6 ms·

19th-century ‘toy book’ demystified the techniques used by mediums

74 points by prismatic 2y ago

ccppurcell 2y ago
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 2y ago
  The title is also wrong. It's more "... to show that mediums could fool you easily."
- hnbad 2y ago
  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 2y ago
    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_in_language https://en.wikipedia.org/wiki/Blue%E2%80%93green_distinction...
    - KTibow 2y ago
      Doesn't the eye have distinct perceptors for green and blue, or am I missing something?
      - jhbadger 2y ago
        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 https://en.wikipedia.org/wiki/Cone_cell
    - jhbadger 2y ago
      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 2y ago
        The classic example is Homer's "Wine-dark sea", but it gets a lot more complicated than that https://en.wikipedia.org/wiki/Linguistic_relativity_and_the_color_naming_debate https://en.wikipedia.org/wiki/Linguistic_relativity_and_the_...
- GuB-42 2y ago
  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 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_(tertiary_names).svg 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 https://en.wikipedia.org/wiki/Impossible_color
  - fmbb 2y ago
    > 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 https://en.wikipedia.org/wiki/Primary_color
FrustratedMonky 2y ago
[flagged]
- voidmain0001 2y ago
  Who would have thought…? It looks like Margaret Atwood read the tea leaves (joke) correctly about the religious right when she wrote The Handmaid’s Tale for publishing 39 years ago. https://en.m.wikipedia.org/wiki/The_Handmaid's_Tale https://en.m.wikipedia.org/wiki/The_Handmaid's_Tale
  - rsynnott 2y ago
    In fairness, that's 1985. Arguably the modern phenomenon of fundamentalist evangelical protestants being a big force in US politics only _really_ got going after Row v Wade; it was a much easier thing to predict in 1985, when that book was written, than in the early 70s. In the 70s, if anything, people would've been more worried about 'new religions'; this was the timeframe in which Hubbard was wiretapping the IRS and so on. I think sci-fi reflects that; 60s and 70s sci-fi, where it touches on religion as a threat at all, concentrates on cults. You start seeing fundie-christians-as-threat stuff, like Handmaid's Tale, a bit later. EDIT: However. Honourable mention to Heinlein, who did this in _1940_: https://en.wikipedia.org/wiki/%22If_This_Goes_On—%22 https://en.wikipedia.org/wiki/%22If_This_Goes_On—%22 (played very straight; crazy preacher becomes US president in 2012, no elections thereafter) - possibly important context is that there had been a surge in televangelism in the 1930s.
    - voidmain0001 2y ago
      I listened to a radio program two days ago which was interviewing a book author that had written about why people accept conspiracy theories over documented truth. The program invited the audience to call in to offer their opinions and one caller who lived through the 50s and 60s thought it was the failure of science to deliver on its promises of a better future (flying cars, cheap food, cheap energy, robots doing our work). He said that governments and people need to get back to trusting science.
  - 2y ago
dukeofdoom 2y ago
Is there a youtube channel that reviews rare books
- miah_ 2y ago
  Several, I have enjoyed the content from https://www.youtube.com/@tomwayling https://www.youtube.com/@tomwayling
  - dukeofdoom 2y ago
    Great Thank you
BugsJustFindMe 2y ago
> 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 2y ago
  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 2y ago
    I agree that it's important to advance knowledge of what's possible, but that is very different from proving a negative.
    - RobertRoberts 2y ago
      When I see a card magic trick, for all intents and purposes it "appears" magic. Once I learn _one_ card trick, I start to realize it's not magic. Regardless if I can prove anything or not. This same applies here with ghosts. People needed to know they _could_ be fooled, how it was done doesn't matter, because people were being scammed and were afraid of things that weren't ghosts. Proving something is a ghost has never been done, so ghost scams is a good thing to educate people on.
    - mistermann 2y ago
      Do you ever notice how in Internet arguments people switch between logic and rhetoric seamlessly to support their argument? In a very real sense, it is a lot like watching children (with their intelligence limits) arguing, thinking what they say makes sound sense. This phenomenon is everywhere, including the most powerful places, and it is essentially not even on humanities radar.
- 2y ago
lancesells 2y ago
Here I was looking to learn some new art technique through various mediums in the 19th century.

74 points by prismatic 2y ago

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 2y ago
The title is also wrong. It's more "... to show that mediums could fool you easily."
hnbad 2y ago
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 2y ago
  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_in_language https://en.wikipedia.org/wiki/Blue%E2%80%93green_distinction...
  - KTibow 2y ago
    Doesn't the eye have distinct perceptors for green and blue, or am I missing something?
    - jhbadger 2y ago
      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 https://en.wikipedia.org/wiki/Cone_cell
  - jhbadger 2y ago
    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 2y ago
      The classic example is Homer's "Wine-dark sea", but it gets a lot more complicated than that https://en.wikipedia.org/wiki/Linguistic_relativity_and_the_color_naming_debate https://en.wikipedia.org/wiki/Linguistic_relativity_and_the_...
GuB-42 2y ago
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 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_(tertiary_names).svg 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 https://en.wikipedia.org/wiki/Impossible_color
- fmbb 2y ago
  > 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 https://en.wikipedia.org/wiki/Primary_color

FrustratedMonky 2y ago

[flagged]

voidmain0001 2y ago
Who would have thought…? It looks like Margaret Atwood read the tea leaves (joke) correctly about the religious right when she wrote The Handmaid’s Tale for publishing 39 years ago. https://en.m.wikipedia.org/wiki/The_Handmaid's_Tale https://en.m.wikipedia.org/wiki/The_Handmaid's_Tale
- rsynnott 2y ago
  In fairness, that's 1985. Arguably the modern phenomenon of fundamentalist evangelical protestants being a big force in US politics only _really_ got going after Row v Wade; it was a much easier thing to predict in 1985, when that book was written, than in the early 70s. In the 70s, if anything, people would've been more worried about 'new religions'; this was the timeframe in which Hubbard was wiretapping the IRS and so on. I think sci-fi reflects that; 60s and 70s sci-fi, where it touches on religion as a threat at all, concentrates on cults. You start seeing fundie-christians-as-threat stuff, like Handmaid's Tale, a bit later. EDIT: However. Honourable mention to Heinlein, who did this in _1940_: https://en.wikipedia.org/wiki/%22If_This_Goes_On—%22 https://en.wikipedia.org/wiki/%22If_This_Goes_On—%22 (played very straight; crazy preacher becomes US president in 2012, no elections thereafter) - possibly important context is that there had been a surge in televangelism in the 1930s.
  - voidmain0001 2y ago
    I listened to a radio program two days ago which was interviewing a book author that had written about why people accept conspiracy theories over documented truth. The program invited the audience to call in to offer their opinions and one caller who lived through the 50s and 60s thought it was the failure of science to deliver on its promises of a better future (flying cars, cheap food, cheap energy, robots doing our work). He said that governments and people need to get back to trusting science.
- 2y ago

dukeofdoom 2y ago

Is there a youtube channel that reviews rare books

miah_ 2y ago
Several, I have enjoyed the content from https://www.youtube.com/@tomwayling https://www.youtube.com/@tomwayling
- dukeofdoom 2y ago
  Great Thank you

BugsJustFindMe 2y ago

> 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 2y ago
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 2y ago
  I agree that it's important to advance knowledge of what's possible, but that is very different from proving a negative.
  - RobertRoberts 2y ago
    When I see a card magic trick, for all intents and purposes it "appears" magic. Once I learn _one_ card trick, I start to realize it's not magic. Regardless if I can prove anything or not. This same applies here with ghosts. People needed to know they _could_ be fooled, how it was done doesn't matter, because people were being scammed and were afraid of things that weren't ghosts. Proving something is a ghost has never been done, so ghost scams is a good thing to educate people on.
  - mistermann 2y ago
    Do you ever notice how in Internet arguments people switch between logic and rhetoric seamlessly to support their argument? In a very real sense, it is a lot like watching children (with their intelligence limits) arguing, thinking what they say makes sound sense. This phenomenon is everywhere, including the most powerful places, and it is essentially not even on humanities radar.
2y ago

lancesells 2y ago

Here I was looking to learn some new art technique through various mediums in the 19th century.