The universe, it seems, is a one way street, moving temporally from the Big Bang to some uncertain destination in one direction only, from the present to the future and never the other way around.
The British physicist Sir Arthur Eddington (that’s he chatting amiably with Albert Einstein, above) memorably described this phenomenon as time’s arrow. In this view, time is a sort of missile that, once launched, may eventually run out of energy, but which can never reverse direction and return to the bow.
You can readily imagine the shenanigans a vintner might get up to in the dim recesses of a cellar organized this way, tempted to boost the quantity of the most valuable wine with a gift from a barrel of lesser value.
It isn’t likely this would take the form of an anything as outrageous as adding generic Burgundy to his grand cru. Instead, it might involve a kind of chain of contributions by which a little wine is pinched from its nearest less important neighbor and used to boost the volume of a more valuable barrel. Every wine receiving such a gift is thereby not only augmented, it’s adulterated — a classic case of wine fraud. The rule say that wine cannot legitimately move UP the quality ladder. But it can, and frequently does, move DOWN in a perfectly legal and consumer-beneficial manoeuver called declassification.
–Stephen Meuse