Abigail and I are back from the Galapagos Islands. This was my fifth time there, and certainly the best yet! Like the two last times, I used Ecoventura to organize the trip, and continue to be impressed by their outstanding dedication to service.
This summer we fulfilled a life-long dream (at least for some of us) and visited the Arecibo Observatory in Puerto Rico.
This is the largest single-dish radiotelescope in the world. The reflector is 305 m (1,000 ft) in diameter – a tad bit larger than our home-brewed radiotelescope. The Arecibo system is a semi-transit telescope that has a fixed primary reflector with secondary (Gregorian reflector) and a delay-line feed.
Our DIY work on Quantum Physics was featured this month in MAKE Magazine and the Philadelphia Exponent!
We had a fantastic time this weekend at the US Science and Engineering Festival in Washington DC. Among the highlights of our visit, we sat insanely close to the stage for the Q&A with Mythbusters Jamie Hyneman and Adam Savage. We also had the pleasure to meet fellow diy Science authors Theo Gray (Mad Science, The Elements, Popular Science’s Gray Matter, etc.) and William Gurstelle (Backyard Ballistics, Whoosh Boom Splat, The Practical Pyromaniac, etc.).
I urgently needed a high-intensity UV/IR/visible light source for a work-related industrial inspection project, so this weekend I recruited Abigail to help me build a 10W LED flashlight that features swappable UV/IR/visible heads. We decided to document the build since this flashlight would fit nicely in a photographer’s kit for light painting, IR illumination, UV reflected photography, or UV fluorescence photography.
Our flashlight is based on LedEngin’s LZ4-40____ series 10W LEDs. These are available in wavelengths ranging from the infrared through the ultraviolet. White-light LEDs of different color temperatures are also available as part of this series.
WARNING! This flashlight is capable of producing very powerful invisible radiation in the UV and IR. The eye’s protection reflexes do not work at these wavelengths, and may thus cause extensive damage if exposed to direct or specular illumination. In addition, UV at 365nm may cause damage to the skin. Never point this flashlight at anyone without taking proper precautions!
I purchased two “Giant Super Sensitive MC6” GM tubes from Electronic Goldmine (Item Number : G18717, Unit Price: $89.95). These are Russian-made new-old-stock model MC6. They are 10.25″ long x 0.9″ diameter. I compared the sensitivity of these tubes to the other GM tubes that I use with my CDV700 Pro Geiger Counter. I posted the results at:
I had some business meetings in England this week, and on my way back to Birmingham Airport I stopped in Stratford-Upon-Avon to see the houses where Shakespeare was born and died. Warwick Castle was also along the way, so I stopped briefly to take a few pictures before sunset. Continue reading
On a recent trip to Israel, Abigail (10) saw a very pretty, large, and expensive sand pendulum. In it, the pendulum was able to swing, while at the same time, the sand pan was able to rotate freely. We applied our motto “Why buy it if we can MAKE it!”.