Introduction:

    Gravitation or the attraction between two objects is a topic of interest in physics that has ties to a number of applications and ideas in mechanics, relativity and other fields of physics.  In the setting of a 11th or 12th grade class, this concept can be difficult to grasp in explaining exactly how two objects attract to one another, including planetary objects.  In teaching about gravitation and Kepler's Laws of Planetary Motion, it can become difficult to find visual representations or laboratory activities that would be useful in explaining these difficult ideas.  It may become apparent that the possibility of using multiple demonstrations during class can pose a problem due to the nature of the topic.  Gravitation cannot be explained easily with tangible objects.

    For these reasons students may struggle with the concept basing most of their learning and understanding of gravitation on equations and words rather than visual representations and demonstrations.  In order to get around this problem, various applet programs or websites with interactive tutorials can provide teachers with tools that will support a visual, interactive learning environment for their students.

 Sources:

The Physics Classroom

Tom Henderson

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The Physics Classroom is a website that is constructed to be beneficial as a support for high school students studying physics.  The page listed is one of a lesson on Universal Gravitation.  It not only includes information on gravitation itself, but also on Newton and a brief history.  At the bottom of the page are a few problems that are useful for checking for understanding of what is on the page.  Animations are also present throughout to give a visual representation of the information.  The subsequent lessons or topics are organized in a constructive fashion as to build on one another.

It is a great resource for students who may need a slightly different perspective on a topic being discussed in class.  It can also be used as a supplementary teaching resource to help teach a lesson.   The animations are a very good addition to act as a visualization and representation resource.

Physics Applets

University of Oregon (Greg Bothun)

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This website is constructed to be beneficial as a support for high school teachers looking for good visual representations of physical concepts, particularly Gravitation, which can be found in the astronomical physics and mechanics sections.  Just like in the introduction above, a website such as this includes free applets that can be used as demonstrations or parts of labs to supplement the content from the book.

It is a great resource for students who may excel by learning through visual representations and hands-on or interactive labs..  It can also be used as a supplementary teaching resource to help teach a lesson.   The animations are a very good addition to act as a visualization and representation resource.

VisionLearning

Nathaniel Page Stites, M.A./M.S.

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This website is a good resource for teachers as a reference site for historical information about gravitation and the planetary models.  The information is laid out chronologically and is very detailed and informative.  Off to the right side of the page are listed news and events, some links with visual sites and other related information.  The topics discussed are Gravity, starting with Newton, planetary models, and information about scientists and astronomers and their discoveries.

This website is a good tool for students as a data source for student investigations as well as a historical resource for both students and teachers.  It would promote more detailed information for a lecture or give background information for a laboratory activity.  Technology would play a minimal role only if the students were to access the links on the side of the page.

Cavendish Experiment

U.E. Kruse and T.N. Tran

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The Cavendish experiment is an experiment that can be difficult to represent in a demonstration.  This website is a very useful tool to show the relationship to gravitational force and how G was found by Cavendish in 1798.  This website is one that displays the background information of the experiment, displays pictures and has video clips of an actual replica experiment for students to observe.  The website is worded very well and easy to navigate.

This website is a very good example of a visualization and representation resource.  It also includes some historical information.  Technology could be used during a lecture as a demonstration or for individual student learning in viewing the video clips of the experiment.

Issac Newton

Michael Fowler (Physics Dept., U. Va.)

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This website is a good resource for teachers as a reference site for historical information about Newton and his work with gravitation.  The information is laid out chronologically and is very detailed and informative.  About ¾ of the way down the page, there is an interactive animated representation of Newton’s cannon experiment.  The user is able to alter the velocity of the object to determine the orbit.

This website is a good tool for students as a data source for student investigations as well as a historical resource for both students and teachers.  It would promote more detailed information for a lecture or give background information for a laboratory activity.  Technology would play a minimal role only if the students were to use the interactive visual either in a lab or see it as a demonstration.

Physics Kinetic Books

Kinetic Books Company

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Kinetic Books is a website that is constructed to be beneficial as a support for high school teachers teaching any topic.  The page listed is a chapter on Universal Gravitation.  It lists each topic in a sequential order, which helps to organize the information and concepts for a lesson format.  It not only includes the information but also has visual representations for labs, demonstrations and other uses in the form of applets, flash and Quick Time clips.  The website can be navigated easily and is a very good supplemental source for a teacher.

This is a great example of another approach to teaching in the area of gravitation.  The information is laid out well so that a teacher can follow along and create a lesson combining ideas from both their own book and the website.  The visuals on the site will allow for the use of technology by both the teacher during demonstrations and visuals and the students in lab and inquiry-based learning in laboratory activities.

Tides and Water Levels

NOAA National Ocean Service Education

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This website on tides and tidal patterns is a very useful resource that includes background information on tides and types of tides but more importantly, explains the relationship of gravitation to the tides and their causes.  This website is laid out so each part of the site, history, definitions, types and causes of tides are listed as links on the right side of the page.  The tidal bulges are explained through gravitational ideas based on lunar and solar effects.

This is a great resource for students to either be used by the teacher as a handout or even a lab exercise where the students are to access the internet and the site and based on the information, answer questions and apply ideas of gravitation to their PCK.  This website is most useful as a data source for student investigations and also as a visualization and representation resource.  The students would be using technology through accessing the information on the internet.

Physics and Astronomy Lesson Plans

The State University of New Jersey, Rutgers

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This site compiles a list of lesson plans of various topics in and around physics and astronomy.  The topics range anywhere from mechanics and force to planetary motion and gravitation.  There are a number of lesson topics on gravitation (weightlessness, orbital motion, and measuring the value of G) that would be useful as both labs and/or interactive demonstrations.  The lessons numbered 10, 25 and 48 are these lesson plans.  By clicking the topic in blue, a rough lesson plan will be displayed in a new window that is easy to follow and understand.

This makes it a great resource for teachers who are planning lessons for a chapter on gravitation.  Some topics such as weightlessness and orbital motion are not easy to visually represent or allow for the inclusion of a demonstration.  This website acts as a tool for exploring processes and is a good example of a visualization and representation resource.  For some of the lessons, computer software is beneficial in allowing students to compile data or information more effectively and accurately.

Sir Issac Newton:  The Universal Law of Gravitation

University of Tennessee (Dept. of Physics and Astronomy)

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The University of Tennessee created a website that is a very useful tool for teachers in a number of ways.  The website is laid out very well for use in a number of different settings.  It starts out by talking about a concept well known to most students about Newton and the apple tree.  With this basic concept and a small visual applet, the students are able to be introduced to the idea of Newton and his ideas about gravitation.  The website builds as it continues down the page on his cannon experiment, the Law of Universal Gravitation, Center of Mass, Kepler and his laws and finally weightlessness and how gravitational force relates to it.  Throughout the website, various calculators and applets are linked to allow students to explore the concepts either more mathematically or visually.

This is a great source for teachers to implement in the classroom either as a visualization and representation resource or perhaps a data resource for student investigations.  The site could be used during a lecture to run through the calculations and applets or as a lab activity where the students are to access the site, read through the information and collect data or answers from the reading or calculations.  This will help with difficult ideas by presenting the information to students in a slightly different fashion.

The ‘why’ of Weightlessness

David Ropeik (MSNBC)

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The very first item seen on the page is an interactive visual that runs through the ideas of weightlessness.  By following through a few slides, a person can explore the ideas of how an astronaut or an object may experience weightlessness, or as the visual tells you, apparent weightlessness.  Most students have different ideas about what weightlessness actually is and their understanding of the issue is usually incorrect.  The website continues on with David’s article on weightlessness.  His topics of his article range from gravity and what it is, how it can change with location and lastly, how to ‘escape’ gravity.  It gives a real world introduction to astronauts in space and the relation to high school physics and the concept of gravity.

The website is a useful tool for teachers as a site that their students can access as a visualization and representation resource as well as an informational data source for student investigations.  The teacher may either use the visual at the top of the page in a demonstration and point out the key ideas that relate to the topics being discussed in class or the teacher may have the students do their own research on the site, running through the visual aid and pulling out important information through questions.

Reflection

When dealing with the topic of Gravitation, there are a variety of ideas that are not easily identified in demonstrations or visual representations in classroom applications.  Students do not have the opportunity to observe real examples other than mathematical calculations or 2-D sketches.  In looking for websites that will enable a teacher to find examples or other means of teaching students, the following list was compiled.

When searching for sites to include in the annotated bibliography, I looked mainly for visual representations or interactive demonstrations of some of the difficult concepts for students to understand and learn.  For instance, the Rutgers, weightlessness, Cavendish and Physics Applet website were good examples of this fact.  These pages included content that was supported by visual applets or applications that would help to clarify difficult concepts more than a student reading a passage or the book.  Since these sites would be different from what students are used to learning about, it would spark interest and allow for them to see a different side of the concept being discussed.  Some students learn more visually than reading and writing, so these students would excel more because of the change.

The resources that I obtained were very useful and were not all the same.  Some of the pages included a plethora of information on a topic or series of topics but did not have many visuals or other ideas.  These pages would be targeted more towards the teacher than the students as a developmental resource for their own content knowledge.  These resources would be very useful and informative for a teacher who was not necessarily well-versed in a particular topic area.  The pages on Issac Newton and the history of the planetary model would be good examples of this style of website.

Other resources were directed more towards the students and could be used for more than one use.  Like mentioned in some of the brief summaries of the sources, the pages could be used a resource for students to access in order to answer a question sheet or work through a laboratory activity.  This would change the learning environment and allow the students to access a different style of knowledge as well as be presented with visual resources or applets to view.  These applets and short video clips would allow the students to observe difficult ideas such as weightlessness or gravitational force between two planetary objects in a visual sense, making it “tangible.”  The students may also be asked to follow through one of the pages for a laboratory experiment plugging in numbers or observing video clips and recording data.  The Kinetic Book Company does a very good job of making these sorts of lessons available for a teacher.

When selecting sites that would fit in the realm of the project, it was important to first determine what kinds of resources I would be looking for.  To help teachers in the areas of gravitation and orbital rotation, it is important to have a number of visual representations and information on the history behind it all.  Students find it hard to observe these particular concepts because they are not like projectiles or moving objects seen everyday, but normally relate to planetary motion or massive objects in motion.  For this reason, I chose to search for resources on weightlessness, orbital motion and the history behind gravitation.  In doing so, the resources necessary that would be beneficial to a learning environment focused on gravitation and the use of technology would profit the teacher more than him/her relying on the textbook.