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πŸš€ Inventions and machines πŸ”§ Machines and tools

Lasers

Lasers

πŸ“– In short

A laser is a device that makes a very thin, very strong, straight beam of light. Light from a lamp spreads out in every direction, but a laser beam stays a small, focused spot even over long distances.

🀩 Did you know?

  • The American physicist Theodore Maiman built the first laser in 1960.
  • Some laser beams are so thin they can make hundreds of holes in the head of a pin.
  • Scientists measured the distance to the Moon by sending a laser beam to mirrors the astronauts left there!
  • The word β€œlaser” is short for a long English phrase describing how the light is made.

πŸ”Ž Find out more

🌟 What's different about it?

Laser light has only one color, and all its waves travel together in step, like soldiers in a line, so it stays focused and doesn't spread out.

πŸ” Lasers in medicine

Doctors use lasers for very precise operations, like correcting eyesight, because they cut with amazing accuracy and little bleeding.

πŸ’‘ Lasers around us

We find lasers in lots of things: in shop barcode readers, printers, the optical fibers that carry the internet, and measuring distances.

🎯 Careful!

Never point a laser beam at a person's or animal's eyes, or at planes, because it can badly hurt the eyes.

πŸ“Έ More pictures

Lasers
Lasers
Lasers

🧩 Test yourself

1 What's special about a laser beam?

2 Where must you never point a laser?

3 Which picture shows β€œLasers”?

πŸš€ Discover more

πŸ“· Picture sources: Wikimedia Commons