|
Find out the latest news about SPS -- the UNO chapter of the Society of Physics Students!
|
|
Need help in introductory physics? Tutoring is available!
Curious about what physics courses are required for a major? Go here to learn more.
|
When a liquid drop is placed on a surface that is held at a temperature much higher than the liquid's boiling point (such as a drop of water in a very hot pan) it hovers on its own vapour cushion, without wetting the surface (figure a below).This phenomenon is called the Leidenfrost effect (or film boiling) and occurs beyond a surface temperature called the Leidenfrost point (about 200 - 300 C for water on flat surfaces, depending on surface quality). ... film-boiling droplets move at speeds of several centimeters per second when placed on asymmetrically structured surfaces (movie), such as a piece of brass with periodic, saw-tooth shaped ridges. (Here is a Quicktime movie (1.1 MB)). The water can even move up-hill!Image Credit: http://www.uoregon.edu/~linke/climbingdroplets/index.html
|
 |
