The mother of all US bombs By Daniel Smith "In December 2001, the US Air Force (USAF) dropped the 15,000-pound (6,800-kilogram) "Daisy Cutter" on the cave complex in Afghanistan known as Tora Bora. At the time, this was the largest bomb in the US arsenal. The same month, the Pentagon sent 10 of the more lethal 2,000-pound (907kg) thermobaric bombs to US forces in Afghanistan. Thermobaric weapons are dual-action: one explosion disperses a fine mist of under-oxidized fuel into a confined space such as a room in a building or a cave. A second explosion ignites the mixture, generating a flash fireball and pressure wave that will kill any person or animal in the immediate effects zone. Anyone who escapes these effects most likely will still die as the spreading fireball consumes all the oxygen in the space. Those old enough to remember Jimmy Carter's US presidency might recall the so-called "neutron bomb", which was supposed to be an alternative to "ordinary" nuclear weapons. Unlike a "conventional" nuclear weapon, the neutron bomb only killed people. It did not destroy things. Thermobarics come close to the same result, although the pressure-wave shock could collapse some structures and the fireball ignites flammables. The latest iteration of "kill people - don't destroy things" (or innocent bystanders) weapon under development is the "focused-lethality munition", touted as a super-precision weapon. Perhaps most people remember the first Gulf War and the videotapes from airplane nose cameras showing a 2,000- or maybe a 1,000-pound laser-designated bomb going down a building chimney or through a window. Today's bomb of choice for urban combat support is a satellite-guided 500-pound bomb, soon to be a 250-pound (113kg) weapon. These bombs work - that is, kill - by the tried and true methods of blasting and spraying shrapnel 360 degrees. Enter tomorrow's bomb, sporting a carbon composite case that, because it fractures more easily than current metal casings, absorbs less of the blast (which goes further) but also doesn't distribute shrapnel as far. The interior of the bomb includes the usual explosives augmented by a metal powder that, riding the blast wave, is lethal but limited in range by gravity. The net effect of all these changes is to reduce the lethality radius, but within that radius to blow away every hard object - including people, says the Wall Street Journal. One hesitates to commend development of weapons with increased lethality even with the prospect that, when used, casualties among innocent bystanders are reduced. Yet there is something less onerous in the "focused lethality" bomb when it is stacked beside another USAF development that will be tested on June 2 at the former Nuclear Weapons Test Site 145 kilometers north of Las Vegas, Nevada. This test will detonate 700 tons (in later reports lowered to just under 600 tons) - that is to say 635,000kg - of conventional explosives in a hole 11 meters deep to allow scientists to measure ground shock waves, and from these to estimate damage to various underground or buried facilities, says the Washington Post. The deeper rationale for the ground test is to try to determine whether a very large conventional weapon could be powerful enough to damage deeply buried bunkers sufficiently to knock them out of a battle (command and control headquarters) or destroy possible chemical, biological, or even nuclear weapons and missiles. Some skeptics think the test will not be conducted fairly or that the results will be skewed to "demonstrate" that the only way to be sure buried targets can be neutralized is by using nuclear weapons. And considering that the administration of President George W Bush is pressing for money to build 125 new nuclear weapons annually - including new designs - on the specious claim that older bombs cannot be (or soon will not be) certified reliable, the skeptics may be on to something. In the aftermath of the Cold War, the United States was a prominent force in the drive for a worldwide moratorium on creating and testing new nuclear weapons that in effect closed the nuclear door. Blocked by Congress from developing a new earth-penetrating nuclear "bunker-buster", the Bush administration is trying to get inside the nuclear-weapons house through the "reliability" window. " john Luv the Skeptics Comment.