ElephantGuts said:
You can't really get so technical and serious regarding the issue of zombies, since the fact that they don't exist means we don't know enough about them. If zombies are actually already deceased corpses, doesn't that mean the organs aren't required to function? I'm don't know very much about zombies (atleast compared to what some people seem to know) but if whatever makes them function can overcome death then who knows what other laws of nature they can prove immune to?
That's the catch, unless some magical property comes along that allows zombies to break all known laws of biology and several well known physical conventions, zombies MUST follow the rules.
As to my assertion that zombies need to eat, this is not entirely true. They simply need some way of creating phospate bonds in adenosine diphosphate molecules (creating adenosine triphosphate). The reason for this is that cellular energy (literally, if you get down to the brass tacks of what makes a cell capable of doing work) is stored in this phosphate bond. Without a significant change in the biological structure of the cell (which I'll grant may theoritically be possible), then this is a simple fact that can not be unmade. Any time one wants to do work they require an expense of energy (physical law), and while the energy souce may be variable it must be present. Furthermore, the second law of thermodynamics states that any process where energy is converted to work is not fully reversible (the very law that says useful perpeutal motion is impossible), which means that even an especially effecient process would still require an external energy souce. You can get into the weeds as much as you like - without resorting to "magic" to explain it, a zombie needs some way to get energy in order to continue being a menace to humanity, and the only system built into a human body is that of our basic metabolism, requiring a constant supply of food.
All of the conventions I stated stand on the same basic premises. It doesn't matter how determined a zombie is, if you shatter it's bones and muscles it simply won't be able to move unless it's propelled (and supported by) magic. Such a body still requires some mechanism or moving energy and waste about, and the only structures that exist in the human body that accomplish this lie in the circulatory system. Though oxygen is a theoritical requirement, it need not be the case, as even within the human physiology there are tissues capable of functioning (at a vastly reduced efficiency) without the use of oxygen, specifically muscles. The troule is, the reaction in which one yields energy produces incredibly harmful byproducts if oxygen is not present (if you ever wondered why your muscles burn when running it's because you're producing lactic acid thanks to a shortage of oxygen). Unfortunately, only muscles are capable of this process, so again some pretty significant changes would be required in the biological structures.
At the end of it all, I'll grant that one can play with the rules to an extent, but at the end of the day a zombie must either conform to physical law or rely on a magical solution. And, let's face it - any process wherein the human body is so dramatically altered that the usual conventions need not apply would require such a tremendous amount of energy that we could reasonably expect only a tiny fraction of potential victims would actually manage to survive the process (another reason to fight obesity I suppose). Just as important, even these zombies would still function under basic laws of physics, so if we simply assumed that they worked on some process wherein they used environmental heat and/or sun for an energy souce, we could rest easy knowing that the minute winter hit their numbers would be easily culled since they wouldn't have the energy to put up much resistance.
