge. I really couldn't let that one  
>>go past - it simply pressed one of my buttons, and that's my problem  
>>rather than yours. Your problem is being forced to read a post as  
>>long as this  :-)
>>    
>>
>
>That scares me. I can't tell if you have "art school syndrome" or if 
>it's something else. If you don't know, art school syndrome is a 
>somewhat common affliction where there is a pathological opposition to 
>the idea that something beautiful can be explained, or quantified.
>
>  
>
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