All fact-checks

27 briefs, each one written because somebody asked. Search, or browse by subject.

Air at -15°C still holds heat; a heat pump uses a refrigerant that boils far below zero to capture it, then compresses it to a useful temperature.

Brain scans show activity across virtually every region over a normal day, and damage almost anywhere causes measurable loss.

Decades of studies, including one man's 60-year experiment on his own hands, find no link between knuckle cracking and arthritis.