Narrator: Listen to a conversation between a student and a professor.
Professor OK, let’s see. Right. Modern Stagings of a Shakespearian Classic. Well, like I told you last week, I think that’s a great topic for your paper.
So the title would be something like … uh …
Student: I am not really sure, probably something like 20th century stagings of A Midsummer Night’s Dream.
Professor: Yes, I like that. Straightforward and to the point. So how is the research going?
Student: Well, that’s what I came to talk to you about.
I was wondering if you happen to have a copy of the Peter Brook production of A Midsummer Night’s Dream in your video collection.
I’ve been looking for it everywhere and I am having a really hard time tracking it down.
Professor: That’s because it doesn’t exist.
Student: You mean in your collection? Or at all?
Professor: I mean at all. That particular production was never filmed or recorded.
Student: Oh no. I had no idea. From what I read, that production, like, it influenced every other production of the play that came after it.
So I just assumed it had been filmed or videotaped.
Professor: Oh, It definitely was a landmark production.
And it’s not like it ran for just a week, but either it was never filmed or if it was the film’s been lost.
And it’s ironic because there’s even a film about the making of the production, but none of the production itself.
Student: So now what do I do? If there is no video.
Professor Well, think about it. This is the most important 20th century staging of A Midsummer Night’s Dream, right?
Student: But how can I write about Brook’s interpretation of the play if I can’t see his production.
Professor: Just because there’s no recording doesn’t mean you can’t figure out how it influenced other productions.
Student: Yeah, I guess there’s enough material around, but it will be a challenge.
Professor: True. But think about it, you are writing about dramatic arts, the theater, and that’s the nature of theater, isn’t it?
Student: You mean because it is live, when the performance is finished …
Professor: That’s it. Unless it’s filmed, it’s gone. But that doesn’t mean we can’t study it.
And of course some students in this class are writing about productions in the 19th century, there are no videos of those.
You know, one of the challenges for people who study theater is to find way of talking about something that’s really so transient, about something that, in a sense, doesn’t exist.
Narrator: Listen to a conversation between a student and a food service manager.
Student: Excuse me, Mrs. Hanson. My name is John, John Grant. I work as a waiter in the campus dining hall, in the faculty dining room.
Manager: What can I do for you, John?
Student: Well, I work week nights, except for Friday. I was wondering if I could switch from working the dinner service to working at lunch.
Manager: That’s going to be a problem. I am afraid we don’t have any openings at lunch time.
A lot of students want to work then, so it is really rare for us to have an open spot at that time of day.
Student: Oh, you see, I have joined this group, the University Jazz Band, and the band’s practice time is right around dinner time.
You know, it is so hard to get into this group, I must have auditioned like ten times since I have been at the school,
so I am … Anyway, so I was really hoping to have the dinner hour free so I can go to practice.
Manager: Well, we do have other open times, like breakfast.
Student: Eh, that won’t work, I am sorry. I mean that, I can’t work that early. I have this very important music class I got to take, and it is like, first thing in the morning.
Manager: Well, if you don’t mind working in the kitchen, we’ve got some pretty flexible hours for students doing food-prep work, anything from early morning to late afternoon.
Student: What’s prep work?
Manager: You prepare food for the cooks. You know, like cutting up vegetables for soup, or cleaning greens for salads.
Student: Oh, that doesn’t sound, I mean… Being a waiter, I get to see a lot of the professors, like in a different light, we joke around a little you know. In the classroom, they always have to be pretty formal, but …
Manager: Well, the money is no different since we pay students the same amount for any of the jobs here in food service, so it’s up to you.
Student: Oh, man. I always thought that sacrificing for my art, that’d mean working long hours as a musician for, like, no money. I didn’t think it’d mean, peeling carrots.
Manager: Let me see, I am offering you something that has the hours you want, it is right here on campus, and you make as much money as you did being a waiter, quite a sacrifice.
Student: I am sorry; I know you are just trying to help. I guess I should look into the food-prep job.
Manager: Ok, then, I’ll tell the kitchen manager that you will stop by tomorrow to talk about the job and schedule your hours.
And I will let the dining hall manager know that he needs to find a new waiter for the evening.
Student: Oh, ok, I guess that’s it. Thanks, Mrs. Hanson.
Narrator: Listen to part of a lecture in an art history class.
Professor: Good morning, ready to continue our review of prehistoric art?
Today, we will be covering the Upper Paleolithic Period, which I am roughly defining as the period from 35,000 to 8,000 BC.
A lot of those cave drawings you have all seen come from this period.
But we are also be talking about portable works of art, things that could be carried around from place to place. Here is one example.
This sculpture is called the Lady with the Hood1, and it was carved from ivory, probably a mammoth’s tusk.
Its age is a bit of a mystery. According to one source, it dates from 22,000 BC. But other sources claimed it has been dated closer to 30,000 BC. Amy?
Amy: Why don’t we know the exact date when this head was made?
Professor: That’s a fair question. We are talking about prehistory here.
So obviously the artists didn’t put a signature or a date on anything they did. So how do we know when this figure was carved?
Tom: Last semester I took an archaeology class and we spent a lot time on, studying ways to date things.
One technique I remember was using the location of an object to date it, like how deep it was buried.
Professor: That would be Stratigraphy.
Stratigraphy is used for dating portable art.
When archaeologists are digging at a site, they make very careful notes about which stratum (strata), which layer of earth they find things in.
And, you know, the general rule is that the oldest layers are at the lowest level.
But this only works if the site hasn’t been touched, and the layers are intact.
A problem with this dating method is that an object could have been carried around, used for several generations before it was discarded.
So it might be much older than the layer or even the site where it was found.
The stratification technique gives us the minimum age of an object, which isn’t necessarily its true age. Tom, in your archaeology class, did you talk about radiocarbon dating?
Tom: Yeah, we did. That had to do with chemical analysis, something to do with measuring the amount of radiocarbon that’s left in organic stuff.
Because we know how fast radiocarbon decays, we can figure out the age of the organic material.
Professor: The key word there is organic. Is art made of organic material?
Tom: Well, you said the lady with the hood was carved out of ivory. That’s organic.
Professor: Absolutely. Any other examples?
Amy: Well, when they did those cave drawings. Didn’t they use, like charcoal or maybe colors, dyes made from plants?
Professor: Fortunately, they did, at least some of the time. So it turns out that radiocarbon dating works for a lot of prehistoric art.
But again there’s a problem. This technique destroys what it analyzes, so you have to chip off bits of the object for testing.
Obviously we are reluctant to do that in some cases. And apart from that, there’s another problems.
The date tells you the age of the material, say, a bone or a tree; the object is made from, but not the date when the artist actually created it.
So, with radiocarbon dating, we get the maximum possible age for the object, but it could be younger.
Ok, let’s say our scientific analysis has produced an age range. Can we narrow it down?
Amy: Could we look for similar styles or motives? You know, try to find things common to one time period.
Professor: We do that all the time. And when we see similarities in pieces of art, we assume some connection in time or place.
But is it possible that we could be imposing our own values on that analysis?
Tom: I am sorry. I don’t get your point.
Professor: Well, we have all kinds of pre-conceived ideas about how artistic styles develop.
For example, a lot of people think the presence of details demonstrates that the work was done by a more sophisticated artist.
While a lack of detail suggests a primitive style. But trends in art in the last century or so certainly challenge that idea.
Don’t get me wrong though, analyzing the styles of prehistoric art can help dating them.
But we need to be careful with the idea that artistic development occurs in a straight line, from simple to complex representations.
Amy: What you are saying is, I mean, I get the feeling that this is like a legal process, like building a legal case, the more pieces of evidence we have, the closer we get to the truth.
Professor: Great analogy. And now you can see why we don’t have an exact date for our sculpture, the lady with the hood.
Narrator: Listen to part of a lecture in an environmental science class.
Professor: Ok, so we have been talking about theories that deal with the effects of human activity on the climate.
But today I’d like to talk a little bit about other theories that can explain variations in climate. And one of the best-known is called the Milankovitch Hypothesis.
Now what the Milankovitch Hypothesis is about? It says that variations in earth’s movements,
specifically in its orbit around the sun, these variations lead to differences in the amount of solar energy that reaches the earth.
And it is these differences in the amount of energy that’s reaching earth from the sun; it is what causes variations in earth’s climate.
Ok, a lot of people think of earth’s orbit around the sun as being perfectly circular,
as smooth and as regular as, say, the way that hands move on a well -made watch, but it just doesn’t work that way.
You are probably aware that the earth’s orbit around the sun, it is not shaped like a perfect circle.
It is more of an oval, it is elliptical. But the shape of this orbit isn’t consistent; it varies over time, over a period of about a thousand years.
Sometimes it is a little more circular, sometimes it is more elliptical. And when earth’s orbit is more elliptical, earth is actually closer to the sun during part of the year.
Which makes earth, and in particular, the northern hemisphere, warmer. And why is that important?
Well, because most of the planet’s glaciers are in the northern hemisphere, and if it gets too warm,
then glaciers will stop forming. And we’ve already talked about how that affects earth’s overall temperature.
The second movement involved in the hypothesis has to do with axial tilt.
The tilt of earth’s axis, that imaginary pole that runs through the center of the earth.
And depending on the angle it tilts at, the seasons can be more or less severe. It makes winters cooler and summers warmer,
or what some might say it is doing now; it makes summers less hot, and more importantly, the winters less cold.
Which just like what I mentioned before, can also stop, prevent glaciers from forming, or cause them to melt.
There is a third movement the hypothesis covers called precession.
Precession basically is the change in the direction of earth’s axis of rotation.
It will take me a million years to explain even just the basics of this movement as precession is quite complex. And all these details are way beyond our scope.
What’s important for you to understand is that these three movements,
well, they are cyclical, and they work together to form, to produce complex but regular variations in earth’s climate, and lead to the growth or decline of glaciers.
Now, when Milankovitch first proposed this theory in the 1920s, many of his colleagues were skeptical. Milankovitch didn’t have any proof.
Actually there wouldn’t be any evidence to support his hypothesis until the 1970s,
when oceanographers were able to drill deep into the seafloor and collect samples, samples which were then analyzed by geologists.
And from these samples they were able to put together a history of ocean temperatures going back hundreds of thousands of years,
and this showed that earth’s climate had changed pretty much the way Milankovitch’s hypothesis suggested it would.
So this evidence was pretty strong support for the Milankovitch Hypothesis. And by the 1980s, most people accepted this theory.
However, in the late 1980s, some scientists were exploring Devil’s Hole, which is basically an extensive water-filled cave, far from the ocean, in Nevada2, in the western United States.
Over millions of years, groundwater left deposits of a mineral called calcite3, on the rock within Devil’s Hole.
And by studying these calcite deposits, we can determine the climate conditions, the temperatures over the last half million years.
Well, the Devil’ s Hole findings contradicted the ones obtained during the 1970s, so basically the question was, were the ages of one or both the samples were wrong,
or were scientists misunderstanding the significance of the evidence.
Well, in the 1990s, a new study was done on the two samples. And the ocean floor samples were found to be correct, as were the samples from Devil’s Hole.
And now it is generally believed that the sample from Devil’s Hole correspond to variations in local climate,
in the western United States, rather than global climate changes.
Narrator: Listen to part of a lecture in a history class. The professor has been discussing ancient Egypt.
Professor: Ok, so one of the challenges that faced ancient civilizations like Egypt was timekeeping, calendars.
When you have to grow food for whole cities of people, it is important to plant your crops at the right time.
And when you start having financial obligations, rents, taxes, you have to keep track of how often you pay.
So today we will look at how the Egyptians addressed these problems.
In fact, they ended up using two calendars, one to keep track of the natural world, or their agriculture concerns, and another one that was used to keep track of the business functions of the Kingdom.
So let’s take a look at the hows and whys of one ancient Egyptian calendar system, starting with the Nile River.
Why the Nile? Well, there’s no other way to put it. Egyptian life basically revolved around the mysterious rise and fall of the river.
The success of their agriculture system depended upon them knowing when the river would change.
So, naturally, their first calendar was divided up into three seasons, each based on the river’s changes: inundation, subsidence and harvest.
The first season was the flooding, or inundation, when the Nile valley was essentially submerged in water for a few months or so.
And afterwards during the season of subsidence, the water would subside, or recede, revealing a new layer of fertile black silt and allowing for the planting of various crops.
And finally the time of the year would arrive when the valley would produce crops, such as wheat, barley, fruit, all ready to harvest.
Ok, so it was important to the ancient Egyptians to know when their Nile based seasons would occur, their way of life depended upon it.
Now, the way they used to count time was based on the phases of the moon, which, regularly and predictably, goes through a cycle, starting with a new moon, then to a full moon, and back again to the new moon.
Now this cycle was then used to determine the length of their month.
So, um, one lunar cycle was one Egyptian month, and about four of the months would constitute a season.
Now, 12 of these months was an approximately 354-day year. So they had a 354-day agricultural calendar that was designed to help them determine when the Nile would inundate the land.
Well, of course it had to be more complicated than that. The average amount of time between floodings wasn’t actually 354 days.
I mean, although it varies, the average was clearly longer than 354 days. So how did they keep this short calendar in step with the actual flooding of the Nile?
Well, their astronomers had discovered that at a certain time of year the brightest star, Sirius, would disappear. Actually, it’d be hidden in the glare of the Sun.
And then, a couple of months later, one morning in the eastern sky just before dawn, Sirius would reappear.
And it happened regularly, about every 365 days. Even more significantly, the reappearance of Sirius would occur around the same time as the Nile’s flooding.
And this annual event is called a heliacal rising4.
The heliacal rising was a fair indicator of when the Nile would flood.
The next new moon, after the heliacal rising of Sirius, which happened in the last month of the calendar year, marked the New Year.
And because the ancient Egyptians were using the lunar cycle in combination with this heliacal rising, some years ended up having 12 lunar months,
while others had 13 lunar calendar months, if Sirius didn’t rise in the 12th month.
Even though the length of the agricultural calendar still fluctuated, with some years having 12 months and others having 13, it ended up being much more reliable than it was before.
They continually adjusted it to the heliacal rising of Sirius, ensuring that they never got too far off in their seasons.
This new calendar was ideal, because, well, it worked well for agricultural purposes as well as for knowing when to have traditional religious festivals. So, that was their first calendar.
But was it any way to run a government? They didn’t think so. For administrative purposes, it was very inconvenient to have years of different lengths.
So another calendar was introduced, an administrative one.
Probably soon after 3,000 BC, they declared a 365-day year, with 12 months per year, with exactly 30 days each month, with an extra 5 days at the end of each year.
This administrative calendar existed alongside the earlier agricultural and religious calendar that depended on the heliacal rising of Sirius.
This administrative calendar was much easier to use for things like scheduling taxes and other things that had to be paid on time.
Over time, the calendar got out of step with seasons and the flooding of the Nile, but for bureaucratic purposes, they didn’t mind.
Narrator: Listen to part of a lecture in a biology class.
Professor: Ok, now I want to talk about an animal that has a fascinating set of defense mechanisms.
And that’s the octopus, one of the unusual creatures that live in the sea.
The octopus is prey to many species, including humans, so how does it escape its predators?
Well, let me back up here a second. Anyone ever heard of Proteus?
Proteus was a God in Greek mythology who could change form.
He could make himself look like a lion or a stone or a tree, anything you wanted, and he could go through a whole series of changes very quickly.
Well, the octopus is the real world version of Proteus. Just like Proteus, the octopus can go through all kinds of incredible transformations.
And it does this in three ways: by changing color, by changing its texture, and by changing its size and shape.
For me, the most fascinating transformation is when it changes its color.
It’s a normal skin color, the one it generally presents, is either red or brown or even grey, and it’s speckled with dark spots.
But when it wants to blend in with its environment to hide from its enemies, it can take on the color of its immediate surroundings: the ocean floor, a rock, a piece of coral, whatever. Charles?
Student: Do we know how that works, I mean, how they change colors?
Professor: Well, we know that the reaction that takes place is not chemical in nature.
The color changes are executed by two different kinds of cells in the octopus’ skin, mainly by color cells on the skin’s surface call chromatophores5.
Chromatophores consist of tiny sacks filled with color dye.
There might be a couple hundred of these color sacks per square millimeter of the octopus’ skin, and depending on the species, they can come in as many as five different colors.
Each one of these sacks is controlled by muscles. If the muscles are relaxed, the sack shrinks, and all you see is a little white point.
But if the muscle’s contract, then the sack expands, and you can see the colors. And by expanding different combinations.
Student: And just with various combinations of those five colors, they can recreate any color in their environment?
Professor: Well, they can no doubt create a lot with just those five colors, but you are right, maybe they can’t mimic every color around them, so that’s where the second kind of cell comes in.
Just below the chromatophores is a layer of cells that reflect light from the environment, and these cells help the octopus create a precise match with the colors that surround them.
The colors from the color sacks are supplemented with colors that are reflected from the environment, and that’s how they are able to mimic colors with such precision.
So, that’s how octopus mimics colors. But they don’t just mimic the colors in their environment;
they can also mimic the texture of objects in their environment.
They have these little projections on their skin that allow them to resemble various textures.
The projections are called papillae6.
If the octopus wants to have a rough texture, it raises the papillae.
If it wants to have a smooth texture, it flattens out the papillae, so it can acquire a smooth texture to blend in with the sandy bottom of the sea.
So the octopus has the ability to mimic both the color and the texture of its environment.
And it’s truly amazing how well it can blend in with its surroundings.
You can easily swim within a few feet of an octopus and never see it.
Student: I read that they often hide from predators by squirting out a cloud of ink, or something like that.
Professor: Yes. The octopus can release a cloud of ink if it feels threatened. But it doesn’t hide behind it, as is generally believed.
Um, the ink cloud is … it serves to distract a predator while the octopus makes its escape.
Um, now there’s a third way that octopus can transform themselves to blend in withor mimic their environment, and that’s by changing their shape and size, well, at least their apparent size.
The muscular system of the octopus enables it to be very flexible to assume all sorts of shapes and postures.
So it can contract into the shape of a little round stone, and sit perfectly still on the seafloor.
Or it can nestle up7 in the middle of a plant and take the shape of one of the leaves. Even Proteus would be impressed, I think.