BSCS Science:
An Inquiry Approach
Level 3
First edition, © 2010 by BSCS
Unit 3 Overview
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TE_ES_Ch01_002-057.indd Page 3 3/19/09 10:01:11 PM u-s082
Unit Overview
The Sun. Your students see it, or its light, each day. But
more importantly, the Sun provides solar radiation and energy
so that Earth can be habitable for life. Yet it is not sufficient for
the Sun merely to shine on Earth. If that were the case, heat
would be redirected to space shortly after hitting Earth. Rather,
energy and heat are retained on Earth by the greenhouse
effect (the theme for chapter 1, Warming Up to Radiation).
The pattern of heating on Earth gives us the seasons. That
energy is then distributed around the planet in the atmosphere
and oceans (chapter 2, Earth’s Heat Engine). Heat moving
around the planet in wind and water can also be harnessed as
a resource by which humans can generate electricity for their
needs (chapter 3, Becoming Current).
In The Sun’s Energy unit, students investigate the flow of
energy on Earth. Understanding how the Sun’s energy interacts
with earth systems will help students learn about other important issues in science, such as global climate change. First,
introduce to students these concepts in the unit Engage, Great
Balls of Fire? This Engage will help students recall some key
features of the Sun.
Goals for the Unit
By the end of this unit, students should understand the
following:
• Energy flow can be monitored using proxy measurements
such as change in temperature, voltage, or current.
• A change in a system may be evidence that energy has
changed forms.
• The greenhouse effect keeps Earth warm enough for
many kinds of life, yet continued global warming could
have some adverse effects for ecosystems and humans.
• Simple models can be used to represent physical
processes.
• Heat is transported by radiation, convection (advection),
and conduction (diffusion).
All the units in Level 3 of BSCS Science: An Inquiry
Approach reinforce specific, overarching themes. The themes
are energy flow and energy transformations, and the use of
models, evidence, and explanations. In The Sun’s Energy,
students will investigate these concepts in three chapters.
/Volumes/103/KHUS025/work%0/indd%0/Earth Science/Chapter 1
Advance Preparation for
the Unit and the Chapters
First, obtain sets of materials that are used throughout
this unit. Materials include globes (perhaps global maps),
photovoltaic cells (PV cells), multimeters, wires, lamps, and
lightbulbs. Purchase PV cells ahead of time if needed.
Second, indicate to students that they will be evaluated
at the end of chapter 1 by how they analyze variations in a
natural pattern—sunspot cycles. The evaluation questions
will relate to the content and activities of the chapter. A key
question is whether natural patterns of variation such as
sunspots appear to correlate with the pattern of increasing
temperatures for Earth’s atmosphere.
Third, a key concept in this chapter and in all units for
Level 3 is to investigate energy flow on Earth. This concept is
important from the perspective of learning how Earth maintains its temperature via the greenhouse effect and learning
how primary producers in ecosystems use that solar energy to
support food webs.
Fourth, in the past few years, scientists have presented
data showing that the temperatures of Earth’s atmosphere are
increasing—global warming. Global warming may be having
adverse effects on climate and ecosystems at a regional scale.
Watch for relevant stories in the news. In this unit, students
will develop a background to evaluate those news reports.
Fifth, check if you have access to a Web site that publishes
daily images of the Sun where students can track motion and
changes in shape in sunspots. It’s best to use current images
that would match what students actually see in a solar observer
that they will construct (binoculars, telescope). In case your
school’s Internet is down (or a satellite is undergoing a bakeout or other mechanical problem), we have provided transparencies with daily clips from a movie.
Finally, changes in scale are not always easy for students.
Such changes in scale are often in terms of large changes in
distance (atoms to people to galaxies) or time (seconds to
years to billions of years). For each of the hands-on processes
that students investigate, it is important that they be able to
scale up their findings. They need to see how the results apply
to Earth, to the planet scale.
Chapter 1 WarmingThe
UpSun's
to Radiation
Energy
3