The year is 2019. The destroyer U.S.S. Mason patrols enemy waters, and is suddenly faced with a barrage of incoming missiles. Almost instantly, dozens of brightly colored lasers beam out of the Mason, intercepting the missiles and destroying them harmlessly in the air. Then a massive deck-mounted gun turns and takes aim at an onshore target 70 miles inland. The ship's lights dim for a moment, and the magnetic railgun fires a projectile at roughly Mach 7. The impact is audible as a dull, subsonic thud. Want to find out what else the Navy's researchers are cooking up?Once each year, the Office of Naval Research holds a conference where they explain what they're currently working on. This year, the ONR detailed several weapons systems that seem like they were lifted straight out of your favorite military sci-fi novel. Solid state fiber lasers could be mounted in "pods" on aircraft, able to deliver 100 kW blasts. Free Electron Lasers will begin development in 2010, and will hopefully have the ability to take out incoming ordinance or even small attack (or suicide) boats. The lasers don't stop there - helicopters could be equipped with laser terrain finding gear to help them land in "brownout" conditions. Lasers not sexy enough? How about directed microwave weapons? I've been dreaming of one of these for years, to take out the thumping audio systems of cars that drive past my house. The Navy would rather use them to fry the electronics in enemy equipment. The ultimate naval weapon might be the hyper-velocity railgun. It could propel projectiles up to 230 miles with killer accuracy at speeds close to Mach 7. The Navy holds a world record for "highest electromagnetic muzzle energy launch of a projectile" using such a weapon. I have no idea what that means, but I know I wouldn't want to get hit by one. These megaguns aren't without their flaws, though. That kind of muzzle velocity tends to destroy the barrel of the gun, and each firing draws something like three million amps. Image by: U.S. Navy. Navy Wants Lots of Lasers [Defense Tech]
@ElijahDProphet: I don't know if that's really the case. Powerful capacitors can be very explosive after a severe knock. (One of my old physics professor used to brag about the explosive power of the capacitors for the particle accelerator he worked on in the late 50s.)
I think the reason they want to develop these things is to improve muzzle velocity and rate of fire.