Model of the Universe
So You Want to Do a Project about the Solar System!
To make a model of what scientists in the past thought the universe looked like.
- drawing compass
- 16-inch (40-cm) -square piece of white poster board
- 7 different colored crayons-l each of blue, yellow, red, and 4 other colors
- strip of adding machine paper (length of the clothes hanger)
- transparent tape
- marking pen
- clothes hanger
- 48-inch (120-cm) piece of string
- Use the compass to draw sixteen (3.75-cm) -diameter circles on the poster board.
- Cut out the circles. You should have 16 circles.
- Using the blue crayon, color the front and back of two of the circles.
- Make a slit from the circumference to the center point of each of the two colored circles.
- Take the two colored circles and join them together at the slits at right angles to model a 3-D sphere.
- Repeat steps 3 to 5 using the remaining crayons and circles.
- Repeat step 5 with the two remaining, uncolored circles.
- Fold the adding machine paper in half three times. Unfold the strip of paper and secure it to the clothes hanger with tape.
- Use the pen to label the parts of the universe on the paper strip, starting with Earth at the left end, in this order: Earth, Moon, Mercury, Venus, Sun, Mars, Jupiter, and Saturn. Put all the labels except "Earth" on the fold lines as shown.
- Cut the string into eight equal pieces, each 6 inches (15 cm) long.
- Tape one end of each piece of string to the top of each model sphere. Attach the free ends of the strings to the hanger. Each sphere represents one celestial body. Tape the blue sphere to the hanger at the Earth label, the white sphere at the Moon label, yellow at the Sun label, and red at the Mars label. The other colored spheres can be attached to represent any planet.
- Hold the Earth end of the hanger in place and rotate the hanger around once. Observe the motion of the celestial bodies.
You have made a model that shows how scientists in the past thought the universe was organized. The celestial bodies moved around Earth.
In this investigation, you have made a geocentric (Earth-centered) model of the universe (Earth and all natural objects in space regarded as a whole). Ptolemy and most scientists of the second century A.D. believed that Earth was motionless and all celestial bodies (natural objects in the sky, such as moons, planets, suns, and stars) revolved (moved in a curved path around another object) around Earth. An outer dome of stars was thought to exist beyond the farthest planet (then thought to be Saturn). Ptolemy believed that in relation to their starry background, the Sun and the Moon moved along regular paths around Earth, while other celestial bodies seemed to wander. These wandering celestial bodies were called planets from the Greek word for wanderers. (Planets today are known to be celestial bodies that revolve about the Sun.)The curved path of one celestial body about another is called an orbit. Orbited and revolved both mean to move in such a path.
In 1543, the Polish astronomer Nicolaus Copernicus (1473–1543) proposed a heliocentric (Sun-centered) model of the universe. Copernicus was not the first to suggest that the Sun was the center of the universe, but he was the first to propose a model that at the time best explained the movement of the celestial bodies.