What is this?

pwnell · Post by **pwnell** » Thu Dec 20, 2012 8:53 pm

Guess if you can... I am tempted to ask Charles not to play along as he ALWAYS figures it out first, but it is Christmas time so I am going to be lenient

20121117-DSLR_IMG_0025_1.jpg by pwnell, on Flickr
10x * 1.6, POL

Pau · Post by **Pau** » Fri Dec 21, 2012 4:15 am

Water bubbles (or droplets) at the limit of the water/air in a drying microscope slide. Some bubbles walls act as mini Bertrand lenses imaging the pol interference cross.

EDIT: I first said air bubbles

darwin · Post by **darwin** » Fri Dec 21, 2012 5:00 am

I agree with Pau!

Litonotus · Post by **Litonotus** » Fri Dec 21, 2012 5:23 am

the background looks like sky, and that is what confuses me...

pwnell · Post by **pwnell** » Fri Dec 21, 2012 6:30 pm

Almost. It is air bubbles underneath clear sellotape stuck to a glass slide, viewed under polarised light.