How to define the Classical Elements, Scientifically, as ranges of a single property?

Question

How do I define the Classical Elements with Science so that it agrees with science?

According to a single property of a substance.

So, no Fire = Energy, Water = Liquid, Earth = Solid, Air = Gas... as I'm quite sure that Energy is not a state of matter...

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For example,

Specific Gravity ranges for each type of element.

Which is something like:

Water Users have control over materials with a Specific Gravity between 20 to 50, inclusive.

Earth for materials with specific gravity higher than 50,

Air for materials with specific gravity between 20 and 10, inclusive of 10

Fire for materials with specific gravity lower than 10

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From Plasma Manipulation

I can't do Plasma, Solid, Gas, Water... as:

See Fire is not plasma. – DJMethaneMan Apr 21 at 18:02

@DJMethaneMan The specific question asked in your link is if burning wood, paper, or gasoline is hot enough to produce plasma. Fire can easily be hot enough to produce plasma. – Samuel Apr 21 at 18:06

However, not ALL Fire is Plasma...

Answer 1

TL;DR - For this one, you'll need to define hard limits on what these people can and cannot manipulate, and I think the breakpoints will be around bond energy and kinetic energy.

Honestly? I think you were better off using the phases. The Gas phase guy would be most capable of starting and controlling fires. Plasma comes out to a kind of electrical thing. Liquid and solid are pretty self explanatory from there. Except for the whole magic thing, if you want hard-science, people controlling classical elements has some problems - since fire is an ongoing process with multiple possible constituents, things get weird. I mean, what is this guy, a Gasoline mage?

Rant over - Now let's see what we can do to make this happen.

Each of these classical types have certain recognizable patterns. Liquids bond poorly, solids bond well, gas (very generally speaking) isn't bonded at all, and fire is a self-sustaining chemical reaction consisting of the ongoing decomposition of other material into flammable gasses.

In order to have any hard science basis for a classical elemental magic scenario, these people have to be able to recognize, manipulate, and/or create these arbitrary patterns. The Earth guy can arbitrarily reshape the bonds of existing solid without breaking them. Water guy can arbitrarily manipulate forces inside a liquid to cause it to take different shapes. Air guy isn't so much different than water guy, but he can only do it to gases - if you need a reason, then all I can offer is that Water guy can't track the gases fast enough to manipulate the particles, and Air guy can't summon enough force to change the bonds of solids and liquids. Perhaps Earth guy can only control bonds he is physically touching through other solid matter, and can't get a lock on anything that is moving.

Now we have to design the fire guy. This is harder, but we're already handwaving the fact that these people are doing impossible things. In that case, I offer that Fire users can only detect and manipulate hot particles - that is, particles that are free to move and contain relatively large quantities of kinetic energy. In order for this guy to not just be Air guy, there must exist some point of exclusion. On this point, I suggest that perhaps Air guy cannot find and use gas particles above a certain energy threshold. The Fire guy must then also not be able to use anything heavier than hot combustible gases that are already burning, or risk just being Uber Air guy - this may or may not be desirable in your work.

Minor edit: I just looked back over this and realized that this creates a spectrum, involving how much force a person can bring to bear on a particle and its bonds, and how fast that particle can be moving and still be manipulated. If you want, now, all magic users are basically Molecule Man with varying degrees of skill and power, and creating the ability for mages to use multiple classical elements.

Answer 2

The problem is that in modern science and chemistry, we've found that these 4 things (water, fire, air, and earth) are not very similar, and by no means all-encompassing categories, so they there's no neat way to define them in similar ways. Because of this, you're going to have to choose if you want to stick close to the ordinary meanings of these terms, and have individual and somewhat arbitrary criteria for each element, or if you want to use the classical elements as a metaphorical basis for a more systematic classification (like in the "states-of-matter" example you give) and have the users be controlling things that don't correspond to our everyday definitions of these four things. You can't have it both ways.

In the rest of this answer, I'm going to outline the most effective individual and arbitrary physical criteria for each element that I think would get you closest to the everyday definitions.

Water = H₂0. This one is simple, since it is the only one that is a defined chemical compound with essentially a homogeneous composition. Usually in these kind of setups, water-users can also manipulate ice and water vapor, but if you don't want them to be able to you can just restrict their control to liquid water.

Fire: one of the things we have learned is that fire is not a substance. It is a process. In general, fire is characterized physically by the chemical process of oxidation, and the release of energy (exothermy). Clearly, fire also has a close connection, both physically and metaphorically, with heat. So a fire-user might be able to control things like oxidation and heat-transfer. One interesting fact is that only gases, not solids and liquids, are capable of sustaining a flame. When something solid or liquid appears to burn, it is really being vaporized and then the vapor is what catches on fire. [Edit: vaporization does occur for burning solids and liquids, but the overall situation seems to be more complicated than I originally stated in this post.]

Air: The most obvious criterion you can use for "air" is simply "substance in the gas state of matter". Earth's atmosphere is mostly composed of nitrogen and oxygen molecules, which are two distinct chemical elements that otherwise don't have any special connection, and that can also be found incorporated in solids and liquids, so it's impossible to define air in terms of chemical composition. This could possibly overlap slightly with water-users with regards to the substance of water vapor; you'd have to decide how to resolve that. I suppose you could restrict "Air" manipulators to control of monoatomic and homonuclear diatomic gases: this is a bit arbitrary, but it would include nitrogen, oxygen and argon (the 3 most common atmospheric gases), as well as a number of trace gases, and exclude water vapor (and also CO₂; I don't know if that would be a problem).

Earth: this one is the hardest to define, as it's rather vague. However, in general, rocks are composed of minerals, which are solids with an ordered crystalline structure that are inorganic in composition (the chemistry definition of this is a bit tricky, but it basically means that the structure doesn't contain carbon backbones). An earth-manipulator might have the power to affect only things with these kinds of crystalline structures. (As with air, this would lead to overlap with water-users, in this case for the category of ice; you'd have to decide which way you want to assign it.)

You can see that each element has a different type of definition. I don't know if this has to be a downside: if you emphasize how the elements contrast rather than how they fit together, this could inspire some unique extensions for each type of power (for example, fire manipulators might gain the ability to manipulate their metabolisms, since this involves a different type of oxidation, while air manipulators might gain the ability to use sonic attacks, and earth manipulators might gain the ability to change the molecular-level structure of crystalline solids, like turning graphite to diamond).

Answer 3

Bond structure.

Earth = Structured bonds Water = Non Structured bonds Air = No Bonds Fire = Individual atoms

So if you interact with an individual atom it will vibrate in place, like a point, causing heat.

A Gas manipulated creates flow like a line.

A liquid manipulated has a surface like a plane.

A solid manipulated has structure, like a cube.

And then you can either work your way up from fire to stronger elements, or you can have people only able to manipulate energy a certain way.

Or you can do Fire as transitions of bonds, since heating and cooling changes elemental states.

Answer 4

(I think) I just got an awesome idea inspired by Mikey's post.

So basically the issue here is that each of the four elements have many unique traits that can't necessarily be sorted by any hard-science forces. What if, based off of each individual's DNA, some kind of structure is formed that bends the forces of science in some way. Each tiny change in DNA could result in a completely different structure that may tend toward another element, or have no change at all. These structures seem to form patterns that allow specific manipulation of similar physical things, such as fire, water, earth, or air.

Although Alice (and her previous ancestors) all in the past have only been restricted to fire, Bob, the next generation, may have a somewhat dissimilar structure resulting in him getting earth instead. The last, more fun, part is that, although you don't have to, you can easily add more elements in whenever needed due to the absolutely massive combinations list DNA provides.

Answer 5

I'm not sure I fully understand your goal. You'll also need a little bit of 'fake' or 'speculative' science, here.

First, there's a bit of good news. As Einstein showed, matter and energy ARE the same. In your story, in your universe, you can suppose that your characters can convert energy into mass, or mass into energy.

In a very cheeky way, you can suggest Hairy can manipulate energy to produce wind, Walter can do the same with water, Dirty Mike can do the same with earth & soil, while Burnadette can manipulate great amounts of energy to create fire.

We're daily surrounded by tremendous amounts of electromagnetic energy, and it just takes your characters having the ability to scavenge it, store it, and use it.

Now, I am going to hide from (1) the real scientists who are going to guffaw when they read this, and (2) people who didn't like my cheesy puns in the third paragraph.

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EDIT, as requested: Why does Dirty Mike have the ability to manipulate dirt, for example?

It turns out that each 'type' of person with the ability is connected very closely to the element at birth. Atoms frequently exchange electrons. In your universe, however, a person dwelling in the foothills has developed very strong bonds with elements in the soil. Walter, on the other hand, grew up by the sea. Occasionally a rare cosmic event creates very strong bonds between one person and the element they're closely surrounded by.