Paper Fibers

A detective investigating a crime looks for any material that might connect a suspect with the crime scene. A burned match found in an ashtray can provide evidence that links a suspect to the crime. Try the following activity to see how the paper fibers of a torn match can help forensic scientists solve a crime.

Materials

- 3 identical unused matchbooks
- magnifying lens
- paper
- pencil

Procedure

CAUTION: Do not light matches during this activity.
1. Tear match out of each matchbook.
2. Use the magnifying lens to examine the torn end of each match.
3. Draw a sketch of the torn end of each match. Do you see any special features that would help you link the match to the matchbook from which it was torn?
4. Use the magnifying lens to examine each matchbook. Carefully examine where each match was removed from the matchbook. Can you find any evidence on the matchbook that would help you link the torn match to it?

More Fun Stuff to Do

While you are out of the room, have a helper remove a match from each matchbook. Can you link each match to the matchbook from which it was torn?

Explanation

Paper is made of various wood fibers that have been pressed together. These are randomly arranged in the paper and can be of various lengths. When you tear paper, the fibers separate. Since no two pieces of paper have fibers that are identical in arrangement and length, all paper tears differently. Even if you tried, you could not make identical tears in two pieces of paper.

Matches in a matchbook are made of paper. The end of a paper match torn from a matchbook is distinctive and can be used to match it to the matchbook from which it was torn. If a match torn from a matchbook is found at a crime scene and can be linked to a matchbook found on a suspect, this evidence could prove that the suspect was at the scene of the crime.