This is My Rifle…(Part 1; Physics)
Posted by PintofStout on September 25, 2006
Have you ever thought about how guns work? What makes guns today different or better than guns of one-hundred years ago or two-hundred years ago? Well, B___ and I talked about this back at the end of February and I have talked about writing something about it ever since. I guess my procrastination is coming to an end.
What makes a weapon different from its predecessors? What is a weapon? Let me put on my physics cap and see if we can discern between shampoo, explosives, guns and knives.
Before outright defining “weapon” (where’s the fun in that?), let’s derive what it is like B___ and I did in February. It all started with my comment about how little guns have changed, a thought I had while cleaning my (former) Ruger 10-22 (semi-automatic; meaning it fires once every time the trigger is pulled and reloads itself with the force of the recoil). B___ begged to differ and pointed out great advances in the last half-century, from muzzle loaders to rifles to repeating rifles.
I was trying to point out that the process that sends that projectile from the barrel is the same; there’s an explosion which is contained inside the barrel thus directing the force, which has since been transferred to the projectile next to the explosion, down the barrel. This process is the same for muzzle loaders, rifles, repeating rifles, and cannons. The materials that create the explosions have changed; the projectiles and methods for directing those projectiles have changed, and the logistics of the whole process have changed; but the principle is the same. I was referring to the principle (I’m a principled guy) and B___ was referring to the other stuff (not that he isn’t principled, too).
When bows and arrows were mentioned the principle became deeper. The similarity between arrows and bullets is that they are both projectiles directed at a specific target. Moreover, they are directing energy (transferred from the tension of the bow or a contained explosion). At this point the nut was cracked (almost). The function of bullets, arrows, thrown stones, knives, swords, bombs, nuclear bombs, or fists is to transfer energy to a target. The purpose of such energy is to create a physical change of the target, usually to make it cease or alter function. The more precise a weapon is in its transfer, the less energy is needed; whereas the less precise, the more total energy is needed in order to achieve the same energy density at the target; i.e. a low-energy arrow and a high-energy hand grenade.
So a weapon can be defined as something used to for the directed transfer of energy to another object with intent to physically alter. But the physical transfer of energy is only half the story, and it is nearly the only side of the story our weapons have existed in to date. It would probably be quite daft to think that guns, even bigger and better guns, are the penultimate in individual weapons; that something better will never ever come along. What about the unspoken half of the story? What does it entail?
So far we’ve spoken of objects physically transferring the energy, usually derived from another source, to the target; the first half of this tale. Why not remove the middle man and transfer the energy directly to the target. Some of these weapons already exist, some will surprise you, and others are still science-fiction. The first and most primitive of weapons that can fall under this category of weapons are the fist, the feet, and basically the human body without any tools. But this is a technicality, since a tool isn’t actually transferring the energy but the energy is transmitted via direct contact or conduction.
Lumping projectiles, swords, fists, etc. into a conduction of energy category, that leaves the convection and the radiation categories. Convection, I think, would entail bombs and other fire or explosion-producing materials. This would essentially be a subset of the conduction weapons due to either the material itself or the surrounding atmosphere conducting the energy to burn the target to a crisp. I know a gun’s (or rather the bullet’s) energy is derived from an explosion, but I’m assuming the final transfer of energy to the target, regardless of intermediate transfers, is what characterized the transaction.
The last category of energy transfer does have some weapons in its midst. There are laser weapons, though not on a scale for individual use (mostly missile and air defense), being developed that transmit energy in the form of concentrated electromagnetic radiation. Concentrating enough energy into a light (or radiation) laser beam to actually damage something takes lots of power. Some of that power can come from the light itself (unconcentrated), such as x-rays, but the laser is made by reflecting the light over and over again while letting a portion of it through the reflective material. A normal laser reflects off of mirrored glass. What does an x-ray reflect off of? Yeah. So there are some hurdles, but some of these are already being stepped over, I believe.
As an aside, B___ asked what a sound wave would fall under if it were to be used as a weapon. I assumed he meant to do physical harm and not just psychological harm by blaring it to deprive someone of sleep or offending someone’s tastes by playing bad music. I concluded it would be like an explosion where the medium carrying the sound (like the fire of an explosion) would transfer the energy. No medium, no transfer. Thus it would be a convection transfer. That ends this aside.
The best example of transferring energy directly (without a middle man) can be found in nuclear weapons which besides radiating heat energy given off by a chain reaction also emit electromagnetic radiation in the form of high energy waves such as microwaves. The heat energy is just like a conventional bomb, which for reasons of categorization, I grouped differently. According to the September 2001 issue of Popular Mechanics a hydrogen bomb detonated over the Pacific in the Fifties shorted out street lights and power systems for several hundred miles around the Pacific, which is the equivalent to an Electromagnetic Pulse (EMP) Weapon. This form of weapon is directing (via location of detonation) pure energy to any electronic target in the vicinity. The same article illustrates how it can be done without a nuclear explosion, but with the detonation of regular explosives inside an electrified coil which creates then shorts out a magnetic field. As the explosion travels down the coil the magnetic field is compressed creating a wave or pulse of magnetic energy. This energy doesn’t affect living creatures beyond the catastrophic failure of anything electrical.
In light of the discussion of what most fundamentally constitutes a weapon, the regulations regarding weapons seem to be based on efficiency and magnitude and perhaps range. For a while this involved scissors and fingernail clippers and most recently any liquid (if it is on an airplane). But is the weapon of the future shampoo? Will it use the same concept of transferring energy via some object and will it desire the same physical effects on the target as today’s weapons? As I tried to illustrate earlier, the future of weapons may lie in transferring the energy directly without a physical transporter. Tomorrow’s weapons may also lean towards a different effect besides physical destruction – perhaps just the temporary incapacitation of the target. So, until I complete the second part of this essay pertaining to chemicals and biology, set your phasers to stun.