The Nature of Planet Earth
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What Causes Night
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Five friends were talking about what causes night and day. They each had different
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ideas. This is what they said:
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Twyla:
"We have daytime became that's when the Sun comes up. When we have
nighttime it is because the Moon comes out."
Marcel:
"I think it is daytime when the Sun comes up. It is nighttime when the
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Sun goes down beneath the Earth."
Tishon:
"The Sun goes around the Earth once a day. So when it comes on our side
of the Earth we have daytime."
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Ashok:
"Earth spins around once a day and that is why we have daytime and
nighttime."
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Joe:
"It must be due to something else."
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Which friend do you agree with the most?
that friend and not the others.
Explain why you agree with
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Uncovering Student Ideas in Astronomy
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21
The Nature of Planet Earth
What Causes Night
and Day?
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Purpose
Administering the Probe
The purpose of this assessment probe is to elicit
students' ideas about the day-night cycle. The
probe is designed to find out if students can
relate the shape of the Earth and its spin to
why we have day and night.
This probe can be used with elementary, middle, and even high school students. Night and
day are typically introduced to children at a
very young age, but it is not likely that they
will fully understand and remember the explanation for night and day until at least upper
elementary, and for most, middle school age.
It is also a good idea to give this probe to high
school students before a unit on astronomy, to
ensure they have a solid understand of Earth's
lllotions before studying the more complex
motions of the other bodies of the solar system
and beyond.
Related Concepts
Day-night cycle
Earth: shape, spin
Explanation
Ashok has the best idea: "Earth spins around
once a day and that is why we have daytime
and nighttime." The Earth makes one complete turn on its axis each day. It is this spin
of the entire Earth that makes it appear that
the Sun rises in the morning and sets in the
afternoon or evening. In fact the Sun does not
actually rise and set (nor do the Moon or stars).
All of the objects we see in the sky only appear
to move as they do because the Earth on which
we are standing is slowly spinning in space.
22
Related Ideas in Benchmarks
for Science Literacy
(AAAS 2009)
K-2 The Universe
• The Sun can be seen only in the daytime,
but the Moon can be seen sometimes at
National Science Teachers Association
(-r~f4\
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The Nature of Planet Earth
night and sometimes during the day. The
Sun, Moon, and stars all appear to move
slowly across the sky.
around the Earth once a day (Danaia and
McKinnon 2007).
An insightful series of studies on children's conception of Earth as a sphere, and
their subsequent explanation for day and
night, involved interviews of children in
first, third, and fifth grades (Brewer 2008;
Vosniadon and Brewer 1993, 1994). All of
the children had learned about the scientific explanation for day and night in their
textbooks. The interviews revealed that the
younger children explained day and night
by extending their everyday experience
with light. If the Sun is no longer visible, it
must be hiding behind something, such as
behind clouds, mountains, or the Moon.
Older children provided explanations that
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3-5 The Earth
The rotation of the Earth on its axis every
24 hours produces the night-and-day
cycle. To people on Earth, this turning
of the planet makes it seem as though the
Sun, Moon, planets, an.dstars are orbiting
the Earth once a day.
*
Related Ideas in National
Science Education Standards
(NRC 1996)
............. e ......................... .
K-4 Objects in the Sky
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The Sun, Moon, stars, clouds, birds, and
were closer to the scientific model, but also
airplanes all have properties, locations,
somewhat muddled, such as that the Sun
and Moon go around the Earth every day.
Most of the fifth graders explained day and
night as due to Earth's rotation but still
had misconceptions, such as that the Sun
and movements that can be observed and
described.
K-4 Changes in Earth and Sky
Objects in the sky have patterns of
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and Moon are stationary on either side,
movement.
Related Research
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Because the explanation for the daily cycle
of light and dark has traditionally been
taught at the early elementary grades,
their explanations to observations of how
the concept as early as preschool (ages 5
and 6). However, they have met with little
the Sun appears in the sky. Some appeared
to work backward from their explanation
to describe what must be happening in the
sky. That suggests it is important to have
students first observe how the Sun changes
its position during the daytime, before
explaining why that happens from the
viewpoint of a spinning Earth.
2000).
The two most common misconceptions
are that the day-night cycle is caused by
the Earth going around the Sun once a
day and that it is caused by the Sun going
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cycle in scientific terms, few could relate
some researchers have attempted to teach
success (Valanides, Gritsi, and Kampeza
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with Earth turning in the middle.
Mant and Summers (1993) interviewed
primary school teachers in England.
Although most could explain the day-night
Indicates a strong match between the ideas elicited by the probe and a national standard's learning goal.
Uncovering Student Ideas in Astronomy
23
The Nature of Planet Earth
Suggestions for Instruction and
Assessment
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o
When discussing the probe, encourage stu-
dents to add to or extend the explanation
of the friend they agree with most. Additionally, you might ask students to critique
the ideas of the other friends.
This probe can be combined with "Darkness at Night" in Uncovering Student Ideas
in Science, Vol. 2: 25 More Formative Assessment Probes (Keeley, Eberle, and T ugel
o
2007).
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It may not make a lot of sense to teach stu-
dents that day and night occur because the
Earth spins on its axis once every 24 hours
until students fully understand that the
apparently flat, solid Earth beneath their
feet is actually a huge ball in space. Most
students acquire the ability to visualize
that idea around fourth grade. Therefore,
first- or second-grade textbook illustrations
of night and day are not likely to make
much sense to most students.
o
o
Although it is too early to teach kindergarteners or first graders the explanation for
References
day and night and expect them to explain
it clearly, they can learn that the Sun is out
during the day but not at night, and that it
is the Sun that determines when day starts
and ends. Nighttime is simply the absence
of sunlight. It is also important for students in kindergarten, first grade, or second grade to observe that the position of
the Sun changes during the day, from one
side of the sky to the other.
Once upper elementary students understand that the Earth is a sphete, they can
American Association for the Advancement of Sci-
come to understand the concept at a deeper
o
24
o
the globe with clay or tape. Darken the
room as much as possible and turn on a
bright light in the center of the room, so
the students can see that just one half of
their globe is lighted. They can then turn
the globe slowly, noting how the "person"
standing on Earth is first in daylight and
then experiences night.
You can follow the globe experience by
having the students simulate the spinning
Earth with their heads. Have the students
slowly turn in place to see the "sunrise" as
they just start to see the light, then watch
the Sun go from one side of their field of
view to the other side, and finally see "sunset" as the Sun disappears on the othet side
of their view.
Revisit this idea at the high school level,
asking students to write their explanation
of the day-night cycle. Demonstrations
like those mentioned above can be used if
formative assessment reveals students have
misconceptions.
level when they apply that understanding
to the day-night cycle.
The day-night cycle can be demonstrated
in a number of ways. Small groups of students can be provided with globes and stick
figures or small dolls that can be placed on
ence (AAAS). 2009. Benchmarks for science
literaCy online. www.project2061.orglpublicationslbsllonline
Brewer, W F. 2008. NaIve theories of observational
astronomy: Review, analysis, and theoretical implications. In International handbook of
research on conceptual change, ed. S. Vosniadou,
155-204. New York:·Routledge.
Danaia, L., and D. H. McKinnon. 2007. Common
alternative astronomical conceptions encountered in junior secondary science classes: Why
is this so? Astronomy Education Review 6 (2):
32-53. http://aaaas.orglresource!Jlaerscz/v6Ii21
p32_s1
Keeley, P., F. Eberle, and]. Tugel, 2007. Uncovering
student ideas in science, vol. 2: 25 more formative
assessment probes. Arlington, VA: NSTA Press.
NatIonal Science Teachers AssocIation
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The Nature of Planet Earth
Mant, ]., and M. Summers. 1993. Some primaryschool teachers' understanding of the Earth's
place in the Wliverse. Research Papers in Education 8 (I): 101-129.
Vosniadou, S., and W Brewer. 1993. Constraints
on knowledge acquisition: Evidence from chil-
dren's models of the Earth and day/night cycle.
In Proceedings ofthe Fifteenth Annual Confirence
of the Cognitive Science Society, 1052-1057.
National Research Council (NRC). 1996. National
science education standards. Washington, DC:
National Academies Press.
Valanides, N., F. Gritsi, and M. Kampeza. 2000.
Changing pre-school children's conceptions
of the day/night cycle. International Journal of
Early Years Education 8 (lJ:"27-39.
Mahwah, NJ: Lawrence Erlbaum Associates.
Vosniadou, S., and W Brewer. 1994. Mental models of the day/night cycle. Cognitive Science 18:
123-183.
Uncovering Student Ideas in Astronomy
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