the Annenberg Foundation
the Harvard-Smithsonian Center for Astrophysics
This is Unit 2 of the free digital course "Physics for the 21st Century", aimed at secondary teachers and adult learners. Unit 2 explores interactions between particles -- the forces that hold them together or tear them apart. It examines the four fundamental forces: gravity, electromagnetism, and the strong and weak nuclear forces. It also provides a historical glimpse of the idea of unification -- the ongoing attempt to explain seemingly disparate phenomena under a common theoretical framework. The resource includes 3 components: written text, short video clips and animations, and an interactive web module on discovering neutrino oscillations. A Facilitator's Guide is also provided.
The video series is produced by the Harvard-Smithsonian Center for Astrophysics Science Media Group in association with the Harvard University Department of Physics. It is sponsored by Annenberg Media.
9-12: 1A/H1. Science is based on the assumption that the universe is a vast single system in which the basic rules are everywhere the same and that the things and events in the universe occur in consistent patterns that are comprehensible through careful, systematic study.
9-12: 1A/H2. From time to time, major shifts occur in the scientific view of how things work. More often, however, the changes that take place in the body of scientific knowledge are small modifications of prior knowledge. Continuity and change are persistent features of science.
9-12: 1A/H3bc. In science, the testing, revising, and occasional discarding of theories, new and old, never ends. This ongoing process leads to a better understanding of how things work in the world but not to absolute truth.
1C. The Scientific Enterprise
9-12: 1C/H6ab. Scientists can bring information, insights, and analytical skills to bear on matters of public concern. Acting in their areas of expertise, scientists can help people understand the likely causes of events and estimate their possible effects.
4. The Physical Setting
4A. The Universe
9-12: 4A/H3. Increasingly sophisticated technology is used to learn about the universe. Visual, radio, and X-ray telescopes collect information from across the entire spectrum of electromagnetic waves; computers handle data and complicated computations to interpret them; space probes send back data and materials from remote parts of the solar system; and accelerators give subatomic particles energies that simulate conditions in the stars and in the early history of the universe before stars formed.
4D. The Structure of Matter
9-12: 4D/H5. Scientists continue to investigate atoms and have discovered even smaller constituents of which neutrons and protons are made.
4G. Forces of Nature
9-12: 4G/H2a. Electric forces acting within and between atoms are vastly stronger than the gravitational forces acting between the atoms. At larger scales, gravitational forces accumulate to produce a large and noticeable effect, whereas electric forces tend to cancel each other out.
9-12: 4G/H6. The nuclear forces that hold the protons and neutrons in the nucleus of an atom together are much stronger than the electric forces between the protons and electrons of the atom. That is why much greater amounts of energy are released from nuclear reactions than from chemical reactions.
10. Historical Perspectives
10C. Relating Matter & Energy and Time & Space
9-12: 10C/H3. The special theory of relativity is best known for stating that any form of energy has mass, and that matter itself is a form of energy. Even a tiny amount of matter holds an enormous amount of energy. This relationship is described in the famous relativity equation E = mc2, in which the c in the equation stands for the immense speed of light.
9-12: 10C/H5. Einstein's development of the theories of special and general relativity ranks as one of the greatest human accomplishments in all of history. Many predictions from the theories have been confirmed on both atomic and astronomical scales. Still, the search continues for an even more powerful theory of the architecture of the universe.
11. Common Themes
6-8: 11B/M4. Simulations are often useful in modeling events and processes.
9-12: 11B/H1a. A mathematical model uses rules and relationships to describe and predict objects and events in the real world.
6-8: 11D/M3. Natural phenomena often involve sizes, durations, and speeds that are extremely small or extremely large. These phenomena may be difficult to appreciate because they involve magnitudes far outside human experience.
<a href="http://www.compadre.org/portal/items/detail.cfm?ID=12497">Harvard-Smithsonian Center for Astrophysics. Physics for the 21st Century: The Fundamental Interactions. Annenberg Foundation, 2010.</a>
Harvard-Smithsonian Center for Astrophysics. Physics for the 21st Century: The Fundamental Interactions. Annenberg Foundation, 2010. http://www.learner.org/courses/physics/unit/text.html?unit=2&secNum=0 (accessed 4 July 2015).
Physics for the 21st Century: The Fundamental Interactions. Annenberg Foundation, 2010. Harvard-Smithsonian Center for Astrophysics. 4 July 2015 <http://www.learner.org/courses/physics/unit/text.html?unit=2&secNum=0>.
%0 Electronic Source %D 2010 %T Physics for the 21st Century: The Fundamental Interactions %I Annenberg Foundation %V 2015 %N 4 July 2015 %9 text/html %@ 1-57680-891-2 %U http://www.learner.org/courses/physics/unit/text.html?unit=2&secNum=0
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