The quantity sorbed is often found to be well represented by the combination of a compartment exhibiting linear, reversible sorption and a compartment that exhibits nonlinear and thermodynamic irreversib[l]e sorption.

But musical ancestry aside, the influence to which [Justin] Bieber is most beholden is the current trends in pop music, which means Believe is loaded up with EDM accouterments, seeking a comfortable middle ground where Bieber’s impressively refined pop-R&B croon can rub up on techno blasts and garish dubstep drops (and occasionally grind on some AutoTune, not necessarily because it needs it, but because a certain amount of robo-voice is expected these days).

He gave me a gentle reminder that we had to hurry up.

The invention of urethane wheels enabled skateboarding on variable terrain (concrete, wood, plastic, and metal) with increase traction and less friction; the reinvention (brought back from the eighteenth century) and popularization of non-unidirectional twin tip skis enabled skiing backward and forward with equal competence; and the invention of the freecoaster rear bicycle hub enabled rolling (and thus landing) backward as well as forward without the crank arms turning along with the wheels.