[HN Gopher] 19th-Century 'Toy Book' Used Science to Prove That G...
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19th-Century 'Toy Book' Used Science to Prove That Ghosts Were an
Illusion
Author : prismatic
Score : 62 points
Date : 2024-11-05 02:27 UTC (2 days ago)
(HTM) web link (www.smithsonianmag.com)
(TXT) w3m dump (www.smithsonianmag.com)
| ccppurcell wrote:
| This article gets the colours wrong. Do the red figure example
| for yourself. If you do it correctly you will clearly see cyan,
| which is the opposite of red in RGB . It has nothing to do with
| the "primary colours" of blue and yellow mixing. Basic science
| facepalm from Smithsonian it seems.
| tgv wrote:
| The title is also wrong. It's more "... to show that mediums
| could fool you easily."
| hnbad wrote:
| It's a common mistake thanks to people learning in school that
| the "primary colors" are red, yellow and blue but the
| explanation is mostly right otherwise: you see cyan because
| it's a mix of blue and _green_ , i.e. what you get when you
| subtract red from white light.
|
| Of course human visual perception is a bit more complex than
| that but the primary mistake here is mixing up RGB and RYB.
| Quirks of color perception then result in referring to the
| resulting color as "green" when it clearly contains blue.
| jhbadger wrote:
| Also, the whole idea that "green" and "blue" are different
| things is culturally determined -- many languages either use
| one word that contains the shades English speakers call
| "blue" and "green" or did so historically before introducing
| separate words after they were influenced by English or other
| languages that make the distinction.
|
| https://en.wikipedia.org/wiki/Blue%E2%80%93green_distinction.
| ..
| KTibow wrote:
| Doesn't the eye have distinct perceptors for green and
| blue, or am I missing something?
| jhbadger wrote:
| No. There are three types of cone cells (S, M, and L)
| that are most responsive to various wavelengths of light,
| but as the picture shows, most "colors" are within the
| high and low ranges of more than one type of cone.
|
| https://en.wikipedia.org/wiki/Cone_cell
| jhbadger wrote:
| For those who downvoted this, did you read the wikipedia
| entry? Seriously, the idea that many languages don't make a
| blue/green distinction is a fact.
| jon_richards wrote:
| The classic example is Homer's "Wine-dark sea", but it
| gets a lot more complicated than that https://en.wikipedi
| a.org/wiki/Linguistic_relativity_and_the_...
| GuB-42 wrote:
| I think there is more to it than a simple "facepalm". In the
| modern RGB model, green and blue are primary colors, and mixed
| together, you get cyan, the opposite of red. So the explanation
| is generally correct, the only thing wrong is that yellow is
| considered a primary color instead of green.
|
| But look here, and remember the book was published in 1864:
| https://en.wikipedia.org/wiki/Complementary_colors
|
| Look at the color wheels of that period and earlier, especially
| this one: https://commons.wikimedia.org/wiki/File:Color_star-
| en_(terti...
|
| And you see that red is the opposite of green. Why not cyan? I
| don't know. I guess cyan simply wasn't a well recognized color
| back then, maybe cyan was called green (a blueish green). Maybe
| our perception changed with the availability of modern pigments
| and screens.
|
| As for the color you see when trying the illusion, it is even
| more interesting because it is actually an impossible color!
| [1] It doesn't correspond to a wavelength of light or a
| combination thereof, you can only perceive it through an
| illusion like this one. If we follow the Wikipedia article, and
| considering that the afterimage appears on a dark background
| that would be "stygian cyan". Spooky! Again, the theory was
| probably unknown in 1864.
|
| [1] https://en.wikipedia.org/wiki/Impossible_color
| fmbb wrote:
| > Why not cyan? I don't know.
|
| Because tradition, and the pigments they used. Red, yellow,
| blue worked great.
|
| https://en.wikipedia.org/wiki/Primary_color
| dukeofdoom wrote:
| Is there a youtube channel that reviews rare books
| miah_ wrote:
| Several, I have enjoyed the content from
| https://www.youtube.com/@tomwayling
| BugsJustFindMe wrote:
| > _Prove That Ghosts Were Simply an Illusion_
|
| This is false. The only thing it proves is that ghosts CAN BE an
| illusion. Failure to recognize the difference between the two is
| why such books haven't stopped people believing in ghosts.
| RobertRoberts wrote:
| You are missing a critical point. Before this, there was likely
| no proof that people could share or rely on to question if
| _any_ ghost could be an illusion.
|
| This is very important to future critical thinking because this
| gave people evidence to back up being skeptical for future
| illusions that they can't immediately explain.
| BugsJustFindMe wrote:
| I agree that it's important to advance knowledge of what's
| possible, but that is very different from proving a negative.
| mistermann wrote:
| Wouldn't the failure to recognize be more like the cause of why
| so many people believe that it is a knowable fact that there
| are no ghosts (and various other "supernatural" phenomena)?
| picture wrote:
| Are any facts knowable? Besides the fact that something
| exists, in some shape or form, at this particular moment,
| that allows the thought about this to happen.
| BugsJustFindMe wrote:
| Also that, yes. But I do see a space where the authors (and
| subsequent article writers) recognizing and acknowledging the
| limitations of proof would help them frame their arguments in
| such a way that they ultimately convince more people of not
| having seen actual ghosts.
| redundantly wrote:
| >> Prove That Ghosts Were Simply an Illusion
|
| > This is false.
|
| It's not false, that's just the headline.
|
| The book targeted a very specific illusion that con artists
| would use to scam people. That did prove the ghosts being
| presented as real were in fact illusions.
| BugsJustFindMe wrote:
| > _It 's not false, that's just the headline_
|
| It is false, and it's also not just the headline.
|
| > _That did prove the ghosts being presented as real were on
| fact illusions._
|
| Again, this is false. It proved only that illusory facsimiles
| of ghosts are possible. You cannot prove that someone didn't
| see a ghost just because there are non-ghost mechanisms for
| people to think they're seeing ghosts. That's not how proving
| things works.
| nuancebydefault wrote:
| I've never seen of a convincing proof that anything exists nor
| that anything does not exist.
|
| 'prove' simply needs not to be taken literally in this context.
| You can replace it here by 'make a suggestion that'
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(page generated 2024-11-07 23:01 UTC)