How to draw dotted lines on chalkboards, MIT style (2021) • Hacker News Board

Re: How to draw dotted lines on chalkboards, MIT style (2021)

#121

Post by eesmith » Fri, Mar 31, 2023, 4:34 AM UTC

jjgreen wrote: post #115

eesmith wrote: post #112

Earlier quoted context omitted.

> Blackboards are not black, they are grey Yes, and tennis shoes aren't only used for tennis. What you wrote is not correct. First, I assume you are not making the technically-correct-only assertion that since everything, including Vantablack, reflects some light, it isn't truly black but only a dark shade of grey. Quoting Wikipedia, "Blackboards were originally made of smooth, thin sheets of black or dark grey slate…

You could be right, but using your favourite n-gram viewer, it looks like there is a relationship https://books.google.com/ngrams/graph?content=%28chalkboard+... Any thoughts on that apparent correlation? My (implicit) assertion was: in times of racial tension, people avoid(ed) using the word 'black' not wanting to appear racist. That seems reasonable to me, could there be some causal relation in the other direction?

There's an old phrase: "Correlation is not causation."

"TV" to "civil rights" - https://books.google.com/ngrams/graph?content=TV%2C%28civil+...

"Plastic" to "civil rights" - https://books.google.com/ngrams/graph?content=plastic%2C%28c...

"Pakistan" to "civil right" - https://books.google.com/ngrams/graph?content=%28Pakistan%29...

The site https://tylervigen.com/spurious-correlations shows a lot of spurious correlations.

What I did instead was present a claim (Wikipedia links to https://books.google.com/books?id=sl5GAwAAQBAJ&pg=PT45 and also describes the technology that made colored chalkboards popular), then double-checked that Ngram was consistent with the claim.

> That seems reasonable to me

Yes, that's because your hypersensitivity is kicking in.

It's causing you to reject the actual reasons given at the time in favor of your pet theory.

I've presented two direct quotes from the 1950s saying the reason for switching to "chalkboard" is because the new boards were not black.

You instead prefer to think these sources were hiding the truth, apparently in order to cover up hypersensitivty to the word "black".

Another problem with your pet theory is that in the 1950s black people were generally referred to as "colored" or "Negro". "Black" didn't start replacing "Negro" until the 1960s. Your James Brown citation is from the late 1960s, for example.

Your belief is that large numbers of people in the 1950s were so hypersensitive to the word "black", because someday in the future it might be used to refer to colored people, that they switched from "blackboard" to "chalkboard"?

While at the same time large numbers of people enforced racial segregation and discrimination.

Your pet theory would need a LOT of historical supporting evidence to hold any water. So, where's your evidence?

Re: How to draw dotted lines on chalkboards, MIT style (2021)

#122

Post by jjgreen » Fri, Mar 31, 2023, 6:44 PM UTC

eesmith wrote: post #121

jjgreen wrote: post #115

Earlier quoted context omitted.

You could be right, but using your favourite n-gram viewer, it looks like there is a relationship https://books.google.com/ngrams/graph?content=%28chalkboard+... Any thoughts on that apparent correlation? My (implicit) assertion was: in times of racial tension, people avoid(ed) using the word 'black' not wanting to appear racist. That seems reasonable to me, could there be some causal relation in the other direction?

There's an old phrase: "Correlation is not causation." "TV" to "civil rights" - https://books.google.com/ngrams/graph?content=TV%2C%28civil+... "Plastic" to "civil rights" - https://books.google.com/ngrams/graph?content=plastic%2C%28c... "Pakistan" to "civil right" - https://books.google.com/ngrams/graph?content=%28Pakistan%29... The site https://tylervigen.com/spurious-correlations shows a lot of spurious correlatio…

    I've presented two direct quotes from the 1950s saying the reason for
    switching to "chalkboard" is because the new boards were not black.

There's an old saying: "One swallow does not make a summer". It means that one should be careful extrapolating from slight evidence.

So how does your pet theory handle that the same phenomenon, a shift from blackboard to chalkboard, also happened in the UK (which also had a period of co-incident racial tension, albeit not as extreme as in the US) while, as others have mentioned, green blackboards are rare?

Re: How to draw dotted lines on chalkboards, MIT style (2021)

#123

Post by eesmith » Fri, Mar 31, 2023, 7:14 PM UTC

jjgreen wrote: post #122

eesmith wrote: post #121

Earlier quoted context omitted.

There's an old phrase: "Correlation is not causation." "TV" to "civil rights" - https://books.google.com/ngrams/graph?content=TV%2C%28civil+... "Plastic" to "civil rights" - https://books.google.com/ngrams/graph?content=plastic%2C%28c... "Pakistan" to "civil right" - https://books.google.com/ngrams/graph?content=%28Pakistan%29... The site https://tylervigen.com/spurious-correlations shows a lot of spurious correlatio…

I've presented two direct quotes from the 1950s saying the reason for switching to "chalkboard" is because the new boards were not black. There's an old saying: "One swallow does not make a summer". It means that one should be careful extrapolating from slight evidence. So how does your pet theory handle that the same phenomenon, a shift from blackboard to chalkboard, also happened in the UK (which also had a period…

My point was to demonstrate that your "hypersensitivity" hypothesis has no evidentiary basis, and in fact runs counter to easily available evidence.

I believe I have done that, in way that other HN readers can easily verify for themselves.

Had you researched the topic yourself you would find more supporting evidence for my pet theory. I only presented a sampling of what I found, to keep my comment from being a wall of text.

Your saying doesn't even apply to you as you have not presented any evidence, not even a single feather.

As you don't seem to care, my interest here is done.

Re: How to draw dotted lines on chalkboards, MIT style (2021)

#124

Post by IIsi50MHz » Mon, Apr 03, 2023, 2:26 AM UTC

snozolli wrote: post #40

choeger wrote: post #6

I have to ask. Why is it "white"-board vs. "chalk"-board? Back in elementary school, I learned to call the former "black"-board.

I was born in the 70s, raised in Oregon, and we called them chalkboards. "Blackboard" sounded old-timey to me, like something you'd hear on Little House on the Prairie . A Google search result points out that green became a common color for chalkboards, and in retrospect I think most of mine in school were green. More googling says that the original blackboards were slate. The green ones were porcelain.

Our green ones varied in quality and material. Most of them seemed to have some cheap coating that was sometimes torn by chalk; after being torn, the edges of green coating seemed stretched like thin plastic. Some of the green ones, the teachers actually liked. Maybe those were porcelain?

Also had blackboards at some of my schools. They seem to last forever without much care.