Transcript A Theory of Everything

A Theory of
Everything
Atomic Structure
1. Be able to describe the history of the
discoveries that lead to our current
understanding of the atom. That is the topic
of this chapter.
2. What is an atom? From where did the
concept of an atom arise?
Matter is not
infinitely
divisible
Leucippus or
Leukippos (first
half of 5th century BC)
Matter
Atoma
is not
(sg.
infinitely
atomon)
"indivisible
divisible
units"
The elements
Matter
is
of fire, air,
infinitely
earth,
and
water
are not
divisible
made of atoms,
but are
continuous.
Democritus
Aristotle
(ca. 460 BC - 370 BC).
Student of Leucippus
(384 BC – 322 BC)
2. What is an element?
Alchemy
In the history of science, alchemy refers to
both an early form of the investigation of
nature and an early philosophical and
spiritual discipline, both combining
elements of chemistry, metallurgy, physics,
medicine, astrology, semiotics, mysticism,
spiritualism, and art all as parts of one
greater force.
The best-known goals of the alchemists
were the transmutation of common metals
into gold or silver; the creation of a
"panacea or the elixir of life," a remedy that
supposedly would cure all diseases and
prolong life indefinitely; and the discovery
of a universal solvent
http://en.wikipedia.org/wiki/Alchemy
Title: The alchemist
Painter: Sir William Fettes Douglas
(1822 - 1891)
3. What was Dalton's contribution to our
understanding of the atom? What is an element?
What is a molecule? What is a compound?
John Dalton
(1766 – 1844)
In 1803, the Englishman John
Dalton, an instructor and natural
philosopher, used the concept of
atoms to explain why elements
always reacted in a ratio of small
whole numbers—the law of multiple
proportions—and why certain gases
dissolved better in water than
others. He proposed that each
element consists of atoms of a
single, unique type, and that these
atoms could join to each other, to
form chemical compounds.
http://en.wikipedia.org/wiki/Atom
Matter
•Occupies space
•Has mass
Pure
Element
•One type of
atom
•Cannot be
decomposed
•Occurs singly
as atoms
•Occurs joined
as molecules
•Gold, O2
Impure
Compound
•More than
one type of
atom/element
•Can be
decomposed
into elements
•Occurs as
molecules
•H2O
Solution
Heterogeneous
Mixture
•Milk
•Sugar in coffee •Granite rock
•Pop
Alloy
•Bronze=Cu+Sn
•Brass=Cu+Zn
3. What is the "billiard ball” model of the atom?
4. What is a cathode ray tube?
1. Control Grid
5. Cathode
2. Anode
6. Cathode ray beam
3. Deflecting coils
7. Focusing coil
4. Heater
8. Fluorescent screen
4. What did J.J. Thompson find out about the
atom's structure?
First experiment
In his first experiment, he investigated
whether or not the negative charge could be
separated from the cathode rays by means of
magnetism… Thomson concluded that the
negative charge was inseparable from the
rays.
Sir Joseph John “J.J.” Thomson
(1856 – 1940)
4. What did J.J. Thompson find out about the
atom's structure?
Second experiment
In his second experiment, he investigated
whether or not the rays could be deflected by
an electric field (something that is
characteristic of charged particles). Previous
experimenters had failed to observe this, but
Thomson believed their experiments were
flawed because they contained trace amounts
of gas. Thomson constructed a cathode ray
tube with a practically perfect vacuum, and
coated one end with phosphorescent paint.
Thomson found that the rays did indeed bend
under the influence of an electric field, in a
Sir Joseph John “J.J.” Thomson direction indicating a negative charge.
(1856 – 1940)
4. What did J.J. Thompson find out about the
atom's structure?
Third experiment
In his third experiment, Thomson measured
the charge-to-mass ratio of the cathode rays
by measuring how much they were deflected
by a magnetic field and how much energy
they carried. He found that the charge to mass
ratio was over a thousand times higher than
that of a hydrogen ion (H+), suggesting either
that the particles were very light or very highly
charged.
Sir Joseph John “J.J.” Thomson
(1856 – 1940)
4. What did J.J. Thompson find out about the
atom's structure?
Third experiment
Thomson's conclusions were bold: cathode
rays were indeed made of particles which he
called "corpuscles", and these corpuscles
came from within the atoms of the electrodes
themselves, meaning that atoms are in fact
divisible. The "corpuscles" discovered by
Thomson are identified with the electrons
which had been proposed by G. Johnstone
Stoney.
Sir Joseph John “J.J.” Thomson
(1856 – 1940)
4. What did J.J. Thompson find out about the
atom's structure?
Thomson imagined the atom as being made
up of these corpuscles swarming in a sea of
positive charge; this was his plum pudding
model… Thomson's discovery was made
known in 1897, and caused a sensation in
scientific circles.
http://en.wikipedia.org/wiki/J._J._Thomson
Sir Joseph John “J.J.” Thomson
(1856 – 1940)
Physics
1906
4. What is the "plum pudding" model of the
atom?
5. What was the Geiger-Marsden experiment
(Gold foil experiment/ Rutherford experiment)
The Geiger-Marsden experiment (also called the Gold foil experiment or the
Rutherford experiment) was an experiment done by Hans Geiger and
Ernest Marsden in 1909, under the direction of Ernest Rutherford
He+2
He+2
5. What was the contribution of Rutherford?
What is the "planetary" model of the atom?
The
“It was
plum-pudding
almost as
model
incredible
is incorrect.
as if
youThe
fired
positive
a fifteencharge(s)
inch shell
must
at abe
concentrated
piece of tissue
in
paper
theand
center.
it came
back and hit you.”
1911
Ernest Rutherford
(1871 – 1937)
Chemistry
1908
6. Consider the planetary model of an atom.
What parts of an atom were known at this
time? What is the charge on each? What is
the mass of each? What is atomic number?
Mass number? Isotopes?
Particle
Mass
Relative
Mass
Charge
Relative
Charge
Electron
0.10953 x 10-31 kg
0
-1.60219 x 10-19 C
-1
Proton
Neutron
1.674 x
10-27
kg
1
1.677 x 10-27 kg
1
1.60219 x 10-19 C
0
1
0
7. What was the contribution of Bohr? What is
the Bohr model? Be able to show how
electrons fill in this model. Postulated (1913):
How are the
electrons
organized?
Niels Bohr
(1885 - 1962)
• Electrons orbit in
distinct paths
analogous to planets.
• Only certain radii
(shells) occur.
• Electrons absorb
energy to move to outer
shells and release
energy when they move
to inner shells
• Electrons do not
release energy in a
shell.
Physics
1922
8. Who was de Broglie? What is the
relationship between waves and particles?
How did de Broglie's work help to explain why
electrons are only found at fixed distances?
Why
This
Electrons
are
is the
only
wave-particle
travel
certain
as
electron
duality
wavesof
(with
paths
ALL
noallowed?
mass)
matter.and
as(1924)
particles
(with mass.)
Louis de Broglie
(1892 – 1987)
l is wavelength
mv is momentum
Physics
1929
8. What was the contribution of Schrodinger?
Y
Equation for
Wave Theory
(1926)
Erwin Schrodinger
(1887 – 1961)
Physics
1933
8. What was the contribution of Born?
Y
Is a
probability
amplitude
(1926)
The Schrödinger equation defines
the behaviour of y , but does not
interpret what y is. Schrödinger
tried unsuccessfully to interpret it
as a charge density. In 1926 Max
Born, just a few days after
Schrödinger's fourth and final
paper was published, successfully
interpreted as a probability
amplitude, although Schrödinger
was never reconciled to this
statistical or probabilistic
approach.
http://en.wikipedia.org/wiki/Schr%C3%B6dinger%27s_equation
Max Born
(1882 – 1970)
Physics
1954
8. What is the electron cloud model? What is
an orbital? What is the orbital model? Be
able to describe this model.
Orbitals are probabilities of finding an electron at any given time.
1926
This doesn’t make sense! How can an electron
be a particle and a wave at the same time?
Packer, J. I. 1961 (reprinted 1991). Evangelism and
the Sovereignty of God. InterVarsity Press,
Downer’s Grove, IL.
Our aim in the present study is to think out the nature
of the Christian’s evangelistic task in the light of this
agreed presupposition that God is sovereign in
salvation. Now, we need to recognize right at the
outset that this is no easy assignment. All
theological topics contain pitfalls for the unwary, for
God’s truth is never quite what man would have
expected; and our present subject is more
treacherous than most. This is because in thinking it
through we have to deal with an antinomy in the
biblical revelation, and in such circumstances our
finite, fallen minds are more than ordinarily apt to go
astray.
What is an antinomy? The Shorter Oxford Dictionary
defines it as ‘a contradiction between conclusions
which seem equally logical, reasonable or
necessary.’ For our purposes, however, this
definition is not quite accurate; the opening words
should read ‘an appearance of contradiction.’ For
the whole point of an antinomy – in theology, at any
rate – is that it is not a real contradiction, though it
looks like one. It is an apparent incompatibility
between two apparent truths. An antinomy exists
when a pair of principles stand side by side,
seemingly irreconcilable, yet both undeniable.
There are cogent reasons for believing each of
them; each rests of clear and solid evidence; but it is
a mystery to you how they can be squared with each
You see that each must be true on its own, but you
do not see how they can both be true together. Let
me give an explain. Modern physics faces an
antinomy, in this sense, in its study of light. There is
cogent evidence to show that light consists of
waves, and equally cogent evidence to show that it
consists of particles. It is not apparent how light can
be both waves and particles, but the evidence is
there, and so neither view can be ruled out in favour
of the other. Neither, however, can be reduced to
the other or explained in terms of the other; the two
seemingly incompatible positions must be held
together, and both must be treated as true. Such a
necessity scandalized our tidy minds, no doubt, but
there is no help for it if we are to be loyal to the
facts.
It appears, therefore, that an antinomy is not the same
thing as a paradox. A paradox is a figure of speech,
a play on words. It is a form of statement that
seems to unite two opposite ideas, or to deny
something by the very terms in which it is asserted…
A Theory of
Everything
Nuclear Physics and
Radioactivity
Chemistry involves the electrons in atoms.
Radioactivity involves the nucleus of atoms.
1. We know that the atom is made of electrons that
are found in orbitals. We also know that the nucleus
is made of protons and neutrons. Since the protons
are positive, they should repel one another. Why
does a nucleus not disintegrate? What are four
fundamental interactions between particles in
nature? Describe their effect, strength, and range.
Physicists hold that there are four fundamental
interactions between particles in nature:
– Gravity
– The Strong Nuclear Force
– The Weak Nuclear Force
– Electromagnetism
1. We know that the atom is made of electrons
that are found in orbitals. We also know that
the nucleus is made of protons and neutrons.
Since the protons are positive, they should
repel one another.
Interaction
Acts…
Electromagnetic
between charged
particles
Relative Range
Strength
(m)
1036
Infinite
1. We know that the atom is made of electrons
that are found in orbitals. We also know that
the nucleus is made of protons and neutrons.
Since the protons are positive, they should
repel one another. Why does a nucleus not
disintegrate?
Interaction
Strong Nuclear
Acts…
Relative Range
Strength
(m)
attractively between
1038
10-15
p-p, p-n, and n-n
Interaction
Acts…
Gravitation
primarily at large
distances
Relative Range
Strength
(m)
Strong Nuclear attractively between
1038
10-15
p-p, p-n, and n-n
Electromagnetic between charged
1036
Infinite
particles
Weak
beta decay
1025
10-15
1
Infinite
2. Not all nuclei are stable. Why? Make a list
of reasons.
There is an optimum
number of neutrons
for each element.
Atoms with more or
fewer than this
number tend to be
unstable.
3. How did we come to our current
understanding of radioactivity? What was the
contribution of Henri Becquerel?
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inthe
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onsun
the for
negative.
a day. …
Henri Becquerel
(1852 – 1908)
Physics
1903
3. What was the contribution of the Curies?
We
We
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then
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studied
also
also
isolated
isolated
uranium.
made
10mg
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ait
fromcharacteristic
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it was taken.
of
chemical bonds. It is
associated with the
nucleus.
Pierre Curie
(1859 - 1906)
Marie Curie
(1867 - 1934)
Physics
1903
3. What was the contribution of the Curies?
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Marie Curie
(1867 - 1934)
Physics
1903
Chemistry
1911
4. What are the types of radioactive emissions?
Radioactivity was first discovered in 1896 by
Henri Becquerel.
Different types of decay can occur, but
Rutherford was the first to realize that they all
occur with the same mathematical
approximately exponential formula.
As for types of radioactive radiation, it was
found that an electric or magnetic field could
split such emissions into three types of
beams. Rutherford coined the terms alpha
and beta to describe the two distinct types of
radiation emitted by thorium and uranium.
Ernest Rutherford
(1871 – 1937)
http://en.wikipedia.org/wiki/Radioactive_decay
http://en.wikipedia.org/wiki/Ernest_Rutherford
Chemistry
1908
4. What are the types of radioactive emissions?
[The term transmutation] was first consciously
applied to modern physics by Frederick
Soddy when he, along with Ernest
Rutherford, discovered that radioactive
thorium was converting itself into radium in
1901. At the moment of realization, Soddy
later recalled, he shouted out: “Rutherford,
this is transmutation!” Rutherford snapped
back, “For xxx's sake, Soddy, don't call it
transmutation. They'll have our heads off as
alchemists.”
http://en.wikipedia.org/wiki/Nuclear_transmutation
Ernest Rutherford
(1871 – 1937)
Chemistry
1908
5. What is alpha decay?
226 Ra
88
 22286Rn + 42He
The Strong
Nuclear Force
6. What is beta decay?
1
1 p + 0en

0
1
137 Cs
55
 13756Ba + 0eThe Weak
Nuclear Force
In β− decay, the weak
interaction converts a
neutron (n0) into a
proton (p+) while
emitting an electron
(e− ) and an
antineutrino (νe)
7. What is gamma decay?
Electromagnetic Radiation
Photons
7. What is gamma decay?
Electromagnetic Radiation
Photons
4. What are the types of radioactive emissions?
Alpha particles may be
completely stopped by
a sheet of paper, beta
particles by aluminum
shielding. Gamma rays
can only be reduced by
much more substantial
barriers, such as a very
thick layer of lead.
Mode of decay
Participating particles
Daughter nucleus
Alpha decay
An alpha particle (A=4, Z=2) emitted from nucleus
(A–4, Z–2)
Proton emission
A proton ejected from nucleus
(A–1, Z–1)
Neutron emission
A neutron ejected from nucleus
(A–1, Z)
Double proton emission
Two protons ejected from nucleus simultaneously
(A–2, Z–2)
Spontaneous fission
Nucleus disintegrates into two or more smaller nuclei and other particles
-
Cluster decay
Nucleus emits a specific type of smaller nucleus (A1, Z1) smaller than, or larger than, an
alpha particle
(A–A1, Z–Z1) +
(A1,Z1)
Beta-Negative decay
A nucleus emits an electron and an antineutrino
(A, Z+1)
Positron emission, also Beta-Positive
decay
A nucleus emits a positron and a neutrino
(A, Z–1)
Electron capture
A nucleus captures an orbiting electron and emits a neutrino - The daughter nucleus is
left in an excited and unstable state
(A, Z–1)
Double beta decay
A nucleus emits two electrons and two antineutrinos
(A, Z+2)
Double electron capture
A nucleus absorbs two orbital electrons and emits two neutrinos - The daughter nucleus
is left in an excited and unstable state
(A, Z–2)
Electron capture with positron emission
A nucleus absorbs one orbital electron, emits one positron and two neutrinos
(A, Z–2)
Double positron emission
A nucleus emits two positrons and two neutrinos
(A, Z–2)
Decays with emission of nucleons:
Different modes of beta decay:
Transitions between states of the same nucleus:
Gamma decay
Excited nucleus releases a high-energy photon (gamma ray)
(A, Z)
Internal conversion
Excited nucleus transfers energy to an orbital electron and it is ejected from the atom
(A, Z)
8. What is a half-life?
8. What is a half-life?
Isotope
26Al
222Rn
14C
235U
40K
238U
87Rb
Half-life
6.345 seconds
3.824 days
5,730 years
70,380,000 years
1,277,000,000 years
4,468,000,000 years
47,500,000,000 years
http://www.kayelaby.npl.co.uk/atomic_and_nuclear_physics/4_6/4_6_1.html
8. What things have been dated using
radioactive materials?
Today's accepted age of
the Earth of 4.55 billion
years was determined by
C.C. Patterson using
Uranium-Lead dating on
fragments of the Canyon
Diablo meteorite and
published in 1956.
8. What is carbon dating? What kinds of things
are dated by this technique?
 147N + 0eHalf-life = 5,730 years
Up to 60,000 years old
Carbon-containing materials
14 C
6
Willard F. Libby
(1918 – 1980)
Chemistry
1960
A Theory of
Everything
Relativity
Are you moving?
1. What is a reference frame?
Reference Frame/ Frame of Reference - A
reference frame is the location from which you
are making your observations.
1. Are the laws of mechanics (motion) the
same for all observers?
The laws of mechanics are the same in all
reference frames moving at constant velocity
with respect to one another.
All motion is relative to some reference frame.
Newton’s first law of motion - An object at rest will
remain at rest unless acted on by a net force and an
object in motion will remain in motion in a straight
line unless acted upon by a net force.
Is this true for both observers? What does each see?
Newton’s first law of motion - An object at rest will
remain at rest unless acted on by a net force and an
object in motion will remain in motion in a straight
line unless acted upon by a net force.
Is this true for both observers? What does each see?
2. What was the concept of the luminiferous
ether?
Sound waves
Mechanical waves
Through what do light waves
travel?
Luminiferous ether
Light waves
2. What was the concept of the luminiferous
ether?
Through what do light
waves travel?
Light waves
1704 - Isaac Newton publishes Opticks, in which he proposes a
particle theory of light. This had trouble explaining refraction, so
he adds a "fudge factor", claiming that an "Aethereal Medium" is
responsible for this effect, and going further to suggest it might
be responsible for other physical effects such as heat.
2. What was the concept of the luminiferous
ether?
Strange characteristics
predicted of the ether:
• Since light travels through
space, the ether would have to
permeate all space.
• Since light travels through
matter, the ether would have
to permeate all matter.
• It does not affect motions in
the sky. It did not affect the
earth’s motion.
• It was stationary.
Light waves
3. Describe the Michelson-Morley experiment
and its significance.
Maxwell noted in the late 1870s that detecting motion relative to
this aether should be easy enough—light traveling along with
the motion of the Earth would have a different speed than light
traveling backward, as they would both be moving against the
unmoving aether. Even if the aether had an overall universal
flow, changes in position during the day/night cycle, or over the
span of seasons, should allow the drift to be detected.
http://en.wikipedia.org/wiki/Luminiferous_aether
Resultant Vector 4 km/hr east
Resultant Vector 2 km/hr west
3. Describe the Michelson-Morley experiment
and its significance.
c = speed of light
v = speed of the ether.
Light going with the ether = c + v
Light going against the ether = c – v
Light going perpendicular to the ether would take longer to
reach its destination.
3. Describe the Michelson-Morley experiment
and its significance.
They changed the direction of their experiment by 90o.
They saw no movement in the pattern. The ether wind did not
show itself.
Light travels at speed c regardless of the motion of the
ether.
There is no ether.
4. Describe Einstein’s theory of special
relativity.
Einstein postulated that:
1. All the laws of physics are the
same for all observers moving at
constant velocity with respect to
one another.
2. The speed of light in a vacuum is
the same for all observers
regardless of the motion of the
source of light or the motion of the
observer.
Special Relativity
Albert Einstein
(1879 – 1955)
Physics
1921
4. How does this affect time for a moving
object?
Moving clocks run slowly.
Time slows as velocity increases.
4. How does this affect time for a moving
object?
Twin paradox
In physics, the twin paradox refers to a thought experiment in
Special Relativity, in which a person who makes a journey into
space in a high-speed rocket will return home to find he or she
has aged less than an identical twin who stayed on Earth.
http://en.wikipedia.org/wiki/Twin_paradox
4. How does this affect length of a moving
object?
Lengths of objects contract in the direction of motion when they
are in motion with respect to an observer. Lengths
perpendicular to the direction of motion are unchanged.
4. How does this affect length of a moving
object?
The ladder paradox or (barn-pole paradox) is a thought experiment in
special relativity. If a ladder travels horizontally it will undergo a length
contraction and will therefore fit into a garage that is shorter than the
ladder's length at rest. On the other hand, from the point of view of an
observer moving with the ladder, it is the garage that is moving and the
garage will be contracted. The garage will therefore need to be larger than
the length at rest of the ladder in order to contain it.
4. How does this affect mass of a moving
object?
The mass of an object increases as its speed increases.
No material object can attain the speed of light
4. How is mass related to energy?
E = mc2
Where
E = energy
m = mass
c = the speed of light in a vacuum
5. Who was P. A. M Dirac? What did he
discover? What is antimatter?
Paul Dirac
(1902 – 1984)
Paul Adrien Maurice Dirac, was a
British theoretical physicist and a
founder of the field of quantum
mechanics. Dirac made fundamental
contributions to the early development
of both quantum mechanics and
quantum electrodynamics. Among other
discoveries, he formulated the so-called
Dirac equation, which describes the
behavior of fermions and which led to
the prediction of the existence of
antimatter.
http://en.wikipedia.org/wiki/Dirac
Physics
1933
5. What is a positron?
[Carl Anderson] is best known
for his discovery of the
positron - the antimatter
counterpart of the electron.
The positron has an electric
charge of +1, a spin of 1/2,
and the same mass as an
electron.
Carl Anderson
(1905 – 1991)
Physics
1936
5. What is an antiproton?
The antiproton is
the antiparticle of
the proton. It was
discovered in
1955 by
University of
California,
Berkeley
physicists Emilio
Segrè and Owen
Chamberlain.
Emilio G. Segre
(1905 – 1989)
Owen Chamberlain
(1920 – 2006)
As shown on his ID
badge from Los
Alamos National Lab
Physics
1959
5. What is a antineutron?
The antineutron is the antiparticle of
the neutron. It was discovered by
Bruce Cork in 1956, a year after the
antiproton was discovered. An
antineutron has the same mass as a
neutron, and no net electric charge.
Bruce Cork
( – 1994)
5. What is pair production?
Pair production refers to the creation of an elementary particle
and its antiparticle, usually from a photon. In nuclear physics,
this occurs when a high-energy photon interacts with an atomic
nucleus, allowing it to produce an electron and a positron
without violating conservation of momentum.
http://en.wikipedia.org/wiki/Pair_production
5. What is pair annihilation?
In physics, the word (annihilation) is used to denote the process
that occurs when a subatomic particle collides with its
respective antiparticle. Since energy and momentum must be
conserved, the particles are not actually made into nothing, but
rather into new particles. During a low-energy annihilation,
photon production is favored, since these particles have no
mass.
http://en.wikipedia.org/wiki/Annihilation
6. What is nuclear fission? What is a chain
reaction?
The Einstein-Szilárd letter was a letter sent to President
Franklin Delano Roosevelt in August 1939 signed by Albert
Einstein but largely written by Leó Szilárd in consultation with
fellow Hungarian physicists Edward Teller and Eugene Wigner.
The letter advised Roosevelt that Nazi Germany might be
conducting research into the possibility of using nuclear fission
to create atomic bombs, and suggested that the United States
should begin researching the possibility itself.
http://en.wikipedia.org/wiki/Einstein-Szil%C3%A1rd_letter
6. What was the Manhattan Project?
The Manhattan Project was the project to
develop the first nuclear weapon (atomic
bomb) during World War II by the United
States, the United Kingdom, and Canada.
Formally designated as the Manhattan
Engineer District (MED), it refers
specifically to the period of the project from
1941–1946 under the control of the U.S.
Army Corps of Engineers, under the
administration of General Leslie R. Groves.
The scientific research was directed by
American physicist J. Robert
Oppenheimer.
Robert Oppenheimer
(1904 - 1967)
6. What is nuclear fission?
Trinity was the first test of technology for
a nuclear weapon. It was conducted by
the United States on July 16, 1945, at a
location 35 miles (56 km) southeast of
Socorro, New Mexico, on what is now
White Sands Missile Range,
headquartered near Alamogordo.
http://en.wikipedia.org/wiki/Trinity_test
http://www.sonicbomb.com/modules.php?name=Content&pa=showpage&pid=43
6. What are the two types of fission weapons
and how do they work?
Hiroshima
Little Boy
Fat Man
Nagasaki
6. What was the “Atoms for Peace” project?
"Atoms for Peace" was the title of a speech delivered by U.S. President Dwight D.
Eisenhower to the UN General Assembly in New York City on December 8, 1953.
“I feel impelled to speak today in a language that in a sense is new—one which I,
who have spent so much of my life in the military profession, would have preferred
never to use. That new language is the language of atomic warfare.”
The United States then launched an "Atoms for Peace" program that supplied
equipment and information to schools, hospitals, and research institutions within the
U.S. and throughout the world.
The speech was possibly a tipping point for international focus on peaceful uses of
atomic energy, even during the early stages of the Cold War. It could be argued that
Eisenhower, with some influence from Albert Einstein, was attempting to convey a
spirit of comfort to a terrified world that the horror of Hiroshima and Nagasaki would
not be experienced again.
http://en.wikipedia.org/wiki/Atoms_for_peace
6. How does a fission reactor generate
electricity?
7. What is nuclear fusion?
7. What is nuclear fusion?
The proton-proton
chain dominates
in stars the size of
the Sun or
smaller.
http://en.wikipedia.org/wiki/Nuclear_fusion
7. What is nuclear fusion?
The CNO cycle
dominates in stars
heavier than the
Sun.
http://en.wikipedia.org/wiki/Nuclear_fusion
7. What is nuclear fusion?
http://www.archive.org/details/CEP_00_032
The only fusion reactions thus far produced by humans to achieve ignition are those
which have been created in hydrogen bombs; the first of which, Ivy Mike, is shown here.
8. What particles are known to physics?
• Elementary Particles
– Fermions
• Leptons
• Quarks
– Bosons
• Composite Particles
– Hadrons
• Baryons (made of fermions)
• Mesons (made of bosons)
– Atomic Nuclei
– Atoms
– Molecules
8. What particles are known to physics?
• Elementary Particles
– Fermions
• Leptons – 6 particles and 6 antiparticles
Charged lepton/ antiparticle
Name
Symbol
Electric charge (e)
Mass (MeV/c2)
Electron / Positron
e− /e+
−1 / +1
0.511
Muon
μ− /μ+
−1 / +1
105.7
Tau lepton
τ− /τ+
−1 / +1
1777
Neutrino / antineutrino
Electron neutrino / Electron antineutrino
νe/νe
0
< 0.0000022
Muon neutrino / Muon antineutrino
νμ/νμ
0
< 0.17
Tau neutrino / Tau antineutrino
ντ/ντ
0
< 15.5
8. What particles are known to physics?
• Elementary Particles
– Fermions
• Leptons
• Quarks – 6 particles and 6 antiparticles
Generation
Weak
Isospin
Flavor
Name
Symbol
Charge
e
Mass
MeV/c2
Antiparticle
Symbol
1
+½
Iz=+½
Up
u
+⅔
1.5 – 4.0
Antiup
u
1
-½
Iz=-½
Down
d
-⅓
4–8
Antidown
d
2
+½
C=1
Charm
c
+⅔
1150 – 1350
Anticharm
c
2
-½
S=-1
Strange
s
-⅓
80 – 130
Antistrange
s
3
+½
T=1
Top
t
+⅔
170900 ± 1800[1]
Antitop
t
3
-½
B'=-1
Bottom
b
-⅓
4100 – 4400
Antibottom
b
8. What particles are known to physics?
• Elementary Particles
– Fermions
• Leptons
• Quarks
– Bosons - All force carrier particles are bosons
Name
Symbol
Charge (e)
Spin
Mass (GeV)
Force mediated
Existence
Photon
γ
0
1
0
Electromagnetism
Confirmed
W boson
W±
±1
1
80.4
Weak nuclear
Confirmed
Z boson
Z0
0
1
91.2
Weak nuclear
Confirmed
Gluon
g
0
1
0
Strong nuclear
Confirmed
Graviton
-
0
2
0
Gravity
Unconfirmed
Higgs boson
H0
0
0
>112
Unconfirmed
Supersymmetric theories predict the existence of more particles,
none of which have been confirmed experimentally as of 2008.
8. What particles are known to physics?
• Composite Particles
– Hadrons
• Baryons - made of three quarks
– Nucleons
» Protons, composed of two up and one down quark (uud)
» Neutrons, composed of two down and one up quark (ddu)
– Hyperons, contain one or more strange quarks
– Charmed and Bottom baryons have also been observed.
8. What particles are known to physics?
• Composite Particles
– Hadrons
• Baryons - made of three quarks
• Mesons - made of two quarks
– pion, kaon, J/ψ, and many others
– Exotic mesons may also exist.
8. What particles are known to physics?
• Composite Particles
– Hadrons
• Baryons (made of fermions)
• Mesons (made of bosons)
– Atomic Nuclei
– Atoms
– Molecules
8. What particles are known to physics?
• Elementary Particles
– Fermions
• Leptons
• Quarks
– Bosons
• Composite Particles
– Hadrons
• Baryons (made of fermions)
• Mesons (made of bosons)
– Atomic Nuclei
– Atoms
– Molecules
A Theory of
Everything
Unification