Transcript (PPTX)

http://www.planetary.org/explo
re/topics/earth/spacecraft.html
Seasons and Shadows –
Understanding the tilt, rotation and orbit of the Earth;
uneven heating of the atmosphere, effects on seasons,
Sun angle and shadows on Earth
Seasons and Shadows –
Understanding the tilt, rotation and orbit of the Earth;
uneven heating of the atmosphere, effects on seasons,
Sun angle and shadows on Earth
Larry Braile, Dept. of Earth and Atmospheric Sciences
Jenny Daugherty, Dept. of Technology, Leadership and Innovation
Helen McNally, Dept. of Electrical and Computer Engineering
Technology
Inez Hua, Dept. of Civil Engineering
Jenniffer Dickensheets, 5th Grade Teacher, Sunnyside Middle
School
Pam Stamm, 5th Grade Teacher, Taylor Intermediate School
Melissa Colonis, 7th Grade Math Teacher, Tecumseh Junior High
School
Seasons and Shadows –
Standards Addressed:
Indiana Science Standards: Content specific
6.2.5 Demonstrate that the seasons in both hemispheres are the
result of the inclination of the earth on its axis, which causes changes
in sunlight intensity and length of day.
5.2.2 Observe and use pictures to record how the sun appears to
move across the sky in the same general way every day but rises and
sets in different places as the seasons change.
K-8 Science Process Standard: The Design Process
As citizens of the constructed world, students will participate in the
design process. Students will learn to use materials and tools safely
and employ the basic principles of the engineering design process in
order to find solutions to problems.
Identify a need or problem to be solved. Brainstorm potential
solutions. Select a solution to the need or problem. Create the
solution through a prototype.
Seasons and Shadows –
Standards Addressed:
Also, Math standards and graphing skills
Lesson Objectives:
Students will be able to:
Explain the tilt, orbit, shape, and motions of the Earth (rotation
and revolution) and their relationship to the reasons for the
seasons and variable heating of the Earth.
Describe the variations in the length of day throughout the year
by graphing the length of day (from sunset to sunrise) for different
latitudes.
Design a prototype awning to maximize shade and light
throughout the year given a scale diagram and specific
dimensions.
Design Activity 1
Seasons and Shadows – Shading a Picnic Table
Design Activity 2
Seasons and Shadows – Shade My Space
Science Background – Design a tabletop physical
model of the Earth-Sun system to effectively illustrate
the tilt of the Earth relative to the plane of the ecliptic,
the movements of the Earth (rotation and revolution),
and develop an understanding of the effects of these
movements on variable heating of the Earth and its
atmosphere, length of day, and the reasons for
seasons*.
* This topic has been well documented to be difficult for
students and involves strongly-held misconceptions
(http://learner.org/resources/series28.html Private
Universe video).
Learning Objectives/Challenges:
1. Understanding motions of the Earth.
2. Demonstrate that Earth’s axis of rotation (northern
pole) currently points to the star Polaris.
3. Illustrate effects of tilt, orbit and spherical shape of
Earth on variable heating with latitude and time of
year (seasons) and length of day.
4. Address 3-D visualization challenges (very common
in most students and with figures in books and on
screens) with a 3-D physical model.
5. Engage students by having them manipulate the
model.
The Anasazi Indians of the southwestern U.S. (mostly in New
Mexico and Colorado) used passive solar concepts about a
thousand years ago to design their dwellings.
Introductory Activity:
Demonstrate that the
Earth’s rotational axis is
tilted relative to the plane
of the ecliptic and that the
axis of rotation (northern
pole) currently points to
the star Polaris. This fact
allows one to determine
their latitude in the
northern hemisphere from
the angle of Polaris above
the horizon.
Time-lapse animation from Earth (northern hemisphere) showing position of
Polaris (“the North star”) and other stars that appear to circle Polaris (actually
due to Earth’s rotation) (http://en.wikipedia.org/wiki/Circumpolar_star)
The geometry of
the Earth’s tilt
and the
rotational axis
pointing to
Polaris
Earth’s axis with its 23 degree tilt (relative to the
plane of the ecliptic), the North directed axis
points towards Polaris (the North Star in the
constellation Ursa Minor), and angle relationships
for a location at 40o North latitude and nighttime
(~midnight) in the northern hemisphere summer
solstice (June 21).
What would be the angle
of Polaris above the
horizon if you were
standing at the Equator?
At the North Pole? In
Australia?
Additional illustrations of Earth’s axis of rotation (northern pole) pointing
to Polaris.
Polaris
http://www.flickr.com/photos/juniorvelo/312672130/
Time-lapse (about one hour) photograph from Earth (northern hemisphere)
showing position of Polaris (“the North star”) and other stars that appear to
circle Polaris (actually due to Earth’s rotation)
Time-lapse (several hours)
photograph from Earth (northern
hemisphere) showing position of
Polaris (“the North star”) and
other stars that appear to circle
Polaris (actually due to Earth’s
rotation)
Polaris
http://www.wainscoat.com/astronomy/
An effective
working model of
the Sun-Earth
system for
“Seasons and
Shadows”
Northern hemisphere
summer
Northern hemisphere
winter
Close-up of Earth
model – can
rotate on its axis
(23 degrees tilt)
and be positioned
at any place inits
orbit around the
Sun. The latitude
lines and map
help with
orientation, etc.
Map to trace onto
sphere
Illustrating different
heating of Earth with
variation with latitude
(angle of the Sun’s rays)
Design Activity 1
Seasons and Shadows – Shading a Picnic Table
Design Activity 2
Seasons and Shadows – Shade My Space
Length of Day data (Sunrise and Sunset times – 24 hr format)
(http://aa.usno.navy.mil/data/docs/RS_OneYear.php) and
graphing (need to subtract sunrise time from sunset time,
then convert to Hours and Decimal Hours to graph):
40 Degrees N, 21st Day of Month (Format = hhmm):
Jan: 0805 1754 Feb: 0734 1830 Mar: 0649 1902 Apr: 0601
1933 May: 0527 2002 Jun: 0519 2020 Jul: 0537 2011 Aug:
0606 1935 Sep: 0635 1846 Oct: 0705 1759 Nov: 0741 1727
Dec: 0807 1726
60 Degrees N, 21st Day of Month (Format = hhmm):
Jan: 0928 1631 Feb: 0813 1751 Mar: 0648 1904 Apr: 0515
2020 May: 0358 2133 Jun: 0324 2216 Jul: 0403 2144 Aug:
0516 2025 Sep: 0629 1852 Oct: 0741 1723 Nov: 0900 1607
Dec: 0950 1542
Average Monthly Temperature data
(http://weatherbase.com/) and graphing:
Lafayette, IN, 40 Degrees N, Month (Format = Degrees C):
Jan: -4 Feb: -2 Mar: 2 Apr: 9 May: 16 Jun: 20 Jul: 21 Aug: 21
Sep: 18 Oct: 12 Nov: 5 Dec: -2
Anchorage, AK, 60 Degrees N, Month (Format = Degrees C):
Jan: -13.9 Feb: -7.9 Mar: 1.6 Apr: 7.2 May: 12.0 Jun: 14.4
Jul: 12.9 Aug: 9.1 Sep: 0.9 Oct: -5.4 Nov: -10.5 Dec: -10.0
24
40o N
B
40o N
Hours
12
A
Hours
12
24
Quiz: Length of Day for Earth With No Tilt (Which One?)
40o S
Equator
0
0
Equator
24
1 2 3 4 5 6 7 8 9 10 11 12
Month
C
40o N
40o S
40o N
40o S
Equator
0
0
Equator
1 2 3 4 5 6 7 8 9 10 11 12
Month
D
Hours
12
24
1 2 3 4 5 6 7 8 9 10 11 12
Month
Hours
12
40o S
1 2 3 4 5 6 7 8 9 10 11 12
Month
Equator
40o N
40o S
Temperature
High
Low
1 2 3 4 5 6 7 8 9 10 11 12
Month
C
40o N
40o S
Equator
1 2 3 4 5 6 7 8 9 10 11 12
Month
Temperature
High
Low
A
B
Equator
40o N
40o S
1 2 3 4 5 6 7 8 9 10 11 12
Month
Temperature
High
Low
Temperature
High
Low
Quiz: Ave. Monthly Temp. for Earth With No Tilt (Which One?)
D
Equator
40o N
40o S
1 2 3 4 5 6 7 8 9 10 11 12
Month
Template for drawing lines of latitude
0o Latitude
45o Latitude
60o Latitude