Mathematicians are hoarding a type of Japanese chalk (2015)
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Re: Mathematicians are hoarding a type of Japanese chalk (2015)
#2> “Maintaining a clean whiteboard is much more of a pain,” he said. There’s the cleaning fluid, which costs money, and the chemicals can cause health problems.
A clean blackboard is not that fun either. To clean it nicely you need to sweep the whole of it down vertically with a wet sponge. This requires a water source and it's a messy deal. In high-school there was a daily designated pupil who was responsible for wiping down the boards and keeping a wet clean sponge.
Re: Mathematicians are hoarding a type of Japanese chalk (2015)
#3(2015) - I wonder if production has been revived since then.
Re: Mathematicians are hoarding a type of Japanese chalk (2015)
#4> “Maintaining a clean whiteboard is much more of a pain,” he said. There’s the cleaning fluid, which costs money, and the chemicals can cause health problems. A clean blackboard is not that fun either. To clean it nicely you need to sweep the whole of it down vertically with a wet sponge. This requires a water source and it's a messy deal. In high-school there was a daily designated pupil who was responsible for wip…
Also the "cleaning fluid" is just isopropyl alcohol
Re: Mathematicians are hoarding a type of Japanese chalk (2015)
#5As I recall, most of my engineer professors used transparencies and overhead projectors.
Re: Mathematicians are hoarding a type of Japanese chalk (2015)
#6[deleted]
Re: Mathematicians are hoarding a type of Japanese chalk (2015)
#7(2015) - I wonder if production has been revived since then.
If I remember correctly, the three machines were sold off to different buyers. Regardless, it is probably far too early to be revived, even under the guise of nostalgia and perhaps too niche a product, say, compared to the Impossible project. Although not the same, there are alternatives available:
https://www.jetpens.com/Rikagaku-Dustless-Chalk-Accessories/...
Re: Mathematicians are hoarding a type of Japanese chalk (2015)
#8Previously discussed on HN:
Re: Mathematicians are hoarding a type of Japanese chalk (2015)
#9> “Maintaining a clean whiteboard is much more of a pain,” he said. There’s the cleaning fluid, which costs money, and the chemicals can cause health problems. A clean blackboard is not that fun either. To clean it nicely you need to sweep the whole of it down vertically with a wet sponge. This requires a water source and it's a messy deal. In high-school there was a daily designated pupil who was responsible for wip…
When I was studying physics, I had a calculus professor who was popular among students for his good use of the blackboard. He would write a ton of text (about 20-25 sqm per 90-minute lecture), but everything was really tidy and well-organized. (He held the same lectures that he gave for the last 20 years, so I guess he got some insane amount of gradient descent going on over time.)
Anyway, for the cleaning, he had a flat mop. The lecture hall had three separate boards, so he used them in rotation. When he was finished filling board A with text, he would wipe board B with his mop while recapping the contents of board A. Then he would rinse the mop and leave it in the sink next to the boards. At this point, board C had dried enough from the previous round of cleaning that he could start writing there again.
Overall, an incredibly efficient and fluent process. The gap in writing gave the students enough time to finish copying everything in their notes or taking a short break to drink something, and it gave him enough time to recap the last 10 minutes before moving on to the next section.
Re: Mathematicians are hoarding a type of Japanese chalk (2015)
#10> “Maintaining a clean whiteboard is much more of a pain,” he said. There’s the cleaning fluid, which costs money, and the chemicals can cause health problems. A clean blackboard is not that fun either. To clean it nicely you need to sweep the whole of it down vertically with a wet sponge. This requires a water source and it's a messy deal. In high-school there was a daily designated pupil who was responsible for wip…
In some (maybe most, but my experience is limited to a few) German university they have sinks, sponges and a thing to dry the blackboard after wiping it with a sponge in every class