Famous People with Name Hessel

Hessel De Vries            Origin/Culture/Country: Dutch

Hessel De Vries: was a Dutch physicist at the University of Groningen who furthered the detection methods and applications of radiocarbon dating to a variety of sciences. He has been called "the unsung hero of radiocarbon dating" by Willis.In 1958, de Vries showed that there were systematic anomalies in the carbon-14 dates of tree rings. His explanation was that the concentration of carbon-14 in the atmosphere had varied over time by up to 1%. He hypothesized that the variation might be explained by (a) something connected with climate, (b) that it was not created in the atmosphere at a uniform rate due to variations in the Earth's magnetic field, or (c) a cause lay in the Sun itself.

Johann Friedrich Christian Hessel            Origin/Culture/Country: German

Johann Friedrich Christian Hessel: was a German physician (MD, University of Würzburg, 1817) and professor of mineralogy (PhD, University of Heidelberg, 1821) at the University of Marburg.[1] In 1830, Hessel proved that, as a consequence of Haüy’s law of rational intercepts, morphological forms can combine to give exactly 32 kinds of crystal symmetry in Euclidean space, since only two-, three-, four-, and six-fold rotation axes can occur.[2] A crystal form here denotes a set of symmetrically equivalent planes with Miller indices enclosed in braces, {hkl}; form does not mean "shape". For example, a cube-shaped crystal of fluorite (referred to as Flussspath by Hessel) has six equivalent faces.