Be a detective!
When you touch a smooth surface, you leave a little bit of oil from your skin: a fingerprint. If you cover it with a fine powder, you can see it clearly. Everybody's fingerprints are different!
You need: a piece of burnt toast, a bowl, a spoon, a smooth white plate, clear sticky tape and a magnifying glass.
- 1🍞 Make carbon powder
Scrape the black crumbs off the burnt toast into the bowl and crush them with the back of the spoon. Heat turns bread into carbon!
- 2👍 Leave a print
Rub your thumb on your forehead or hair, then press it lightly on the plate.
- 3🫙 Dust it
Sprinkle carbon powder on the print and gently shake off the extra.
- 4🩹 Lift it
Cover the print with sticky tape, peel it off and stick it on white paper.
- 5🔍 Compare
Look at your print and your classmates' prints with the magnifying glass. Are the patterns different?
Today, forensic scientists use computers to compare fingerprints from a crime scene with thousands of prints stored in a database, in just a few seconds.