# Two Versions of Gravity: Newton and Einstein

Suggested Grade Level(s): 11-12

Estimated class time 2 -45 minute periods

# Summary

Students will be presenting information to their peers about both
Newton's Law of Gravitation and Einstein's General Theory of Relativity.
Students will need to have either studied both Newton's Law of
Gravitation and Einstein's Theory of Relativity or be given the time and
resources to look up this information. The lesson plan below assumes
that they have been taught both, but it could easily be modified to
incorporate an independent research approach to covering Einstein's
theory.

# Objectives

-   Students will be able to compare and describe the key differences
    between Einstein's Theory of General Relativity and Newton's Theory
    of Universal Gravitation.

-   Students will be able to organize and be able to orally describe an
    idea or concept.

-   Students will be able to construct and analyze a scientific
    argument.

-   Students will be able to describe science as a process and define
    the key components that make a theory valid.

-   Students will be to describe the importance of new data as the
    determining factors as to if a scientific theory is valid and
    accurate.

-   Students will be able to display analytical and critical questioning
    skills.

# National Standards

**National Science Standards**

-   NS.9-12.1 SCIENCE AS INQUIRY

> As a result of activities in grades 9-12, all students should develop

-   Abilities necessary to do scientific inquiry

-   Understandings about scientific inquiry

```{=html}
<!-- -->
```
-   NS.9-12.2 PHYSICAL SCIENCE

> As a result of their activities in grades 9-12, all students should
> develop an understanding of

-   Motions and forces

-   Interactions of energy and matter

```{=html}
<!-- -->
```
-   NS.9-12.4 EARTH AND SPACE SCIENCE

> As a result of their activities in grades 9-12, all students should
> develop an understanding of

-   Origin and evolution of the earth system

```{=html}
<!-- -->
```
-   NS.9-12.7 HISTORY AND NATURE OF SCIENCE

> As a result of activities in grades 9-12, all students should develop
> understanding of

-   Science as a human endeavor

-   Nature of scientific knowledge

-   Historical perspectives

**National Language Arts Standards**

(From the National Counsel of Teachers of English)

-   NL-ENG.K-12.7 EVALUATING DATA

Students conduct research on issues and interests by generating ideas
and questions, and by posing problems. They gather, evaluate, and
synthesize data from a variety of sources (e.g., print and non-print
texts, artifacts, people) to communicate their discoveries in ways that
suit their purpose and audience.

-   NL-ENG.K-12.8 DEVELOPING RESEARCH SKILLS

Students use a variety of technological and information resources (e.g.,
libraries, databases, computer networks, video) to gather and synthesize
information and to create and communicate knowledge.

# Knowledge Prerequisite

-   Newton's Theory of Universal Gravitation

-   The fundamental concepts of Einstein's theory of General Relativity.
    A mathematical understanding is not necessary

-   General knowledge of planetary motion.

-   An understanding of how both Einstein's and Newton's theories apply
    to the 1919 solar eclipse

# Teacher Background

The goal of this lesson is to create two groups of students with the
purpose of exchanging information about how two different theories
explain a natural phenomenon and to illustrate how the scientific
process allows a new, more complete theory to take the place of an older
theory that does not produce accurate results for a new discovery. This
can be done several ways. Some suggestions are poster presentations, Pod
casts, debates, or PowerPoint. The main objective is for each group to
become an expert of the material for their topic and then present that
material to their peers for discussion. Regardless of how you choose for
the information to be presented, the key objectives are:

1)  Students will be able to research and formulate arguments using both
    General Relativity and Newtonian Mechanics to explain a phenomena

2)  Students will be able to describe science as a process and
    demonstrate the role of data as the guiding force in what is
    accepted a scientific theory.

It is left open to you whether you want to impose a limitation of using
only data available prior to the 1919 eclipse in their project. If you
choose to use this limitation, it does make a clear example of how data
provides the ultimate answer as to which theory is more complete.
Through out the lesson pay attention to the **Teacher Note** sections.
These sections are for your benefit, with the information contained to
be revealed to the students, as you deem necessary, to facilitate the
flow of the lesson.

# Materials

-   Books including that include descriptions of Einstein's theory of
    General Relativity and Newtonian Physics

```{=html}
<!-- -->
```
-   Access to research material so that students can do additional
    research for their arguments

# Procedure:

## Day 1 Prep

### I. Engagement: 

Have the students think about the differences between Einstein's theory
of General Relativity and Newton's theory of Universal Gravitation. Have
them share their ideas with a neighbor.

### II. Exploration: in this section students are given time to think, plan, investigate, and organize collected information 

1.  Organize the students so that they form two groups or teams. Group
    One will represent Einstein's Theory and Group Two will represent
    Newton's Theory. Each group is then comprised of 5 smaller
    sub-groups.

**Teacher Note**: Be sure that students at this point realize that they
will be researching information to present to their peers. It is at this
point that you must decide whether to limit them to only information
that was available previous to 1919 or not. If you do, the data about
the eclipse is not available and Newtonian mechanics has a strong
accepted footing from the data acquired to that point. It is the task of
the Newtonian physics groups to work under this old guard mentality
while the General Relativity groups should demonstrate that their theory
works as well, and should point out the holes in the Newtonian picture.

2.  The main question for the project is whether Newton's Theory of
    Gravitation or Einstein's Theory of Relativity is responsible for
    the movement of the planets. The students will be making a case for
    why each theory is valid.

**Teacher Note**: If used as a pre-1919 project, it should be clear to
the students that Newtonian mechanics has had recent success with the
discovery of Neptune due to gravitational perturbations. In fact all
planetary motion as of the early 1900's had indeed been shown to follow
the Newtonian model, the only exception to this rule being the
precessions of the planet Mercury. It should be noted that General
Relativity did correctly predict the precession and that this knowledge
was known at the time. However several ad-hoc fixes were attempted to
counter this notion such as the belief of dust particles between mercury
and even the belief that a planet nicknamed Vulcan were responsible for
the discrepancy between data and theory. A search was actually conducted
for the planet Vulcan at the time using the same technique that was used
to discover Neptune. Obviously, no planet was ever found but this
clearly illustrates the confidence in Newtonian Physics at that time.

3.  Each group will be responsible for developing 5 components
    (introduction, history, theoretical description, testing the theory
    and closing argument) to justify the validity of their chosen
    theory.

4.  The ideal size for each sub- group is 2-3 students.

    a.  Sub-group 1 will create an introduction for their theory. They
        will introduce the claims to be made by their group.

    b.  Sub-group 2 will create the argument concerning the history of
        the formulation of the theory. The argument must explain the
        historical context of how the theory came to be written. The
        argument must explain what evidence and experiments went into
        the theories formulation.

**Teacher Note**: Both groups for the historical content should relate
how their theories came to be founded. This does not include how the
theory directly relates to planetary motion but rather how both Newton
and Einstein formulated their ideas.

c.  Sub-group 3 will create the argument addressing the theoretical
    description of the theory. They must explain to the class how the
    theory relates to the data gathered about planetary movements of the
    planets.

**Teacher Note**: In this section the students explain how each theory
address planetary motion. The Newton group should include the leap made
by Newton that falling objects and planets are subject to the same
forces. Einstein's group should include discussion of mass as a
Space-Time warping agent. The Newton group can also include information
about the success of Newtonian ideas with regard to planetary discovery
while the Einstein group can point out the problem of mercury.

d.  Sub-group 4 will create the argument that focuses on how the theory
    can be tested with regard to the 1919 eclipse. They must describe
    how their theory relates to the upcoming eclipse of 1919 and why
    they believe that their theory will yield the actual result.

**Teacher Note**: If using a pre 1919 format, it should be made clear to
the students that no results have been obtained at this point. They are
just making a case for how the upcoming 1919 eclipse data will yield
final solution to the debate. If not, this group should include
references to success by Einstein's theory regardless of time period. It
should also be noted here that the bending of light as explained by
Newton has to do with the momentum of the light and it because of this
momentum that light "feels" gravity.

e.  Sub-group 5 will create a closing statement for their group. They
    will summarize the ideas put forth and come up with a strong ending
    statement

**Teacher Note**: Both Introduction and Conclusion groups should make
sure they communicate with the other sub-groups about what is to be
presented so that strong opening and closing presentations can be made
that demonstrate the usefulness of their groups' theory.

### III. Explanation: Students are now involved in an analysis of their exploration. Their understanding is clarified and modified because of reflective activities

5.  Each group must prepare a statement describing what they are going
    to cover for their argument. The statement should take about 3-5
    minutes. They then must be prepared to answer any questions issued
    by the other side about what they talked about with there argument.
    Each argument should be supported by ideas from their theory.
    Because of this questioning opportunity, both sides should be
    familiar with both theories to a degree.

**Closure:** Have the students share with other members of their group
what they learned about their piece of the presentation through the
creation of their piece.

## Day 2 Presentation

Have the students review what they did the day before. Then set the
students up for the presentation.

**Teacher Note**: The actual presentation of information depends on how
you decided for the students to present their information. Either one
group can go completely followed by the other or you can do a back and
forth method. What follows below is an example of a back and forth
method.

1.  Split the room in half with the groups on either side.

    a.  Newton's group will present their opening presentation.

    b.  Einstein's group will present their opening presentation.

2.  Each group will then take turns presenting their information.

    a.  They will alternate presentations of their work for Newton or
        Einstein for each sub-group.

    b.  During the presentation, the other group should develop
        questions to ask the presenting group. After each presentation,
        the other group should ask their questions.

        i.  The questions should either be a clarification of what they
            presented, i.e. did they explain it correctly?

        ii. They should ask questions regarding validity of the ideas
            addressing the orbit of the planet.

3.  The presentation will then finish with the closing statements.

4.  At the conclusion of the presentations, the students will write a
    1-page summary describing the ideas presented by each theory during
    the debate and how the ideas relate to the upcoming eclipse (**If
    done using a pre-1919 format. You could also do just a comparison of
    the theories here**)

**Teacher Note**: At the conclusion of the presentations, the idea that
science is a process and that the 1919 eclipse yields the data necessary
to prove which theory is valid should be reinforced. The main objective
of the activity is to develop the idea that the process of science is
reinforced through the debates of various theories. Yet in the end, it
is the data and observations that yield the actual accepted theory hence
as data improves, theories change. The idea that the story is never over
should be made clear and that from 1919 onward to today, the ideas
behind how our world behaves have changed and as we move into the future
they will continue to do so. It is at this point that the idea that the
1919 debate data proves Einstein right should be made clear to the
students.

**Closure:** To bring closure to the presentation activity, students
should share what they learned about the scientific process and the
theories as a result of the debate activity.