'Panta rhei' – all things are in flux
– Heraclitus
Flux is a form of flow, but with one crucial difference. Water can flow in a river, or traffic down a street. What goes in at one end and what comes out at the other is the same thing— water, or cars.
In biochemistry, flux is the flow of things that are transformed along the way.
Imagine a car entering a street; let’s say it’s a VW Beetle. No sooner has it gone ten yards down than there’s a blinding flash and it’s become a Volvo. Bang! It’s a white van. Zap! Now it’s a minibus. Flash! It’s a tractor, which leaves the street.
But the strangest thing about this street is that the same thing keeps on happening: only VW Beetles ever enter the street; only tractors ever leave. The same succession of transformations takes place each time.
Of course, that’s just this street. Take a look at the street around the corner. There you’ll see only Vespa scooters entering, transforming into Harley motorbikes. And just across town there’s a canal where canoes change into speed boats.
– Nick Lane
up the up-hierarchy it is the strange world of memory
The concrete pulses of experience appear pent in by no such definite limits as our conceptual sustitutes for them are confined by. … The tiniest feeling that we can possibly have comes with an earlier and a later part and with a sense of thier continuous procession. … Every smallest state of concretely taken, overflows its own definition.
– William James