Timeline for What's a great christmas present for someone with a PhD in Mathematics?
Current License: CC BY-SA 4.0
16 events
| when toggle format | what | by | license | comment | |
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| Dec 14, 2020 at 16:41 | comment | added | Rita Geraghty | @DeaneYang There are edible chalks that you can buy or make your own. If they are edible, they can't be toxic. Recipes are available at Youtube. Some people make edible chalks with flour, cornflour, icing sugar, etc, but well, they mightn't be as good as Hagoromo chalks. | |
| Dec 14, 2020 at 16:16 | comment | added | Deane Yang | @RitaGeraghty, truth is that few of us will have the patience to figure out the optimal recipe. There are other features such as a coating on the outside of the chalk to reduce the amount of chalk dust produced. Here's New York Times story about the chalk that shows some of the manufacturing process. nytimes.com/2020/11/17/world/asia/hagoromo-chalk.html | |
| Dec 14, 2020 at 16:07 | comment | added | Rita Geraghty | @DeaneYang. If you want opaque whiteness and smoothest grains in your chalks, go for the most finely grounded powder of titanium dioxide, which you can find it at most professional art stores. Most artists buy that white pigment in bulk, as it is the most used pigment on palettes, especially for mixing colours with. For binders, you can use wallpaper paste or paper gum or Arabic gum. You probably won't paste or gum if plaster of Paris can binds all ingredients together. If you are in UK, visit Russell & Chapple, or Dick Blick if you are in USA or whatever your favourite art stores. | |
| Dec 14, 2020 at 15:50 | comment | added | Rita Geraghty | @DeaneYang I remember watching my art professor teaching students how to make all his own paints and pastels. Here is the video. You have to experiment with ratios of ingredients and achieve whatever you want in chalks. Here is the video showing how to make art pastel. youtube.com/watch?v=aRMi24FasHI You may have to change ingredients for chalk making. For colouring chalks, use kids' non-staining poster paints instead of powdered pigments. Decide the ratios of calcium carbonate and plaster of Paris. More calcium carbonate to reduce dustiness in chalks. To shape chalks, use a funnel | |
| Dec 12, 2020 at 23:35 | comment | added | Deane Yang | @RitaGeraghty, if you happen to try this yourself and it works out well, please post the recipe. | |
| Dec 12, 2020 at 16:35 | comment | added | Bob Jarvis - Слава Україні | @JoeSilverman - you can still use chalk on your iPad. Admittedly, it's a little messy...:-) | |
| Dec 12, 2020 at 15:31 | comment | added | Rita Geraghty | To make chalks, you can find many ingredients at good art stores for professional artists and paint makers. They would have all the ingredients that are used to make Hagoromo chalks. They would have books & videos on making soft pastels. | |
| Dec 12, 2020 at 15:26 | comment | added | Rita Geraghty | I googled online as to the ingredients. I see that there is another brand that is Umajirushi, the nearest rival to Hagoromo. Both use calcium carbonate to minimise dusting. I guess the rest of ingredients might be titanium dioxide (opaque soft white pigment), plaster of Paris, etc. If you want colouring, use watercolour paints. Specks from Cotman paints will suffice. Add binding agent. amazon.com/Kedudes-Non-Toxic-Dustless-Colored-Chalkboard/dp/… | |
| Dec 12, 2020 at 14:59 | comment | added | Rita Geraghty | You can always make your own chalks in your kitchen. Artists make their own pastels at home. In Youtube, there are videos on recipes for soft pastels. Experienced artists might know what ingredients are gone into making Hagoromo chalks, if they test them. | |
| Dec 12, 2020 at 13:39 | comment | added | Joe Silverman | @AsafKaragila Ah, I see, that completely went by me. Makes a lot of sense now. | |
| Dec 12, 2020 at 13:32 | comment | added | Asaf Karagila♦ | @Joe: That's a joke, suggesting that you're expecting to fail using the chalk with an iPad. It's a common joke, e.g. "I don't think I can eat a 2kg steak.", "Not with this attitude you can't.", etc. | |
| Dec 12, 2020 at 13:31 | comment | added | Joe Silverman | @AsafKaragila Sorry, not quite sure what "attitude" you're attributing to my post. It was meant to partly reflect sadness that such a gift wouldn't be of immediate use, with an underlying unexpressed hope for the future that by the following Christmas we'll be back in the classroom and reunited with our students. But as always, it can be difficult to exactly convey one's meaning in a short online comment. And BTW, I think Deane's suggestion for a gift is excellent. | |
| Dec 12, 2020 at 9:39 | comment | added | Asaf Karagila♦ | @Joe: Not with that attitude... | |
| Dec 12, 2020 at 1:02 | history | made wiki | Post Made Community Wiki by François G. Dorais | ||
| Dec 12, 2020 at 0:57 | comment | added | Joe Silverman | Sadly, those of us who already purchased a lifetime supply (well, a 10 year supply) haven't been able to use it while teaching remotely on our iPads. :( | |
| Dec 11, 2020 at 23:33 | history | answered | Deane Yang | CC BY-SA 4.0 |