Listening audioscript

5. WHY DOES THE STUDENT GO TO SEE THE PROFESSOR? 
6. WHY ARE THEY DISCUSSING THIS MATERIAL?
PASSAGE FOUR 
Page 153
[ mp3 015-016]
Questions 7 and 8. 
Listen to part of a lecture in a meteorology class. 
(Professor) 
Today, I’m going to be lecturing about the theories of William Redfield 
and James Espy. Both of them were American meteorologists in the 
nineteenth century. However, they had different ideas about how storms 
behave, and they each argued for their own models for years. And in 
fact, it became a wider debate as different groups of scientists in different 
places lined up behind one or the other of each man’s hypothesis. So
Uh … for example, at one point, meteorologists from England were 
supporting Redfield’s model while many of those in France were 
supporting Espy’s. But the real point I want to make concerns how 
competing models and approaches can sometimes actually be 
complementary. 
OK. So now let me outline the models. Espy argued that centripetal force 
was at work in storms. Now As you know, centripetal force would cause 
winds to move inward from all directions toward the center of the storm. 
So he was basing this on his hypothesis that storms are caused by rising 
currents of moist, wet air, or convection currents, that form clouds. As the 
air rises, air is drawn in from all directions. But, as logical as it sounds, 
this model hasn’t proven completely accurate in the case of the biggest 
and most powerful storms. Now, that brings us to the theory of the other 
meteorologist, William Redfield. He argued that the winds in a storm 
rotated around the center of the storm, so the winds would be moving in 
a circular path. And he believed that the winds moved in a 
counterclockwise direction. This theory was based on his own 
observations, especially from a hurricane he witnessed that hit uh New 
York City directly in 1821 and uh also affected surrounding states. He 
noticed that uh crops, um … corn, fruit trees … had been flattened in 
different directions in different parts of the state of Connecticut, where he 
was living at the time. So, this led him to believe that the winds were 
going in different directions around the center of the storm. Um … and he 
also collected a lot of eyewitness accounts to back this up. 
 
 
Now, it’s important to note that Redfield didn’t know why the winds were 
rotating around the centers of the storms. He was basing his assertion on 
empirical evidence … uh, that is on what he saw with his own two eyes, 
not on the results of a hypothetical prediction. This was in stark contrast 
to how Espy had arrived at his claims for wind direction in storms. And uh 
in fact, this was another point of argument between the two men. 
Redfield disrespected Espy for relying on his model of storms instead of 
uh observation. 

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LPREP IBT 3 E AudioScript 
11
 

In any case, Espy believed that centripetal force caused winds to 
move inward toward the center of a storm, and, um, Redfield believed 
that the winds in a storm moved in a circular, counterclockwise direction. 
So it turns out that Redfield was correct in terms of big storms, due to the 
effect of the Earth’s rotation. Uh you see, winds do indeed rotate 
counterclockwise around the center of the storm. Oh, and incidentally, 
they go in the opposite direction in the southern hemisphere, uh 
however, Redfield wasn’t making his observations there. But, and here’s 
where the complexity of meteorology becomes apparent, it turns out that 
Espy was not entirely incorrect. Winds do move toward the centers of 
storms because of convection currents. Uh Espy just didn’t take into 
account the effect of the rotating Earth on those inward moving winds. 
So, to sum it up, there are a couple of important themes for us to uh to 
think about here. One is the different approaches toward scientific 
explanations of natural phenomena—Redfield’s emphasis on what he 
observed and Espy’s on what his hypothesis predicted. Uh another is the 
idea that sometimes the competing hypotheses that scientists fight 
furiously over turn out instead to be complementary models. That is, 
each one can help explain some specific aspect of a process, or the 
process under certain conditions. So if Espy and Redfield had put aside 
the desire to win the argument, maybe they would have appreciated this 
fact sooner.