A traditional bomb's casing is made of metal, which shatters when the bomb explodes and provides most of the blast's killing power. The new Air Force munition is encased in a carbon-fiber composite. When the bomb goes off, the special case breaks into thousands of harmless fibers -- limiting the bomb's killing range. On the other hand, the new case fractures more easily than a metal one -- meaning the explosion is stronger close to the target. "More of the blast energy is available as blast as opposed to being absorbed in the steel case," says Dennis Baum, a special technical adviser on munitions in the Pentagon.

The inside of the bomb, which will weigh 250 pounds, is also different. Along with the traditional explosive found in most bombs, the new bomb mixes in a special dense metal powder. The initial blast propels the powder out at such speed that it is highly deadly. Then after traveling a short distance, drag and gravity cause the heavy powder to fall quickly to the ground.

The result is an explosion that is powerful and lethal, but relatively well-contained.

In tests using dummies made out of a special gel that replicates human flesh the blast obliterated everything in the bomb's immediate area, including the gauges the Air Force uses to measure the power of the blast. Scientists at Eglin Air Force base in Fort Walton Beach, Fla., where the tests were conducted, eventually had to design new, hardier pressure gauges.

The shrapnel used in the cancer tests were "tungsten cobalt" and "tungsten cobalt nickel" alloys. Pure tungsten metal powder has been used in medicine for ages, biomedical implants, and even nutritional suplements. It is an inert element, and has never been linked to cancer.

It's interesting to note that the Gov't is stuck with Hundreds of tons of DU, Tungsten costs about 200X that of DU, and the cancer tests conspicuously avoided using pure tungsten powder (cobalt has been known to cause cancer for years, and nickel is poisonous as well).

If I mixed sugar & tobacco, had rats smoke it, then published on the resulting cancer, I could easily say "Sugar product linked with cancer." Although the effects of pure sugar smoking was never tested, I could easily say "There is much more to learn about sugar, and it's possible effects on human beings."

The spin works for everyone. The military gets to use more DU, the government spends less money, the scientist gets to do more testing because "There is much more to learn." Tungsten carbide cobalt is dangerous and there are procedures to handle the material safely.