The Day Sun Stood Still
J. Peter Harris, 1999
Unit 3 Extension
Introduction:
This lesson is designed for students in a first year high school Physics
course. Students should have a basic
understanding of Newton’s laws of motion for linear and rotational
mechanics. They should also have been
introduced to the conservation of momentum and kinetic energy. Students should have a basic understanding
of the Internet before attempting this exercise for it is highly speculative in
nature. Students should spend their
time contemplating different possibilities and not worrying about Internet
basics
Objectives:
After this lesson the students will be able to access the Internet, choose
a search engine, and find information relating to their speculations. They should also be able to research
something that is initially only an opinion.
New topics such as plate tectonics and the overall structure of Earth
will be introduced.
Materials:
A computer with access to the Internet (one per student), and the
following data sheet.
Procedure:
The Day the Sun Stood
Still
Name:
Date:
It
is reported by historians that records of the Chinese during the reign of
Emperor Yeo, who lived at the same time as Joshua, report a “long day.” Also, Heroditus, a Greek historian, wrote
that an account of a “long day” appears in records of Egyptian priests. Others cite records of Mexico that the Sun
stood still for an entire day in a year denoted as “Seven Rabbits”, which is
the same year in which Joshua defeated the Philistines and conquered Palestine.[1] References have also been found in the
historical lore of the Aztecs, Peruvians, and Babylonians for a day of twice
the natural length.
1)
What
mechanism(s) do you believe could cause both Sun and Moon to stand still in the
sky for a period of time? Explain how
they could cause this event.
2)
Using a search
engine of your choice try to find any information about the mechanism(s) you
have speculated about.
Mechanism to search for
_______________.
Name of search engine
_______________.
Number of hits returned
_______________.
3)
Did you find
any useful information on the mechanism you have speculated about? Describe how the information is or is not
helpful.
In 1970, a story appeared in “The Evening World”, a newspaper in Spencer, Indiana, about a consultant to the space program named Harold Hill (deceased) citing that he was told a computer program had found a missing day in Earth’s history. Though the computer program story could never be validated, interesting speculations and studies ensued about what astronomical mechanism might result in “Earth standing still” for 24 hours
4)
What
approach(s) might be used to determine the date of the missing day if the event
actually happened?
One suggestion
is that a large asteroid, perhaps 480 miles in diameter, may have struck
Earth’s mantle slowing Earth’s rotation to a standstill by causing the hard
mantle and molten core to separate for 24 hours. After 24 hours, the friction between the stationary mantle and
rotating core would accelerate the mantle to rotate once again.
5) Does this theory sound plausible to you? Why or why not.
6) How would Earth’s inhabitants experience this
acceleration? (F = ma)
7) Calculate the kinetic energy of this asteroid in
joules. You will have to find
information about the mass density and average velocity of asteroids in order
to do this calculation. (Kinetic Energy
= ½ mv²)
8) Does this information shed any light on the collision
theory? Explain.
9) Using a search engine of your choice research the
following topics:
a)
dinosaurs
b)
Cretaceous
period
c)
Tertiary period
d)
K-T boundary
10) Does any of this information shed any light on the
collision theory?
Explain.
11) What kind of mechanism would describe a collision of an
asteroid and Earth where the inhabitants would not notice the impact?
12) Based on what you have found
out, do you consider the collision theory as a plausible one? Explain.
The collision
would have to be as such as to cause Earth to decelerate and then to accelerate
so gradually as to go unnoticed by its inhabitants. Professor Totten writes that Newton described a way in which
Earth’s rotation could abruptly be slowed without its inhabitants noticing the
slowing. A close encounter with the
asteroid Hermes (500,000miles) by Earth in 1937 is given as an example of the
likelihood that such a collision may have occurred in the time of Joshua.
13) What laws of Physics must be
considered as affecting the inhabitants of Earth if the deceleration of Earth’s
rotation was abrupt?
14) How could a close encounter
with an object like the asteroid Hermes cause the crust of Earth to stop moving
with the molten core?
15) What force would be
responsible for this?
The existence of a depressed
(sink) region of great size between Hawaii and the Philippines featuring long
fracture lines at the bottom of the Pacific Ocean which extend outward to the
continents is offered as the remains of the asteroid causing the loss of a day
in Earth’s history.2
16) Go to http://www.math.montana.edu/~nmp/. Click on Geosphere and then the Layered
Earth. Does this site shed any light on this theory? Explain.
17) Go to http://cddis.gsfc.nasa.gov/926/slrtecto.html. Does this shed any light on this
theory? Explain.
18) Go to http://seismo.unr.edu/ftp/pub/louie/class/100/interior/html.
Does this shed any light on this theory? Explain.
19) Can the size of the asteroid be quantified knowing the
characteristics of Earth’s mantle? How?
20) If Joshua commanded Sun to stand still, did he have to
command Moon to stay fixed on the horizon as well? Why or why not?
21) In your searches, did you come across any other events
or accounts of Earth’s crust behaving in this way? Explain.
22) Please discuss your final views here. Make sure to cite research that you have
done here as well as any other source.
(Not yet
adopted)
This activity meets some of the
proposed standards for Science and Technology in Pennsylvania.
Physics Grade 12 part B. Discern and apply the principles of motion and force.
· Communicate
motion concepts in words, models, and mathematical symbols.
· Interpret
a model that illustrates circular motion and acceleration.
Physics Grade 12 part C. Apply energy sources and conversions and their relationship to
heat and temperature.
· Apply
physical science concepts through the creation of models.
· Demonstrate
an understanding of complex fluid power systems through the design and
construction of appropriate models.
This activity asks
students to research a mathematical model and to see how it applies to the real
world. (Earth’s structure)
Technology Grade 12 part A. Apply problem solving in Technology as a
systematic process.
· Evaluate
the significance of experimental information in answering the question
· Project
additional questions from a research study.
This activity asks
students to speculate based on what they know and what they can find out.
Grade 10 part C.
Apply appropriate instruments and apparatus to examine a variety of
objects and processes.
Students
use a computer connected to the Internet to conduct an investigation. They should realize that not all search
engines are suitable for every topic and that not all Internet sites contain
useful information. Some are better
suited for science topics while others might be better suited for news and
current issues.
I
think this activity will work because it is interesting and speculative in
nature. Students will use the Internet
to back up their theories instead of just surfing around. This may not be the most scientific of
topics but sometimes students need to be asked to prove something wrong instead
of just always proving something right.
One problem with this
activity is that sometimes students end up on sites that are not particularly
appropriate to their topic or education in general. This may not be their fault.
Sometimes Internet searches turn up inappropriate results. I see no way of dealing with this issue yet,
other than close supervision. We have
installed a program called “CyberPatrol” on our network at school. In my opinion this software is more trouble
that it is worth. It keeps stopping me
from accessing certain sites like the New York Times. It also keeps me from e-mailing someone from his or her own
site. And most of the inappropriate
sites change their Internet addresses so often that it’s hard to keep a current
list of them.
Even with this said, I
still think that this activity and others involving the Internet should be
pursued. Students need exposure to the
technology in the world around them as soon as possible. They also need to learn to theorize and
speculate. This activity is a step in
both of those directions.