5 Washington University of Virginia STUDENT NAME Midterm exam 2019 International Business 1. ) In terms of international business, it is most accurate to say that ________. A) there is a universal "best way" to conduct business B) global competition affects large companies but not small ones C) most firms depend either on foreign markets and supplies or compete against companies that do D) government regulation of international business has little effect on a company's profits 2) Devon, an accounts manager at a large electronics firm, does not have any direct international responsibilities. However, Devon would most likely benefit from studying international business issues so that he can ________. A) conduct better job interviews B) better understand how foreign operations affect the company's competitive position C) supervise and evaluate subordinates who have global assignments D) understand the legalities of importing and exporting products overseas 3) Which of the following has NOT been a major force increasing globalization in recent decades? A) liberalization of cross-border trade B) increase in and expansion of technology C) growing pressure from consumers D) decreasing prices of natural resources. 4) A company starting out with a global focus, usually because of the international experience of its founders, is called a ________. A) multinational enterprise B) transnational company C) strategically allied company D) born-global company 5) What is the most likely reason that governments cooperate with each other through treaties, agreements, and consultations? A) to gain an advantageous division of labor B) to be in compliance with United Nations' requirements C) to attack problems jointly that one country acting alone cannot solve D) to assure that all countries get an equitable share of taxes from multinational enterprises 6) Which of the following best describes a result of cultural collision in international business? A) A company implements practices that are less effective than intended. B) Local employees are overlooked for promotions by home country managers. C) Expatriate managers rely too heavily on local employees for negotiating business deals. D) Foreign and domestic companies make adjustments for the local culture and legal environment. 7) Businesspeople seeking to understand more about another culture in order to successfully conduct business within that culture would be best advised to do which of the following? A) observing the behavior of people who have gained respect within that cultural environment B) relying on stereotypes, which are based on averages, to gain an understanding of the culture C) avoiding cultural research studies because they perpetuate unjustified stereotypes and behaviors D) memorizing the cultural variations that are typically encountered in a specific cultural environment 8) Although English is referred to as the "international language of busin ...

1. 5
Washington University of Virginia STUDENT
NAME
Midterm exam
2019
International Business
1. ) In terms of international business, it is most accurate to say
that ________.
A) there is a universal "best way" to conduct business
B) global competition affects large companies but not small
ones
C) most firms depend either on foreign markets and supplies or
compete against companies that do
D) government regulation of international business has little
effect on a company's profits
2) Devon, an accounts manager at a large electronics firm, does
not have any direct international responsibilities. However,
Devon would most likely benefit from studying international
business issues so that he can ________.
A) conduct better job interviews
B) better understand how foreign operations affect the
company's competitive position
C) supervise and evaluate subordinates who have global
assignments
D) understand the legalities of importing and exporting products
overseas

2. 3) Which of the following has NOT been a major force
increasing globalization in recent decades?
A) liberalization of cross-border trade
B) increase in and expansion of technology
C) growing pressure from consumers
D) decreasing prices of natural resources.
4) A company starting out with a global focus, usually because
of the international experience of its founders, is called a
________.
A) multinational enterprise
B) transnational company
C) strategically allied company
D) born-global company
5) What is the most likely reason that governments cooperate
with each other through treaties, agreements, and consultations?
A) to gain an advantageous division of labor
B) to be in compliance with United Nations' requirements
C) to attack problems jointly that one country acting alone
cannot solve
D) to assure that all countries get an equitable share of taxes
from multinational enterprises
6) Which of the following best describes a result of cultural
collision in international business?
A) A company implements practices that are less effective than
intended.
B) Local employees are overlooked for promotions by home
country managers.
C) Expatriate managers rely too heavily on local employees for
negotiating business deals.
D) Foreign and domestic companies make adjustments for the
local culture and legal environment.

3. 7) Businesspeople seeking to understand more about another
culture in order to successfully conduct business within that
culture would be best advised to do which of the following?
A) observing the behavior of people who have gained respect
within that cultural environment
B) relying on stereotypes, which are based on averages, to gain
an understanding of the culture
C) avoiding cultural research studies because they perpetuate
unjustified stereotypes and behaviors
D) memorizing the cultural variations that are typically
encountered in a specific cultural environment
8) Although English is referred to as the "international
language of business,"________.
A) it is less frequently used than French in international
business
B) there is a growing disagreement over which version of
English to use, e.g. British, American, or Australian
C) companies headquartered outside English-speaking countries
all use their official language as their operating language
D) monolingual English speakers may experience more
difficulty in the future in communicating on a worldwide basis
9) ) Raj, an engineer, works long hours and takes full
responsibility for both his good and bad work performance. Raj
most likely believes in ________.
A) self-determination
B) low power distance
C) collectivism
D) fatalism

4. 10) Assume a U.S. firm plans to expand into either Mexico,
Germany, or Japan. Its executives are traveling to each country
to meet with local businesspeople in the decision-making
process. Which of the following would be LEAST beneficial
when the executives make a presentation?
A) requesting a translator with technical vocabulary knowledge
B) simplifying vocabulary and terminology for the audience
C) conducting back translations for written work
D) avoiding repetition to prevent boredom
11) In societies where trust is high, there tends to be a lower
cost of doing business.
Answer: TRUE/FALSE
12) In a practical sense, the term political system is meant to
signify the ________.
A) organization of military power in a country
B) working government in a country
C) philosophical orientations in a country
D) cultural values in a country
13) The distinguishing feature of political ideologies along the
political spectrum is ________, with some emphasizing its
primacy and others opposing it.
A) capitalism
B) socialism
C) freedom
D) liberalism
14) Which of the following statements about approaches to

5. political risk management is NOT true?
A) Passive political risk management discourages managers
from fully or partially hedging their bets against exposure to
political hazards.
B) Passive political risk management assumes that it is difficult,
if not impossible, to systematically model political risk.
C) Active political risk management assumes that positive and
negative political events in any country are neither independent
nor random events.
D) Active political risk management assumes that political
events unfold in observable patterns that statistical methods can
detect
15) Ian, a financial manager, is preparing to transfer to
Germany where he will serve as an expatriate manager of his
employer's European office. With which type of legal system
will Ian most likely have to deal with in Germany?
A) mixed
B) common
C) civil
D) theocratic
16)Which of the following is most likely a true statement about
the global economy since the 1980s?
A) Socialist governments are intervening more in global
exchanges.
B) Wealthy countries are exercising total control over emerging
markets.
C) Developing countries are losing growing shares of their
foreign-exchange reserves.
D) Emerging economies are adopting the principles and
practices of free markets.
17) An economic system is the set of structures and processes
that ________ in a country.

6. A) guides the allocation of resources and shapes the conduct of
business activities
B) directs the movement of specific products to specific
consumers
C) sets the standards of competitive success for companies in
the economy
D) stipulates the roles and responsibilities of consumers
18) Pender Pharmaceuticals is considering expanding overseas
and is focusing primarily on the BRICs. Which of the following
countries is one that Pender is considering?
A) Indonesia
B) Chile
C) Russia
D) Bangladesh
19) Taylor Enterprises wants to expand its operations into Asia.
Managers are focusing on countries with high degrees of
economic freedom most likely because the firm is interested in
a country with ________.
A) minimal government intervention
B) standardized minimum wages
C) laws favoring sustainability
D) state-run corporations
20) Describe the three ways economies can be categorized.
Answer:

7. Syllabus
Co-Requisite: AST 111 Astronomy of the Universe Lab (core
requirement only)
Textbook: Cosmic Perspective 8th Edition: Bennett et al
Course Topics:
1. Formation and evolution of the Universe
2. Electromagnetic spectrum and observations
3. Formation and evolution of stars and galaxies
4. Forces and particles
5. Miscellaneous Topics
Course Objectives:
1. Learn how observations lead to theoretical models
2. Understand foundation level astrophysical concepts
3. Understand the major forces and structure of the universe
4. Understand the importance of particle interaction
Related UAB QL Core Learning Outcomes:
1. Demonstrate the ability to interpret graphical information
2. Demonstrate how to use quantitative evidence as a basis for
1. Reasoning
2. Problem solving
3. Argument
3. Demonstrate how to communicate quantitative information
1. Using numbers
2. Using words
Star formation and evolution.
Stars form in molecular clouds.
The core of the star is a plasma.
Hydrogen fusion begins and is sustained making a star.

8. Once a star begins to fuse hydrogen in the core it is referred to
as being on the main sequence. A star on the main sequence
remains the same size because the outward pressure from fusion
is balanced by the inward pull of gravity … this places the star
in equilibrium.
Be familiar with the proton-proton chain.
Once hydrogen fusion is no longer sustainable in the core, the
fusion moves outward. This increases the outward pressure,
causes the star to increase in size, and it is now considered to be
in the giant phase. Remember that moving the location of the
fusion does not change the mass of the star and initially does
not change the size. This means that the force of gravity is
unchanged.
As the star continues to get bigger, the mass is unchanged but
the density decreases. This means that the gravitational field
inside the star decreases and the star gets much bigger.
At this point, what is happening in the core of the star? Since
there is no longer injection of energy into the core by the
fusion, the temperature of the core decreases. This means that
while the star is getting bigger the core is actually getting
smaller.
Remember that the hydrogen fusion is releasing energy and
generating helium. The energy is being released into the
environment in the form of photons. The helium, which is
heavier than its surroundings, is building up around the core of
the star.

9. As the star progresses through the giant phase, more helium
builds up around the core. As with the initial plasma core; the
temperature, density, and pressure of the helium increase. This
continues until the helium is at a high enough temperature to
sustain fusion.
Helium fusion takes place via the triple-alpha process.
A helium four nucleus is referred to as an alpha particle. The
triple alpha process combines three helium nuclei to make
carbon-12.
Be sure to understand that lithium, beryllium, and boron are all
present in the star but don’t contribute directly to the star’s
evolution. This is why we are not concerned with them in this
class.
When the helium begins to fuse, there is energy being injected
into the core again so the core grows in size. Also, the star
itself shrinks (this is beyond the scope of the class). Understand
that the star getting smaller means that now the gravitational
force outweighs the outward pressure from fusion. It will
continue to collapse until these two forces balance (this is the
equilibrium state), and its momentum will allow it to continue
to shrink. This leads to the star oscillating back and forth about
an equilibrium position. This is a variable star.
So far we have:
1) Stars form in molecular clouds
2) Plasma core is generated and hydrogen fusion begins
3) This is the main sequence
4) Hydrogen fusion moves away from the core
5) This is the giant phase
6) Helium builds up around the core
7) Helium fusion begins
8) Star gets smaller and becomes a variable star
9) Eventually the helium fusion will move outward

10. 10) Similarly, now the carbon builds up around the core
Hertzsprung Russell Diagram
The horizontal axis is temperature (sometimes referred to as
color). Cooler temperature is to the right and hotter temperature
is to the left. This is surface temperature. The surface of a star
(referred to as the photosphere) is the distance from the center
where the star changes from being opaque to transparent. It
appears to be a surface because external light would bounce
back upon striking it.
The vertical axis is luminosity (brightness or intensity or
magnitude). There are two different magnitudes to consider:
absolute magnitude and apparent magnitude. Absolute
magnitude is a physical property of the star while apparent
magnitude is how bright it appears based on the observation
location.
Magnitude should be thought of as a flux rate (the rate at which
photons are being emitted or observed). The absolute magnitude
is the rate at which photons leave the star. The apparent
magnitude is the rate at which photons are observed at a given
location.
When creating an HR diagram, the vertical axis should be the
absolute magnitude and not the apparent magnitude.
A star forms in a molecular cloud. At this point it is collapsing
due to gravity but there is no fusion. This means that a protostar
(a star that is forming due to gravitational collapse) will have a
low surface temperature and be relatively dim. This places it in
the bottom right corner of the HR diagram.

11. Once fusion begins, the star is said to be on the main sequence.
From *lots* of observations, the main sequence occupies a
certain region of the HR diagram. The location on the main
sequence is based on mass. Higher mass stars are further to the
left while lower mass stars are further to the right.
The surface temperature is the rate at which energy leaves the
surface per unit area. When hydrogen fusion leaves the core, the
star enters the giant phase and gets considerably larger. The
total energy output increases, but the surface temperature
decreases.
This is because the rate at which energy is leaving the star per
unit area has actually decreased (the increase in surface area is
large compared with the increase in total energy output).
This means that when the hydrogen fusion leaves the core, the
location of the star on the HR diagram moves up and to the
right.
At some point on the HR diagram, the star begins moving
downward and to the left. This means that the star is getting
smaller. From previous discussion, we know that this means that
the helium fusion has begun around the core. The point on the
HR diagram where this takes place is called the helium flash.
Effectively the HR diagram is a visual representation of how the
surface temperature and luminosity change as the star evolves.
Once carbon has built up around the core, low and high mass
stars evolve differently. Low mass stars won’t generate a high
enough temperature to cause the carbon to fuse.
Since the carbon won’t fuse, the star eventually becomes
unstable because there’s not enough hydrogen and helium to
continue the current fusion processes
In the above diagram, the hydrogen burning shell is the outer

12. boundary of the red area. The outer boundary of the blue area
(which is also the inner boundary of the red area) is the helium
burning shell.
The red area is referred to as helium rich. The blue area is
referred to as carbon rich.
At some point the lack of carbon fusion and the decreasing
availability of hydrogen and helium make the low mass star
unstable. This leads to a process known as a planetary nebula.
Planetary nebulae have nothing to do directly with planets. The
name stems from the fact that low under low magnification they
look like planets.
The instability created causes the star to eject the outer 1/3 of
its mass. This ejection forms a nebular region around the star.
The 2/3 of the mass that remains becomes a white dwarf.
This ejection is considered to be an extreme stellar wind.
Understand that the mass loss is occurring from the low density
region of the star. This means that the remaining object is at a
much higher average density than before.
The increase in average density causes the gravitational field
inside the star to increase while the decrease in fusion causes
the outward pressure to lessen. This combination causes the
remaining object to shrink.
The result is an object called a white dwarf at the center with an
expanding nebular cloud around it.

13. Understand that the outward flowing gas is three dimensional.
When viewing the central region the line of sight passes through
a much thinner sheet of gas. This makes it appear as though
there is little or no gas in front of the white dwarf.
Recall that a scale up model of a hydrogen atom using a tennis
ball as the proton would require the electron to be about two
miles away. After the mass is ejected, the remaining object
begins to shrink. This continues until the molecules are as
tightly packed as possible.
Since fusion will no longer support the star from collapsing, the
star continues to shrink until the individual molecules provide
resistance against further collapse.
This should be thought of as a three dimensional grid where
there are tennis balls placed four miles apart. This is because
the individual electron orbital shells will not overlap. Because
of this the object cannot shrink any further.
This situation is referred to as electron degeneracy. Basically
this means that no two electrons can occupy the same space at
the same time.
Finally, the resulting object is a white dwarf. It has its
molecules packed as tightly as possible without overlapping the
electron orbital shells. This is considered to be one of the final
evolutionary steps of a low mass star (a star that is eight times
the mass of our sun or less).
The final stage of evolution is that the white dwarf eventually
stops giving off energy and becomes a black dwarf. Once the
white dwarf quits releasing energy it is still there but not
visible. This is referred to as a black dwarf.

14. Unlike with low mass stars, high mass stars are able to fuse
carbon and heavier elements.
A better description is that the hydrogen burning shell is the
outer boundary of the bronze area and that the bronze ring is the
helium rich zone where the helium created by the hydrogen
fusion is falling toward the core because it is heavier than its
surroundings.
The product of the silicon fusion process is iron. Iron does not
fuse in the core of a high mass star for two reasons. The first is
that the temperature is not high enough, and the second is that
iron fusion is endothermic while the other fusion processes are
exothermic.
The result of these is that usually the star’s core is not hot
enough for iron to fuse. If the star is very large and such a
temperature is attained, the fact that iron fusion is endothermic
causes the fusion to pull energy from its environment and the
temperature drops.
After the iron builds up and the star begins to run out of fusion
material, the star proceeds to becoming a supernova. As the
amount of fusion decreases, so does the outward pressure. This
causes the star to begin to collapse. Understand that the star is a
giant ball of fluid, so when it begins to collapse there are
pressure waves sent toward the core.
These pressure waves will not reach the core because they
overlap and bunch up together. While this is happening, there
are still more waves coming in behind them. This means that the
inward pressure is increasing greatly.
Eventually the inward pressure will be high enough that it
causes the core to collapse and rebound. The rebound is what

15. creates the supernova and blows the star apart. This is the only
observed time in the universe that temperatures and pressures
are high enough so that fusion will create elements that are
heavier than iron.
When a high mass star explodes, it does not always explode
completely. Sometimes a supernova remnant (SNR) is left
behind. In theory there are three possible remnants although
current research suggests that only two are probable.
1) White dwarf – this is exactly the same type of object as the
one that forms during a planetary nebula. This will be 1.44
times the mass of our sun or less
2) Neutron star – this is a heavier remnant between 1.44 and 3.0
times the mass of our sun.
3) Black hole – this is the heaviest remnant and is 3.0 times the
mass of our sun or greater.
The type of remnant left behind is dependent on the mass of the
remnant itself, not on the mass of the star.
Remember that a white dwarf is supported against gravitational
collapse by electron degeneracy. This means that the electron
orbital shells of the molecules do not overlap. By increasing the
mass of the remnant (and thereby increasing the pressure at the
center), the molecules at the center will have their electrons
pushed into the nuclei. This causes electrons and protons to
collide and form neutrons.
The result of this is that the neutrons are now pushed together
and the density of the remnant is much higher. This is referred
to as a neutron star (which is probably better named a neutron
ball). As before, no two neutrons can occupy the same space at
the same time. This means that a neutron star is supported

16. against gravitational collapse by neutron degeneracy.
In order to learn more about neutron stars we need to talk about
the Earth’s magnetic field first. The Earth’s magnetic field is
generated in the core (remember that moving charges generate a
magnetic field). This is due to three reasons:
1) The core of the Earth is molten. This allows for greater
movement of charged particles.
2) The core of the Earth is conducting. Even though it is molten
it will still conduct.
3) The Earth rotates at a quick rate. This basically acts as a
stirring rod for the fluidic core.
The Earth has two major axes: rotational and magnetic
The rotational axis of the Earth is fixed. Basically this means
that it rotates about the same axis continually. A result of this is
that the Earth’s equator does not change location.
A consequence of the physics principle of conservation of
angular momentum is that when a rotating body is placed into a
smaller volume it will rotate faster.
Apply this to a neutron star. Remember that when a high mass
star explodes, the remnant that is left behind will shrink. If its
mass is between 1.44 and 3.0 times the mass of our sun, it will
form a neutron star. This means that it has overcome electron
degeneracy and is being supported against gravitational collapse

17. by neutron degeneracy.
When the neutron star forms, it may have a very slow rotation
rate. However, the fact that it is collapsing considerably
increases that rotation rate due to conservation of angular
momentum.
At this point several nuances need to be considered in detail.
1) In the process of forming the neutron star, would you expect
every electron to run into a proton?
No, especially not in the heavier nuclei. This is because of the
distribution of protons throughout the nucleus. The result of this
is that there are more neutrons than there were before, but there
are also isolated protons and neutrons.
2) Will the rotational axis of the neutron star be fixed? Yes.
This is because the internal pressure is so high that none of the
particles are able to move relative to one another.
3) Will the magnetic axis of the neutron star be fixed? Yes. This
is because each individual charged particle remains in the same
place relative to one another and is in a cyclic rotation around
the rotational axis.
The purpose of the Earth’s magnetic field is to act as a shield
against high energy charged particles.
Most of the charged particles are diverted around the Earth.
Some of them, however, congregate at the magnetic poles. This
is referred to as the charged particles being captured in the
upper atmosphere.

18. Once the atmosphere is saturated with these charged particles,
they are released and fall toward the Earth. This is observed as
the Northern and Southern Lights.
In similar fashion, charged particles that encounter a neutron
star will also build up around the poles. Again, there will be a
saturation level for the particles around then neutron star. This
will cause them to be ejected from the poles, but the result is
much different.
Since the neutron star is rotating very quickly, instead of falling
toward the surface they are ejected outward like a slingshot.
The material is ejected outward in jets along the magnetic field
axis.
Will the magnetic axis and the rotational axis of the neutron star
be aligned? The answer is no because the charge distribution is
not symmetric about the rotational axis. This means that there
will be an angle between the two axes.
Observers that are fixed will not see a continuous output of
light from the neutron star’s jets, but they *may* see them in
pulses. These are referred to as pulsars. The fastest pulsars have
over 1,000 pulses per second, which means that the neutron star
is rotating more than 1,000 times every second.
Would we expect for the majority of neutron stars to be pulsars?
Yes, because we would expect the neutron star to be rotating
quickly and have a strong magnetic field as a result.
When we know that we are observing a neutron star through our
telescope, would we expect it to appear as a pulsar?

19. Homework 1 notes
1st part
Electromagnetic Spectrum
Components:
Light behaves as both a particle and a wave. At this moment we
are only going to focus on the wave properties.
There are two major divisions for waves:
1) Transverse: A distortion that is perpendicular to the direction
of travel. Be comfortable with understanding that waves at the
beach coming toward the shore are transverse waves.
2) Longitudinal: A distortion that is parallel to the direction of
travel.
Shorter wavelength corresponds to higher energy.
Also know the colors of visible light in order of decreasing
wavelength
1) Red
2) Orange
3) Yellow
4) Green
5) Blue
6) Indigo
7) Violet
There are three different types of spectra:
1) Continuous

20. 2) Emission
3) Absorption
Is the speed of light constant? NO
The correct way to think of this is “All observers measure the
speed of light in a vacuum to have the same value.”
A prism changes the medium through which the light is
traveling. This causes the light to slow down and change
direction. When the light leaves the prism it speeds up again.
The change in angle due to the change in speed is dependent on
the wavelength (color) of the light.
A continuous spectrum occurs when light at all wavelengths
(within the visible light portion of the spectrum) is present.
Consider hydrogen as the simplest example for all elements
(and molecules, etc.).
Hydrogen has a proton for the nucleus and an electron that
orbits around the nucleus at various distances. These are
referred to as the orbital shells.
1) The laws of physics are the same everywhere in the Universe.

21. This cannot be proven (with current technology and
understanding of physics).
However, we have observational data that supports this.
A consequence of this is that all protons (in reality all particles)
in the Universe must have exactly the same properties. This
verifies that all interactions between protons will have the same
results.
Expanding on this idea requires that all electrons in any given
hydrogen molecule orbit at the same distance.
2) The Universe is lazy.
This means that the Universe tries to do everything using as
little energy as possible, and entities (molecules, systems of
particles, etc.) try to remain in their lowest energy state.
For our hydrogen molecule, this means that the electron wants
to be in the first orbital shell (closest to the nucleus).
Any interaction between charged particles that results in the
release of energy will release that energy in the form of
photons.
When electrons move toward a nucleus, energy is released and
photons are observed. These are called “transitions” and are
categorized by where the electron lands.

22. These transitions are defined by the electron landing on shell
1) First shell Lyman transition UV photons given off
2) Second shellBalmer transition Visible light photons
3) Third shell Paschen transition IR photons
4) Fourth shell Brackett transition IR photons
This gives me the information needed to create “fingerprints”
for emission spectra to use for comparison with observation.
The Doppler effect applies to waves and changes the apparent
wavelength based on motion.
Applying this to light, if a light source is moving toward an
observer then the light’s wavelength appears shorter than it
really is and this is referred to as a blue shift.
Conversely, if the light source is moving away from an observer
then the light’s wavelength appears longer than it really is and
this is referred to as a red shift.
Overall the effect is the same whether the light source and/or
the observer are moving. If the distance between them is
decreasing then there is a blue shift. If the distance between
them is increasing then there is a red shift.
If a light wave is blue shifted that does not mean that it is blue
in color. Similarly, if a light wave is red shifted that does not
mean that it is red in color.

23. 2nd part
When a galaxy forms, gravity pulls all of the material toward
the center of the mass distribution.
Conservation of angular momentum – one consequence of this is
that if a rotating object’s volume is decreased the object will
rotate faster.
Remember the discussion about randomness. While the material
that will make up the galaxy is collapsing, the individual
molecules still have some random motion. The way to think
about this is that there is a bulk motion (gravitational collapse)
and a random motion (particles moving individually) and the
combination of this determines the outcome.
In this random motion, it is expected that roughly (but not
exactly) half of the material is rotating clockwise and half of
the material is rotating counterclockwise. Combining these
thoughts means that as the bulk motion causes the material to
collapse, an overall rotation will become significant.
Now consider our solar system. The planets that are further
from the Sun are in a weaker gravitational field. This means
that they orbit around the Sun more slowly.
As the material collapses to form a galaxy, much of it will gain
an orbital speed that is high enough to keep it from moving
inward further. In other words, the gravity pulling the material
together is not strong enough to pull in material with significant
rotation. The result of this is that the majority of the material
forms a supermassive black hole at the center and the remainder
creates a debris field around it.
Initially, this debris field will have a spherical distribution.
Eventually, it will flatten out into a disk. This forms our spiral

24. galaxy. The debris in the disk eventually forms the stars,
planets, etc.
Stars form basically the same way as a galaxy. Gravity pulls
together material to form the star. There is a debris field around
the star which becomes planets, asteroids, comets, etc.
Solar vs Stellar … Solar refers to our Sun while stellar refers to
stars in general. The name of our sun is Sol.
Stars form from molecular clouds. Are the molecules within the
molecular clouds moving or at rest? They must be moving fast
enough to keep the cloud from collapsing due to gravity. They
must also be moving slow enough to keep the cloud from
dispersing.
What is an arbitrary volume? It is a defined region of space that
does not have any physical boundaries and is used to describe
the behavior in that region.
Consider an arbitrary volume in the molecular cloud. The
motion of the individual molecules leads to density fluctuations
within this volume.
How do the density fluctuations affect the gravitational field
within the arbitrary volume? Remember that gravity is
determined by mass and separation. This means that at low
density the gravitational field is weaker. This is because there
are fewer molecules (less mass) and on average the molecules
are further apart. Conversely, at high density the gravitational
field is stronger.
In order for a star to form, an arbitrary volume with enough
mass (an amount of mass equal to the mass of a star) must reach
a high enough density that the gravitational field is strong
enough to collapse just the arbitrary volume in question.

25. After the first star forms, the outward flow of energy through
the cavity left behind triggers more star formation. The majority
of the material in the molecular cloud eventually becomes either
part of a star or the stellar system around it.
As the material is collapsing the density, temperature, and
pressure are all increasing. The increasing temperature leads to
the formation of a plasma core. This plasma core will eventually
sustain nuclear fusion and at this point you have a newly formed
star.
At low enough temperature, water is a solid. The molecules are
held together in a lattice structure and there is minimal motion.
When enough energy is added that the water melts, it is now in
liquid form and the molecules clump together due to surface
tension.
Continuing to add energy will lead to the liquid evaporating to
form a gas. Now the molecules are completely dissociated from
one another.
What happens when the gas continues to be heated (more energy
is continually added to the gas)? At significant temperature the
molecular bonds begin to break and now there are isolated
hydrogen and oxygen molecules instead of water molecules.
The final stage in the generation of the plasma is collisions that
can strip the electrons away from their respective nuclei. The
end result is protons (hydrogen nuclei), oxygen nuclei, and
individual electrons. This means that the constituents are now
ionized (electrons are negative and the nuclei are positive).
Assuming that the Big Bang Theory is correct, the universe
began as roughly 75 percent hydrogen and 25 percent helium
with trace amounts of other material. Observations today
suggest that the universe is 70 percent hydrogen, 25 percent
helium, and 5 percent other stuff.

26. A consequence of this is that molecular clouds will be roughly
70 percent hydrogen. This means that when a star forms inside a
molecular cloud its plasma core will be roughly 70 percent
protons (hydrogen nuclei). This means that once a star forms, it
and all other stars will evolve through the same process.
What is nuclear fusion?
1) Nuclear – pertaining to the nucleus (mostly to the protons).
2) Fusion – to combine
3) Nuclear fusion is the combining of protons to form heavier
elements.
Individual protons will repel one another. In order to have them
fuse they need to be traveling at very high speeds (they need to
be in a high temperature environment). After two protons fuse
together they will be highly unstable due to the repulsive force
between them.
One of two things is going to happen. Either the protons are
going to rip back apart or something must happen to remove the
repulsion. The answer is that one of the protons becomes a
neutron and the repulsive force disappears.
The model for this is that protons and neutrons are made up of
quarks. For now, the agitation in the protons after they fuse
causes one of the quarks to change its properties. This causes
the proton containing that quark to change from being a proton
to being a neutron.
In physics we assume that the total amount of energy in the
universe is constant. This means that energy can’t be created
from nothing and it won’t just magically disappear.

27. In physics the work-energy theorem says that the change in
energy is equal to the amount of work done.
The initial fusion process in any star (regardless of mass) is
going to be hydrogen fusion. Specifically this is the proton-
proton chain.
The first of three parts for the proton-proton chain is the fusion
of two individual protons to form deuterium. Remember that
deuterium is one of the isotopes of hydrogen. A deuterium
nucleus has one proton and one neutron.
The second part is where a third proton is added and a helium-3
nucleus is made. Now this is an isotope of helium
The third part is where two helium-3 nuclei fuse together and
form a helium-4 nucleus. This is the most stable isotope of
helium.
The overall result is that after a star forms and develops a
significant plasma core, hydrogen fusion begins and produces
both helium-4 and excess energy (in the form of photons). The
star holds on to the helium that was made and releases the
excess energy into the environment.
Does the star have an infinite amount of hydrogen (fuel)? No
This means that eventually the core will no longer be able to
sustain hydrogen fusion in this way. This means that one of
three things must happen:
1) More hydrogen is added to the core
2) The fusion relocates to where there is more hydrogen
3) The fusion ceases
For the purposes of this class (and most astrophysics) a star is
considered to be a sphere that is spherically symmetric.

28. An object that is spherically symmetric can be considered as a
collection of infinitely thin spherical shells that are concentric.
A consequence of this is that the only variation in the star’s
parameters are based on changes in distance from the center
(radius).
Given this, once the core can no longer support hydrogen
fusion, the fusion relocates to where there is more hydrogen. It
moves outward because that is where the hydrogen fusion can
take place efficiently.
Why does our sun stay the same size?
Gravity is always trying to make everything smaller. The energy
being released by fusion is counteracting this and trying to
make the star bigger. Think about this as a continuous outward
flow of energy. The reason the star stays the same size is
because these two effects are balanced and the star is in
equilibrium.
Moving the hydrogen fusion outward means that it is taking
place on a larger surface. The fusion process is the same, but
there is more of the process occurring. This means that the
outward pressure goes up. Gravity has not changed. The end
result is that the star gets bigger because it is no longer in
equilibrium and the outward pressure is greater than gravity’s
ability to try and make the star smaller.
Now that the fusion is making energy and helium, but this
fusion is no longer taking place at the core, where does the
helium go? The helium is heavier than its surroundings so it
migrates toward the core and begins to stockpile
3rd part
Observation

29. First Observation:
All observed galaxies are red shifted (except for one). The
exception is the Andromeda galaxy (M31) which is close
enough to us that the mutual gravitational attraction overpowers
the expansion.
Having already assumed that there is no preferred spot in the
Universe, there is no reason to believe that our galaxy is at the
center of the Universe.
This means that we need to find a model that will allow for all
of the galaxies to be moving randomly and yet their overall
motion will be away from us.
The uniform expansion model can be thought of as placing a
grid over the Universe and allowing the grid to expand. This
results in every point in the Universe being further away from
every other point.
This leads to two separate types of redshift. The physics
principle involved is a Doppler shift for a wave. If the observed
wavelength is shorter than it should be (shorter than the emitted
wavelength) then the light is blue shifted. If the observed
wavelength is longer than it should be then the light is red
shifted.
The two classifications for redshift are derived from
1) Classical motion – motion through the environment
2) Cosmological motion – motion with the environment
If the motion of galaxies in the Universe were purely classical
we would expect to see roughly half red shifted and half blue
shifted. We would also expect the same degree of shift

30. regardless of distance.
If the motion of galaxies in the Universe were purely
cosmological we would expect to see all the galaxies redshifted.
We would also expect galaxies that are further away to have
larger red shifts.
What we actually observe is galaxy motion that is
cosmologically dominated. This means that all of the galaxies
(except Andromeda) are moving away from us and the further
galaxies have a larger red shift.
Second Observation:
Several decades ago the US military was experimenting with
microwaves. This led to a very interesting discovery with large
astrophysical implications.
** In class number line example ** Develop the idea of an
extremely small set that still has an infinite number of members.
This can be expanded to a thought exercise where I have a large
sphere filled with photons. There are enough photons that they
behave like an infinite set. This sphere is moved far enough
away that it occupies an infinitely small portion of the sky.
The result is that I have a system that behaves like an infinite
number of photons residing in an infinitely small part of the
sky.
The universe today is transparent and assuming the BBT is
correct it should have started out being opaque. This requires
that at some point in the past the universe changed from being
opaque to being transparent.
What is the difference between intensity and energy as far as
light is concerned? Energy is associated with wavelength and
intensity is associated with photon count.

31. Low intensity microwaves are observed coming toward us from
all directions. This is associated with the universe changing
from being opaque to being transparent.
If the Big Bang Theory is correct then this would be expected.
Specifically, when the universe changed from being opaque to
being transparent photons were released from all points in space
and in all directions. The result of this is that regardless of
where you are in the universe you will see background radiation
coming toward you in the form of microwaves.
Third Observation:
What is a visible light map? Basically this is a star chart – it is
a diagram that shows you where on the sky the visible light is
coming from. This is something that allows you to determine
which particular star, galaxy, etc. you are observing.
What then is a radio light map? As expected this would be a
diagram that shows you where on the sky the radio waves are
coming from.
Several decades ago (part II) astronomers began a project where
they overlaid visible and radio light maps. The purpose of this
is to determine what objects in the sky give off both types of
radiation.
Several objects that were originally considered to be “small
blue stars” were also demonstrated to be giving off radio waves.
This was unexpected because stars were not thought to give off
radio waves.
Now these objects are going to be studied in more detail. One of
the first steps is to pass the visible light through a prism to gain
information from the spectrum.
Doing this led to a very surprising result. Each of these “little
blue stars” have a very large red shift. The next step becomes

32. trying to determine if the red shift is classical or cosmological
in nature.
If the red shift is classical, then it very well could be a nearby
star but determining how it was accelerated to such a high rate
of speed becomes an issue.
If the red shift is cosmological, the fact that it is very far away
but still appears similar to stars in our galaxy means that it must
be extremely large and intense.
The answer is that the red shift is cosmological in nature and
the object is a forming galaxy. The formation process consists
of gravity pulling the material together and the material
coalescing to form the stars and everything else.
While gravity is pulling the material together, three measurable
parameters are increasing:
1) Density
2) Temperature
3) Pressure
The outer regions of the forming galaxy will be at a lower
energy. This means that the radiation given off there will show
up as radio waves. The visible light being given off will come
from locations nearer the center where the forming galaxy is
more energetic.
This object is called a Quasar (often abbreviated QSR).
This stands for Quasi-stellar radio source.
As the forming galaxy evolves, the outer regions will settle
down first. This means that the outer regions will quit giving
off light before the interior. Another way to think about this is
as the galaxy formation process continues, the outer regions
settle down and stop emitting radio waves while the interior

33. continues to emit visible light.
This is the same object type, just more evolved.
These are called QSO instead of QSR.
This is an abbreviation for Quasi-stellar object.
DUE 19TH OCT
1) Describe the process of a plasma core forming at the center
of a forming star. Be sure to explain the role that temperature
plays in this process.
2) Why does our sun remain the same size (what forces are in
balance)? How will this change when the hydrogen fusion
moves away from the core?
3) Explain why a giant star has a lower surface temperature
even though it is giving off more energy. What does this say
about the change in size of the star as a whole (does it get
slightly bigger or considerably bigger)?
4) Why does a white dwarf form during the planetary nebula
process? What causes the white dwarf to cease collapsing? What
is the absolute final product from the evolution of a low mass
star?
DUE 19TH OCT
Textbook: Cosmic Perspective 8th Edition: Bennett et al
CH 5
Answer the following four questions. You must use relevant
information to justify your answer to receive full credit. You
may use any reference source you like, including working in
groups. Make sure that the work you turn in is in your own
words.
1) Describe how the molecules in a gas produce an emission
spectrum. How is this useful in astronomy if we assume that the

34. laws of physics are the same everywhere?
2) Why was the uniform expansion model adopted? How does
this lead to a necessary differentiation between classical and
cosmological redshift?
3) Why does the Big Bang Theory imply that there should be
background radiation coming toward us from all directions?
4) Explain the significance of finding quasars in all directions
but none of them are nearby. Use the assumption that these
objects are forming galaxies.