Listen to part of a lecture in a geography class.
Professor: As most of you may know, we’ve created a, um, a series of imaginary lines in places around Earth for the purposes of navigation and the accuracy of time. The most obvious line is the Equator, which divides Earth into its, uh, northern and southern hemispheres. The Equator is a line of latitude. The lines of latitude and lines of longitude form a grid over the surface of Earth, which allows us to navigate successfully from place to place. We can also use it to know where on Earth a place is, even this classroom. We use the circle as the reference for these lines, based on three hundred and sixty degrees. Each degree is divided further into sixty minutes and each minute into sixty seconds. Now remember, don’t confuse this with time. It isn’t time. Since one degree of latitude or longitude can represent many miles on the surface of Earth, it’s necessary to use minutes and seconds to narrow the range of navigation accurately to pinpoint a location.
Latitude lines start at zero degrees at the Equator and then run north to the North Pole, which is ninety degrees north latitude. They also go south to the South Pole, which is ninety degrees south latitude. So we have two kinds of latitude lines, north latitude and south latitude. Latitude has been used for a long time, hundreds of years, even before Columbus reached the Americas. Sailors could judge latitude with ease based on the position of the sun above the horizon. Observations over many years gave navigators, uh, accurate charts that could tell at what angle the sun would be on a certain day of the year at a certain latitude.
Longitude was more difficult to judge. Lines of longitude run from the North to South poles. The Prime Meridian, or zero degrees, runs through Greenwich, England, which is close to London. Then we have lines of longitude running to the west of London for one hundred eighty degrees and to the east of London for one hundred eighty degrees. The two sets meet in the Pacific Ocean at what is called the International Date Line. The International Date Line is both one hundred eighty degrees west and east. This line distinguishes between when one day begins and another ends and is used for time purposes as well as navigation. Since Earth revolves on its axis from west to east, the sunrise of a new day begins in the Pacific Ocean near Guam and then moves west to Japan, Korea, China, and so on across the world. It may be Tuesday morning in Tokyo, but it’s Monday evening in New York.
Now, for centuries, longitude was almost, uh, impossible to judge. The only way to do so was with an accurate timepiece set for the time one left port. Unfortunately, until the eighteenth century, there were no accurate timepieces.
On a voyage, say, from England to Jamaica, a timepiece could be off by as much as two hours. This was caused by the imperfections of the mechanical clock in an age without batteries. The metal parts in the clock would expand and shrink depending on the temperature and air pressure and were also influenced by a ship’s motion. Not until a clock was developed that was immune to these variables were ocean navigators able more accurately to judge longitude. I’ll bet you didn’t know that, did you? Nowadays, of course, we have the GPS system, and almost anybody can know where he is with a simple handheld device.
There are two other imaginary lines I want to talk about. They are not as well known as the Equator or latitude or longitude. The first is the Tropic of Cancer, located at twenty-three degrees thirty minutes north latitude. Here on this map you can see it passes through northern Mexico and North Africa. On the first day of the summer in the northern hemisphere, usually June twentieth or twenty-first, the sun shines directly overhead at the Tropic of Cancer. This is called the summer solstice. In the southern hemisphere, we have the Tropic of Capricorn at twenty-three degrees thirty minutes south latitude. Again, you can see it here on our map passing through southern Brazil and South Africa. On December twentieth or twenty-first, the sun shines directly on the Tropic of Capricorn, marking the summer solstice in the southern hemisphere. The zone between the two lines is called the tropical zone, and all of the world’s tropical regions fall into this zone. Those to the north and south of the zone are the temperate zones.
Finally, we have the Artie Circle at sixty-six degrees thirty minutes north latitude and the Antarctic Circle at sixty-six degrees thirty minutes south latitude. These lines mark what are called the northern and southern frigid zones, where the temperatures are extremely cold and the land is almost permanently frozen.
Listen to part of a lecture in a sociology class.
Professor: Now, as we discussed last class, our current system of prisons is a legacy of the history of the nature of penal reform and the attempts at social reform at all levels of society in the 1960s. Currently, we have three types of prisons: federal, state, and local. Federal prisons house the most dangerous criminals and those who have committed serious crimes against the government. State prisons have different levels, with maximum security housing violent offenders such as murders and rapists while minimum security prisons house large numbers of white collar and minor offenders.
Local jails, sometimes called county jails, house people awaiting trial and those serving very short sentences for minor infractions. Unfortunately, in local jails, criminals committing all levels of offense are housed in the same facilities and are often separated to avoid violence… This isn’t always successful. An example would be the Los Angeles County jail, which is notorious for being divided along racial lines. White, black, Hispanic, and Asian prisoners are segregated, not by official policy, but by a jailhouse policy established by the prisoners themselves. Each group has a “shot caller,” a de facto leader whose job is to represent his group in any negotiations with the others in order to keep the peace or, at times, go to war. The LA County jail has a history of prisoner-on-prisoner murder, most of which is related to the rival street gangs of the city.
While crime in the nation has gone down, our prisons still have one of the largest inmate populations in the world. Between 1990 and 2000, the number of prisoners has almost doubled from 1.2 million to just over two million. It may not surprise you that most of the nation’s prisoners are males. Females account for only six percent of all prisoners. In addition, the prisoners are not representative of America’s social groups. Blacks and Hispanics comprise two thirds of the prisoners yet are less than one third of the nation’s population. This is a telling statistic concerning the social woes of our nation’s minority groups. As for the type of crime, approximately half are in jail for violent crimes, including murder, rape, robbery, and assault. Most of the remaining prisoners are in jail for property crimes, which include burglary and various types of theft. Finally, there is a large and growing group that is incarcerated for drug offenses, whether manufacturing, selling, or using drugs.
Despite these dire numbers… or maybe because of them, crime in America is on the decline. The murder rate for the whole United States has declined from a 1980 high of 10.2 people murdered per 100,000 people to 5.6 at present. Once-famous murder capitals such as New York and Los Angeles are now enjoying reputations as safe tourist destinations. However, this doesn’t mean that every American city can be considered safe. New Orleans, Detroit, and St. Louis all currently have the nickname Murder Capital, USA. All three cities have large black communities, where crime is rife. Statistically, blacks account for almost fifty percent of the murder victims in America while representing only twelve percent of the population. State wise. New England and the Dakotas have the lowest crime rates in America. This is based on an index of crimes per 100,000 people. Arizona and Hawaii top the list for crime rates, with the majority of crimes being against property.
In general then, crime is on the decline, and our prisons are overflowing with criminals. Some of this is the result of new policies in recent years, especially the “three strikes you’re out” rule that has been adopted by many states. Habitual criminals, those that commit crime almost as a career, are now being sent to prison for very long terms, sometimes for life, if they have been arrested and found guilty for the third time. Many cities and states are praising the system, claiming it has rid their streets of crime. Others criticize it, claiming that people who commit minor crimes, even if for the third time, should not be deprived of their freedom for life as if they were violent offenders. Coupled with this has been the large–scale crackdown on drug crimes. All of this has led to our exploding prison population.
At the heart of the prison system is this question… Do prisons reform criminals? The answer seems to be a resounding “no.” The fact that there are habitual criminals, who still commit crime even after being in jail twice, means that they haven’t been reformed. But we should also look at a bigger picture. Finding honest employment is extremely difficult for released prisoners, especially now when many companies require criminal background checks. If a released criminal cannot get a job, the more likely it is he’ll return to a life of crime.
Listen to part of a conversation between a student and a university employee.
Student: Excuse me, but is this the Financial Affairs Office? There’s no sign on the door, but I think I’ve got the right place.
Employee: Yes, you’re correct. Sorry about having no sign. It should be back up this afternoon. Anyway, what can I do for you this morning?
Student: I’m a sophomore here, and I really love everything about this university, but I’m afraid that, with the new ten–percent increase in tuition, it’s going to be very difficult for me to continue studying here. So, uh, I guess I’d like to know what kind of financial options are available to me.
Employee: All right. You’ve definitely come to the right place. I have no doubt at all that I’ll be able to help you out. First, though, I need to ask you a few questions. To begin with, what kind of financial aid, if any, are you currently receiving?
Student Okay, let me think about that for a second. First, I’ve got a two-thousand-dollar need-based scholarship. I’ve also got a student loan for the same amount. I’ve had one of those every semester since I’ve been here. Oh, and I’m also receiving money through the work-study program. But that’s only a few hundred dollars. So my family and I have to pay the rest of my tuition ourselves, which isn’t the easiest thing in the world for us.
Employee: Really? Why is that? Can you give me a little bit of information about your family’s finances?
Student: Sure. My dad is a school teacher, and my mom stays home to help raise my brothers and sister. I have three brothers and a sister, so you can imagine that my father’s salary—he’s a high school science teacher—doesn’t go very far.
Employee: Yes, I think I see your point. Hmm… Well, it’s possible that you could get another need-based scholarship this year. I don’t see why the school wouldn’t increase the amount of money they’re giving you.
Student: That would be wonderful, but it’s rather arbitrary, isn’t it?
Employee: Well, yes, you’re right about that. The financial aid officers try to be as fair as possible, but there are times when deserving students slip through the cracks.
Student: Exactly. So, my question is… Are there any other forms of financial aid I could, uh, I don’t know, apply for, I guess, that would provide me with the extra help that I need to continue studying here?
Employee: Well, the school provides athletic scholarships. You don’t happen to play any sports, do you?
Student: Sorry, I can’t stand them. The library’s my home.
Employee: Okay. Then we also offer a number of academic-based scholarships. You could apply for a couple of those. How are your grades?
Student: My grades? Oh, I have a 3.8 GPA. It’s a perfect 4.0 in my major. You know, I never even thought of academic scholarships. Are they easy to apply for?
Employee: Oh, yeah. There is a general form that you fill out, and then you’ll automatically apply for all of the scholarships for which you qualify. Aren’t computers amazing, sometimes?
Student: Great. So how do we get started?
Employee: Fill out this form, and turn it back in to me.
Listen to part of a lecture in a chemistry class.
Professor: Since this is our first class, I thought we’d review what you may or may not have learned in high school chemistry. So some of this will be old stuff for most of you… I hope. Anyway, we’ll begin with the basic building block of all matter, the atom and its components. The word atom comes from the Greeks and means “indivisible” because the Greeks thought that all matter was made of small components that couldn’t be divided into smaller parts. Of course, we now know that isn’t exactly true. The early twentieth century saw advances in our understanding of atoms with the discovery of their component parts: the neutron, proton, and electron. Most of the mass of an atom is made up of the nucleus, which contains the neutrons and protons. The proton has a positive charge, and the electron has a negative charge. The neutron is neutral, meaning it has no charge.
The number of protons of an atom gives us, uh, its atomic number. This number always stays the same. Some elements have different isotopes, or types, of the same element. For example, carbon can have isotopes like carbon-12, carbon-13, and carbon-14. Isotopes reflect, uh, the different number of neutrons in the atom. Chemical bonding can occur between elements when electrons are shared. This, of course, makes molecules, things like water, which consists of one oxygen and two hydrogen atoms.
Of the more than one hundred elements we know of today, only twelve were known to man before 1700. This included such basic metals as gold, silver, and iron. Oxygen, for example, which we all breathe every second, wasn’t discovered until the 1770s. Amazing, huh? By the middle of the nineteenth century, there were dozens of elements, and scientists were trying to find a way to organize them according to their similarities. The result is the Periodic Table of the Elements that you see here on the board. First, I’ll explain the table. Then I’ll tell you a bit of the history of its development.
Presently, there are 118 known elements, and scientists believe we’ll, uh, discover more. Each block and symbol represents an element. The table is divided into columns, called groups, and rows, called periods. Let’s look at hydrogen here in the top left comer, the first group of the first period. Hydrogen has only one proton, so its atomic number is one. So you can see the number one in the top right hand comer of the hydrogen block. The elements are organized from left to right in the row, or periods, in increasing atomic numbers. The columns are based on the similar physical properties the elements have. For example, on the far left are the light metals while in the middle are the heavier metals.
On the extreme right in group eighteen are what are called the noble or inert gases. These gases include helium, neon, and argon and are called inert because they bond with other elements only with extreme difficulty.
Most of the elements you see, up to element 94, are naturally occurring on Earth. The remaining ones have been created by man, mostly in atomic reactors and particle accelerators. Now you’ll see this big gap here between elements 56 and 72 in the seventh period. These are shown below and are called the rare earth elements. Below them is another gap between elements 88 and 104, which represents the radioactive earth elements, also shown below.
The history of the periodic table is one of, well, ironically, of experimentation. Different systems were tried over the years. A German chemist noticed that certain elements could be placed in groups of three, with one of their atomic weights exactly between the other two’s atomic weights. This so-called Law of Triads led other scientists to examine the elements for organization. The big breakthrough came in 1869 with the work of Russian chemist Dmitri Mendeleev. Let me spell that for you on the board. It’s M-E-N-D-E-L-E-E- V, Mendeleev. He wrote all the information for each known element on a separate card and then moved them around until what he had started to make some sense, chemically-wise that is. Anyway, he is considered the creator of the modem periodic table. He also believed that a number of elements had not been discovered and left gaps in the table for them to be added later. One problem with Mendeleev’s table was that it organized elements by atomic weight. With the discovery of the proton, a further revision by Henry Mosley, an English scientist, was made to the table in
1914. He determined that the table was best organized by atomic number based on the number of protons. Additions were later made for the rare and radioactive earth elements. Right now, scientists are trying to create new elements.