Until yesterday for most Scots those words probably conjured up the 1996 science fiction disaster film about an alien invasion timed to coincide with US July 4 independence celebrations. Now, following the publication of the Scottish Government's paper outlining its vision of the transition from the referendum vote to Scottish independence, those two words take on a different meaning. And there is a date for Independence Day: March 2016.
The document, entitled "Scotland's Future", sets out in broad terms what would happen following a Yes vote in the 2014 independence referendum. SNP ministers would join opposition parties and civic organisations to negotiate independence terms with the Westminster Government, write a Scottish constitution, agree the division of assets and liabilities and recast Scotland's relations with the rest of the world, including the EU. All of this would be achieved in just 16 months.
The document is not short on aspiration, a characteristic the SNP has deployed with some success and one that Nationalists will have to harness fully to achieve their goal of independence, given polling consistently showing support for independence stuck at between one-quarter and one-third of the electorate.
The politics behind this document are not difficult to discern. First, and taking account of the polling, the SNP needs to give credence and weight to the idea of a Yes vote, seize the initiative and deliver the message that its campaign is on course.
Secondly, the Scottish Government's campaign has to suggest that the transition to independence would be a smooth and seamless process. Thirdly, the strategy is designed to portray the Better Together campaign as negative. It is a strategy that has been successful for the Nationalists in the past.
The most striking revelation, perhaps, is that a timetable for independence that looked challenging to many constitutional experts as it previously stood has been further truncated. Instead of the 18 months previously mentioned by First Minister Alex Salmond, it appears that the exercise would be virtually completed in 16 months.
That would leave two months for campaigning for the 2016 Holyrood elections. This would mean that the SNP Government would oversee the transition and powers would be transferred before those elections, thereby stopping the opposition Unionist parties from using these elections as a second referendum on the negotiated terms.
The scale of the challenge cannot be underestimated. Talks would have to take place on policies as diverse as energy, currency, welfare, pensions, broadcasting, the national debt, oil and gas revenues, defence, the intelligence services and nuclear weapons.
Moreover, the Westminster General Election, scheduled for May 2015, must also be factored in. (Would there be Scottish constituencies in that election?) The SNP has been criticised for setting a timetable with unrealistic deadlines and for concentrating its efforts on the process of independence. These are criticisms Mr Salmond will have to answer if he is to convince the waiverers to vote Yes. His party's ambition cannot be faulted but there will be a sharper focus on the nitty gritty of independence now that the SNP has produced its timetable for its ultimate goal.
The challenge in the months ahead will be to produce policies for an independent Scotland that will now, correctly, come under greater scrutiny. Ambition is one thing. Winning the argument is another.