“I don’t know” are words that should never cross the lips of a politician, pundit or press person. Acknowledging complexity is the last taboo in the media.

The two biggest questions today are unanswerable. Is the Ash Cloud dangerous to flights? Will the Lib Dem surge sustain?

And if you want some longer-term complexity, try How Serious Is Climate Change? or Should We Fight A War In Afghanistan?

The task of journalism is to find certainty amidst complexity. The idea is that if we ask enough of the right questions then answers should come. Facts will emerge blinking into the studio spotlights, future trends will reveal themselves in print and digital pixels.

But the Ash Cloud is a wonderful example of chaos theory at its most chaotic. The variables of wind speed, engine parts, economic cost and personal disruption are almost infinite. The calculations of risk and the value of life are impossible to contain in a calculus.

Add in politics during an election campaign and you don’t need conspiracy theories to work out that some stories do not have clear narratives.

So the honest answer – which you won’t hear very often – is ‘I don’t know’.

One of the positive aspects of digital journalism is that it allows the media to acknowledge this complexity. The space of online allows newsrooms to give a greater diversity of fact and opinion and more depth in analysis – if only by linking to sources.

The public are becoming increasingly used to garnering a diverse range of opinions and experience from social media to give a more sophisticated picture than headlines provide. How much they actually do that is open to question. But I do hear increasingly hear and read people referring to wider sources that they have accessed.

Of course, in the end, some issues are very complex. I honestly don’t know how sustainable Nick Clegg’s revival will be. I am sure that it will slip back but the factors that brought it about are too dynamic to predict with any confidence. And as for planes and the plumes from  Eyjafjallajokull? Well, I don’t know.