142 Unit 4 Applied critical thinking
Summary
• Explanations differ from arguments,
despite resemblances.
• There may be many possible explanations
for an outcome or event, though some are
more plausible than others.• The best explanations are those that are
simple and that explain the most (have
the widest ‘scope’).
• Even the best explanations may be wrong:
they are, strictly speaking, hypotheses.was weightless. But in all three
locations the amount of matter
remains the same, and this constant
amount is what is meant by its mass.
D He did it for sure, because no one
else had the opportunity, the motive
or the training to do such a thing.
E He did it because he needed the
money and because an opportunity
came his way.2 Study the following information and then
answer the question that follows.
Measurements were taken showing
the growth of 16 fir trees planted at
the same time but at different
altitudes on a hillside. The results
were recorded as shown in the graph.25Height of tree (m)Altitude (m above sea level)(^0500)
1 Which of the following short passages are
arguments, and which are explanations?
A Icebergs are formed from glaciers
breaking off into huge chunks when
they reach the sea. The process is
known as ‘calving’. The glacier is
formed from snow, so it consists of
freshwater ice. The oceans consist
of brine (salt water), which has a
significantly lower freezing point than
fresh water. Therefore the sea
around icebergs remains in a liquid
state.
B Ice is less dense than liquid water.
Consequently, ice forms on the
surface of lakes and ponds, instead
of sinking to the bottom.
C In our ordinary everyday lives we use
the word ‘weight’ as if it meant the
same as ‘mass’. For example, we
‘weigh’ cooking ingredients in the
kitchen to tell us how much to use, not
to measure how much downward force
they exert on the scales. But there is a
distinction, and in science-teaching it
must be preserved and stressed. A
bag of flour on the surface of the Earth
has a different weight from the same
bag on the moon: here it is
approximately six times heavier. And in
an orbiting spacecraft we would say it
End-of-chapter assignments