In the first independent paper on the volume of the Gulf oil spill, scientists have affirmed heightened estimates of what is now seen as the largest marine oil accident ever. Using a new technique to analyze underwater video of the well riser, they say it leaked 56,000-68,000 barrels daily -- maybe more -- until it was capped. Their estimate of total oil escaped into the ocean is 4.4 million barrels -- close to the most recent consensus of government advisers....