Across Scotland a new energetic, dynamic political culture has emerged which has reshaped public debate and conversations.

The idea of the public as passive, inert spectators and with it the notion of politics as a minority pastime, no longer holds.

It could be seen in the massive turnouts which saw poorer and disadvantaged communities turn out in record numbers. What I called "the missing Scotland" - those who haven't voted in a generation or more - re-emerged as a potent political force with the potential to reshape long-term politics. It was also seen in the re-imagining of public spaces, the emergence of flash mobs and protest, and a culture of celebration and carnival on the Yes side.

The other dimension found expression in "the third Scotland" - the self-organised, independent-minded supporters of independence - very different from the SNP. These groups - Radical Independence Campaign, National Collective, Common Weal, Women for Independence and others - saw independence not as an end in itself, but as a means to an end.

They brought DIY culture, network politics, flat organisations and part of a new generation of young people into public life. They did things that were messy, fuzzy, creative and fun.

They staged happenings, art installations, and national tours across Scotland, and in the case of Radical Independence they doorstepped and challenged Nigel Farage when he came to Edinburgh last year. All of this contributed to a different kind of politics which circumvented the "official" version.

Scotland has finally become a democracy, which is a watershed moment and transformation. Previously, Scotland had never had what could be called a democratic moment. Pre-Union, it had been an absolutist pre-democracy; post-Union, it was defined by the "holy trinity" of three elites: the Kirk, law and education which shaped autonomy for most of the 18th and 19th centuries.

That institutional gridlock morphed into the expression of a quasi-corporate state from the 1920s and 1930s onwards, which formed the foundation of the post-war welfare state settlement.

This gave Scots an anchor into a progressive British citizenship, resistance to Thatcherism, and a place for an elite support for devolution to grow and be nurtured.

Yet for all its avoidably centre-left sentiment, this was never a culture or practice of democracy; in recent times this order has weakened and in places collapsed.

The new political dispensation will, with the demise of the old order, be less predictable and controllable. It raises the question of what Scotland's new radicals and progressives will do in this new environment post-indyref? Is there sufficient room beyond the panglossian Yes and pessimism of No? Can the managerial, technocratic SNP find a different way of doing politics? And what of the Scottish Labour Party, which found itself on the winning side but which seems to have learned little about how to campaign and understand the terrain of politics and its opponents?

Then there is the attachment of a large swathe of voters to Britishness and the Union, some of whom might constitute a culture of "shy Noes" and a supposed silent majority?

The challenge to the new radicals will be if, and how, they can give voice to the new energy and dynamism. One option is to form a new left-orientated party which will have to find a form which does not constrain or control its potential too much. Some of this will be more difficult, with less room for manoeuvre in the light of the No vote.

In the aftermath of the vote things began to move very quickly. From Scots Labour MP Tom Greatrex came the observation that despite the No victory it represented "a last chance" for the Union; similar language was used by Tory right-winger Bernard Jenkins.

Welsh Labour First Minister Carwyn Jones declared: "The establishment almost lost the union" and said the old union was dead. Constitutional expert and pillar of British liberal elite opinion Vernon Bogdanor said the indyref "was meant to close a debate, but instead it has opened one", or more accurately several: about Scotland, England, Wales and the future of the UK.

One Labour MP said to me the morning after that it was "back to normal", oblivious to the lack of the normal across Scotland, the UK and most of the West. The Queen resisted calls during the campaign by Cameron and Tory supporters to be dragged into the debate, and then proclaimed after the vote: "We have in common an enduring love of Scotland, which is one of the things that helps to unite us all."

Scottish society and politics is in a profound state of flux and change. The SNP will remain centre-stage post-Salmond and their project of self-government and independence will reconfigure and re-emerge in a new form, content and language. The party will, under the leadership of Nicola Sturgeon, undoubtedly shift to the left, focus more on the west and central belt, and aspire to win over more Labour voters.

Where does this leave Scotland and the UK? The close vote is not a bold reaffirmation of the Union. Within hours of the polls closing and the result becoming clear, the three party pro-Union deal of Labour, Tories and Liberal Democrats fell apart, as Cameron announced any further Scottish devolution plans would be conditional on addressing the English question, without consulting the LibDems and with Labour's Ed Miliband indicating his opposition.

This gives the Union a significant window in which it has the chance to change and embrace far-reaching reform. That has to be about more than more powers to the Scottish Parliament, or dealing with the English question by bringing in English votes for English laws. It is about more than constitutional reform and change; it is about breaking free of what is now widely seen as the failed state of Westminster.

It will be touch and go whether the British political class has the intelligence and insight to realise the scale of the crisis. If it does not, the movement for democratisation and social change which has offered so much vibrancy and hope north of the Border will be back, more mature, astute and knowing how to build even better, more sustainable alliances and networks. The British state has bought itself precious time. If it does not use it wisely, this debate will be back in a decade and Scotland will produce a second referendum different from the first.

Britain is on borrowed time. Scotland's moment has begun.