Heat Transfer in Solids, Liquids, and Gases
The Little Heat Engine: Heat Transfer in Solids, Liquids and Gases
The question now is wherein the mistake consists and how it can be removed.
Max Planck, Philosophy of Physics, 1936.
While it is true that the field of thermodynamics can be complex,1-8 the basic ideas behind the study of heat (or energy) transfer remain simple. Let us begin this study with an ideal solid, S1, in an empty universe. S1 contains atoms arranged in a regular array called a "lattice" (see Figure 1). Bonding electrons may be present. The nuclei of each atom act as weights and the bonding electrons as springs in an oscillator model. Non-bonding electrons may also be present, however in an ideal solid these electrons are not involved in carrying current. By extension, S1 contains no electronic conduction bands. The non-bonding electrons may be involved in Van der Waals (or contact) interactions between atoms. Given these restraint, it is clear that S1 is a non-metal.
Ideal solids do not exist. However, graphite provides a close approximation of such an object. Graphite is a black, carbon-containing, solid material. Each carbon atom within graphite is bonded to 3 neighbors. Graphite is black because it very efficiently absorbs light which is incident upon its surface. In the 1800's, scientists studied objects made from graphite plates. Since the graphite plates were black, these objects became known as "blackbodies". By extension, we will therefore assume that S1, being an ideal solid, is also a perfect blackbody. That is to say, S1 can perfectly absorb any light incident on its surface.
Let us place our ideal solid, S1, in an imaginary box. The walls of this box have the property of not permitting any heat to be transferred from inside the box to the outside world and vice versa. When an imaginary partition has the property of not permitting the transfer of heat, mass, and light, we say that the partition is
The question now is wherein the mistake consists and how it can be removed.
Max Planck, Philosophy of Physics, 1936.
While it is true that the field of thermodynamics can be complex,1-8 the basic ideas behind the study of heat (or energy) transfer remain simple. Let us begin this study with an ideal solid, S1, in an empty universe. S1 contains atoms arranged in a regular array called a "lattice" (see Figure 1). Bonding electrons may be present. The nuclei of each atom act as weights and the bonding electrons as springs in an oscillator model. Non-bonding electrons may also be present, however in an ideal solid these electrons are not involved in carrying current. By extension, S1 contains no electronic conduction bands. The non-bonding electrons may be involved in Van der Waals (or contact) interactions between atoms. Given these restraint, it is clear that S1 is a non-metal.
Ideal solids do not exist. However, graphite provides a close approximation of such an object. Graphite is a black, carbon-containing, solid material. Each carbon atom within graphite is bonded to 3 neighbors. Graphite is black because it very efficiently absorbs light which is incident upon its surface. In the 1800's, scientists studied objects made from graphite plates. Since the graphite plates were black, these objects became known as "blackbodies". By extension, we will therefore assume that S1, being an ideal solid, is also a perfect blackbody. That is to say, S1 can perfectly absorb any light incident on its surface.
Let us place our ideal solid, S1, in an imaginary box. The walls of this box have the property of not permitting any heat to be transferred from inside the box to the outside world and vice versa. When an imaginary partition has the property of not permitting the transfer of heat, mass, and light, we say that the partition is