Lene Hau. Lene Vestergaard Hau (born November 13, 1959 in Vejle, Denmark) is a Danish physicist. In 1999, she led a Harvard University team who, by use of a Bose-Einstein condensate, succeeded in slowing a beam of light to about 17 metres per second, and, in 2001, was able to stop a beam completely.
Zeta is the sixth letter of the Greek alphabet. In the system of Greek numerals, it has a value of 7. It was derived from the Phoenician letter zayin. Letters that arose from zeta include the Roman Z and Cyrillic Ð.
What can be derived (and measured) is an electrokinetic potential â termed the zeta potential Î¶. This quantity, defined as the potential at the shear plane, has become a very useful experimental parameter to monitor electrokinetic behavior of suspensions, especially changes in such behavior2.