Pioneers of Heat Theory
 People have not always known about the nature of
heat.
 Is it a fluid of some sort?
 Some type of energy?
 Do things just get hot because you add heat?
Different substances have different
heat capacities. I regard heat as a
fluid called caloric. When an object
heats up, it gains caloric, and when
it cools, it loses caloric.
Logical conclusion in my opinion!
Caloric has no mass or volume…
While drilling out cannons in Munich,
I noticed that the cannon became hot
as long as the friction of boring continued.
I concluded that
heat was not a substance,
but a form of vibratory motion.
Hence my views are in
contradiction to the caloric theory.
And, I might add,
much more logical...
I agree with Count Rumford!
Heat is a form of motion.
Heat is not a substance.
I was able to prove this
experimentally
by rubbing two ice cubes
together at below zero,
and observing
that they melted…
contradicting the
caloric theory.
Cool, eh?!
I was able to quantify Heat!!
I did this by measuring changes
in temperature produced by the
friction of a paddlewheel
attached to a falling weight.
This work led to the idea that
1 calorie = 4.18 Joules.
Science teachers often
tell you to memorize this,
and they round it off to
4.2 J…
I’m Maxwell!
And
I’m
Boltzmann !
Alright!
Go ahead –
you tell them...
I… (ahem)…
WE formulated
the Maxwell-Boltzmann
Kinetic Molecular
Theory…known as the KMT…
Pretty impressive, eh?
This theory
states that heat
is a form of
energy, and…
Temperature is a
measure
of the kinetic energy
of the individual
particles - atoms,
molecules, etc.
Heat Versus Temperature
 Temperature is the amount of average kinetic energy
within an object.
 Heat is a form of energy.
 The amount of heat an object holds depends on
several factors: temperature change (∆T), mass,
and the specific heat capacity (C) of the
object.
 Q (quantity of heat in joules) = m C ∆T