Archimedes
In this exploration students explore the possibility of the tale told by Plutarch about Archimedes. Did he really set Roman ships on fire with the sun's light?
To Start: Read the story of Archimedes here. Do the experiments. Then reread the story to decide if you think the events are really possible based on your experiences. Why or why not? Write about your experiences and your conclusion about the story in your journal.
Materials Required:
• Plastic Mirrors, Mylar Tape, or Tagboard covered with aluminum foil
• Thermometer
• Black Paper
• Clay or similar
• Journal
Procedure:
1. Collect a set of small mirrors. A bag of mirror squares or mylar tape can be found at a craft store or you can make your own mirrors by gluing aluminum foil to a piece of stiff paper or cardboard.
2. Arrange the mirrors so that they focus on a particular point.
The example above shows three mirrors arranged to focus light toward the center. You can hold mirrors in place by using a piece of clay. Observe the way sunlight can be reflected from the mirrors. Experiment with several mirrors to see if you can focus light on one spot.
3. You can also experiment with a mirror made from aluminum foil and stiff paper. You can make your mirror so that it can bend and make a curve. See if you can curve your mirror to focus light on a point. If you have a thermometer put the bulb at the vocal point to see how much the temperature will raise.
4. Once you have your mirror or mirrors set up, build a boat! Make a small boat out of black paper to simulate a Roman ship attacking the harbor at Syracuse. It can be a small replica. In this example below we tried a pie tin to reflect light onto a paper boat filled with tiny rocks as cargo.
5. Focus your mirrors on the boat. Remember how Archimedes told the soldiers to aim their mirrors. Can you warm up the paper boat? You can use a thermometer to see if there is a temperature change in the boat. Can you get your boat to burst into flames?
Extensions
Mirrors can be arranged to focus light on a particular point. This is called the focal point. In the example below, a curved mirror is used to focus light on a piece of paper. What is the result?
Depending on the curve of the mirror, the focal point can be near or far.
Is it possible that the Archimedes story is true? Read more at http://www.unmuseum.org/burning_mirror.htm
