The curators over at the Exploratorium in San Francisco had an interesting question regarding the Golden Gate Bridge: It’s large, and made of metal, and so must expand and contract as it heats up during the day and cools off at night. But in what way, and by how much?
It turns out that as the sun heats the cables that suspend the roadway they expand and the deck lowers. As the sun sets and the bridge cools off, the deck rises back up. At the outdoor exploratorium, two miles away from the bridge, they installed a spotting scope trained on the bridge. The scope has a reticle that allows them to measure how much the bridge moves. The answer? The total excursion of the bridge deck, from hottest to coldest, is about 16 feet! The thermal mass of the bridge means that the position of the deck lags the change in temperature by about two hours.
Public TV station KQED produced a short video explaining the phenomenon. If you live in the Bay Area, or plan to visit, be sure to spend some time at the Exploratorium and visit their temperature-measuring spotting scope.
The final showdown is under way in our first-ever Gadget Freak of the Year contest. Who will win an all-expenses-paid trip to the Pacific Design & Manufacturing Show? It's up to you, dear readers, to tell us.
For industrial control applications, or even a simple assembly line, that machine can go almost 24/7 without a break. But what happens when the task is a little more complex? That’s where the “smart” machine would come in. The smart machine is one that has some simple (or complex in some cases) processing capability to be able to adapt to changing conditions. Such machines are suited for a host of applications, including automotive, aerospace, defense, medical, computers and electronics, telecommunications, consumer goods, and so on. This discussion will examine what’s possible with smart machines, and what tradeoffs need to be made to implement such a solution.