Category: sciences

Sciences: what is a cross-sectional study?

Tutoring science, you might encounter experimental design. The tutor mentions the idea of a cross-sectional study. cross-sectional study: Let’s imagine a characteristic of interest, C. In its simplest form, a cross-sectional study will select two groups – group A with

Science: what is sublimation?

Tutoring science, you cover changes of state. The tutor defines sublimation and relates an example. Sublimation means the change from solid to gas state without becoming liquid in between. In everyday life, sublimation is seldom observed, but there is a

Physics: what is parallax?

Tutoring physics or general science, the term parallax might arise. The tutor gives a definition. parallax: the phenomenon that the position of an object seems to change as the viewer’s location changes. Source: Gilmour, Lorna (ed). Collins Essential Canadian English

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Science, Climate change: the albedo effect

Tutoring high school science, you may be asked about the albedo effect. The tutor explains it simply. Albedo means loss of incoming radiation due to reflection. Light and heat are examples of radiation (see my previous post). Regarding Earth’s climate,

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Science, physics: what is radiation?

Tutoring science, the concept of radiation arises. The tutor explains it. Radiation is electromagnetic energy travelling from its source. Imagine a radio receiver which you can tune to any frequency. Actual radio station signals will be at the low end,

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Cooking: temp of a warm object

Cooking means constant self-tutoring. The tutor speculates about the actual temperature of a warm object. Yesterday I took a glass casserole dish of mac and cheese from the oven. Its baking temp was 177C. An hour later, most of the

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Botany: black walnut: juglone

The tutor researches the effects of juglone from black walnut trees. Juglone is a toxin produced by the black walnut tree; it’s found throughout the tree and in its leaves, shells and nuts. Apparently, to humans eating the walnuts, the

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Stainless steel: magnetic or not?

The tutor investigates the idea that stainless steel is non-magnetic. I’ve heard from more than one source that stainless steel is non-magnetic: if you put a magnet to it, there isn’t attraction like you might expect with “ordinary” steel. According

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Biology: protists: diatoms

The tutor mentions a few points about diatoms. In my Feb 4 post I introduced protists, which constitute a kingdom of eukaryotic, mainly single-celled organisms. Protists are divided into plantlike and animal-like ones. Diatoms, from phylum Chrysophyta, are among the

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Physics: models of the atom

The tutor reviews the progress of thought about atoms through the ages. Democritus, a Greek philosopher living around 400 BC, is credited as the first promoter of the concept of the atom. He proposed that all matter consists of tiny,

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