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Hey, Vsauce, Michael here.
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This appears blue, this appears yellow, and this appears green. Those of us with normal
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color vision can probably agree. But, that doesn't change the fact that color is an illusion.
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Color, as we know it, does not exist in the outside world, beyond us, like gravity, or
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protons do. Instead, color is created inside our heads. Our brains convert a certain range
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of the electromagnetic spectrum into color. I can measure the wavelength of radiation,
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but, I can't measure, or observe, the experience of a color inside your mind.
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So, how do I know that when you and me look at a strawberry, and, in my brain, this perception
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occurs, which I call "red," that, in your brain, a perception like this doesn't occur,
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which you have, of course, also learned to call red. We both call it red. We communicate
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effectively and walk away never knowing just how different each of our internal experiences
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really were.
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Of course, we already know that not everybody sees color in exactly the same way. One example
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would be color blindness. But, we can diagnose and discuss these differences because people
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with the conditions fail to see things that most of us can.
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Conceivably, though, there could be ways of seeing that we use that cause colors to look
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differently in different people's minds, without altering their performances on any tests we
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could come up with.
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Of course, if that were the case, wouldn't some people think other colors look better
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than others? Or, that some colors were more complimentary of others? Well, yeah, but
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doesn't that already happen?
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This matters because it shows how fundamentally, in terms of our perceptions, we are all alone
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in our minds.
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Let's say I met an alien from a far away solar system who, lucky enough, could speak english,
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but had never, and could never, feel pain. I could explain to the alien that pain is
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sent through A-delta and C fibers to the spinal chord. The alien could learn every single
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cell, and pathway, and process, and chemical involved in the feeling of pain. The alien
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could pass a biology exam about pain, and believe that pain, to us, generally is a bad
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thing.
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But, no matter how much he learned, the alien would never actually feel pain. Philosophers
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call these ineffable, raw feelings "Qualia." And our inability to connect physical phenomenon
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to these raw feelings, our inability to explain and share our own internal qualia is known
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as the "Explanatory Gap." This gap is confronted when describing color to someone who's been
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blind their entire life.
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Tommy Edison has never been able to see. He has a YouTube channel where he describes what
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being blind is like. It's an amazing channel. In one video he talks about colors, and how
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strange, and foreign of a concept it seems to him. Sighted people try to explain, for
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instance, that red is "hot," and blue is "cold." But, to someone who has never seen a single
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color, that just seems weird. And, as he explains, it has never caused him to finally see a color.
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Some philosophers, like Daniel Dennett, argue that qualia may be private and ineffable simply
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because of a failure of our own language, not because they are, necessarily, always
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going to be impossible to share.
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There may be an alien race that communicates in a language that causes colors to appear
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in your brain without your retina having to be involved at all. Or, without you having
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to have ever needed actually to see the color yourself. Perhaps, even in English, he says,
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given millions and billions of words used in just the right way, it may be possible
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to adequately describe a color such that a blind person could see it for the first time.
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Or, you could figure out that, once-and-for-all, yes, or, no, in fact, you and your friend
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do not see the same red.
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But, for now, it remains the case that we have no way of knowing if my red is the same
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as your red. Maybe one day our language will allow us to share and find out, or, maybe,
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it never will. I know it's frustrating to not have an answer, but, the mere fact that
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you guys can ask me about my internal experiences, and the mere fact that I can ask my friends
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and we can all collectively wonder about the concept of qualia is quite incredible, and
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also quite human.
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Animals can do all sorts of clever things that we do. They can use tools, problem solve,
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communicate, cooperate, exhibit curiosity, plan for the future, and, although we can't
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know for sure, many animals certainly act as if they feel emotions- loneliness, fear,
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joy.
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Apes have even been taught to use language to talk to us humans. It's a sort of sign
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language that they've used to do everything from answer questions, to express emotion,
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or even produce novel thoughts. Unlike any other animal, these apes are able to understand
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language and form responses at about the level of a 2.5 year old human child.
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But, there is something that no signing-ape has ever done. No ape has ever asked a question.
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Joseph Jordania's "Who Asked the First Question?" is a great read on this topic, and it's available
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for free online.
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For as long as we've been able to use sign language to communicate with apes, they have
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never wondered, out loud, about anything that we might know that they
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don't.
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Of course, this does not mean that apes, and plenty of other animals, aren't curious. They
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obviously are. But, what is suggests is that they lack a "Theory of Mind": An understanding
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that other people have separate minds. That they have knowledge, access to information
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that you might not have. Even us humans aren't born with a "theory of mind," and there's
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a famous experiment to test when a human child first develops a "theory of mind." It is called
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the "Sally-Anne" test.
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During the test, researchers tell children a story about Sally and Anne. Sally and Anne
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have a box, and a basket, in their room. They also happen to have a delicious cookie. Now,
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Sally takes the cookie and puts it inside the box, and then Sally leaves the room. While
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Sally is gone, Anne comes over to the box, takes the cookie out, and puts the cookie
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inside the basket. Now, when Sally comes back, the researchers ask the children "where
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will Sally look for the cookie?" Obviously, Sally will look in the box- that's where she
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left it. She has no way of knowing what Anne did while she was gone. But, until the age
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of about 4, children will insist that Sally will check the basket because, after all,
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that's where the cookie is. The child saw Anne move the cookie, so why wouldn't Sally
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also know? Young children fail to realize that Sally's mental representation of the
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situation, her access to information, can be different than their own.
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And apes who know sign language, but never ask us questions, are doing the same thing.
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They're failing to recognize that other individuals have similar cognitive abilities, and can
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be used as sources of information.
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So, we are all alone with our perceptions. We are alone in our own minds. We can both
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agree that chocolate tastes good. But, I cannot climb into your consciousness and experience
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what chocolate tastes like to you. I can never know if my red looks the same as your red.
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But, I can ask.
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So, stay human, stay curious, and let the entire world know that you are. And, as always,
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thanks for watching.