Access to fresh water is one of the biggest problems people face around the world, and I believe that many mad scientists (myself included) like to explore outside-the-box approaches to separating water molecules from brine. One of the obligations we have here in the FoMS is to provide critical information that highlights the real-world challenges involved in solving important problems, so that the newer members of our community can wrap their minds around the full scope of the challenges that need to be solved to create working solutions. I really wish the guy presented hard numbers such as the latent heat of vaporization of water (2260 kJ/kg), energy required by reverse osmosis to desalinate 1 cubic meter of sea water (these days, roughly 3 kWh) and did a few calculations to help illuminate the scope of the challenge. To me, a good visual here is provided by asking how much water one could boil away with the potential energy held in a system consisting of a 1 metric ton block (1000 kg) that's lifted 1 meter above the ground (assume g = 10 m/s^2). You'd have 10,000 J (10 kJ) of energy available which, if you used it with perfect efficiency, would allow you to boil off just 4.4 grams of water. (Or, you could boil away 44 grams of water if you lifted the block 10 meters, or about 30 feet.) I think that really puts the central problem into perspective. Despite this, I think this video does a fairly good job at sketching the landscape of providing fresh water on a large scale via desalination. (I think it's a lot easier to do on a small scale for homesteaders and people in the developing world, but that's a discussion for a different time.) Enjoy!

I have wanted to build an X-ray machine. I have an X-ray tube and an intensifier screen. But I had not found a high voltage power supply design that I liked. This video describes one that I like. DIY X-ray Machine Alas too many other projects in the way. Comments suggest using a mirror to keep the camera out of the X-ray beam. Good idea.

Ferrofluid is a great thing to have around the workbench, especially if you want to quick demonstration to show friends, family, and friends of family, how fun and amazing the fundamental workings of the universe can be to explore. I tried to make home-brew ferrofluid once and failed spectacularly. I couldn't get the procedures I found online to work, and frankly I didn't have time to turn it into a big project. So I was really delighted when Nile Red published his own exploration into the challenge. He apparently had similar results, but, being a relatively well-off YouTuber, he also had to time and the resources to make it work. So if you'd like to do it, here's the secret! Enjoy.

If you're like me, you love learning about the brilliant technologies that led to the marvelous world we live in today. While researching avenues that were suggested to me by our fellow Mad Scientist, Dave Glass, I came across this remarkable vintage introduction to vacuum tube tech that I just had to share. Enjoy! Shawn

Let's talk a little about safety. Some of the things that members may post here may have a bit of danger associated with them. Those of us who have been in the amateur, and professional, scientific community for a while usually know how to assess the safety related aspects of an experiment. Sometimes, this is via the School of Hard Knocks, where we've survived close encounters with injuries. Mostly, however, it's due to being able to consider all of the possible ways that an experiment can go wrong, and taking steps to protect oneself from that. But, for many beginners, they don't have the experience nor wisdom as to how things may go wrong. Thus, I think it's appropriate to include safety warnings for all potentially dangerous experiments, even if this gets to be a bit boring for the more experienced experimenters. However, even with warnings, everyone should understand that it's impossible to cover all of the possible ways something can go wrong, so some responsibility needs to be assumed by the experimenter. And, while many of the precautions may seem extreme, sometimes those precautions may save one from serious injury. Also, remember that, just because something worked once, doesn't mean that it will work every time. And, familiarity breeds contempt. Many of my experiments have involved electricity (given that my training is as an electrical engineer). A common danger associated with that is high voltage electrical shocks. A few of the safety precautions are to always keep one hand in your pocket, while working with high voltage, such that any accidental contact won't cause current to flow through the chest area, and cause cardiac arrest. Standing on an insulated floor is also a good idea. Having an emergency power off (EPO) switch, which can be activated easily, is another good idea (Remember that an electrical shock may paralyze muscles, such that you can't "Let go", so an EPO button that you can "hip check" may be desirable.). Another precaution is to include bleeder resistors on high voltage power supplies, and then realize that these bleeder resistors may fail open, such that they don't remove the high voltage. Therefore, it's good to include redundancies (paralleled resistors), as well as using a "hot-stick" to discharge any capacitors which may retain a charge. Also, realize that some capacitors have the annoying tendency to build up a charge, even once they're discharged, and to hold that charge for a seemingly impossibly long period of time (I've seen the aquadaq coating capacitor on a CRT store a 27KV charge for over a week!). Also remember that even a mild electrical shock can cause uncontrolled muscle movement, which may propel your arm in a sharp object, and produce a nasty and painful cut.