TPO 17 Conversation 1
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 you 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.
TPO 17 Lecture 1 Art History(Prehistoric Art Dating)
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 necessarilly 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 chacoal 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 similiarities 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.
TPO 17 Lecture 2 Environmental Science(Milankovitch Hypothesis)
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 imaginery 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 clacite 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.
TPO 17 Conversation 2
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.
TPO 17 Lecture 3 History(Ancient Egyptian Calendar)
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 adressed 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 wes 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 inunadate
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 eartern 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 calender 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.
TPO 17 Lecture 4 Biology(Octopus)
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 Proteous? 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 chromatophores
5
.
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 mimic colors.
But they don’t just mimic the colors in their environment; they can alos 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 with
or 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.