If you’re completely landlocked like I am, you may dream of ocean waves lapping at the shore, but you probably don’t think much about the tides. The movement of the ocean tides is actually quite important to many groups of people, from fishermen to surfers to coastal zone engineers. The behavior of the tides over time is helpful data for those who study world climate change.
Early tide prediction was based on observed changes in relation to the phases of the Moon. These days, tide-predicting is done quickly and with digital computers. But the first purpose-built machines were slow yet accurate analog computation devices that, as they were developed, could account for increasing numbers of tidal constituents, which represent the changes in the positions of tide-generating astronomical bodies. One of these calculating marvels even saved the Allies’ invasion of Normandy—or D-Day— in World War II.
Continue reading “How Analog Tide Predictors Changed Human History”



Video arcades may be a thing of the past, but they’re still alive, well and were ready to play at this year’s World Maker Faire. The offerings weren’t old favorites, all were brand new games many being shown for the first time like the long-awaited VEC9. The Hall of Science building was filled with cabinets and no quarters were necessary, all were free-play.


