The Summer Solstice is Here
Many years ago I was teaching an introductory physics course using Paul Hewett’s Conceptual Physics textbook. There I read about the Eratosthenes’s experiment that allowed him to measure the radius of the Earth. This happened more than 2000 years ago (see Wikipedia: http://en.wikipedia.org/wiki/Eratosthenes) … Eratosthenes’s ingenuity drew my attention – to measure something so big using beautiful geometrical considerations and a “down to Earth experiment” was something I appreciated very much. Later on I enrolled in an Astronomy Course for future teachers at the University of TX at Austin, which was a wonderful hands-on mid-night experience for me. My interest to Summer solstice phenomenon has been growing ever since… I just found about about the following web site that is very helpful in explaining summer solstice phenomena (or winter solstice for that reason) and why and how it happens: http://www.srh.noaa.gov/abq/?n=clifeatures_summersolstice 