Turning the question “Is fire alive?” on its head, perhaps the better question is “Is life afire?” Life fundamentally involves oxidation, so perhaps one good way to deal with this issue is to categorize life as a kind of fire. Certainly this makes more sense than attempting to redefine life so broadly as to include things that just don’t seem alive.
That word “seem” is crucial to defining life, because some prefer a strictly categorized definition based on authority from afar (that “God” person-thingy) and these folks hate “seem-y” definitions. They feel it’s important to have clear-cut answers to murky questions. Indeed, I have found that “simplism” (the desire to resolve complex issues with simple rapid clarity; you heard it here first) is essentially synonymous with conservatism, at least with American conservatism.
But you’d have to be pretty far off the opposite end of that pool to really see fire as alive. So I says it ain’t. Instead, life is on fire. Paul Simon even says so (name the song and album for extra credit)
Indeed, although this was probably not the sense in which he meant it.
Continuing this silliness (if someone wants to talk about life being a form of fire, feel free. Maybe folks “have no opinion about this, no opinion about that”) here’s a new question. Who said:
“Life. Don’t talk to me about life.”
OK, it has nothing to do with fire, but I bet most straight-dopers will know this one instantly.
If only someone had replaced the diodes on his left side …
Anyway, life is a lot more complex than oxidation of chemicals. We get energy from that process, but living things have refined it and added other chemistry on top of it. For example, you’d have a tough time convincing me the sodium in nerves is related to fire. And how much oxidation goes on when RNA is used to create proteins? No, I define life as cellular with physical traits passed on through chain chemicals. That’s elementary biology, but it works for all life yet found on Earth.
BTW, how is ‘simplism’ associated with any political postions?
I would say that any process that concentrated local energy would suffice. Simple things like photosynthesis that capture radiant energy and convert it into useful chemicals for instance.
Other processes that use external energy also work. Bacteria living off heat and chemicals produced by volcanic activity, or even radioactive decay, are examples of life that doen’t rely on its primary energy source from oxidation.
The definition of life really has to include any process that concentrates energy in a repeatable way and then uses that energy to propagate itself.
Not all life involves binding oxygen to molecules for it's metabolic processes. There are anerobic bacteria for whom oxygen is toxic, and there are the creatures of the hydrothermal vents with very exotic metabolisms whose prime energy source is various compounds of sulfur.
Not all life involves binding oxygen specifically to other atoms, but all life does involve oxidation of some sort: The term “oxidation” in chemistry actually means “combination with any high-electronegativity element”. Usually, this means oxygen, but it can also be fluorine, sulfur, or a variety of other elements over there on the right side of the Table.
This is still not to say that oxidation alone is sufficient to define life.