April 21, 2010: Fire boats battle the blaze on the Deepwater Horizon rig. U.S. Coast Guard/Getty Images hide caption

itoggle caption U.S. Coast Guard/Getty Images

Oobleck has some novel physical properties. When it's moved slowly, it acts smooth and runny, like a liquid. But move it quickly and forcefully, and it locks up, becoming almost solid. Jonathan Makiri/NPR hide caption

itoggle caption Jonathan Makiri/NPR

As the Deepwater Horizon oil rig burned last April, millions of barrels of oil were beginning to make their way out of the blown-out well underneath. U.S. Coast Guard/Getty Images hide caption

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This image, from a video feed from a remote submarine, shows BP's Macondo well leaking natural gas on May 12, 2010. A new study concludes that the vast quantity of methane gas that spewed from the well in the Gulf of Mexico was rapidly eaten by bacteria. BP PLC/AP hide caption

itoggle caption BP PLC/AP

The Deepwater Horizon oil rig burns in the Gulf of Mexico last April. An excerpt of a presidential commission's probe into the rig explosion says risky decisions contributed to the disaster. Gerald Herbert/AP hide caption

itoggle caption Gerald Herbert/AP

Attorney General Eric Holder announces a civil lawsuit against BP and eight others in an effort to recover billions of dollars from the Gulf oil spill. At right is Environmental Protection Agency Administrator Lisa Jackson. Alex Wong/Getty Images hide caption

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Oysterman Mitch Jurisich steers a small boat around his family's oyster beds off the coast of Empire, La. He hasn't harvested many oysters since oil from the BP spill drifted into the area in June. Tamara Keith/NPR hide caption

itoggle caption Tamara Keith/NPR

Fred Bartlit Jr., chief investigator of the National Commission on the BP Deepwater Horizon Oil Spill and Offshore Drilling, at the public hearing in Washington, D.C., on Monday. J. Scott Applewhite/AP hide caption

itoggle caption J. Scott Applewhite/AP

Boats battle a fire at the Deepwater Horizon oil rig in April. Eleven people were killed in the blast. U.S. Coast Guard/Getty Images hide caption

itoggle caption U.S. Coast Guard/Getty Images