The Magic of Invisibility


I’ve heard people ask, ‘would you rather fly or be invisible?’ I think both! But invisibility may be closer than we think! Researchers are working on exactly that. They’ve had success on a small scale.

Invisibility seems safer than using makeshift wings, so I looked into advances in cloaking.

I re-created an experiment done by the University of Rochester. The experiment uses four lenses, arranged in a way to bend the light–sort of like a doughnut, so that when you put an object between two of the lenses, it disappears!

For an object, person, for anything to be seen, light waves must come in contact with it. If a room is dark enough, you can’t see at all. (Once I walked right into the bedroom door, thinking it was open. No bruises, but it was a shocker)

Here’s a look at the set up.  Yes, that’s a ping pong table! I needed a long, flat surface. And a way to keep our boxer, Louie from helping too much!



In the photo, the pencil is not seen between the two lenses, even during the day. That’s because the visible light waves bend around it. Think prism and how it can bend light. (Prisms also separate the visible light waves into their individual wavelengths, or colors, but that’s another topic) The lenses I used for the experiment bend the light.


The formula is below, with a graphic, courtesy of the University of Rochester.

  1. Purchase 2 sets of 2 lenses with different focal lengths f1 and f2 (4 lenses total, 2 with f1 focal length, and 2 with f2 focal length)
  2. Separate the first 2 lenses by the sum of their focal lengths (So f1 lens is the first lens, f2 is the 2nd lens, and they are separated by t1= f1+ f2).
  3. Do the same in Step 2 for the other two lenses.
  4. Separate the two sets by t2=2 f2 (f1+ f2) / (f1 f2) apart, so that the two f2 lenses are tapart.

I can provide more details or cheer you on if you want to try it. Contact me.

Which would you choose? Flying or invisibility?

4 thoughts on “The Magic of Invisibility”

Leave a Reply

Susan Berk Koch
Follow Sue via email

Enter your email address to subscribe to this blog and receive notifications of new posts by email.