Again, Guess What’s Being Described

We're not looking for the name of the clouds in the picture. If we were, we might mistake them for cirrus clouds, whose quantity is probably affected by our mystery. In fact, the bluish clouds are noctilucent clouds composed of ice particles that crystallise around meteoric dust. In the late 1800s, the astronomer Otto Jesse examined simultaneous pictures that were taken 35 km apart, and by comparing... Continue Reading →

Two Offbeat Questions About Greenhouse Gases

In science, something fruitful can arise from innocent or atypical questions.  One of many examples of this was a recent query in Quora, " Can chlorine be potentially a greenhouse gas? Why or why not?" Here's what I wrote, but I've since added a little more detail. Short answer , no.  🙂 Now here's why.... An infrared spectrum is used to check... Continue Reading →

Even When Pure, Water Is Blue

We have all seen supposedly colorless water in a glass and in raindrops on a windshield. If there's little air in it, water even looks colorless when it forms ice cubes. The fixed but incorrect idea that water is intrinsically without color survives in many of our minds even though we all observe various shades... Continue Reading →

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