LIVERMORE, Calif. -- U.S. troops blew up enemy bridges with explosives in World War II to slow the advance of supplies or enemy forces.
In modern times, patrollers use explosives at ski resorts to purposely create avalanches so the runs are safer when skiers arrive.
Other than creating the desired effect (a destroyed bridge or avalanche), the users didnt exactly know the microscopic details and extreme states of matter found within a detonating high explosive.
In fact, most scientists dont know what happens either.
But researchers from Lawrence Livermore National Laboratory and the Massachusetts Institute of Technology have created the first quantum molecular dynamics simulation of a shocked explosive near detonation conditions, to reveal what happens at the microscopic scale.
What they found is quite riveting: The explosive, nitromethane, undergoes a chemical decomposition and a transformation into a semi-metallic state for a limited distance behind the detonation front.
Nitromethane is a more energetic high explosive than TNT, although TNT has a higher velocity of detonation and shattering power against hard targets. Nitromethane is oxygen poor, but when mixed with ammonium nitrate can be extremely lethal, such as in the bombing of the Alfred P. Murrah Federal Building in Oklahoma City.
Despite the extensive production and use of explosives for more than a century, their basic microscopic properties during detonation havent been unraveled, said Evan Reed, the lead author of a paper appearing in the Dec. 9 online edition of the journal, Nature Physics. Weve gotten the first glimpse of the properties by performing the first quantum molecular dynamics simulation.
In 2005 alone, 3.2 billion kilograms of explosives were sold in the United States for a wide range of applications, including mining, demolition and military applications.
Nitromethane is burned as a fuel in drag racing autos
|Contact: Anne Stark|
DOE/Lawrence Livermore National Laboratory