[Phys-L] frozen bubbles

[John Denker <jsd@av8n.com>]

We are coming up on the season for frozen bubbles.

The temperature has to get down to near zero Fahrenheit, or below.
I don't fully understand why it has to be quite so cold, but evidently
it does.

In addition to the freezing-point depression there is some
supercooling / nucleation business going on.

In any case, they are interesting and pretty.
  https://www.youtube.com/watch?v=b0eCAL_t7pg
  https://www.youtube.com/watch?v=UZ4BQK5rAPA
  https://www.youtube.com/watch?v=pB90qXcYLuE
  https://www.youtube.com/watch?v=b1Qrr50K0V0
  https://www.youtube.com/watch?v=8kk9VG1fHAg (giant bubbles)