Ksu Shachmeister/Alamy
What is the most efficient way to stir to dissolve something in water: with circular motions, chaotic ones, fast or slow?
Scott Haslam,
Manchester, UK
Marco Bottigelli/Getty Images
Is it possible to distinguish sunrise from sunset from an image (i.e. with no knowledge of the direction in the sky or time of day, and in a time frame with no discernible solar motion)?
Jeremy Smith,
Plymouth, Devon, UK
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