The question “what is matter?” has two wildly different answers, depending on what the person asking the question is looking for. The simple, obvious, intuitive answer is that matter is anything that has mass and takes up volume. By contrast, the long, counterintuitive answer deals with quantum theory, Higgs fields, Higgs bosons and the quantization of space.
Matter as we usually encounter it comes in three basic varieties (though there are a total of five possible:
– Solid: Solids have crystalline structures, and strong bonds between particles. This means that, as the name suggests, they feel solid. Examples include furniture, cars, and buildings.
– Liquid: Liquids are defined as substances with constant volume, which will take on the shape of their container. This basically means that a liquid is anything that can be poured from one glass to another. Examples include water and gasoline.
– Gas: Gases are substances which take on the shape of their container and do not have constant volume. This means, in effect, that a gas will expand forever until it reaches the edge of its container. Examples include air.
The two other possible states are:
– Bose-Einstein Condensate: This is what particles become when they get so cold that they have absolutely no energy left. Although Einstein had theories about what happens at “absolute zero” no one will ever know, because achieving absolute zero is a physical impossiblity.
– Plasma: Superheated matter, which has lost all of its electrons. The sun is an example, as is the center of any nuclear bomb at detonation.
Although most atoms behave the same at different temperatures, the atom itself has a dozen or so components. These are the electron and various “flavors” (the consensus among physicists is that a “don’t ask” approach to their names for particle properties is wisest) of quarks. The latest theories dictate that quarks and electrons are in fact varieties of strings, and that the properties we see (among them, mass) are simply a product of the higher dimensions that particular string exists in. Make sense? No one thinks it does. But it makes the equations work.
Now, to that “more complicated” answer: when boiled down to its essentials, quantum theory dictates that all matter can be described by wave functions, that nothing has definite energy, momentum, location or time (until you interact with it, and make it choose values for each of those), and that the universe, more generally, is a completely insane place. Even quantum theory’s inventor remarked that anyone who claims to know quantum theory is a liar.
