And America's willingness to sustain casualties on a European battlefield remains one of the imponderables of the Kosovo war.Another is the likely effect of a land war on the hundreds of thousands of Kosovars who have been uprooted but remain inside the province.
Economically, Russia has turned into a commodity exporter, dependant on the imponderables of the global energy market, while simultaneously dreaming that it can use energy as a tool to revise the post-Soviet order in its neighbourhood.
Now he will have the time to contemplate the universe, to gaze at the stars, to go for long walks and ponder the imponderables, to sit on top of a mountain or under a tree and meditate.
But rain was one of the great imponderables of Wimbledon.
Mike Jay, in his introduction, imagines Davy's experiments with the drug as a "philosophical theatre" in which "the standard medical question, 'How do you feel?' took on imponderable, existential dimensions".
The imponderables of bridge keep us thinking and playing.
The imponderables of the unseen cards bring some guesswork into the equation.
Everything for the evening's show must be rehearsed and ready for taping by five-thirty, apart from the central, imponderable element, on which all else depends: Carson's handling of the guests.
As to whether a WMD-armed Saddam would anyway have proved a danger to the region or beyond, nobody mercifully will now have to find out.A change in Arab moodHowever, not all of the much-debated questions about the wisdom of the war turn on imponderables.
But these prizes are like horse races, they depend on so many imponderables".
If Ireland had failed to score in those opening minutes … well, that's the least of the many little imponderables, behind Jamie Heaslip's tackle on Stuart Hogg just as he crossed the try-line, which hit him just hard enough to make him spill the ball before he got it down.
