Posted by finelinebob on September 3, 2006, at 1:45:22
In reply to Re: Biopsychosocial vs Biological Reductionism » finelinebob, posted by Estella on September 3, 2006, at 1:03:22
ROY G BIV, Estlla, ROY G BIV ...
... or VIB G YOR, since they got it backwards.
Mathemagically, it's prolly pretty simple. You have A as your lowest detectible count or just set it to 1, black being 0. You have Z has the highest detected count. Violet light has a short wavelength (low number), red a long wavelength (high number). Match your lowest violet to A, your highest red to Z, and let the computer figure out the rest in-between.
Of course, the visible spectrum expressed that way is a linear progression. If your theory behind what you're studying suggests a non-linear response, then you have to get tricky.
> > Changing the brightness not only does not add to the interpretation of, say, a PET scan, it actually introduces a non-existent variable or, rather, a variable indicating the "goodness" or the "badness" implicated by the colors.
>
> I find that very interesting indeed.
> :-)It's like this:
Say I'm doing a PET scan of a stroke patient trying to read something and I get lots of yellow and red (woohoo!) in the visual cortex but blue to violet to black wherever it is in our brains that turns those visual stimuli into language and then meaning ... uh oh.
Then again, I got this pre-chemo scan of a patient with a tumor somewhere, all nasty bright yellow and red (boo!) but then I put up the post-chemo scan and that area is now blue to violet to black. Coooooll! (figuratively and literally)
> > As an aside, I always find it a bit amusing that red tends to be assigned to high evergy levels and violet to low energy levels. The physicist in me just wants to giggle at how they got it backwards.
>
> I didn't know it was reversed in physics.Yep. Particularly if you are measuring something like decay events from a radiological tracer. Each event is a little ping of energy on the scanner's sensors. Lots of pings, lots of energy.
Well, when it comes to the visible spectrum, red is at the low energy end and violet at the high evergy end. ROY G BIV (red orange yellow green blue indigo violet) is the spectrum from low to high energy. So for red to represent areas of high activity is to abandon science and cave in to cultural biases of what's hot and what's not.
Come to think of it, they DO do this even in astronomy. Nothing's sacred.
poster:finelinebob
thread:680731
URL: http://www.dr-bob.org/babble/20060901/msgs/682563.html