Listen to a conversation between a student and her professor.
P: Before we get started, I…I just wanted to say I’m glad you chose food science for your major courses study.
S: Yeah, it seems like a great industry to get involved with. I mean with the four-year degree in food science, I’ll always be able to find a job.
P: You’re absolutely right. Before entering academia, I worked as a scientist for several food manufacturers and for the US Food and Drug Administration.
I even worked on a commercial fishing boat in Alaska a couple of summers while I was an undergraduate. We bring in the day’s catch to a floating processor boat where the fish got cleaned, packaged and frozen right at sea.
S: That’s amazing! As a matter of fact, I’m sort of interested in food packaging.
P: Well, for that, you’ll need a strong background in physics, math and chemistry.
S: Those are my best subjects. For a long time, I was leading towards getting my degree in engineering.
P: Well, then you should have a problem. And fortunately, at this university, the department of food science offers a program in food packaging. Elsewhere, you might have to hammer courses together on your own.
S: I guess I like it a lot then. I am… so since my appointment today is to discuss my term paper topic, I wanted to ask, could I write about food packaging?
I realize we’re supposed to research food-born bacteria, but food packaging must play a role in all of that, right?
P: Absolutely! Maybe you should do some preliminary research on that.
S: I have! That’s the problem. I’m overwhelmed.
P: Well, in your reading, did anything interest you in particular? I mean something you’d like to investigate.
S: well, I was surprised about the different types of packaging used for milk. You know, clear plastic bottles, opaque bottles, carton board containers…
P: True! In fact, the type of packaging has something to do with the way milk’s treated against bacteria.
S: Yeah, and I read a study that showed how light can give milk a funny flavor and decrease the nutritional value. And yet most milk bottles are unclear. What’s up about that?
P: Well consumers like being able to visually examine the color of the milk. That might be one reason that opaque bottles haven’t really called on. But that study… I’m sure there is more study on the subject.
You shouldn’t base your paper on only one study.
S: Maybe I should write about those opaque plastic bottles. Find out if there are any scientific reasons they aren’t used more widely?
Maybe opaque bottles aren’t as good at keeping bacteria from growing in milk after the bottle has been opened for something… but where to begin researching this? I don’t have a…
P: You know, there is a dairy not far from here in Chelsea. It was one of the first diaries to bottle milk in opaque plastic, but now they’re using clear plastic began.
And they’re always very supportive of the university and our students, and if you want it…
S: Yeah, I like that idea.
Listen to a conversation between a student and a librarian employee.
S: Excuse me. Can you help me with something?
L: I’ll do my best. What do you need?
S: Well, I’ve received a letter in my mailbox saying that I’m supposed to return a book that I checked out back in January, it’s call “Modern Social Problems”.
But because I’m writing my senior thesis, I’m supposed to be able to keep the book all semester.
L: So you signed up for extended borrowing privileges?
L: But we are still asking you to bring the book back?
L: Well, let me take a look and see what the computer says. The title was “Modern Social Problems”?
L: OK. Oh, I see, it’s been recalled. You can keep it all semester as long as no one else requests it. But, someone else has.
It looks like one of the professors in the sociology department requested it. So you have to bring it back, even though you’ve got extended borrowing privileges.
You can check out the book again when it’s returned in a couple of weeks.
S: But I really need this book right now.
L: Do you need all of it or is there a certain section or chapter you’re working with?
S: I guess there is one particular chapter I’ve been using lately for a section of my thesis. Why?
L: Well, you can photocopy up to one chapter of the book. Why don’t you do that for the chapter you’re working on right now?
And by the time you need the rest of the book, maybe it will have been returned. We can even do the photocopy for you because of the circumstances.
S: Oh, well, that would be great.
L: I see you’ve got some books there. Is that the one you were asked to return?
S: No, I left it in my dorm room. These are books I need to check out today. Is it Ok if I bring that one by in a couple of days?
L: Actually, you need to return it today. That is if you want to check out those books today. That’s our policy.
S: Oh, I didn’t know that.
L: Yeah, not a lot of people realize that. In fact, every semester we get a few students who have their borrowing privileges suspended completely because they haven’t returned books.
They’re allowed to use books only in the library. They’re not allowed to check anything out because of unreturned books.
S: That’s not good. I guess I should hand back onto the dorm right now then.
L: But, before you go, what you should do is fill out a form requesting the book back in two weeks. You don’t want to waste any time getting it back.
S: Thanks a lot. Now I don’t feel quite so bad about having to return the book.
Listen to part of a lecture in a theater class
Pro: As we have seen, the second half of the 18th century was an exciting time in Europe: it was not only an age of great invention,
but social changes also led to a rise in all sorts of entertainment, from reading to museums, to travel.
And finding himself in the middle of this excitement was an accomplished French painter named Philippe Jacques de Loutherbourg.
Loutherbourg arrived in England in 1771, and immediately went to work as a site designer at the famous Drury Lane Theater in London.
From his first shows, Loutherbourg showed a knack for imagination and stage design, all in the interest of creating illusions that allowed the audience to suspend disbelief completely.
He accomplished this by giving the stage a greater feeling of depth, which he did by cutting up some of the rigid background scenery, and placing it at various angles and distances from the audience.
Another realistic touch was using three-dimensional objects on the set, like rocks and bushes as opposed to two-dimensional painted scenery.
He also paid much more attention to lighting and sound than had been done before.
Now, these sets were so elaborate that many people attended the theater more for them than for the actors or the stories. At the time, people were wild for travel and for experiencing new places; but not everyone could afford it.
Loutherbourg outdid himself however, with a show that he set up in his own home. He called it the “Eidophusikon”.
Eidophusikon” means something like representation of nature, and that’s exactly what he intended to do: create realistic moving scenes that change before the audiences’ eyes.
In this, he synthesized all his tricks from Drury
Lane: mechanical motions, sound, light, other special effects to create, if you will, an early making production. The “Eidophusikon” was Loutherbourg’s attempt to release painting from the constraints of the picture frame.
After all, even the most action field exciting painting can represent only one moment in time; and any illusion of movement is gone after the first glance.
But Loutherbourg, like other contemporary painters, wanted to add the dimension of time to his paintings. You know, the popular thinking is that Loutherbourg was influenced by landscape painting.
But why can’t we say that the “Eidophusikon” actually influenced the painters? At the very least we have to consider that it was more … it was more of a mutual thing. We know, for example,
that the important English landscape painter Thomas Gainsborough attended almost all of the yearly performances, and his later paintings are notable for their increased color and dynamic use of light.
Loutherbourg’s influence on the theater though, he was incredibly influential:
the way he brought together design and lighting and sound as a unified feature of the stage, can easily be seen in English theater’s subsequent emphasis on lighting and motion.
Now, the “Eidophusikon” stage was actually a box: a few meters wide, a couple meters tall and a couple meters deep. That is, the action took place within this box. This was much smaller of course than the usual stage.
But, it also allowed Loutherbourg to concentrate the lighting to better effect.
Also, the audience was in the dark, which wouldn’t be a common feature of the theater until a hundred years later.
The show consisted of a series of scenes, for example, a view of London from sunrise that changes as the day moves on;
mechanical figures, such as cattle, moved across the scene, and ships sailed along the river. But what really got people was the attention to detail, much like his work in Drury Lane.
So, for example, he painted very realistic ships, and varied their size depending on their distance from the audience.
Small boats moved more quickly across the foreground than larger ones did that were closer to the horizon.
Other effects, like waves, were also very convincing. They reflected sunlight or moonlight depending on the time of day or night. Even the colors changed as they would in nature.
Sound and light were important in making his productions realistic. He used a great number of lights,
and he was able to change colors of light by using variously colored pieces of glass, to create effects like passing clouds that suddenly change in color.
Furthermore, he used effects to make patterns of shadow and light, rather than using the uniform lighting that was common at the time.
And many of the sound effects he pioneered are still in use today, like creating thunder by pulling on one of the corners of a thin copper sheet. One of his most popular scenes was of a storm.
And there is a story that on one occasion, an actual storm passed over head during the show. And some people went outside, and they claimed Loutherbourg’s thunder was actually better than the real thunder.
Listen to a part of lecture in an environmental science class.
Lecturer: So since we’re around the topic of global climate change and its effects, in Alaska, in the northern Arctic part of Alaska, over the last thirty years or so, temperature has increased about half a degree Celsius per decade,
and scientists have noticed that there’ve been changes in surface vegetation during this time. Shrubs are increasing in the “tundra”. Tundra is flat land with very little vegetation.
Just a few species of plants grow there because the temperature is very cold, and there’s not much precipitation. And because of the cold temperatures, the tundra has two layers:
top layer, which is called the active layer, is frozen in the winter and spring, but thaws in the summer. Beneath this active layer is the second layer called “permafrost”, which is frozen all year around, and is impermeable to water.
Female Student: So because of the permafrost, none of the plants that grow there can have deep roots, can they?
Lecturer: No, and that’s one of the reasons that shrubs survive in the Arctic. Shrubs are little bushes. They’re not tall and being low in the ground protect them from the cold and wind.
And their roots don’t grow very deep, so the permafrost doesn’t interfere with their growth. OK?
Now since the temperatures have been increasing in Arctic Alaska, the growth of shrubs has increased. And this is presented to climate scientists with a puzzle…
Male Student: I’m sorry, when you say the growth of shrubs has increased, do you mean the shrubs are bigger, or that there are more shrubs?
Lecturer: Good question! And the answer is both. The size of the shrubs has increased and shrub cover has spread to what was previously shrub-free tundra. Ok, so what’s the puzzle?
Warmer temperatures should lead to increased vegetation growth, right? Well, the connections are not so simple. The temperature increase has occurred during the winter and spring,
not during the summer. But the increase in shrubs has occurred in the summer. So how can increase temperatures in the winter and spring result in increased shrub growth in the summer?
Well, it may be biological processes that occur in the soil in the winter, that cause increased shrub growth in the summer, and here’s how:
there are “microbes”, microscopic organisms that live in the soil. These microbes enable the soil to have more nitrogen, which plants need to live and they remain quite active during the winter.
There’re two reasons for this: first, they live in the active layer, which, remember, contains water that doesn’t penetrate the permafrost.
Second, most of the precipitation in the Arctic is in the form of snow. And the snow, which blankets the ground in the winter, actually has an insulating effect on the soil beneath it.
And it allows the temperature of the soil to remain warm enough for microbes to remain active. So there’s been increase in nutrient production in the winter.
And that’s what’s responsible for the growth of shrubs in the summer and their spread to new areas of the tundra. Areas with more new nutrients are the areas with the largest increase in shrubs.
Female student: But, what about run-off in the spring, when the snow finally melts? Won’t the nutrients get washed away? Spring thaw always washes away soil, doesn’t it?
Lecturer: Well, much of the soil is usually still frozen during peak run-off. And the nutrients are deep down in the active layer anyway, not high up near the surface, which is the part of the active layer most affected by run-off.
But as I was about to say, there’s more to the story. The tundra is windy, and the snow is blown across the tundra, it’s caught by shrubs. And deep snow drifts often form around shrubs.
And we’ve already mentioned the insulating effect of snow. So that extra warmth means even more microbial activity, which means even more food for the shrubs, which means even more shrubs and more snow around etc..
It’s a circle, a loop. And because of this loop, which is promoted by warmer temperatures in winter and spring, well, it looks like the tundra may be turning into shrub land.
Female student: But will it be long term? I mean maybe the shrubs will be abundant for a few years, and then it’ll change back to tundra.
Lecturer: Well, shrub expansion has occurred in other environments, like semiarid grassland, and tall grass prairies. And shrub expansion in these environments does seem to persist, almost to the point of causing a shift.
Once is established, shrub land thrives, particularly in the Arctic, because Arctic shrubs are good at taking advantage of increased nutrients in the soil, better than other Arctic plants.
Lecturer: So, continuing our discussion of desert lakes, now I want to focus on what’s known as the “Empty Quarter”. The “Empty Quarter” is a huge area of sand that covers about a quarter of the Arabian Peninsula.
Today it’s pretty desolate, barren and extremely hot.
But there’ve been times in the past when monsoon rains soaked the Empty Quarter and turned it from a desert into grassland that was dotted with lakes and home to various animals. There were actually two periods of rain and lake formation:
the first one began about 35000 years ago; and the second one dates from about 10000 years ago.
Female Student: Excuse me, Professor. But I’m confused. Why would lakes form in the desert? It’s just sand, after all.
Lecturer: Good question! We know from modern day desert lakes, like Lake Eyre, South Australia, that under the right conditions, lakes do form in the desert.
But the Empty Quarter lakes disappeared thousands of years ago. They left behind their beds or basins as limestone formations that we can still see today.
They look like low-lying, white or grey builds, long, narrow hills with flat tops, barely a meter high. A recent study of some of the formations presents some new theories about the area’s past.
Keep in mind though that this study only looked at 19 formations. And about a thousand have been documented. So there’s a lot more work to be done.
According to the study, two factors were important for lake formation in the Empty Quarter: first the rains that fell there were torrential. So it would’ve been impossible for all the water to soak into the ground. Second, as you know,
sand dunes contain other types of particles, besides sand, including clay and silt.
Now, when the rain fell, water ran down the sides of the dunes, carrying clay and silt particles with it. And wherever these particles settled, they formed a pan, a layer that water couldn’t penetrate.
Once this pan formed, further run-off collected, and formed a lake. Now, the older lakes, about half the formations, the ones started forming 35000 years ago, the limestone formation we see,
they’re up to a kilometer long, but only a few meters wide, and they’re scattered along the desert floor, in valleys between the dunes.
So, the theory is, the lakes formed there, along the desert floor, in these long narrow valleys. And we know, because of what we know about similar ancient desert lakes, we know that the lakes didn’t last very long, from a few months to a few years on average.
As for the more recent lakes, the ones from 10000 years ago, well, they seemed to have been smaller, and so may have dried up more quickly.
Another difference, very important today for distinguishing between older lake beds and newer ones, is the location of the limestone formations.
The more recent beds are high up in the dunes. Why these differences? Well, there are some ideas about that, and they have to do with the shapes of the sand dunes, when the lakes were formed.
37000 years ago, the dunes were probably nicely rounded at the top, so the water just ran right down their sides to the desert floor.
But there were thousands of years of wind between the two rainy periods, reshaping the dunes.
So, during the second rainy period, the dunes were kind of chopped up at the top, full of hollows and ridges, and these hollows would’ve captured the rain right there on the top.
Now, in grassland of Lake Ecosystem, we’d expect to find fossils from a variety of animals, and numerous fossils have been found at least at these particular sites.
But, where did these animals come from? Well, the theory that has been suggested is that they migrated in from nearby habitats where they were already living.
Then as the lakes dried up, they died out. The study makes a couple of interesting points about the fossils, which I hope will be looked at in future studies.
At older lake sites, their fossil remains from hippopotamuses, water buffalo, animals that spend much of their lives standing in water, and also, fossils of cattle.
However, at the sites of the more recent lakes, there’re only cattle fossils, additional evidence for geologists that these lakes were probably smaller, shallower, because cattle only use water for drinking.
So they survive on much less. Interestingly, there are clams and snail shells; but, no fossils of fish. We’re not sure why. Maybe there is a problem with the water.
Maybe it was too salty. That’s certainly true of other desert lakes.
Listen to part of a lecture in a linguistics class. The professor has been discussing Animal communication systems.
L: OK, so last time, we covered the dances honey bees due to indicate where food can be found and the calls and sounds of different types of birds.
Today, I’d like to look at some communication systems found in mammals, particularly in primates, such as orangutans, chimpanzees, gorillas… Yes, Thomas?
T: Excuse me, Professor. But when you talk about gorilla language, do you mean like, those experiments where humans taught them sign language or a language like…
L: OK, wait just a minute. Now, who in this class heard me use the word “language”? No one I hope. What we’re talking about here, are systems of communication, all right?
T: Oh, sorry, communication, right. But could you maybe, like, clarify with the differences?
L: Of course, that’s a fair question. OK, well, to start with, let’s make it clear that language is a type of communication, not the other way around.
OK, so all communication systems, language included, have certain features in common. For example, the signals used to communicate from the bee’s dance movements, to the word and sentences found in human languages.
All these signals convey meaning. And all communication systems serve a purpose, a pragmatic function of some sort. Warning of danger perhaps or offering other needed information.
But there’re several features peculiar to human language that have, for the most part, never been found in the communication system of any other species.
For one thing, learn ability. Animals have instinctive communication systems. When a dog, a puppy gets to certain age, it’s able to bark.
It barks without having to learn how from other dogs, it just barks. But much of human language has to be learned from other humans. What else makes human language unique? What makes it different from animal communication? Debber?
D: How about grammar? Like having verbs, nouns, adjectives?
L: OK, that’s another feature. And it’s a good example…
D: I mean I mention this cause like in my biology class last year, I kind of remember talking about a study on prairie dogs, where, I think the researchers claimed that the warning cries of prairie dogs constitute language,
because they have this, different parts of speech. You know, like nouns, to name the type of predator they spotted, adjectives to describe its size and shape, verbs…, but now it seems like…
L: All right, hold on a moment. I’m familiar with the study you’re talking about. And for those of you who don’t know, prairie dogs are not actually dogs.
They’re type of rodent who burrows in the ground and the grasslands of the west United States and Mexico. And in this study, the researchers looked at the high-pitched barks a prairie dog makes when it spots predator.
And from this they made some pretty.., well, they made some claims about these calls qualifying as an actual language, with its own primitive grammar.
But actually, these warning calls are no different from those found among certain types of monkeys.
Well, let’s not even get into the question whether concepts like noun and verb can be meaningfully applied to animal communication. Another thing that distinguishes a real language is a property we call “discreteness”.
In other words, messages are built up out of smaller parts, sentences out of words, words out of individual sounds, etc.
Now maybe you could say that the prairie dog’s message is built from smaller parts, like say for example, our prairie dogs spot a predator, a big coyote approaching rapidly.
So the prairie dog makes a call that means “coyote”, then one that means “large”, and then another one to indicate its speed.
But you really suppose it makes any difference what order these calls come in? No. But the discrete units that make up language can be put together in different ways.
Those smaller parts can be used to form an infinite number of messages, including messages that are completely novel, that have never been expressed before.
For example, we can differentiate between: “A large coyote moves fast.” and say “Move the large coyote fast.” or “Move fast, large coyote.”, and I truly doubt whether anyone has ever uttered either of these sentences before.
Human language is productive and open-ended communication system, whereas no other communication system has this property.
And another feature of language that’s not displayed by any form of animal communication is what we call “displacement”.
That is, language is abstract enough that we can talk about things that aren’t present here and now. Things like “My friend Jo is not in the room.” or “It will probably rain next Thursday.”
Prairie dogs may be able to tell you about a hawk at circling over head right now, but they never show any inclination to describe the one they saw last week.