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Botany lab 13 Chromatography failure

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The Chromatography laboratory failed spectacularly.  Every single plate, with three different plate types, looked like this. The solvent above was 70% ethyl alcohol. The pasty white appearance is likely a result of too much calcium carbonate.  Most of the class used 91% isopropyl alcohol with a result seen as above. Ethyl alcohol was used successful last year. 70% isopropyl alcohol was also used successfully last year.  Perhaps the plant leave mix was problematic. Alternanthera sessifolia was the dominant plant in the mix. Some Codiaeum variegatum and Cordyline fruticosa leaves were added in. Last year only Alternanthera sessifolia was used. Was that contributory to the issues?   The calcium carbonate was locally sourced. Was too much added? Not enough? About a half to one teaspoon was used. Perhaps there were impurities in the calcium carbonate. The use of an eye dropper tended to create larger blobs, but n...
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Google Sheets one function to rule them all and in the darkness bind them

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I first began using the spreadsheet software Lotus 1-2-3 in 1986 and have memorized and mastered an ever increasing number of spreadsheet functions over the decades since. Google has introduced a new AI function in Google Sheets that acts like the one ring in the Lord of the Rings: one function that rules all other functions.  I spend a couple of weeks in MS 150 Statistics covering the normal distribution, standard error of the mean, t-distribution and t-critical, and 95% confidence intervals. The students learn to calculate the mean, the standard deviation, the standard error of the mean, t-critical, and then the lower and upper bounds of the 95% confidence interval. The Google AI function replaces all spreadsheet functions with a single function () and a prompt inside the function. Tell the function what you want, and the function constructs the functions that give you the answer. I have only entered a prompt inside the new AI function in cell C1 with data in column A of the...
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Fruit salad

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A fruit type presentation developed for botany class was used in ethnobotany fall 2025. The videos that had been used up until spring 2025 tended to be ignored by the students and were not well focused on the fruits encountered in the fruit salad activity. The students are of a generation that can tune out a YouTube video as background noise. And the fruits shown in the videos were of a temperate climate focus. The botany slide deck, however, included material that is relevant to agriculture majors in a botany course, material that is not part of a general education non-major non-lab science course. A slide deck more tightly focused on the activity was prepared for use.  The class was scheduled to end early to accomodate student evaluations of the course. With this in mind a handout of fruit types based on the one in the text and used on botany was prepared. The handout lacked a header label and doesn't line up the fruit types into a common column. This proved confusing. The hand...
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Optics

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This term optics week was not hit with a holiday. Monday was DVD throwback. Two years since the reflection and refraction DVD was hauled out and shown.  Wednesday was optical demonstrations including the disappearing beaker.  The double beakers are in the optics container along with the coins for the hidden coin. The 60-60-60 prism is also in the optics container and is not with the other prisms. The board shows the progression from left to right of the demonstrations using the laser. The demonstrations wrapped up with the image produced by a convex lens. Rainbow refraction was also mentioned.  A rainbow has a primary bow and, in reversed order, a secondary bow, with Alexander's dark band between the bows.  The set up song was Chemical Brothers Sometimes I Feel so Deserted. The set up coffee was caramel macchiato three-in-one. The fruit salad bowl was disincluded - fall 2025 the bowl ...
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