When plans were first being disclosed last week for the installation of the new cap on the blown out BP oil well gushing beneath the Gulf of Mexico, the explanation was that the new cap and its associated piping system would be dedicated to catching all of the oil flowing from the well. Sometime on Tuesday, the story changed to a discussion of BP slowly closing all of the valves on the piping system in an attempt to stop the flow of oil rather than catch the flowing oil. Late Tuesday night, however, it was announced that BP’s test of closing the valves was abruptly halted before it began. The key determinant of whether the flow can be stopped from above with a series of valves appears to be whether the well bore itself can withstand the pressure that is needed to stop the oil flow.