# Development of Thermodynamics

Urban and Civil

Nov 15, 2013 (4 years and 5 months ago)

97 views

Jieyu Tang

PHYS 1010

Development of Thermodynamics

Heat

Heat is the expression of the science of energy conversion.
Heat is an energy that transfers
from one
object to another. An object may
absorb certain energy or release
s certain energy in the form of

heat.
Heat is
related

to power. D
ifferent object
s,

will transfer heat to each other when they have different
temperatures.

Heat usually flows from the higher temperature object to the lower temperature object
spontaneously
. These two different temperature objects

will stop to

exchange heat when they have the
same temperature
; this is called
thermal equilibrium
.

Cold

In thermodynamics, an object will have high temperature
s
, low tempera
ture
s
, and average
temperature
s
. When an object has high temperature it is
referred

to as

hea
t; similarly, an object

that
has low temperature is cold. As usual, the cold temperature refers to the average temperature, so we
can know that
an
object is cold or not. T
he
oretically the coldest

temperature is absolute

zero, but we
still can have this ext
remely cold temperature.

The average temperature is dependent on what type
object it is.

William Thompson

William Thompson is the first person who started the Kelvin scale. Lord
Kelvin
is the name from William Thompson. He was born in Ireland in
1824, and

he was a mathematical physicist and engineer. He has great
effect o thermodynamics, and his study subject is heat. At the
beginning, he was educated by his father. Later, he went to

Glasgow
University at his 10 after his father moved to that Scottish city
. At 1847,
he defined the absolute temperature scale, Kelvin scale. 1856, he was
the first to introduce the kinetic energy. He introduced Bell’s telephone
into Britain and helped to plan the first transatlantic cable. Also, Kelvin
made an estimate of the a
ge of the Earth.
1

Thermodynamics

Thermodynamics
is a physical theory about heat. It describes why an object has heat, what
heat is
, and
how this relative to energy and work etc.

In physics theory,

an Object consists of molecules and

1

The source comes from
textbook, Conceptual physics.

Jieyu Tang

PHYS 1010

molecules consist of
atoms
.
So, in other words, an object is made up of numerous

molecules
, and these

of molecules are moving randomly. The spee
d of these moving molecules relate

to their temperature

and therefore the temperature of the object
. when these molecules are movin
g fast, the objec
t’s
temperature will increase
. In contrast, if they
are moving slow, the temperature decreases.

Therefore
,
the speed of the moving
molecu
les relate to their

own temperature.

Also, heat
and cold have a

strong relationship with temperature,
and temperature is the
way to
describe
heat or cold. In physics

theory, there are three scales to describe temperature.
They

are
Fahrenheit,
Celsius, and Kelvin scale. Kelvin scale
is
usually use
d

in
scientific
theory instead of society, and the
absolute z
ero is d
escribed by Kelvin scale. In

daily life, we use thermometer
s

as a tool
to measure
temperature
. There are different types of t
hermomete
rs and they measure in
Celsius and Fahrenheit.

Furthermore, thermodynamics has lots of principle. For example, th
ermodynamics laws, heat transfer,
and some major thermodynamics scientists who discover the thermodynamics
theory.

Thermometer

A t
hermometer is a tool that measure
s

the
temperature

of an
object
. Usually, thermometer is
using the
liquid
’s (mercury,
alcohol, or kerosene) expansion and contraction principle to
measure object’s temperature. The thermometer includes
two elements: the temperature sensor

and

physical change
value.
Also, we have different kinds of thermometer
s

such as
body thermometer
, cook
ing thermometer,

and
outdoor/indoor thermometer.

Method of

thermometer

usage
:

Before using thermometer, we should look at its physical
changing value
s, and note

its minimum value.

the temperature sensor of
a
thermometer should
come
in
full

contact with the

object.

the
temperature sensor should stay in full contact with the object until the temperature on the
reader has stabilized. (Note: Some thermometers have a warning mechanism and the device will beep
when the most acc
urate temperature is read.).

Laws of Thermodynamics

Thermodynamic has two main
laws
: the primary thermometers and
secondary thermometers
.

Jieyu Tang

PHYS 1010

The first law of thermodynamics mandates conservation of energy
and states in particular that the flow of heat is a
form of energy
transfer.
2
According to the first law, energy can’t
be
create
d

or
just
disappear, it just change
s from one form

to another form or transfer
s

from one place to another
. As a result, energy can
’t be lost or

gained;

the total amount of energy is always the same.
Also,
if the heat
transfers from outside to a system, the heat is equal to the change of
internal energy and work.

The first law was discover
ed

by Rudolf Clausius in 1850.
He is a
German
physicist and mathem
atician
.

He is one of the
pioneers of the
sciences

of thermodynamics.

He said, “There is a state function E,
called ‘energy’,
who’s

differential equals the work exchanged with surroundings during an adiabatic
process.”
3

F
or example,

hot water mix
ed with

c
old wate
r,

the
temperature of the mixture
becomes neither hot nor
cold. These two different temperature
of
water transfer their temperature to each other, so their
temperature changes. However, according to the first law of thermodynamics, the energy
is ne
ither
create nor

destroy, so the total e
nergy is the same, the energy is exchange. This

is

called

heat transfer
.

The second law of thermodynamics states that the entropy of an isolated macroscopic system never
decreases, or, equivalently, that perpetual m
otion machines are impossible.

4
According to the second
law, there is no way that
spontaneous

process will happen

backward
s

in the natural world. For example,
heat can be transferred from the high temperature object to the low temperature object, but
it ca
n’t be
transferred

backward
s
. Different kinds of liquids will always
mix together, but

different kinds of liquids
can’t be separated by themselves. Work can
completely
change into heat
, but heat can’t turn into work.

Discovery of absolute zero

In
physics, the

principle

of

absolute zero means
that
the
re is no internal energy in the

lowest
temperature.
Although absolute zero can’t
be
measured in Fahrenheit or Celsius, But it is possible

to
measure it
in
the
Kelvin scale as
-
273.15
°C (
equal to
-
459.67°F)
.

I
n reality, heat
is
generated

through

the movement of
molecules
. In
absolute zero, move
me
nt has

stopped completely.

Robert Boyle is the one who discuss the absolute zero as the minimum temperature.

2

The source comes from Wikipedia

3

The source comes from Wikipedia

4

The source comes from Wikipedia

Jieyu Tang

PHYS 1010

Refrigeration

In our daily life, a cooler use
s to freeze food and drinks is refrigerator. Also, it’s refrigeration.
Refrigeration transfer heat from one object to another.

In the past, the refrigeration used to prevent the
food spoil by using ice.

With the invention of synthetic refrigerants based m
ostly on a
chlorofluorocarbon

(CFC) chemical, safer
refrigerators were possible for home and consumer use.

Freon

is a

of the

Dupont
Corporation
and refers to these CFC, and later

hydrochlorofluorocarbon

(HCFC) and
hydrofluorocarbon
(HFC)
, refrigerants developed in the late 1920s. These refrigerants were con
sidered at the time to be
less harmful than the commonly used refrigerants of the time, including

methyl
formate
,
ammonia
,

methyl chloride
, and

sulfur dioxide
. The intent was to provide refrigeration
equipment for home use without danger: these CFC
refrigerants answered that need. However, in the
1970s the compounds were found to be reacting with

atmospheric ozone
, an important protection
against solar

, and their use as a refrigerant worldwide was curtailed in the

Montreal
Protocol

of 1987.
5

Refrigerati
on is widely use. At home, we have freeze to store foods and drinks, so we can prevent the
foods go bad. Also, we have air condition to cooler the house or keep the house warm. Similar, it
is used
on foodstuffs, trains, airplanes and so on.

Boyle’s Law

Wh
en t
he temperature and the mass are stable, the

volume

of gas

is inversely proportion
ate

to its pressure.

For example, i
n the
illustration on the right
, the mass and
the temperature wi
ll be the same. When
volume increase
s
,
the pressure
will decrease.

C
harle
s

Law

Charles' law

(also known as the

law of volumes) is an
experimental

gas law

which describes
how

gases

tend to expand when heated. It was first

French
natural philosopher

Joseph Louis
Gay
-
Lussac

in 1802, although he credited the

5

The source comes from Wikipedia

Jieyu Tang

PHYS 1010

discovery to unpublished work from the 1780s by

Jacques Charles
. The law was independently
discovered by
British

natural philosopher

John Dalton

by

1801, although Dalton's description was less
thorough than

Gay
-
Lussac
's. The basic principles had already been described a century earlier
by

Guillaume Amontons
6
.

According to the Charles’ law,
the volume of
certain mass gas
es

with consistent
pressures

is directly
proportional to the temperature.

Caloric Theory

Caloric Theory was generated by Antoine Lavoisier in the 1770s, which stated that heat, as a fluid,
moves from hot substances to cold substances while the quantity of substances remains constant
throughout the entire universe. This theor
y was first applied to measure the heat changes during
chemical reaction.

Carnot engine

Carnot engine is a hypothetical reversible engine. The Carnot engine uses a
thermoelectric

cycle. The
Carnot engine will go through all the process and it will go back

to the initial
starting point at the end;
consequently, the Carnot engine will go though the whole
system again and again by using the thermoelectric cycle. Also
the Carnot engine will transfer from a warm area to a cool area.
In this process, certain
energy will change into the mechanical
w
ork. The most interesting part of this system is that the
process will be able to be reversed, so the Carnot engine can be
a heat pump or refrigerator.

The basic model of Carnot engine was discovered by
Nicolas
Léona
rd Sadi Carnot in 1824
.
Nicolas Léonard Sadi Carnot

was a
French physicist and military engineer.
The Carnot engine
model was graphically expanded upon by Benoît Paul Émile
Clapeyron in 1834 and mathematically elaborated upon by
Rudolf Clausius in the 1850
s and 60s from which the concept of
entropy emerged.
7

6

The source comes from Wikipedia

7

The source comes from Wikipedia

Jieyu Tang

PHYS 1010

Heat Transfer

Heat transfer means that the heat transfer from the higher temperature object to the lower
temperature object, or
the heat transfer
s

from the higher temperature element to the lower
temperature element in the same object. Heat transfer is a common natural
phenomenon
. If there is a
difference in temperature, heat transfer will occur until they have the same temperature. Consequently,
he
at transfer only happens in
the difference in temperature
.

Boltzma
n
n

Boltzmann is an Austrian physicist. He is one of the founders of st
atistical physics. He is the man

who
promotes the JC Boltzma
nn kinetic theory of Maxwell a

potential energy.
He was bor
n in Vienna and
studied physics at the University of Vienna, received PhD in physics in 1866. Throughout his academic
career, Boltzmann taught mathematics and physics at
various institutions such as the University of Graz,
the

University of Vienna, and th
e University of Munich,

and later became the president of the University
of Graz.

His kinetic theory includes the Maxwell
-
Boltzmann distribution, Maxwell
-
Boltzmann statistics
and the Boltzmann distribution.
Maxwell Boltzmann distribution
is a special sce
nario of Boltzmann
distribution;

it is a function of the temperature, mass and speed of the particle. The purpose of the
distribution is to describe the probability of a particle’s speed being near a given value. Maxwell
-
Boltzmann statistics describes th
e distribution of particles over various energy states in thermal
equilibrium.
In addition, Boltzmann equation is one of the famous equations
in
which explains the
dynamics of an ideal gas.

Cryogenics

Cryogenics is a study about extremely low temperatur
e. The people who study cryogenics will use the
Kelvin scale to measure the temperature in order to study the behavior of materials at this low
temperature instead of using
the
Celsius or Fahrenheit

scales
.

The field of cryogenics advanced during World War

II when scientists found that metals frozen to low
temperatures showed more resistance to wear. Based on this theory of

cryogenic hardening
, the
commercial
cryogenic processing

industry was founded in 1966 by Ed Busch. With a background in
the

heat treating

industry, Busch fou
nded a company in
Detroit

called

CryoTech

in 196
6.
8

Also cryogenics is widely used in society
for such as the fuel industry and
other applications.

Antoine Lavoisier

He
is a French nobleman, and he found oxy
gen and hydrogen. He is famous in chemistry

and biology.
Lavoisier was born in Paris, and studi
ed topics such as chemistry, botany, astronomy and mathematics.

8

The source comes from Wikipedia

Jieyu Tang

PHYS 1010

He became a member of the French Academy of Science at age of 25.

Some of his discoveries include
inconsistency

of phlogiston theory w
hile conducting experiments on respiration,
formation of

water by
combining oxygen with hydrogen,
and

air i
s the source of acidity which is responsible for combustion.

In
addition, he has also conducted many quantitative chemical experiments. For example, Lavoisier

demonstrated that

the total mass of an objec
t remains the same throughout the different state in a
chemical reaction.

Lavoisier’s Elementary Treatise on Chemistry, 1789 is the first modern chemistry
textbook in which he famously described the law of conservation of mass.

Besides chemistry, Lavoisi
er
also made contributions to biology, law and politics.

Jieyu Tang

PHYS 1010

Works Cited

Boyle's law.

29 04 2011 <http://en.wikipedia.org/wiki/Boyle%27s_law>.

Carnot heat engine.

29 04 2011 <http://en.wikipedia.org/wiki/Carnot_heat_engine>.

Charles's law.

29 04 2011 <http://en.wikipedia.org/wiki/Charles%27_law>.

Cryogenics.

29 04 2011 <http://en.wikipedia.org/wiki/Cryogenics>.

29 04 2011 <http://www.google.com/imghp?hl=en&tab=wi>.

Guggenheim, E.S.
First laws of thermodynamics.

1985. 29 April

2011
<http://en.wikipedia.org/wiki/Laws_of_thermodynamics#cite_note
-
Guggenheim_1985
-
0>.

Hewitt, Paul G.
Conceptual Physics (11th Edition).

Kittel, C. Kroemer, H.
Laws of thermodynamics.

1980. 29 04 2011
<http://en.wikipedia.org/wiki/
Laws_of_thermodynamics#cite_note
-
Guggenheim_1985
-
0>.

Refigeration.

29 04 2011 <http://en.wikipedia.org/wiki/Refrigeration>.

Wikipedia.

29 04 2011 <http://en.wikipedia.org/wiki/First_law_of_thermodynamics>.