Coke-Propane Rocket Blasts Off Without Ignition

Everyone’s seen the Diet Coke and Mentos “experiment” that ends in a brown eruption. But have you seen the Coke and Propane experiment insanity that results in a rocket launch? As [Itay] pointed out when he sent us the tip, this doesn’t need to be lit. The simple act of turning the bottle upside down starts a powerful reaction without any ignition.

coke-propane-rocket-thumbOf course it’s the how of this that tickles our brains, but let’s finish the setup. This starts with a bottle of Coke which is about 3/4 full. The head space is displaced by spraying propane into the bottle; propane is heavier than air. All that’s left is to turn the bottle upside down and pray it doesn’t smack anyone in the noggin as it takes off.

In trying to find an explanation for this phenomenon we came across a plausible answer on the Chemistry StackExchange. It points to the Mentos phenomenon combined with the temperature differential caused by the very cold propane. The answering user theorizes that tiny ice crystals form and when the bottle is turned upside down the cold propane and micro crystals rise through the warmer soda acting as a much more rapid catalyst than Mentos alone. Of course this is just a theory so please share your own ideas below.

We thought the folks who microwave stuff outside of a microwave enclosure had their fill of danger but this videos is also one of theirs. It should be no surprise that they also tried the experiment with an ignition source. That video is found after the break and should immediately convince you to never try any of this yourself.

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Quick and easy Thermic Lance is hot Enough to melt Rocks

Heat can be a hacker’s best friend. A little heat can help release a stubborn nut cleanly, and a lot of heat can melt a rusty bolt clean off. An oxy-acetylene torch is handy for these applications, but if you need a more portable setup, and you want enough heat to melt rocks, you might want to look into this field-expedient thermic lance.

Thermic lances have been around a long time in the demolition industry, where cutting steel quickly is a common chore. Commercial thermic lances are just a bundle of steel fuel rods which are set on fire while oxygen is blown down a consumable outer tube. The resulting flame can reach up to 4500°C with impressive results. In need of a similarly destructive device, [NightHawkInLight] came up with a super-simple lance – a small disposable tank of oxygen and regulator, a length of Tygon tubing, and a piece of 5/8″ steel brake line. No need for fuel rods in this design; the brake line provides both fuel and oxygen containment. As you can see in the video below, lighting the little lance without the usual oxy-acetylene torch is no problem – a “wick” of twisted steel wool is all that’s needed to get the torch going. The results are pretty impressive on both steel and rock.

You say you’re fresh out of brake line and still need some “don’t try this at home” action? No problem at all – just hit up the pantry for the materials needed for this tinfoil and spaghetti thermic lance.

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Ctrl-X, Ctrl-V for DNA

Once upon a time, the aspiring nerdling’s gift of choice was the Gilbert chemistry set. Its tiny vials of reagents, rack of test tubes, and instruction book promised endless intellectual stimulation and the possibility of stink bombs on demand. Now a new genetic engineering lab-in-a-box Kickstarter, with all the tools and materials needed to create your own transgenic organisms, may help the young biohacker’s dreams come true.

The Kickstarter has been wildly successful. The initial goal was $1200AUD was met in a day, and currently stands at almost $6200AUD. Despite that success, color me skeptical on this one. Having done way more than my fair share of gene splicing, there seem to be a few critical gaps in this kit. For example, the list of materials for the full kit includes BL21 competent E. coli as the host strain. Those cells are designed to become porous to extracellular DNA when treated with calcium chloride and provided with a heat shock of 42°C. At a minimum I’d think they’d include a thermometer so you can control the heat shock process. Plenty of other steps also need fairly precise incubations, like the digestion and ligation steps needed to get your gene into the host. And exactly what technique you’d be using to harvest DNA from the animal, plant or fungal cells is unclear; the fact that most of the techniques for doing so require special techniques leads me to believe there’s a lot less here than meets the eye.

To be fair, I’ve been off the lab bench for the better part of two decades, and the state of the art has no doubt advanced in that time. There could very well be techniques I’m not familiar with that make the various steps needed to transform a bacterial culture with foreign DNA trivial. It could also be the case that the techniques I used in the lab were optimized for yield and for precise data, while the GlowGene kit provides the materials to get a “good enough” result. I hope so, because a kit like this could really expand the horizons of hackerdom and start getting the biohacking movement going.

[Thanks, Michael!]

Nuclear Reactor Eye Candy From Around the World

Everyone loves a field trip. It’s always fun to visit a manufacturing plant to see how the big-boys make all the cool toys we love. But there are a few places you might not want to go exploring, like inside a nuclear reactor.

Well fear not, now you can spend as much time as you would like with these amazing cut-away of nuclear facilities from across the globe. You can thank University of New Mexico Libraries Exhibition for hosting these photos that have been published in “Nuclear Engineering International” magazine over the years. If you happen to have a pdf allergy, you can also browse most of them on flickr here.

And if you want to see more amazing cutaways, there is this photo pool full of some 1300 other cutaway images to look at. If you know of other amazing engineering photos sets, leave us a note in the comments.

Liquid Metal Changes Shape to Tune Antenna

Antennas can range from a few squiggles on a PCB to a gigantic Yagi on a tower. The basic laws of physics must be obeyed, though, and whatever form the antenna takes it all boils down to a conductor whose length resonates at a specific frequency. What works at one frequency is suboptimal at another, so an adjustable antenna would be a key component of a multi-band device. And a shape-shifting liquid metal antenna is just plain cool.

The first thing that pops into our head when we think of liquid metal is a silvery blob of mercury skittering inside the glass vial salvaged out of an old thermostat. The second image is a stern talking-to by the local HazMat team, so it’s probably best that North Carolina State University researchers [Michael Dickey] and [Jacob Adams] opted for gallium alloys for their experiments. Liquid at room temperature, these alloys have the useful property of oxidizing on contact with air and forming a skin. This allows the researchers to essentially extrude a conductor of any shape. What’s more, they can electrically manipulate the oxidative state of the metal and thereby the surface tension, allowing the conductor to change length on command. Bingo – an adjustable length antenna.

Radio frequency circuits aren’t the only application for gallium alloys. We’ve already seen liquid metal 3D printing with them. But we need to be careful, since controlling the surface tension of liquid metals might also bring us one step closer to this.

Hackaday Prize Semifinalist: Water Quality Monitoring

The theme of this year’s Hackaday Prize is to build something that matters, and there is nothing more important than water quality and pollution. Everything we eat and drink is influenced by the water quality in rivers and reservoirs. C4Derpillar, a semifinalist for the Hackaday Prize, is solving the problems of water-related health issues with innovative sensors for under $500 USD per unit.

The C4Derpiller is using capillary electrophoresis (CE) to detect anions and cations in waterways. CE pulls a water sample through a very thin tube with an electric current. As water is moving through this capillary, a sensor is able to detect heavy metals, pesticides, and other pollutants in a water supply. The team behind C4Derpiller has written a few posts about the separation chemistry of their device

Commercial CE equipment costs tens of thousands of dollars. The team behind the C4Derpillar are hoping to develop their pollution monitoring device and make it available for about $500 USD. That’s cheap enough for multiple pollution monitoring stations in the third world, and by pushing the results to the cloud, the C4Derpillar will be able to monitor pollution in real time.

You can check out C4Derpillar’s Hackaday Prize video below.

The 2015 Hackaday Prize is sponsored by:

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Could Solid-State Batteries Last a Lifetime?

Researchers from MIT and the Samsung Advanced Institute of Technology have been developing a new material that could potentially revolutionize the battery industry. A solid electrolyte that won’t wear out, lasting exponentially longer than current battery chemistry.

It also has the possibility to increase battery life, storage, and the safety of batteries — as liquid electrolytes are the main reason batteries catch on fire.

Sound too good to be true? The idea for solid-state batteries has been around for awhile, but it sounds like MIT and Samsung may have figured it out. The current materials used for solid electrolytes have difficulty conducting ions fast enough in order to be useful — but according to the researchers, they’ve discovered formula for the secret sauce. They’ve published their findings on, which is sadly behind a pay wall.

Another great benefit of solid-state batteries is they would be able to operate at freezing temperatures without a problem. What do you think? Is Samsung blowing smoke, or will they actually release a battery you never have to replace?