Listening audioscript

5. HOW DOES THE PROFESSOR SEEM TO FEEL ABOUT THE DESIGN OF THE 
IROQUOIS VILLAGE?
6. LISTEN AGAIN TO PART OF THE LECTURE. THEN ANSWER THE QUESTION? 
 (Professor)
 Even if you can’t really draw, I’d really prefer that you not do this on the 
computer. If it’s done on the computer it loses its organic nature…I 
mean, it’s harder to appreciate what I want you to. Playing around with 
buttons and a mouse doesn’t feel as simple and elegant as hand-drawing 
lines. Plus I don’t like getting artificially perfect pictures that all look the 
same. 
WHAT IS THE PROFESSOR’S ATTITUDE TOWARD DOING THE ASSIGNMENT ON 
THE COMPUTER? 
 
PASSAGE FOUR 
Page 182 [ mp3 053-054] 
Questions 7 and 8
Listen to part of a lecture in a meteorology class.
(Professor) 
So, now let’s talk about another weather phenomenon that can do great 
damage, but one that we are also getting better at understanding and 
predicting … uh, though not so much at preventing. 

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I’m talking about hail. Now, hail is just frozen droplets of water, but the 
process by which water turns into little balls of ice that plummet from the 
sky and destroy roofs, windows, and crops…well this process is one of 
those things that is actually a bit more complicated than we used to think. 
Hail starts in cumulonimbus clouds, which you will recall, are very tall 
clouds indeed—as tall as 6 miles in some cases. Because they’re so tall, 
they’re much warmer at the bottom than at the top. This warm air creates 
updrafts that blow drops of water higher and higher into the clouds. As 
these drops become super-cooled, they will freeze on contact with ice or 
dust particulates. Now, it used to be thought that these frozen droplets 
would descend through gravity or downdrafts, then get pushed back up 
into the cloud by updrafts, and finally gather more water, and refreeze. 
But … due to recent research … um … it appears that it’s more 
complicated than that, with hail forming not just within the interior of the 
cloud, but possibly on the backside of the storm. The humidity of the air 
that the hailstone is passing through and whether the humidity is liquid 
water or vapor, also have an effect on the rate of growth of the hailstone. 
In fact, it will also have an effect on the appearance of the hailstone. If 
you’ve ever seen a hailstone split open, you’ve probably observed that 
it’s kind of like an onion because it has several layers … and these layers 
are different from each other, as well. That is, some of the layers are 
clear, like ice cubes from your freezer. And some of the layers are white 
ice—I guess, again like the frost that collects in your freezer.
Now, why are the layers different? This is all part of the complexity of 
storms that I find truly fascinating. You see, it depends on the form of 
water that is surrounding a little hailstone when it gets pushed by 
updrafts higher into the air. If it comes into contact with liquid water 
droplets, the water condenses on the hailstone and freezes, but not so 
fast that bubbles of air don’t have time to escape. This process forms a 
transparent layer on our little hailstone. However, if the water is in the 
form of super-cooled vapor, it will freeze onto the hailstone so fast that 
air bubbles are trapped, and make the layer white.
OK, so in a minute I’m going to talk more about the latest research into 
hail formation … you know, some people find it so annoying that just 
when we think we understand something, along comes some evidence 
that blows apart all of our carefully conceived ideas of how things work. 
As a researcher, I personally find this constant adjustment of what we 
know truly inspiring. There’s always more to find out, and I can continue 
in my job for the foreseeable future. 
Uh, … OK, back to what I was saying, other new developments have 
come in the form of imaging devices that can identify what is likely to be 
hail within a storm system. And again, as I said, we’ve found hail in 
places we didn’t use to think we ever would. Right now, we can predict 
the likelihood that any one area will be experiencing hail with radar and 
weather models. However, it’s only a matter of years until we’ll have the 
models and equipment in place to definitively say where the hail is. 
As for prevention, my next point … obviously, the old, Medieval practice 
of firing cannons or ringing church bells has not proven terribly effective. 
Way back then, people were hoping that the blast waves from one or the 
other of these would break up the hailstones. And, oddly enough, there 

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39
are modern versions of cannons that have been used. If you’re curious, 
you could search for some pictures of those. I apologize; I forgot to bring 
some to show you. Um … needless to say, any of those neighbors who 
have had to endure repeated cannon blasts from the time the storm 
approached until it passed are probably on the front lines of those who 
question the use of big guns like a hail cannon. And this lack of proven 
effectiveness also goes for the practice of shooting the chemical 
compound, silver iodide, into clouds to prevent the formation of 
hailstones. It’s just not backed up by solid evidence. In contrast to now 
having better prediction and localization techniques, I see hail prevention 
as remaining out of reach for a long time to come.