Explainers at NYSCI

NYSCI Explainers talk shop, the art of explaining science, museum careers and professional know-how. Subscribe for tips, tricks, videos and fun things to do with science. Share your ideas too!
Contributing Authors
Recent Tweets @nysci

DIY Experiment #10 - Invisible Love Letters!

Send one of these letters to a friend, family member, Valentine, or loved one and be sure to reveal the awesome science behind decoding them!  

Materials: Paper, lemon juice, a cotton swab, heat source (light bulb or flame, with parent’s permission)

  1. Squeeze lemon juice into a small bowl. 
  2. Dip the cotton swab into the lemon juice and use it as your pen. Begin to write your message on the paper. It appears invisible, right?
  3. To decode the message, expose the paper to heat. Hold it under direct light or a flame without burning the paper (be sure to get your parent’s permission before handling fire) and voila! Your message has appeared. 

How does it work? Lemon juice oxidizes, or combines with oxygen when heated. This makes it turn brown. If the message is still visible from the start, adding water to the lemon juice makes it harder to see before it is heated. Also, it works best to hold the message slightly above a candle.

Source

  1. periodically-aura reblogged this from explainers-nysci
  2. lurkermooncalf reblogged this from explainers-nysci
  3. pokingdeadbodies-withsticks reblogged this from explainers-nysci
  4. d0nt-believe-in-walc0tt reblogged this from explainers-nysci
  5. myworldasdianna reblogged this from explainers-nysci
  6. gabsstergabi reblogged this from explainers-nysci
  7. jordanmellark12 reblogged this from explainers-nysci
  8. ieatsoulsforlunch reblogged this from explainers-nysci
  9. putoutthelight13 reblogged this from explainers-nysci
  10. wabbitmon reblogged this from explainers-nysci
  11. sweet-dispositionxo reblogged this from explainers-nysci
  12. explainers-nysci posted this