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What would we see, and how would Earth be affected, if Sirius, the brightest star in our night sky, were to go supernova? Would it be over in a blink or a decade? And would it be visible in daylight?

Jan De Wilde,

Ghent, Belgium

Why, when I first step into a hot shower, do I get a brief shiver down my back?

Brian Forty,

via email

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