Snippet Lesson Plan: Thermonuclear Reactions in the Sun and As a Source of Unlimited Energy for Mankind
Subject: Science & Technology — Astronomy — The Sun, Thermonuclear Reactions; The Environment; Science Fiction
Ages: 12+: Middle School Level
Length: Snippet: Approximately eight and 1/4 minutes in two segments. Lesson: approximately 30 minutes.
Students will be introduced to the thermonuclear reactions that take place in the nucleus of the sun. They will come to know why it would be a major technological breakthrough to be able to control thermonuclear reactions to make electricity and the difficulties that have made this endeavor impossible to date. Students will be introduced to the magnetic fields of the Sun and see films sunspots and solar prominences.
The film “Spiderman 2” provides a cinematic representation of an attempt to control a nuclear fusion reaction with strong magnetic fields in order to produce a limitless amount of energy. Showing these short segments will provide interest and variety to enhance classes on the Sun, thermonuclear reactions, and the Environment.
DESCRIPTION OF SNIPPET
A scientist is being funded by Peter Parker’s former school mate, Harry Osborn, now turned wealthy corporation manager. The scientist, Dr. Otto Octavius, is doing research on a clean and limitless energy source that could provide cheap electricity to the whole world. He is trying to devise a way to hold nuclear fusion in a controlled environment. During a conversation with Peter Parker, Dr. Octavius describes his research and invites Peter to a demonstration in his lab. In order to manipulate the mini-Sun he is about to create, Dr. Octavius plugs an artificial intelligence device into his spine through which he can control four arms that can withstand the high temperatures involved and which are not affected by the strong magnetic fields produced by the mini-Sun. Initially it all seems to work as desired, but soon the mini-Sun gets out of control, its magnetic fields attract most metallic objects in the room and large prominences form arcs of hot matter. Dr. Octavius refuses to admit his failure and insists on carrying on with the experiment. Spiderman has to come to help stop the device.
Location: Minute and second calculations may differ from what is set out below. Check your disc for exact locations before using the film in class.
Segment #1 starts in chapter 8 at 0:18:53 minutes into the film and ends at 21:08. It lasts for 2 minutes 15 seconds. (The segment starts with Peter Parker being introduced to Dr. Octavius by Harry Osborn. It runs through their conversation at a coffee table, until they stop talking about the science and Peter Parker is asked if he has a girlfriend.)
Segment #2 starts in chapter 16, 33:07 minutes into the film and runs for six minutes until 39:03. (The segment starts as Dr. Octavius has invited some prominent members of the city to witness the performance of his first prototype. Peter Parker is also invited. The segment runs until Spiderman has to intervene once the experiment goes wild and the lab is destroyed.)
Possible Problems with this Snippet: None.
What about showing the whole movie? TWM does not recommend showing the entire film in class because it is a waste of time. Students will get all that the movie has to offer by watching the two film clips identified in the Snippet Lesson Plan.
This film is available from Amazon.com.
1. Review the two film clips suggested for this lesson plan and make sure that they are suitable for the class.
2. Review the links referenced below; pick those that are appropriate for the class and the lesson. Decide when to present them to the class.
3. Be familiar with the location of the clips on the DVD, check for accuracy of the minute and second locations of the clips on the DVD, and practice getting quickly from one film clip to the other. Cue the DVD to the beginning of the first segment. Assemble all other materials necessary for the class.
STEP BY STEP
1. Introduce the first clip by providing the following information through a lecture or a student handout. The handout can be created by copying and pasting the text into a file in a word processing program, deleting any instructions, and adapting it to the needs of the class.
This lesson is an introduction to thermonuclear energy. The search for a clean and limitless source of energy would be over if we were able to reproduce the thermonuclear reactions that take place in the interior of the Sun. Our current main source of energy, fossil fuels, contaminates the air and drives global warming. In the not too distant future, we’ll run out of oil and gas. Eventually, we’ll run out of coal. The current technology for creating nuclear power employs fission reactions which produce tons of radioactive waste. This material will be dangerous for hundreds of thousands of years and no one knows how to safely store or dispose of it. Non-polluting alternatives such as solar panels that create electricity from sunlight and wind power have not yet shown that they can fulfill the power needs of modern society.
Energy from the Sun is a major contributor to almost all the energy sources we use to provide the power necessary for contemporary life.
Fossil fuel comes from dead plants and animals which directly or indirectly captured their energy from Sunlight through photosynthesis.
Wind energy comes from the movement of large masses of air that occur when hot air rises and cold air falls. The heating of the air takes place at the surface of the Earth, from Sun-warmed ground or Sun-warmed ocean water.
Hydroelectric energy harnesses the potential energy of waterfalls and rivers. These bobies of water accumulate from rain and snowfall, which in turn rises and gets to the clouds primarily by evaporation from the surface of the oceans. The evaporation is caused by heat from the Sun.
Solar panels obviously get their energy from the Sun, which they convert directly to electricity.
[Show these categories on a board or screen and have students write them in their notes so that visual and kinesthetic learners can easily conceptualize them.] The only major energy source that does not obtain its energy from the Sun is produced by power plants employing nuclear fission to create heat to drive electric turbines.
Explain that either way, be it from the Sun or from nuclear power, ultimately most energy we use comes from processes that take place in the nuclei of atoms. When the atoms in the universe formed, shortly after the Big Bang, the most abundant element by far was hydrogen. It is the simplest element, being made of a single proton and a single electron. This hydrogen formed dense lumps of gas. The gravitational force on the particles grew as the lumps of gas became denser and denser and adopted a spherical shape. Eventually, the pressure and temperature in the center of the sphere were high enough to force hydrogen nuclei (protons) to separate from the electrons (become ionized), overcome the electric repulsion of their positive electric charges, and stick together to form an isotope of helium nuclei made up of two protons and two neutrons. Once the Sun’s hydrogen runs out, the helium nuclei will start merging into heavier elements, and so on.
The Sun is in the first stage of the development for stars of its kind. In this stage, hydrogen nuclei are joined to form helium. Other stars in later stages of development transform helium into carbon, or build oxygen, neon and magnesium from helium and carbon nuclei. All these reactions are called fusion reactions and are exothermic, which means that there is a net balance of energy being released in the process. This works only for elements lighter than iron. Heavier nuclei than iron do not release energy when built from smaller ones, they need to absorb energy for the fusion to take place. Such processes are called endothermic. This energy is only available in supernova explosions: all elements heavier than iron are formed in such high energy environments.
Strong magnetic fields protrude from the Sun at various locations. Sunspots are caused by intense magnetic activity which results in an area that is less hot than usual at the surface of the Sun. Prominences are large bright eruptions of hydrogen gas, often in a loop shape that are anchored to the Sun’s surface and extend outward thousands of miles into the corona of the Sun. Prominences are formed along the magnetic fields of the sun.
3. Ask the question of why many oppose nuclear energy. Issues such as safety (the Fukushima Daiichi disaster, Chernobyl, Three Mile Island) and radioactive residues will surely come up. In fact these are the two major arguments against nuclear power. Without attempting to start a debate on nuclear power, let alone to reach a conclusion about it, introduce the fact that if we were able to reproduce the fusion reactions that take place in stars, there would be no debate on nuclear power nor the need for any other alternative energy source. Hydrogen the fuel for the thermonuclear processes of the Sun is all around us (as in water, H20) and there are no toxic or dangerous residues. The result would be clean and unlimited energy for the whole planet.
4. Show segment # 1. (Dr. Octavius explains precisely that if successful, he would be able to provide clean and cheap electricity for everyone, as just explained.)
5. Ask students why they think that controlled fusion as devised by Dr. Octavius is not being done in real life. Make sure that the discussion includes the concept that fusion thermonuclear reactions require high temperatures and pressures. Such a hot lump of matter could not be contained anywhere on Earth — any structure built to hold the material would burn or melt. Explain that the only theory that scientists have come up with to control a Sun-like fusion reaction on Earth, is to use magnetic fields of opposite polarity to control the very hot material. the resulting repulsion would force the mini-Sun to hover, not touching any material support.
6. Show the second segment. (Dr. Octavius creates a mini-Sun and tries to demonstrate how he can actually contain it with magnetic fields. However, the experiment runs out of control. Also seen are large prominences from the mini-Sun. These are large arcs or matter that flows out of the surface of the mini-Sun and fall back onto it. In fact, these prominences are the first to cause damage once the system becomes unstable.)
7. Ask the class what has happened in the segment. Lead the discussion toward the following concept: What appears to have happened to the experiment of Dr. Octavius is that the interaction between the magnetic fields used to keep the mini-Sun from expanding and those within the mini-Sun itself have rapidly and exponentially enhanced the strength of the magnetic fields within the mini-Sun. This first affects anything that could be attracted by a magnet, and then forms such large prominences that they get out of control destroying the whole laboratory.
8. Explain that another visible feature of the magnetic fields that come out or into the surface of the sun are sunspots. Where magnetic fields cross the surface, the temperature is somewhat lower than in the surrounding areas of the Sun, although they are still in the thousands of degrees. Show the class pictures and films on the Internet of Sunspots and solar prominences. A view of Sunspots on the solar surface is located at Sunspots. Movies of sunspot evolution over time are available at: Movies of Sunspot Activity. Dramatic movies of prominences are shown at SOHO Gallery. These sites are from NASA.
- Interesting and high-quality images are also becoming available at the website of the Solar Dynamic Observatory (SDO) launched in 2010;
- Closely related to sunspots and magnetic fields are SDO’s observations of a “coronal hole”
- NASA has created a collection of the latest images of the sun taken by various terrestrial and space-based observatories:
If conducting a solar observation, be sure to give students strict warnings about the dangers of looking directly at the sun and research other recommended precautions.