My bet would be a ph difference in the glass versus the sink. Many "red" things turn "blue" when acid is shifted to basic or vice versa ( I never remember which way it goes. )
It is like growing hydrangeas in pine needles or lime. Two different colors w from the same plant. Sent from my iPhone Suzi Shapiro On Feb 1, 2013, at 3:17 PM, "David Wheeler" <[email protected]> wrote: > I don't know about wine, but blue dye is often used for the colors black, > violet, and blue depending on the concentration of dye. Black licorice is > really a very concentrated blue dye. My guess is that this is because the > colors reflected off of the dye are at the lower limit of the visible > spectrum. As you increase the concentration, less and less visible light will > be reflected. > > =David Wheeler > Robert Morris University > Pittsburgh PA > > On 2/1/13 2:16 PM, Marc Carter wrote: >> Hi, all -- >> >> Although this is not directly teaching-related, it will be the next time I >> teach color vision. >> >> I have dried-up wine residue in the bottom of a glass, left from the night >> before. It's purple. >> >> I put water in the glass to rinse it, and the water has a purple tint. >> >> I pour this into a white enamel sink. It's *blue*. >> >> The sink is as far as I can see not yellowish -- it really looks white. >> >> Any ideas on why this happens? Anyone care to try to replicate this and >> report back? >> >> Thanks, >> >> m >> >> -- >> Marc Carter, PhD >> Associate Professor of Psychology >> Chair, Department of Behavioral and Health Sciences >> College of Arts & Sciences >> Baker University >> -- > > > --- > You are currently subscribed to tips as: [email protected]. > To unsubscribe click here: > http://fsulist.frostburg.edu/u?id=13048.2053ea869f5c78d1a98b73ae63133ea1&n=T&l=tips&o=23416 > or send a blank email to > leave-23416-13048.2053ea869f5c78d1a98b73ae63133...@fsulist.frostburg.edu --- You are currently subscribed to tips as: [email protected]. To unsubscribe click here: http://fsulist.frostburg.edu/u?id=13090.68da6e6e5325aa33287ff385b70df5d5&n=T&l=tips&o=23421 or send a blank email to leave-23421-13090.68da6e6e5325aa33287ff385b70df...@fsulist.frostburg.edu
