How many years will it be before the world runs out of oil? The question is far from an academic exercise. This year oil hit a near record high of $40 a barrel, and Royal Dutch/Shell Group downgraded its reserves by 4.5 billion barrels. While consumers pay for perceived shortages at the pump, scientists and economists struggle to reach consensus over 'proven oil reserves,' or how much oil you can realistically mine before recovery costs outstrip profits. Economist Leonardo Maugeri fired up the debate that accused the 'oil doomsters' of crying wolf. Oil pessimists estimate that maximum oil production around the globe will peak in 2008 as demand rises from developing economies such as China. 'If you squeezed all the oil in Iraq into a single bottle, you could fill four glasses, with the world consuming one glass of oil each year,' says a physicist. 'We've consumed nine bottles since oil was discovered, and we have another 9 or 10 in the refrigerator. How many more are there? Some say five or six, but we say three.' Others believe, like Maugeri, that the number of glasses is virtually limitless. John Felmy, chief economist at the American Petroleum Institute, argues that peak oil-production estimates are so far off that. 'Ever since oil was first harvested in the 1800s, people have said we'd run out of the stuff,' Felmy says. In the 1880s a Standard Oil executive sold off shares in the company out of fear that its reserves were close to drying up. Some scientists said in the 1970s that we'd hit peak oil in 2003. It didn't happen. If there is an end to the debate, advanced oil-recovery technologies will most likely find it. A new seismic survey technique, for instance, sends sound waves of varying frequencies thousands of meters belowground. Microphones arrayed aboveground record the reflected signals, and computer software models a 3-D portrait of possible oil hot spots. The surveys have now added a fourth dimension, creating a time-lapse simulation of fluid movements. Companies are also finding sophisticated ways to mine more oil from existing wells. Flexible, coiled-tube drills that carve out horizontal side paths are a marked improvement over conventional, rigid drills that move only straight down. Using such technology, companies hope to soon harvest 50 to 60 percent of oil from existing wells, up from today's 35 percent. Biotechnology, too is keeping the black gold flowing. University of Albert scientists are searching for microorganisms that could dilute viscous, hard-to-recover oil and make it flow more freely. 'Technology can help push peak oil production further and further out,' says an expert. But only time will tell when oil production will peak. According to the passage, which of the following statements is true?