All Matter Has Potential Energy?

[Asagard]

Correct me if I'm wrong, all matter has potential energy

[Edit: clarify title - GC]

Edited June 20, 2006 by GreedyCapitalist

[IAmMetaphysical]

From what I understand from high school science there is energy stored in the chemical bonds between atoms and also between particles in the nucleus of the atoms as well.

Edited June 20, 2006 by IAmMetaphysical

[intellectualammo]

Correct me if im wrong, all matter has potential energy

Matter is just frozen energy...to paraphrase Einstein. Refer to his famous equation.

[Maarten]

I'm not sure if this is always true. All matter has energy, but I think in some cases it may be all kinetic energy instead of potential. I know that in some models the potential energy of molecules is assumed to be zero (like the ideal gas).

[Bold Standard]

Matter is just frozen energy...to paraphrase Einstein. Refer to his famous equation.

But I thought "energy" was a term that designates a quality posessed by an entity, or a relationship of qualities or of entities (hence: "equation"). This makes it sound as though energy is an entity. I don't know much about physics, but that doesn't sound right to me...

[Maarten]

Granted, I am not very knowledgeable about physics, but the reason he said that was because of the discovery that (all) matter can be converted into energy; so perhaps a good way to describe it would be that matter is just one way to store energy, so to speak. This might be confusing the potential with the actual, though (i.e. just because you can turn matter into energy doesn't make it the same). But someone who knows more about this should verify it

[LaszloWalrus]

I believe at a certain level, matter is a form of energy. Nevertheless, I think that when more is discovered, we'll know more about their essential differences.

[Lathanar]

Correct me if im wrong, all matter has potential energy

Are you refering to potential and kinetic energy as in this book sitting on this shelf has potential energy, i.e. it can fall?

[Olex]

Correct me if im wrong, all matter has potential energy

I could correct you if you had said something wrong, but you are "not even wrong." (Pun from critics of Spring Theory)

Here's the deal. There is no single potential energy. See http://en.wikipedia.org/wiki/Potential_energy Pick one and read more about it.

[LaszloWalrus]

I would be careful about using Wikipedia as a source.

[JMeganSnow]

Does anyone want to take a stab at defining "energy"? From my high-school physical science class, all I can remember is that they called energy "the ability to do work" ("work" being defined as, basically, moving shit around). It's a (sort of) functional definition, but it tells you precisely squat.

[Olex]

Does anyone want to take a stab at defining "energy"?

Why bother? It's a scientific term, just look it up in any decent source. We are not getting into philosophical debate here, are we?

[Adrian Hester]

From my high-school physical science class, all I can remember is that they called energy "the ability to do work" ("work" being defined as, basically, moving shit around).

Well, moving something through a certain distance d with a force F, and defining the work W as F*d. Force you measure by, say, the distance through which the force causes a spring to lengthen or shorten. Then you work it out from there. There are many different kinds of energy, but they are all measured in terms of the amount of work they can be caused to do if coupled with a mechanical system (such as, say, by moving a mass on a spring); that is, work is the form of energy most readily measured, and other forms of energy are measured (for the most part, but not heat) by transforming them into work. The equivalence of all these kinds of energy and their conservation when transformed from one kind to another is a pretty abstract idea, of course, that requires such an abstract definition as "ability to do work," and it wasn't until the mid-19th century that it was stated in full generality. (And thermodynamics complicates things because although heat is a form of energy, or rather is the amount of thermal energy transfered, not all of it can be converted into work. On the other hand, you can convert all of a given amount of work into heat--hook a steam engine up so that it drives a bore into metal, converting all the work into heat; then measure the amount of heat generated by how much water it boils off, as Count Rumford did.)

It's a (sort of) functional definition, but it tells you precisely squat.

You have to unpack it. That's not so easy to teach.

Edited June 21, 2006 by Adrian Hester

[Olex]

You have to unpack it. That's not so easy to teach.

I have got to comment this line. It's true and really funny.

[jrs]

Einstein's equation "E = m*c*c" says that energy and mass (inertia) are two different names for the same thing, but measured with different units. Energy is a quantitative attribute of matter and radiation; it is not an entity in its own right. Potential energy is difficult to define because it depends on what you take as a reference level (starting point). For example, the binding energy of atoms in molecules is negative compared to the energy which they would possess as separated atoms. But the energy of diatomic oxygen and diatomic hydrogen is positive compared to water.

[Asagard]

Einstein's equation "E = m*c*c" says that energy and mass (inertia)

energy is mass mulitplied by the speed of light right?

all matter has a mass

so shouldnt all matter have stored energy in them

+the defination of potential energy is stored energy

so isnt my statement quite true?

[miseleigh]

Yes. It just wasn't clear what you meant by 'potential energy'- there are different forms. All matter has potential energy in the sense that it can be converted into energy under the right conditions.

[Bold Standard]

The equivalence of all these kinds of energy and their conservation when transformed from one kind to another is a pretty abstract idea, of course, that requires such an abstract definition as "ability to do work," and it wasn't until the mid-19th century that it was stated in full generality.

Okay, so, if energy is "the ability to do work," that reinforces my suspicion that matter couldn't possibly "be" energy. Because how can something do work if it's not "something"?

Matter can't possibly be "the ability to move shit around," if "shit" is taken to be "matter," because that would boil down to matter being the ability to move the ability to move matter around, which seems to me completely absurd.

I'm comfortable with the formulation that matter can "have" energy (potential or kinetic) but the idea of it being energy seems like it's got a faulty premise.

[DavidOdden]

Okay, so, if energy is "the ability to do work," that reinforces my suspicion that matter couldn't possibly "be" energy. Because how can something do work if it's not "something"?

I take it this refers to the "=" of "E=mc^2". I think it's always best to understand that symbol to mean "equals, sorta", rather than "is actually the same thing as".

[Adrian Hester]

Okay, so, if energy is "the ability to do work," that reinforces my suspicion that matter couldn't possibly "be" energy. Because how can something do work if it's not "something"?

Matter can't possibly be "the ability to move shit around," if "shit" is taken to be "matter," because that would boil down to matter being the ability to move the ability to move matter around, which seems to me completely absurd.

I'm comfortable with the formulation that matter can "have" energy (potential or kinetic) but the idea of it being energy seems like it's got a faulty premise.

The formula E=mc^2 gives the amount of energy you obtain if you convert a mass m into energy. It gives the energy equivalent of a mass at rest in a given reference frame (there is a slightly longer formula that includes momentum, and which reduces to mc^2 + 1/2 mv^2, with the second term the classical formula for kinetic energy, at small velocities). For example, if you split an atomic nucleus so that energy is released, the difference between the mass of the products and the mass of the original nucleus is the same as the amount of energy released divided by c^2. Similarly, if you cause an electron to collide with a positron (the antimatter counterpart of the electron), both particles will disappear and you'll end up with two photons of the same frequency going in opposite directions (due to conservation of momentum, and here assuming the collision occurs in a frame of reference in which the center of mass of the two particles before collision was at rest) whose total energy is that of the mass of two electrons times c^2. Basically, matter (particles that have mass when at rest) can be converted into photons and vice versa under certain circumstances. In one respect, it's just a change of one type of particle to another; in another, it is the interchange of matter and energy since photons comprise radiant energy--they are massless (that is, they have no rest mass, so the energy they carry is purely due to momentum, which is indicated by their frequency) and simply transport the energy equivalent of the rest mass as momentum. So yes, under certain circumstances, matter can be caused to do work on other matter--more precisely, it can be converted into work, since it disappears in the process.

Look at it this way: Let's say you have ice in water. Over a short time, you can treat them as different (though eventually either the water will freeze or the ice will melt). Ice can only move other ice if it is set in motion and caused to collide with it, but flowing water will cause it to move without having to hit anything with a stick or whatnot. Admittedly, it's a rather dodgy analogy, but it gives the basic idea--matter is often described as a particularly condensed form of energy. If you think of the conversion of matter into energy or vice versa as some sort of phase change, the idea might not seem as counter-intuitive. (Though I still think that thinking of photons as particles essentially having only kinetic energy is more helpful, since photons basically "bridge the gap," if you will, between matter and energy.)

Edited June 28, 2006 by Adrian Hester

[Bold Standard]

Look at it this way: Let's say you have ice in water. Over a short time, you can treat them as different (though eventually either the water will freeze or the ice will melt). Ice can only move other ice if it is set in motion and caused to collide with it, but flowing water will cause it to move without having to hit anything with a stick or whatnot. Admittedly, it's a rather dodgy analogy, but it gives the basic idea--matter is often described as a particularly condensed form of energy. If you think of the conversion of matter into energy or vice versa as some sort of phase change, the idea might not seem as counter-intuitive. (Though I still think that thinking of photons as particles essentially having only kinetic energy is more helpful, since photons basically "bridge the gap," if you will, between matter and energy.)

That's a really interesting analogy. I'll have to think about that (sorry I didn't notice your response sooner!).

I guess I've just confused myself, because I usually see "energy" represented as if it were a potentiality for action or a process, and "matter" represented as if it were a substance or entity, or maybe the end result of a process. So I have a certain prejudice to think of matter as a subject, and energy as a predicate. But I guess it isn't really that simple-- or may be totally incorrect. One of these days, I'm going to need to go through Stephen Speicher's recommended reading lists of physics books and just teach myself all this stuff. I definitely have something to consider now, though. Thanks. : )