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Comment by obastani | Hacker News Reader

I'm not sure about that. If Mary knows all the physics of light, she can design and set up a sensor to detect the color of the apple and the instructions, just like we have sensors that detect ultraviolet and infrared light. Just as we will never know how it feels to "see" ultraviolet light, this thought experiment is about Mary's subjective experience perceiving color, not her ability to determine the color of the world around her.

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Mary is using sensors either way: they either come pre-installed or after market.

On a more serious note, I'm taking the question in the article at face value, "Has Mary learnt anything new about the colour red upon seeing the colour for the first time?" If the author really meant it to be a question about the subjective experience of seeing, they should have simply written a better question.

Your confusion is not the author's fault. You ignored the parameters of the thought experiment, which clearly state that she can discern colors without "seeing" them. The question is whether the subjective experience of "experiencing" color adds new information.

I'm familiar with the thought experiment and have been for decades. I still think the author could write more clearly.

Besides, we can clearly perform a proxy experiment today by way of enchroma glasses and colorblind people. Simply devise a way to test for information predicated on trichromacy using bichromatic metamers. Did the subject experience a functional difference? If so, it's a pretty easy question to answer. If there's no functional difference then why does it matter?

"Simply devise a way to test for information predicated on trichromacy using bichromatic metamers." lol... "Simply..." this is literally the 'the explanatory gap' described in the article. We don't currently have a way to measure if the brain "acquired new information" when it knows about something but then sees it for the first time... which is the whole point. "experience a functional difference" -- what does that even mean?

Let me get this straight. What you're saying is that we categorically don't have an examination which tests if someone has acquired new information?

AFAIK, we have no way of assessing whether “someone” has acquired new information other than that someone demonstrating their knowledge. We can’t MRI “acquisition of information”. So, as per this thought experiment, we have no way of telling if Mary gained new information by “seeing” red when she already “knew” what red was and could interpret it as such. That’s the whole point of the the thought experiment, which clearly went over your head.

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