Ok, from what little we've seen throughout the books, Andalite shredders and Yeerk Dracon beams (which are based on the shredders they originally stole from the Andalites as well as certain particle-wave physics taken from other species) work much like the fictional phaser weapons employed by the Federation on Star Trek. AT LEAST they aren't ergonomic nightmares as seen in Star Trek, with a more real-life gun-like design, but they are still far from what you would expect to see in a REAL futuristic army wielding energy-based weapons.
First, let's turn to the aforementioned weapon used on Star Trek. Phasers act as much of a mystery, seemingly self-contradictory and apparently in violation of the very fundamental laws of physics. They can make organic matter disappear and punch through solid rock and masonry, but they can do little against heavily armored structures or objects. HOW they disintegrate matter is something of a debate. Some posit that they cause the organic subject to vaporize into invisible gas, but that would require A LOT of heat and would cause so much steam in the room that it would likely melt the flesh off your bones! Next theory: Some speculate that it causes disruption into subatomic particles, but this is even worse as it would create a huge cloud of ionized hydrogen plasma and a large neutron radiation flux, which would also be highly flammable! Next theory: Complete conversion into electromagnetic energy, or a better way of saying that is that it becomes photons, but this is the worst explanation given yet, as the result of such a mass/energy conversion would generate the equivalent of a 1700 megaton blast of gamma radiation! Could you survive long next to a 1700 megaton explosion? I don't think so. The final theory, that it converts organic matter into neutrinos, seems to have more basis, as neutrinos could pass harmlessly through matter without adverse effects, and this seems to be the general theory regarded as to how phasers work.
Now, enough science, let's get back to Animorphs.
Working backward from those theories, the last explanation, that shredders/Dracon beams can cause complete conversion into neutrinos, CAN'T be the case in the Animorphs universe because we've SEEN a few battle scenes and the shredders and Dracon beams generate A LOT of heat. Furthermore, in #24. The Suspicion, Cassie remarks as they fly away from the disintegrating Helmacron that its flesh suddenly turns very, very hot, though how they survived so close to such heat is up for debate. Complete conversion into neutrinos can't work, for various reasons. The next theory is no good, as we've seen phasers, er, shredders and Dracon beams used in tight, confined close-quarters combat situations, and no one could survive so close to 1700 megatons of gamma radiation. The theory after that also wouldn't work, since if the air turned flammable it would ignite the very second after the discharge is fired from a shredder/Dracon beam, setting fire to everyone nearby. The first and final theory, conversion into invisible gas, is probably the most likely explanation, as we see way back in #1. The Invasion that when they are set on their "disintegration" setting, Dracon beams and shredders generate heat. But as I said above, we've SEEN these weapons used in close quarters, and if they generate that much heat then the person wielding the weapon most likely wouldn't survive for very long due to the resulting hot steam! Especially the unarmored Andalites, Hork-Bajir, and Taxxons and humans using them.
KA would have done better to have based her energy weapons on blasters, as they CAN punch through solid armor, and are much more like real-life weapons, but, forever the Trekkie at heart, she instead based it on the almost magical phasers we see in Star Trek, highly contradictory devices that would NEVER make it into a real-life army. The explanation for this is simple; she needed a simple reason to explain how way back in the first book they can eliminate all traces of Elfangor's ship and body so the humans don't recover it, but THAT could have easily been solved simply by having the Yeerks steal the fighter, and this would have made the "Visser Three eating Elfangor" angle much more sensible, as he was eliminating the physical evidence in his typical blunt, direct way.
Now, keep in mind my knowledge of physics is pretty rusty, and most of the information I'm getting came direct off StarDestroyer.net, so I might be 100 percent wrong about all this. If anyone cares to enlighten me, please do so.
Now, discuss!