In the April 14 SN: Killer heat, mass insect migrations, the latest Saturn updates, rethinking the Nobel Prize, tectonics on Venus, the science of mass shootings, ancient tool trends and more.

MATH GETS REAL Chaos theory explains why it’s so difficult to predict weather — a small change in conditions at any point in time can have a large effect on future conditions in, for example, a hurricane’s trajectory (Tropical Storm Harvey shown).

NASA

NOT PIOUS Pi, the ratio of a circle’s circumference to its diameter, is revered as an all-important number in mathematics. But some are starting to question that devotion.

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PRIME TIME The largest known prime number has more than 23 million digits — a new record.