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  • Hey, Vsauce, Michael here.

  • This appears blue, this appears yellow, and this appears green. Those of us with normal

  • color vision can probably agree. But, that doesn't change the fact that color is an illusion.

  • Color, as we know it, does not exist in the outside world, beyond us, like gravity, or

  • protons do. Instead, color is created inside our heads. Our brains convert a certain range

  • of the electromagnetic spectrum into color. I can measure the wavelength of radiation,

  • but, I can't measure, or observe, the experience of a color inside your mind.

  • So, how do I know that when you and me look at a strawberry, and, in my brain, this perception

  • occurs, which I call "red," that, in your brain, a perception like this doesn't occur,

  • which you have, of course, also learned to call red. We both call it red. We communicate

  • effectively and walk away never knowing just how different each of our internal experiences

  • really were.

  • Of course, we already know that not everybody sees color in exactly the same way. One example

  • would be color blindness. But, we can diagnose and discuss these differences because people

  • with the conditions fail to see things that most of us can.

  • Conceivably, though, there could be ways of seeing that we use that cause colors to look

  • differently in different people's minds, without altering their performances on any tests we

  • could come up with.

  • Of course, if that were the case, wouldn't some people think other colors look better

  • than others? Or, that some colors were more complimentary of others? Well, yeah, but

  • doesn't that already happen?

  • This matters because it shows how fundamentally, in terms of our perceptions, we are all alone

  • in our minds.

  • Let's say I met an alien from a far away solar system who, lucky enough, could speak english,

  • but had never, and could never, feel pain. I could explain to the alien that pain is

  • sent through A-delta and C fibers to the spinal chord. The alien could learn every single

  • cell, and pathway, and process, and chemical involved in the feeling of pain. The alien

  • could pass a biology exam about pain, and believe that pain, to us, generally is a bad

  • thing.

  • But, no matter how much he learned, the alien would never actually feel pain. Philosophers

  • call these ineffable, raw feelings "Qualia." And our inability to connect physical phenomenon

  • to these raw feelings, our inability to explain and share our own internal qualia is known

  • as the "Explanatory Gap." This gap is confronted when describing color to someone who's been

  • blind their entire life.

  • Tommy Edison has never been able to see. He has a YouTube channel where he describes what

  • being blind is like. It's an amazing channel. In one video he talks about colors, and how

  • strange, and foreign of a concept it seems to him. Sighted people try to explain, for

  • instance, that red is "hot," and blue is "cold." But, to someone who has never seen a single

  • color, that just seems weird. And, as he explains, it has never caused him to finally see a color.

  • Some philosophers, like Daniel Dennett, argue that qualia may be private and ineffable simply

  • because of a failure of our own language, not because they are, necessarily, always

  • going to be impossible to share.

  • There may be an alien race that communicates in a language that causes colors to appear

  • in your brain without your retina having to be involved at all. Or, without you having

  • to have ever needed actually to see the color yourself. Perhaps, even in English, he says,

  • given millions and billions of words used in just the right way, it may be possible

  • to adequately describe a color such that a blind person could see it for the first time.

  • Or, you could figure out that, once-and-for-all, yes, or, no, in fact, you and your friend

  • do not see the same red.

  • But, for now, it remains the case that we have no way of knowing if my red is the same

  • as your red. Maybe one day our language will allow us to share and find out, or, maybe,

  • it never will. I know it's frustrating to not have an answer, but, the mere fact that

  • you guys can ask me about my internal experiences, and the mere fact that I can ask my friends

  • and we can all collectively wonder about the concept of qualia is quite incredible, and

  • also quite human.

  • Animals can do all sorts of clever things that we do. They can use tools, problem solve,

  • communicate, cooperate, exhibit curiosity, plan for the future, and, although we can't

  • know for sure, many animals certainly act as if they feel emotions- loneliness, fear,

  • joy.

  • Apes have even been taught to use language to talk to us humans. It's a sort of sign

  • language that they've used to do everything from answer questions, to express emotion,

  • or even produce novel thoughts. Unlike any other animal, these apes are able to understand

  • language and form responses at about the level of a 2.5 year old human child.

  • But, there is something that no signing-ape has ever done. No ape has ever asked a question.

  • Joseph Jordania's "Who Asked the First Question?" is a great read on this topic, and it's available

  • for free online.

  • For as long as we've been able to use sign language to communicate with apes, they have

  • never wondered, out loud, about anything that we might know that they

  • don't.

  • Of course, this does not mean that apes, and plenty of other animals, aren't curious. They

  • obviously are. But, what is suggests is that they lack a "Theory of Mind": An understanding

  • that other people have separate minds. That they have knowledge, access to information

  • that you might not have. Even us humans aren't born with a "theory of mind," and there's

  • a famous experiment to test when a human child first develops a "theory of mind." It is called

  • the "Sally-Anne" test.

  • During the test, researchers tell children a story about Sally and Anne. Sally and Anne

  • have a box, and a basket, in their room. They also happen to have a delicious cookie. Now,

  • Sally takes the cookie and puts it inside the box, and then Sally leaves the room. While

  • Sally is gone, Anne comes over to the box, takes the cookie out, and puts the cookie

  • inside the basket. Now, when Sally comes back, the researchers ask the children "where

  • will Sally look for the cookie?" Obviously, Sally will look in the box- that's where she

  • left it. She has no way of knowing what Anne did while she was gone. But, until the age

  • of about 4, children will insist that Sally will check the basket because, after all,

  • that's where the cookie is. The child saw Anne move the cookie, so why wouldn't Sally

  • also know? Young children fail to realize that Sally's mental representation of the

  • situation, her access to information, can be different than their own.

  • And apes who know sign language, but never ask us questions, are doing the same thing.

  • They're failing to recognize that other individuals have similar cognitive abilities, and can

  • be used as sources of information.

  • So, we are all alone with our perceptions. We are alone in our own minds. We can both

  • agree that chocolate tastes good. But, I cannot climb into your consciousness and experience

  • what chocolate tastes like to you. I can never know if my red looks the same as your red.

  • But, I can ask.

  • So, stay human, stay curious, and let the entire world know that you are. And, as always,

  • thanks for watching.

Hey, Vsauce, Michael here.

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Is Your Red The Same as My Red?

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    Ting posted on 2013/07/06
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