A trick of tether dynamics

If you drop a metal ring down a straight chain loop, rather than falling straight off it’ll catch itself into a loop. This is because a travelling wave moves down the chain. The whiplash of the wave kicks the end of the chain upwards. The ring falls into the whole and gets stuck.

Tether dynamics at a larger scale - such as for very high balloons or deep offshore oil and gas platforms - can get very complex. Hear Hilary Costello discuss her PhD research into tether dynamics in this video on the Ri Channel.

What You Need To Know About The Keystone XL Oil Pipeline

"A Senate vote approving completion of the pipeline is scheduled for today— less than one week after the House approved the same legislation. That means President Obama may soon have a chance to sign off on the pipeline — or to veto it.

Before today’s vote, here are a few things to help you make sense of the Keystone XL debate.”

(via npr)

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     F-16 N816NA is unique because of just that, the fact that it has an “N number”, which is a civilian aircraft identifier. She is the only F-16 in the world with an N number and thusly, is the only civilian operated F-16. Before she was on loan to NASA, her USAF serial number was 82-0976. Additionally, this is an A model F-16 with a C/D Model tail. In her civilian life, this bird flew chase on F-16XL NASA flight research missions. 816 is on display in front of the Lockheed Skunk Works in Palmdale, California.

World’s first solar road opens in the Netherlands

A bike path that services 2,000 cyclists per day as they travel between the suburbs of Krommenie and Wormerveer in Amsterdam is now dotted with solar panels. Set to open next week, the 70-metre path is the first solar road in the world - a proof of concept that engineers around the world are eager to copy.

The path, which the local government plans to extend to 100 metres in 2016, cost €3m (AUD$4.3m) to build, says Philip Oltermann from The Guardian. Named the SolaRoad, it was made using rows of crystalline silicon solar cells, which were embedded into the concrete of the path and covered over by a thick, tempered glass. The surface of the road has been treated with a special non-adhesive coating, and the road itself was built to sit at a slight tilt in an effort to keep dust and dirt from accumulating and obscuring the solar cells.

While the amount of solar energy generated from the road will be pretty modest - once stretched to 100 metres, it’s expected to produce enough energy to power three households - the point of the project is to show that solar roads can actually be practical.

The team behind the bike path, Netherlands’ TNO Research Institute, is now looking into extending the technology to some of the country’s 140,000 km of public road. Having already performed tests on how much weight - say, a tractor and a semitrailer - these embedded solar cells can withstand, engineer Sten de Wit from the institute told Oltermann that up to 20 percent of the Netherlands’ roads would be suitable for a solar upgrade.

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