What is time?

You ask: What is time?

Caveman watch sun climb, cross sky, fall. Watch again, again — always same order. Time just that: the order things happen, one after next, and how much happen between. Caveman measure it by counting steady beats — sun-ups, drips, heartbeat, sand falling. Best beat of all: science tribe watch one special atom shiver over nine thousand million times to mark one single count Caveman call a second. Why time only go one way, past to future, never back? Best answer: mess always grow (call it entropy) — broken egg never un-break — so 'forward' is the way toward more mess. Strange thing: time not same for all. Move fast or sit near heavy mountain-of-weight, Caveman clock tick different. Science tribe still argue what time truly IS deep down — some say real river, some say just how brains line up memory. Cave wisdom: time is change, counted — and it flow toward mess.