Book 13, Question 119
Why Can a Scanner Copy a Picture Using a Moving Line of Light?
A scanner copies a picture by sliding a bright bar of light across it! Tiny sensors measure how much light bounces back from each spot. The scanner builds the picture line by line.
More fun facts
- In 1957, Russell Kirsch at the U.S. National Bureau of Standards, now NIST, created the first ever digital image.
- His team built a rotating drum scanner and the programming to feed pictures into the SEAC computer.
- The first picture scanned was a photo of Kirsch's three month old son, Walden.
- The image was just 5 centimeters by 5 centimeters and only 176 pixels on a side.
- In 2003, Life magazine named it one of the 100 photographs that changed the world.
- Kirsch's work helped lead to satellite imaging, CAT scans, bar codes and digital photography.
Sources: NIST
Questions kids ask
What is a pixel?
A pixel is one tiny dot in a digital picture. Many pixels together make the image.
Why did the first scanner use a drum?
The photo was wrapped around a spinning drum so a sensor could read it bit by bit.