With the recent explosion on an oil rig in the Gulf of Mexico and the oil slick heading toward the shore, on today's Please Explain, we're looking into how offshore drilling is done how much oil might be discovered under the Atlantic now that the Obama administration is proposing to open vast expanses along the Atlantic coastline, the eastern Gulf of Mexico and the north coast of Alaska to oil and natural gas drilling. Paul Bommer, Senior Lecturer in the Dept. of Petroleum and Geosystems Engineering, University of Texas at Austin, and Tyler Priest Professor and Director of Global Studies in the Bauer College of Business at the University of Houston, and oil historian.