Listen to a conversation in a university library.

M: Hi. May I help you?

W: Yes. I placed a book on hold, and I got an e–mail saying that the book was here at the reference desk. Oh, yes. I think I sent that e–mail. Ah … are you Miranda?

W: Yes, that’s right.

M: Okay, good. Sorry it took a while to get this book. It had to be shipped from another library. And … here it is.

W: Thanks!

M: Now, as you know, this book is rare, so there are conditions for using it.

W: Yes, you said something about that in your e–mail. Can I … uh … how long will I be able to check it out for?

M: Well, see, that’s the thing. Because it’s a rare book, you can’t check it out. You have to use it here in the library. It’s here for a month, and if you need it any longer, you can renew it.

W: I have to use it here? I didn’t realize.

M: Sorry. Yeah, that’s the rule for rare books.

W: I didn’t know it was rare. It’s in great shape. It looks old.

M: We don’t get a lot of requests for books like this. Most of these old works have been scanned, and so they’re available online.

W: Not this one, apparently. But I like old books anyway, so it’s a real treat to get to use this one. Oh, wow, it looks like it has writing in it, like someone in the past wrote notes in the margins.

M: Huh. Interesting.

W: So, then what are the rules? If I have to use the book here in the library, what do I do when I leave? Do you keep it for me?

M: Yes, we keep it here. You can use the book anywhere in the library, but then when you leave, you just have to give it back to me or anyone at this desk until the next day, or whenever you need it again. We keep it here, with your name on it—oh, I just need to scan your student I.D. card—and … uh … we keep it here for a month.

W: Am I allowed to photocopy pages?

M: Sure, if it’s for your own research. The rules are like for any other book. But if you do make copies— because the book is so old, you need to be careful with the binding. You don’t want to crack it.

W: Yikes.

M: Or you could ask one of the people in Copy Services to do it for you.

W: Hmm. I might. But … maybe … uh … could I take pictures with my own camera? That might be safer than putting it on the copy machine.

M: It might. Sure, that would be okay.

W: I’m not even sure the images would be clear enough. I’ll have to experiment.

M: Yeah.

W: Right now, I’m eager to take a look at this book.

M: Okay, good. I just need to scan your I.D.

W: Oh, okay. Sure.

Listen to part of a discussion in a biology class.

W1: To a scientist, a “fact” is simply a statement of our current understanding. The facts of science are really just attempts to state our best understanding of the natural world. Facts are based on observations we make and experiments we do. And a fact is only valid until it’s revised or replaced by a new understanding. Even the facts presented in your biology textbook are subject to change. Uh … yes, Andrew?

M: Uh, yeah. If a fact … if a fact is something that’s true, how can it be replaced? Does that mean, even in science, I mean … how can a fact change?

W1: Uh–huh. Okay. All right … let’s take, for example, cell biology. The field of cell biology is full of “facts” that were once widely held as true, but were later revised when biologists acquired a better understanding of cells. For example, it was once widely held as fact that living matter was made of substances that were very different from the substances in nonliving matter. According to this view—called vitalism—the chemical reactions in living matter did not follow the known laws of chemistry and physics, but were instead directed by some type of “vital force.” Vitalism was thought to be based on facts, that is, until Friedrich Wohler showed that the biological compound urea could be synthesized in the laboratory from an inorganic compound. Wohler’s work undermined the previously held “facts” of vitalism. He proved that the chemical reactions of organic matter follow all the laws of chemistry and physics.

M: So he gave us new facts to work with.

W1: Yes, that’s right. He did. To scientists, facts are not hard and fast truths. So, how does new information change our understanding? Well, scientists usually follow a systematic approach to new information. And what do we call this systematic approach? Jodie?

W2: Are you talking about the scientific method?

W1: Yes, absolutely. The scientific method: how scientists
deal with new information. The scientific method begins as a researcher makes observations, either in the field or in a research laboratory, and then formulates a hypothesis. And a hypothesis is simply a statement or explanation that’s consistent with the available evidence. Sometimes a hypothesis takes the form of a model that appears to provide a reasonable explanation for a phenomenon. And to be useful, a hypothesis must be testable.

W2: Excuse me, professor, but could you say that a hypothesis is kind of a yes–no question? Like, is this model true? Is it a true explanation for something we observe … yes or no?

W1: You could put it that way, yes. Is this hypothesis correct? Is it supported by data? And this is where the scientific method gets very systematic. The hypothesis must be testable, so the experiment must be designed so it either confirms or discredits the hypothesis. And when a hypothesis has been tested critically, under many different conditions, by many different researchers, using a variety of approaches, and the hypothesis is consistently supported by the evidence, it gradually acquires the status of a theory. And by the time an explanation or model is regarded as a theory, it’s widely accepted by most scientists in the field. For example, there’s little or no disagreement about the three tenets of cell biology: first, that all organisms consist of one or more cells; second, the cell is the basic unit of structure for all organisms; and third, all cells arise only from preexisting cells. In other words, biologists agree that the cell is the basic unit of life.

M: So that’s a fact?

W1: The three tenets of cell biology are facts until we know otherwise.

Listen to part of a lecture in a history class. The professor is talking about aboriginal Canadians.

At the time of the first European settlement in North America, as many as half a million Native people were already living in what would later become Canada. Aboriginal peoples inhabited all areas of present–day Canada, but they were unevenly scattered across the land. The majority lived along
the Pacific Coast, in the area of the Great Lakes, and in the southeast. The vast interior of the country was thinly populated.

Aboriginal Canadians lived in a close relationship with nature. Wherever they lived, the people were well adapted to their environment. Their economies were organized around the food supply. Most of the people were hunters and gatherers, living in mobile bands and following the seasonal rhythms of the food supply—the fish and game they depended on.

All right. Let’s take a look at some of the cultural characteristics of the aboriginal peoples. Generally, we can divide aboriginal Canadians into five major groups, based on geography.

First, across most of Canada, from the Yukon to the Atlantic, were the various forest tribes who shared the hunting– gathering lifestyle. Despite their different languages and belief systems, all of the hunter–gatherers faced similar environmental challenges, so they shared many aspects of everyday life. They lived in small bands that migrated frequently. They used technology such as the birch–bark canoe. They made tools, weapons, clothing, and ceremonial objects from materials that were available locally. They were skilled in trapping fur–bearing animals and in curing animal skins, which gave Canada its first staple industry.

Second, to the north, were the Inuit. These were people well adapted to life in the Arctic, a region of cold, dark winters and short summers. The Inuit were completely dependent on fish and animal life. At sea they traveled in the kayak, and on land, the dog–sled. In the winter they lived in snow huts called igloos, and in the summer they lived in skin tents. They made clothing from caribou hides. They were skilled at making tools from animal bones and ivory.

The third major group lived to the south, in the area around the Great Lakes. Many of these people lived year round in permanent villages. They were the only group who pursued agriculture. The main crops were corn, beans, squash, and tobacco. Agriculture enabled thousands of people to live together in societies and develop complex political systems. The largest of these societies formed separate nations, and these nations dealt with each other through networks of kinship, trade, and sometimes war. They had well established trade routes and methods of trade. They exchanged goods and information long before the Europeans arrived.

The fourth group of aboriginal Canadians lived on the western plains. These were the tribes with the organization to hunt the large herds of prairie bison. The Plains people were excellent hunters. They developed efficient methods for hunting the bison that gathered in the same winter and summer ranges every year, moving back and forth along well–established pathways. The Plains people also hunted other animals, but the bison remained the basis of their economy, not to mention their ability to endure the long prairie winters.

Finally, in the far west, were the people adapted to a life of fishing. Food was abundant in this region of many rivers. The West Coast tribes were the great traders of aboriginal Canada. Both food and trade centered on salmon. The rich resource base of salmon and cedar enabled the coastal tribes to accumulate considerable amounts of wealth.

Listen to a discussion between a student and her tutor.

W: I want to go over a few things before the midterm exam. Okay?

M: Okay.

W: Dr. Peters said galaxies would be on the exam. So … uh … especially I wanted to … uh … talk about galaxies.

M: Okay. Cool.

W: Like how … um … I know that some galaxies are relatively close to one another. In the lecture she said galaxies don’t act alone. They can influence each other and even collide with other galaxies.

M: Uh–huh

W: She said that small galaxies can be pulled together by gravity, and then they can blend to form more massive galaxies … except … uh … let me ask you this … about galaxies colliding. If two galaxies collide, then don’t the stars run into each other? I mean, if stars collide, then why don’t they just blow up or make bigger stars, or is it they just combine into bigger galaxies?

M: Well, you see, when galaxies collide, they actually pass through one another.

W: They do?

M: Yeah.

W: How?

M: Let’s back up a bit … uh … okay. So … yeah, galaxies
can be pulled together by their mutual gravitational attraction. But the individual stars don’t actually bump into each other. That’s because of the huge distances between stars. I mean, interstellar distances are really enormous.

W: Astronomical.

M: Yeah, astronomical distances between stars. I mean,
the distances between galaxies are very large, but compared to stars, galaxies are relatively close to one another. And when gravity pulls two galaxies together, they sort of collide, but the stars just pass by each other, and what really happens is, the galaxies don’t actually crash. But these so–called collisions do tend to distort a galaxy’s shape. Eventually, two smaller galaxies become a large elliptical galaxy. So, we can say that the interaction between the galaxies has the effect of—it sort of plays a role in their evolution. The evolution of galaxies—the process of formation—is always going on.

W: Yeah, that’s what Dr. Peters said. And she said we know this from computer models.

M: Yeah, that’s right. The models suggest that collisions between spiral galaxies tend to make elliptical ones. The Milky Way is expected to collide with the Andromeda Galaxy in the next few billion years, and this will create an even huger elliptical galaxy.

W: So, then a spiral galaxy like the Milky Way probably never collided with any others?

M: Well … hmm … we’re always learning new things about galaxies. Astronomers argue and speculate about this stuff all the time. They don’t know everything about the evolution of galaxies. But they do have some idea about their origins.

W: You mean the Big Bang.

M: Yup. The Big Bang.

W: The Big Bang—that’ll be on the exam. Why don’t we
go over that too?

M: Sure. We can do that.

Listen to part of a discussion in a communications class.

M1: Most consumers believe they are immune to advertising. They believe they buy things based purely on the value of the product. They think advertising plays little or no role. But advertisers know better. Surveys and sales figures show that advertising can be very effective. This is because advertising works below the level of our awareness. It works even on people who think they’re immune to its message. In fact, ads are designed to have an effect while being laughed at, criticized, mocked … anything except being ignored. To understand how ads work, we need to analyze the language used in the advertising claim. The claim is the spoken or text part of an ad that makes a statement about the superiority of the product. If you study advertising claims, you should be able to recognize ads that are misleading. Some claims are complete lies. Some are honest statements about a truly superior product. But most claims fall somewhere in between. They’re not exactly lies, nor are they helpful information. They fall on the narrow line between true and false … through a careful choice of words. Many claims fall into this category because they’re applied to “parity products.” And what do I mean by parity product? Uh … Jessica?

W: A parity product is something just like everything else. I mean, there are lots of different brands for the same product—like cereal or … shampoo or … something—and they’re all basically the same.

M1: Yes, that’s correct. And because no single product is truly better than others, the ad has to create the illusion of superiority. In fact, the largest advertising budgets are those that promote parity products—such as cereal and shampoo—also soft drinks, beer, detergents, and headache remedies—all parity products, with several brands that are all similar in quality. If any product is truly better than others, the ad will provide solid evidence of its superiority. But for a product that’s merely the same quality as others, the advertising has to create the illusion of being superior. To create this illusion, advertisers depend on a handful of basic techniques. One technique is to compliment the consumer. This is when the claim says that the consumer is special or has good taste. The ad flatters the consumer by using some sort of praise to make him or her feel good. Another technique … another type of claim … is the celebrity endorsement. You’ve all seen this one. Somebody famous or someone with authority appears in the ad to give his or her endorsement to the product.

M2: Like when a basketball player endorses sneakers.

W: Right! Or when an actor or an actress sells clothing or makeup—

M2: Or cars.

W: They even endorse pizza. Or how about when a— when someone who used to be in politics sells vitamins or painkillers? That always seems funny to me.

M1: And remember, one way ads work is by seeming funny or amusing. If something is funny to you, it’s having an effect on you. Okay then. I think you all know how the celebrity endorsement works. Another advertising technique is the scientific or statistical claim. This kind of ad uses some sort of scientific proof or experiment, very specific numbers, or an impressive–sounding mystery ingredient.

M2: Like when they say their toothpaste causes 50% fewer cavities.

W: Or their breakfast cereal has all 25 of the essential vitamins and minerals, or 50% more nutrition. Or whatever.

M1: Whatever is exactly it! The claim will be some number that may not be true, but it sure does sound impressive. You see, advertisers make any outrageous claim because it sounds good and because they know that few people will think about it critically. After all, smart consumers aren’t influenced by ads … are they?

Listen to part of a lecture in a geology class. The professor is talking about streams.

Streams are the most dynamic agents of geological change on the surface of the planet. The force of moving water has the ability to erode, carry, and deposit sediment. A stream can cut down through uplifted land toward its base level, the lowest level its channel can erode to, which for most streams is sea level.

Streams respond immediately to changes in their environment. For example, when a heavy storm drops 25 centimeters of rain on a drainage basin, the streams in that region will rise quickly and flow more rapidly. The increase in stream flow will erode greater volumes of sediment. The sediment is later deposited downstream in places where the flow becomes blocked or slowed by debris.

A stream’s environment is always changing. A stream’s gradient—that is, the slope of the stream bed—must constantly adjust to maintain a balance between erosion and deposition — deposition being the deposit of sediment in the stream bed. A stream in a state of dynamic equilibrium is called a graded stream. The equilibrium of any graded stream is only temporary. It lasts only until the next change in the environment. For instance, there may be a sudden increase in sediment load—say, from a volcanic mudflow or the collapse of a stream bank—and this increase in sediment will upset the stream’s equilibrium. Any change in sediment load will force the stream to adjust. Anything that disturbs the stream’s equilibrium will cause a response.

Streams also respond to tectonic events. For instance, if normal faulting occurs across a stream channel, and the downstream section drops during an earthquake, a waterfall will form immediately. The stream then uses its increased energy to erode the edge of the newly uplifted portion. The stream always responds in a way that reduces the effects of the change and M: establishes a new graded state.

Waterfalls and rapids occur at sudden drops in the ground level along a stream’s course. Usually they occur where erosion removes softer sections of rock, leaving harder rock as a “step” in the stream’s profile. They also occur where faulting lowers or raises a portion of the stream bed. A waterfall exists only as long as the conditions that created it. A waterfall’s plunging water cuts a deep pool at the base of the falls, called a plunge pool. The plunge pool undermines the step where the water falls off. As the falling water erodes the step away, the waterfall migrates upstream. Sometimes a waterfall gradually wears down to rapids, which over time completely erode, eventually M: returning the stream to its original graded state.

The best known waterfall in North America is Niagara Falls. Niagara Falls is roughly 55 meters high and 670 meters wide. It was created about 12,000 years ago, when the last great ice sheet retreated. The withdrawal of the ice uncovered a ridge of dolostone, which is resistant to erosion. Since then, the falls has migrated southward 11 kilometers from its point of origin. Billions of liters of water flow over the falls every year. The plunging water erodes the shale bed below the resistant cap of dolostone, and this continues to undercut the falls. In the past, the falls retreated at a rate of approximately one meter per year. However, today the United States and Canada divert approximately 75 percent of the river’s discharge to generate hydroelectric power, and this diversion of water has greatly slowed the retreat of the falls.

Listen to a conversation between a student and a professor.

M: Hi, Professor Campbell. I’m glad I caught you.

W: How are you, Tyler?

M: I’m doing great, looking forward to summer … and I wanted to thank you again for your recommendation … you know, the camp counselor position.

W: Oh, no problem. I was happy to do it. So, have you heard?

M: Yeah! I got the job!

W: Oh, that’s great news! Congratulations!

M: Thanks. Yeah, I just found out this morning. Next week I go in to meet the rest of the team, I mean the other counselors … and the director of the youth program. Some of them—the director, of course—I already met during the interview.

M: That’s wonderful, Tyler! I know you’ll do a great job, and this is an excellent way to get started in environmental education. I know the director very well. The summer youth program is one of the best in the country.

W: It’s a big deal. I know! I’m really excited about it. You’ll have to let me know how it goes.
I will! Actually, in the interview the director asked if I’d write for their blog, and I said, of course, that’s something I had hoped to do. They have a great website, and I look forward to contributing.

W: It’s good exposure. Will you post some of your photographs?

M: Sure, of course. I’m sure to get lots of good pictures. Mainly I’ll be working with the kids, supervising hikes … teaching ecology … but also have to document our trips in words and photos. We’ll also have journal writing and photography workshops for the kids.

W: This job is perfect for you.

M: Yeah, I think so, and I’m sure your recommendation helped. Oh, another thing … did you see my photograph in the new brochure … the one for environmental studies?

W: I probably did. I’ve seen some of the new brochures. Which photo was yours?

M: The one of students fishing.

W: Oh, yes! With the boats?

M: Yeah, that’s the one. They were catching fish for tagging.

W: Then I did see it. Good job!

M: I submitted five images, and that was the one the editor picked. They put it on the website too.

W: Good, good. Well, I look forward to your blog posts and seeing more of your photos.

M: I start right after finals. In fact, I only get three days off after my last exam, and then we have orientation with the kids. My first blog post will be about the orientation.

W: You’ll be busy this summer.

M: Yeah, I will, but in a good way.

W: Mm–hmm. Well, I’m glad you dropped in. I have a lecture in five minutes, so I … uh …

M: Okay. I just wanted to let you know I got the job. And thanks again. I really mean that.

W: It’s my pleasure, Tyler. Stay in touch!

Listen to part of a discussion in a psychology class.

M1: Where in your body is this entity known as the “self ”? Where is this you that perceives? Well, a few researchers have been asking this question. They’ve used various methods to find out where people believe their selves to be, and basically, the responses divide into two groups, two regions of the body. Where do you think the self is?

W: I’d say somewhere in the chest … like in the heart … or somewhere around the heart.

M2: I’m guessing it’s in the brain because it’s where our thinking goes on.

M1: Those are both good answers. That’s exactly it. The research shows that the vast majority of people say their self is located either in their heart or their head. Some researchers probed further. They tried to find out whether more people chose the heart or the head. At first, the head seemed to be ahead. For example, one study used structured interviews to probe the location of the self.

W: How did they define the self? I mean, doesn’t the word mean different things to different people?

M1: Good question. This particular study defined the self as “the I that perceives.”

W: Where perception is. Consciousness.

M1: That’s right. And the results were that 83 percent of the subjects said their self was a point between and behind their eyes … in other words, in the center of their head.

M2: Interesting. So, this supports the position that the brain is the center of consciousness. That makes sense to me.

M1: Other studies used a different approach to the question. In another study, the researchers showed 87 online volunteers an outline of a human form and asked them to place an X on the spot where they felt their self was. Two general groups of responses emerged. The larger of these groups indicated that the self was near the brain, and a smaller group said near the heart.

M2: The same two responses as the other study.

W: But don’t these different responses suggest that some studies are better than others at getting people to locate their true selves?

M1: That’s another good question. Methodology is key. So, let’s look at another study and another method. This time, the researchers used physical pointers to probe the location of the self. The pointer was a short metal stick clamped to a longer pole. The researchers slowly moved this pointer up and down people’s bodies, telling them to call out when the stick pointed directly at them … at the “I” spot, the self. Their results were interesting and significant. They found that if they started from the top, subjects were more likely to respond when the pointer hit the upper face. However, when they started from the bottom, at the person’s feet, the same subjects were more likely to call out when the pointer reached the upper torso, the chest. So, depending on the direction the pointer moved, the subjects said that both locations—the head and the chest—felt right.

M2: Wow. So, the “I” spot can change, depending on the context?

M1: Uh–huh … according to this study anyway.

M2: I guess that makes sense … sort of … well … considering there are different things we could mean when we talk about the self.

W: Maybe there just isn’t one right answer to the question. What if the self really does exist in different places for different people? For some people, maybe the self is where thinking takes place. For others, maybe the self is their emotional center.

M1: However we define the self, these three studies suggest that people lean toward the idea of a specific place where their self resides. One place is in the head. Another is in the heart. And for some people, both places are true in different contexts.

Listen to part of a lecture in a music appreciation class.

In Western classical music, singing voices are classified for male and female singers. The various male and female voices describe performers who sing in different ranges of high and low sound frequency. The high and low female voices are the soprano and the alto, with the mezzo–soprano as an intermediate class. The high and low male voices are the tenor and the bass, with baritone as an intermediate class. Today, we’ll be listening to recordings of some of the more significant male roles in opera, so I’ll talk more about the male voices: the tenor, the baritone, and the bass. Tomorrow we’ll focus on the female voices.

In general, men have deeper voices than women do. This is because men have longer and thicker vocal cords. The average man’s voice has a peak sound frequency of about 125 hertz, while that of an average woman’s voice is about 250 hertz.

For the male voice, the high range is the tenor. The name “tenor” comes from the Latin word meaning “to hold.” In early choral music, the tenor was the middle voice that held all of the other voices together. Beneath the tenor—voices lower in sound frequency—are the baritones and the basses, and above the tenor—voices higher in frequency—are the altos. The earliest surviving opera that’s still widely performed is Monteverdi’s Orfeo. The title role of the character Orfeo was written for the tenor. The role of Orfeo set the standard for leading male roles to be taken by the tenor voice.

There are several types of tenors, including the lyric tenor, which is the graceful tenor found in several of Mozart’s operas. Another is the heldentenor, the most heroic male voice, a voice typical for the heroes in Wagner’s operas. In fact, some of Wagner’s roles are the most demanding ever for the tenor voice. Italian opera, too, has a multitude of heroic roles for a tenor voice that can accomplish high, trumpet–like tones. In a few minutes, we’ll listen to some examples of these different tenors, but I just want to give you a brief introduction now.

Okay. The middle range of the male voice is the baritone. In general, German opera demands an especially strong middle– range baritone. The baritone voice is the so–called “normal” range of the male voice. The majority of male concert singers and singing actors in musical theater are baritones. This is because a man singing in his natural range can articulate words more clearly than a singer who is in some way extending his voice—either upward or downward—an effort that increases
the risk of straining the voice.

Finally, we have the lowest range of the male voice: the bass. Throughout the history of opera, the bass voice has been used to portray father figures and elder statesmen, as well as the darkest villains. The first internationally successful Russian opera gave the main role to a bass singer. Since then, leading roles for the deep and powerful bass have become especially prized by performers and opera lovers everywhere. There are several variations on the bass voice. One is the lighter bass– baritone, which Mozart favored for many of his characters. Another is the basso profundo, the lowest male voice and the rarest of all singing voices. Because performers who can sing basso profundo are so rare, composers seldom write roles for it.