Recent content by wildwildebees

  1. W

    High School Why does foam form on orange squash?

    Yes surfactants - presumably these don't actually create bubbles but just allow any air bubbles which enter the liquid to be contained? Since the surface tension is lower, so the restoring force which acts to close the bubble to reduce surface area is lower. I've had a look around to see what...
  2. W

    Graduate Josephson current in normal metals

    Yes I agree with f95, the Josephson effect involves coupling of the wavefunctions of 2 superconductors on either side of a thin barrier (less than about 10 Angstroms). If a supercurrent is driven across the junction, the relative phase between the two wavefunctions adjusts itself, up until the...
  3. W

    High School Why does foam form on orange squash?

    Why do I get a foam forming on my glass of squash, but not just a glass of water? i.e. If I fill a glass with water from the tap, with the water flowing pretty fast, there are only a very few, quite large, bubbles which form on the surface of the water, and they quickly dissipate away...