Get Your Science On: Polarized Privacy

 In Get Your Science On, Shopcasts and Videos

This week, Katie shows us how to build a cool science experiment while recycling an old laptop computer.

What’s Going On:

Liquid crystal display (LCD) screens use two polarizing filters with liquid crystals sandwiched between them. The two filters are crossed (one is horizontal and one is vertical), so that ordinarily no light can get through. However, the liquid crystals rotate the polarization of light, letting colors through where you want them to be displayed.

We removed the second polarizing filter so that all colors of light get through and you see white. However, when you wear polarizing sunglasses, the glasses take the place of the filter and you can see them image that on the screen.


  • Old laptop computer with LCD screen
  • Polarized sunglasses

How To Build It:

We carefully removed the outer polarizing filter from the glass on the LCD screen. It was attached with adhesive, and had to be done slowly as to not break the glass. The put on some polarizing glasses and enjoy!