|
Astronomy became an exact (numerical) science very early in
human history, whereas physics only became an exact science around
the 17th century. Discuss the possible reasons for this.
|
[3] |
-
First, note the mark allocation: 3 marks = 10% of the exam = 10-15 minutes.
You need to write a fairly substantial answer - a few sentences will not do. The
notes below are a skeleton, not a full model answer.
-
The main topic to discuss is probably calendar regulation. Early societies
need to develop a standard calendar because:
-
the calendar year is important to early societies because the seasons regulate
agricultural practices;
-
societies in which the bulk of the population is not literate cannot keep track
of the year using a written calendar;
-
however, organised societies need advance planning, and so cannot rely on simple
seasonal cues such as the arrival of migrating birds.
Since astronomical phenomena such as the lunar phases are fairly obviously periodic,
they are a natural candidate for providing calendar cues. This encourages
the development of an exact science of (planetary) astronomy because:
-
the year itself is too long for a preliterate population to keep track of directly;
-
the lunar month, which is easy to keep track of, is not an integral divisor of
the solar year;
-
therefore you need to develop a system for synchronising the lunar year with the solar
year by intercalation.
This requires at least a reasonable knowledge of the lengths of the (synodic) lunar month
and the solar year. The better your knowledge, the more you can systematise your calendar,
and the less you have to rely on observational adjustment. Therefore, there is an incentive
to develop a good numerical understanding of the relevant periods, which implies a
numerical science of astronomy.
-
You should probably also discuss astrology/religion. Timing of religious festivals
requires the same sort of astronomical knowledge as calendar regulation. If it is
important to predict eclipses, even more detailed numerical understanding is
required.
- Navigation/alignment - particularly, finding true north - also encourages
an understanding of astronomy, in particular the diurnal motion of the Sun and the stars.
-
In contrast, the uses of physics in the ancient world, while significant, do not
require exact numerical calculations. For example, improvements in the design of
projectile weapons are more easily achieved by trial and error than by inventing a
quantitative science of aerodynamics. (They're still easier to do by trial and
error, hence the invention of the wind tunnel!)
|
| Compare and contrast the motivations for studying astronomy in
the Hellenistic era (around 200 BC), the 17th century, and
today.
|
[3] |
-
First, note that this is a "compare and contrast" question. You will not get full
marks if you do not answer the question, which in this case means focusing on
similarities and differences between the three cases.
-
Similarities:
-
it is probably fair to say that all three are interested in increasing our
understanding of the natural world ("pure research");
-
all three are interested in comparing observations with mathematical models;
-
the first two are both predominantly interested in planets (and the Sun and Moon),
and their application to time-keeping and navigation;
-
the second two are both interested in using astronomy as a laboratory to test
physical laws, at least for the later 17th century.
-
Differences:
-
the Hellenistic astronomer, unlike the other two, does not use astronomy as a testbed
for physical laws (he does not expect the heavens to follow the same physical laws as
Earth);
-
the modern astronomer, unlike the other two, has little interest in planetary motions, and
is not likely to apply astronomical knowledge to timekeeping or navigation;
-
an early 17th century astronomer might well be studying planetary positions
for application to astrology - neither the Hellenistic philosopher nor the modern astronomer
would do this (probably a post-Newton 17th century astronomer wouldn't either);
-
the modern astronomer, unlike the other two, is a professional who is paid to do astronomy
(the Hellenistic philosopher would probably have private means, and the 17th
century natural philosopher might be independently wealthy, have a wealthy patron, or support
himself by other means - Newton was a Master of the King's Mint as well as a university
professor).
- The three marks for this question are probably allocated as half a mark per valid
point made, which is somewhat different from the previous question where the mark
allocation would be less precise.
-
Note that this question asked about the motivation for studying astronomy. It
would be possible to ask a very similar question about the topics studied by the
three astronomers, which would have a significantly different answer.
Always read the question carefully, and answer exactly what you have been
asked.
|