But in fact it does, at least if we can ignore any adiabatic effects (insulation). The rates at which a monolithic object will convect, conduct, or radiate away heat are dependent upon its temperature, which is in turn dependent upon the amount of thermal energy it contains. The rates at which it will transfer through are dependent upon the propoerties of that object, but as long as there are no barriers to transmission the observed temperature for an object of known properties will correlate to the heat-energy content of it.
It is a conceptual misnomer, by the way, to think of heat as literally seperate from the medium it transfers through. Although for the purposes of thermodynamics we assign Q as a quantity of “substance” to a theoretical system within a box as if it is just raisins or ball bearings, in reality Q a measure of the amount of randomized kinetic energy of the particles within the medium (for a material substance, not withstanding heat contained within black holes and such). Energy in the form of heat doesn’t exist outside of a particulate medium in any normal context. In other words, in material terms heat is a extrinsic property of an aggregate of particles in individual random, stochastically determinant motion, not some extra condiment that you add to or take away from the system in question. It is, however, mathematically convenient for the purposes of classical thermodynamics to treat heat as its own unique intrinsic quality that continually gets shifted around from one box to another like an unloved foster child.
>But the gas can also lose thermal energy by doing work, e.g. by pushing a piston. In this case there’s no energy transferred as heat
Hmm. This sounds on point, sounds like a good basis for the distinction. But couldn’t you say that any form of energy can be lost to conversion to another form? That is, there’s chemical potential energy in a battery, and electrical energy comes out of it, to spin a motor that converts it into rotational mechanical energy. All of these kinds of energy are happily named the same way whether they are changing or not. Heat and internal energy are special in the sense that their randomness and availability to do work are wound up in the whole issue of entropy; perhaps there is something about this that makes the distinction critical? I mean, you can tap all the electrical energy that comes out of an electrical device, but not so with thermal energy.
There is something about thermal energy and entropy and heat and the second law of thermodynamics and information theory and quantum states and causality that is still out of my grasp, though it’s not for want of trying. I’ve read Carnot and Kelvin and Clausius and Joule and Clapeyron, not to mention websites at several universities and three different books entitled “Thermal Physics”, but there’s still something I’m not getting…
Please help me wrap my brain around the concept of “heat is the transfer of energy from one thing to another thing” and “it’s incorrect to say that an object possesses heat.” On a sciency level, I can grasp it, but it sure throws a monkey wrench into common speech. For example:
*Don’t touch that, baby, it’s hot.
It’s hot outside today.
I can’t put the skillet away yet. It’s still hot.
Then the figurative, as in, is Muffy Jiggler still hot?
And, Paris Hilton says you’re hot.*
In theory, most of those are incorrect. Will today’s children speak of heat in a new way, or will the reality of heat remain a secret to most people?
The only thing we’re debating is the word “heat”. Heat is a transfer of thermal energy, not the amount of stored thermal energy. So it’s correct to say "Apply heat to the joint " or “use the electric heater to heat the room.” But it’s incorrect to say that molten rock contains a lot of heat.
The word “hot” is understood to mean “high temperature.” There’s nothing wrong with that, temperature is a measurable quantity of an object.
However, it is quite possible for the temperature of an object to measure very high, but to not be perceived as “hot” in the colloqual sense. For instance, the thermal protection tiles on the underside of the Space Shuttle can get to a temperature of several hundred degrees but you can hold them in your hand because the heat content and rate of heat transfer is very, very low.
In physics heat is defined as the energy transfered from a region of one temperature, to a region of lower temperature, by either conduction, convection or radiation.
Everyday terms like hot and cold will remain, because they’re useful in everday contexts.
But even though most people’s everyday understanding of hot and cold relates it to temperature, they’re actually more related to the physics concept of heat. In your parked-in-the-sun-all-day car the belt buckle is much hotter than the belt itself, even though they’re the same temperature, because the heat transfered from it to you is higher. An ice cube is colder than the plastic ice cube tray it sits in, because the heat transfered from you is higher.
>In physics heat is defined as the energy transfered
>Everyday terms like hot and cold will remain…
Well, we’re about to lose the clarity we were just building towards. “Heat” is not a technical term, it’s part of common English. And as such it has meanings that aren’t attached to the transfer of thermal or internal energy. Here are some online dictionary definitions:
>A form of energy associated with the motion of atoms or molecules and capable of being transmitted through solid and fluid media by conduction, through fluid media by convection, and through empty space by radiation.
>the state of a body perceived as having or generating a relatively high degree of warmth
