Making Red Lights for Astronomical Observing
Mike writes “While LED circuits are pretty simple by Make standards, they are essential to amateur astronomers. This is because red light affects the human eye less than other colors, allowing astronomers to see their gear without destroying their night vision. This article shows how easy it is to create red LED light sources and give some examples of how to use them, including map readers, flash lights and interior lights for an eyepiece case.” Link.
Chris writes “Considering how many people bought the HP Bluetooth stereo headphones and got disappointed when the headband snapped, I thought that it was time to do something useful with the ‘broken’ headphone. We’ll take you through all steps of dismantling the Bluetooth receiver and building it into a nice mouse housing with 12v in and line out. And as the device keeps its battery, you can also use this as a portable Bluetooth stereo receiver and plug in you high quality headphones or even connect it to your stereo at home.” 
This might make a good low cost DIY centrifuge for here on Earth too – “For most space travelers, the first effect of weightlessness they feel is nausea. But over the next few days and weeks, the lack of gravity takes its toll on the rest of the body, leading to muscle and bone mass depletion and troubles regulating blood pressure…researchers at UC Irvine and the National Space Biomedical Research Institute (NSBRI) have developed a two-person, centrifuge-like, one-stop workout machine that makes its own gravity. They call it the Space Cycle.” 
“The nitrogen laser will give 100kW pulses of light at 337.1nm (UVA light). The pulses are only 6ns long, so the energy per pulse is just 0.6mJ. It is a very simple laser, and it does not require mirrors or glass working at all! But using a mirror at one end of the laser will boost the output to over 250%. And if the nitrogen entering the laser (it is a flowing gas laser, but it can be made sealed) is cooled, it can go up to 120 pps. So if it is running at 120 pps, and has a mirror at one end, the average power output will be 180 mW. Although the beam is invisible it can be used to pump dye lasers to give beams with wavelengths ranging from infrared to ultraviolet.” 
Clever instructable for protecting and camouflaging your bike using an old innertube – “An old innertube or two can be artfully used to protect your bicycle frame from damage. This is excellent in preventing damage to your frame from using U-Locks to lock them up. Also great to dress down your bicycle for urban environments.” 
“The Quarter Shrinker uses a technique called high velocity electromagnetic metal forming, or “Magneforming”. This technique was originally developed by the aerospace industry in conjunction with NASA, and has been popularized by Aerovox, Grumman, and Maxwell. It involves quickly discharging a high energy capacitor bank through a work coil to generate a very powerful and rapidly changing electromagnetic field which then “forms” the metal to be fabricated. While it works best with metals of relatively high electrical conductivity such as copper or aluminum alloys, it will work to a more limited extent with many poorer conducting metals and alloys such as steel or nickel.” Thanks Derek! 
