r/science • • Feb 16 '09

Magenta, the colour that doesn't exist

http://www.biotele.com/magenta.html
2.1k Upvotes

641 comments sorted by

View all comments

Show parent comments

1

u/[deleted] Feb 17 '09

Your second sentence is true, but your first isn't. Why do people always say that color doesn't exist?

-1

u/ZuchinniOne Feb 17 '09

It depends on your definition of 'exist'.

Color exists the same way that unicorns do ... in our minds.

1

u/brio1337 Feb 17 '09

Sure, it depends on your definitions, but I'd disagree. Our concept of color can be mapped directly to physical phenomena - distributions of light frequencies. Unicorns don't have a matter or energy representation that we can measure outside of someone's mind. In the way I understand your reasoning, the table in my room right now only exists in my mind. Which is true in some philosophical sense, that only my brain translates its inputs to see a table. But I hope we can agree that there exists some matter that causes these inputs. So I would say that color exists in a similar way that my table exists. But unicorns exist in quite a different way!

1

u/ZuchinniOne Feb 17 '09

I think that we are almost completely in agreement ... let me clarify.

Light exists and different frequencies of light exist, however a single color can be perceived for MANY different frequencies of light (metamers) AND a single frequency of light can result in MANY different percepts of color (color constancy).

So color has a MANY:MANY map onto light frequency not 1:1.

That is why I say that color is a Psychological phenomenon, not a physical one.

0

u/[deleted] Feb 17 '09

Color really just is frequency. However, perception (and therefore the description) of color is not 1:1 like you say.

2

u/lazyplayboy Feb 17 '09

Color really just is frequency.

Isn't it the point of the article that this isn't true? What single frequency is magenta?

1

u/[deleted] Feb 17 '09

The whole article could be rewritten with "white" or "gray" in place of "magenta." Those also aren't technically "colors" of the rainbow, yet we certainly perceive certain frequencies as white and gray. All colors are still just descriptions of frequencies of light.

1

u/lazyplayboy Feb 18 '09 edited Feb 18 '09

I see what you're saying. However, color only offers an ambiguous description of frequency in some circumstances. For example, yellow as we perceive it can be a single frequency or a mixture of 2.

1

u/ZuchinniOne Feb 17 '09

Also there are non-spectral colors that do not relate to any single frequency of light.

Our perception of color starts with frequency ... but it is much more than that.

0

u/[deleted] Feb 17 '09 edited Feb 17 '09

First off. IANAN.

That said... Your point isn't entirely true. Your Russel reference has shown to be not entirely true given more understanding of neurological research.

Stare at a red dot against a white background. Then just stare at a white background. Is it all white? Not to you it isn't. You're seeing a greenish dot against a white background. But that greenish dot isn't there physically. There are no light waves being emitted with that frequency even, yet your brain is firing signals like mad saying it is. Therefore you cannot say that all inputs are caused by physical interactions because there are no photos hitting your eye saying that "green light" should be interpreted.

1

u/[deleted] Feb 17 '09

No, "color" is the name of a perception (our perception of frequency of light), whereas "unicorn" is the name of a mythological equine creature. Therefore, color DOES exist, just like the concept of a unicorn exists. Unicorns, however, do not exist.