We present an analysis of a sequence of light curves of the RS CVn-type binary II Pegasi extending from 1974 to 1998. The distribution of the spotted area versus longitude is derived by Maximum Entropy and Tikhonov regularized maps, assuming a constant spot temperature (Lanza et al. 1998a). The spot pattern on the active K2 IV star can be subdivided into a component uniformly distributed in lon...

Sometimes the breakthrough for a new technology does not materialize in one of those fields which receive most attention and where everybody expects the solution. When the British needed a practical method for determining a ship's longitude in the 18 century, they spent many decades gazing at the stars, compiling lunar tables and searching for astronomic methods for determining longitude. But t...

In the 1700s, scientists, sailors, engineers and explorers were trying to work out how to navigate east to west at sea. The stakes were high; many lives were lost because sailors could not reliably measure longitude. Eventually, the invention of accurate timepieces allowed sailors to use the time in their current location, and the time at a fixed reference, to calculate longitude. But how do lo...

At each point during your walk, the altitude reading will give some indication of your progress, especially when compared to readings from earlier points, but at no time will you receive complete directions to the top of the mountain. You will always be guessing, but in an educated manner based on your previous longitude-latitude locations and their altitudes. For example, if, during the past 2...