It's the day of reckoning for the 300 year old union between Great Britain and Scotland. Scottish voters will decide whether they are "Better...Together" as the unionist slogan goes, or whether they would do better as an independent nation.

Polls opened at 7 AM local time and will close at 10 PM (2 AM to 5 PM US Eastern time). A result isn't expected until around 3 AM Eastern.

CNN:

Voting was brisk at one polling station in Glasgow as the polls opened, with many people voting on the way to work or before taking their children to school.

Results from the different areas will come in overnight into Friday morning local time, with Chief Counting Officer Mary Pitcaithly expected to announce the outcome "around breakfast time."

Bad weather or the sheer volume of votes cast could slow down the counting process. However, the weather forecast appears good so far -- important when some ballot boxes must be collected by helicopter, plane or boat from polling stations on distant islands.

A simple majority is needed for either side to claim victory.

Scotland's First Minister Alex Salmond, who has led the pro-independence "Yes Scotland" campaign, cast his ballot Friday morning in the village of Strichen, Aberdeenshire.

Labour lawmaker Alistair Darling, who has headed the pro-union "Better Together" campaign -- backed by the main parties in Westminster -- voted in Edinburgh, while former Prime Minister Gordon Brown, another pro-union campaigner, voted in the town of Kirkcaldy.

For the first time, the vote has been extended to 16- and 17-year-olds living in Scotland. Nearly 110,000 people younger than 18 have registered to vote.

Voters in the referendum do not have to be British citizens; Commonwealth, Irish and EU citizens who live in Scotland and are registered to vote there can cast a ballot. However, Scots living outside Scotland do not have a say.

Nearly 790,000 people applied for a postal vote -- the largest volume of registration for postal votes ever in Scotland.

The close vote and the fact that only a simple majority is necessary for Scottish independence raises questions about what the unionists will do if they lose. You would think that such a wrenching decision would have been decided by a 2/3 or 3/4 margin, as amendments to the American Constitution are decided. Our founders recognized that a major change in governance required a supermajority of the people support it, or opposition to the change would thwart the will of the people..

Whatever side loses is not going to be happy. We should all hope that the Scots - an eminently practical and sensible people - will keep their emotions in check and funnel their frustrations into democratic channels. But the mood over the last few days has gotten uglier and some unionists have become targets. AT contributor from Great Britain Scott Varland says that because of this intimidation, there may be a closet "no" vote that will come out in the privacy of the voting booth. He thinks it may be enough to swing the election to the unionists.

We shall see. In the meantime, both sides are on edge as the fate of the union - and possibly the EU - hangs in the balance.