This well-made video from Practical Engineering explains why soil is not a good building material, and then shows how to mechanically stabilize it so it can bear weight.
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Dirt is probably the cheapest and simplest construction material out there, but it's not very strong compared to other choices. Luckily geotechnical engineers have developed a way to strengthen earthen materials with almost no additional effort - Mechanically Stabilized Earth (aka MSE or Reinforced Soil). If you look closely, you'll see MSE walls are everywhere. Thanks for watching, and let me know what you think!
As high rises replace their elevator up/down buttons with panels that you enter a floor into, which then direct you to a specific elevator, they create the possibility of adding more cars to each shaft, radically increasing the efficiency and throughput of a building's lifts. Read the rest
University of Cambridge researchers have built the world's smallest working engine. The device, powered by light, could be the basis of future nanoscale machines that are just billionths of a meter in size. Fantastic Voyage, here we come! From the University of Cambridge:
The prototype device is made of tiny charged particles of gold, bound together with temperature-responsive polymers in the form of a gel. When the ‘nano-engine’ is heated to a certain temperature with a laser, it stores large amounts of elastic energy in a fraction of a second, as the polymer coatings expel all the water from the gel and collapse. This has the effect of forcing the gold nanoparticles to bind together into tight clusters. But when the device is cooled, the polymers take on water and expand, and the gold nanoparticles are strongly and quickly pushed apart, like a spring. The results are reported in the journal PNAS.
“It’s like an explosion,” said Dr Tao Ding from Cambridge’s Cavendish Laboratory, and the paper’s first author. “We have hundreds of gold balls flying apart in a millionth of a second when water molecules inflate the polymers around them.”
“We know that light can heat up water to power steam engines,” said study co-author Dr Ventsislav Valev, now based at the University of Bath. “But now we can use light to power a piston engine at the nanoscale.”
Architects love to render their buildings covered and ringed in trees: trees that sprout from balconies, dot roofs, climb walls. Read the rest
Stanford engineers demonstrated how six tiny microTug robots -- with gripping, adhesive feet inspired by geckos -- can work together to pull a 4,000 pound car on polished concrete, albeit very very slowly.
Martin Howard from Toronto's Howard Collection writes, "The Salter is one of England’s first typewriters and is a stunning example of a piece of Victorian engineering. It was made by The Geo. Salter & Co. of West Bromwich who were well known at the time as the makers of penny scales, which were a common feature in train stations and other public areas." Read the rest
A fantastic working papercraft model of a V6 engine that runs on compressed air. Read the rest
Jerboas use their long tails to transfer energy to their legs, allowing them to hop many times their body length. It turns out the hair on the bottoms of their their feet also serves a number of purposes, including insulation, traction, and stealth on the sand.