Water bridge (physics)
The water bridge is a physical experiment in which high voltage is used to pull a thread of water between two glass vessels.
For this purpose, a DC voltage of around 15 kilovolts is applied between two closely spaced glass beakers with highly pure and therefore very poorly conductive water . This causes the water to rise up the inner walls and, after brief sparking, forms a strand of water a few millimeters thick between the two vessels. By slowly pulling the vessels apart, a water bridge of up to 25 mm long can be achieved. The absorption of pollutants from the air increases the conductivity of the water over time. The increasing current flow through the bridge leads to the water heating up and the bridge breaking off.
Such an effect was first described in 1893; the water thread was created by means of a cotton thread, but was only retained for a few seconds after it was removed.
No practical application is known to date for the phenomenon; The electrostatic movement of aerosols , on the other hand, is known and is used, for example, in high-voltage- assisted paint spraying and in electrostatic precipitators .
Web links
Individual evidence
- ↑ Elmar C. Fuchs et al .: The floating water bridge 2007 J. Phys. D: Appl. Phys. 40 6112-6114 Article on the experiment carried out at TU Graz
- ^ Armstrong WG Electrical phenomena The Newcastle Literary and Philosophical Society, The Electrical Engineer 10 February 1893, pp 154-5
- ↑ Elmar C Fuchs et al .: Dynamics of the floating water bridge 2008 J. Phys. D: Appl. Phys. 41 185502