Weaponizing Elementary Science Experiments

[austiwawa] was playing around with one of those simple linear motors people build as friendly little science experiments. There’s an AA battery in the middle of a set of magnets. When you put it inside of a spring it zips around inside until you run out of spring or magic pixies in the battery.

Of course, the natural question arose, “How do I make it go fast!? Like fast!” After making explosion and woosh noises for a bit (like any good hacker would) he settled down and asked a more specific question. If I made the coil the barrel of an air gun, and then shot the battery out… would it go faster?

So, he built an air cannon. It took some ingenuity and duct tape, but he managed to line the barrel with a copper coil. After that he built an experimental set-up, because making something dangerous is only okay if it’s science. That’s the difference between sensible adults and children.

He shot three “dead” rounds through the cannon, and got a baseline result. These dead rounds were made so by placing the magnets at the improper polarity to forego the motion-boosting properties. Then he shot three live ones through. It went measurably faster! Neat!

What’s the silliest thing you’ve ever seen properly characterized? Let us know in the comments below.

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Forget Lithium Battery Technology, Just Boil A Potato

These researchers are taking this development so seriously we can’t help but be suspicious that, perhaps, they are all deeply embroiled in a bet to see who could get funding for and complete research in the most absurd technological advancement.

Most of us have had a science teacher desperately try to alleviate the drudgery of standardized test centric science education by dramatically putting a copper nail and a zinc nail into a potato or lemon. “Behold, we can measure a voltage with this voltmeter. If you get asked what a voltmeter is on a test, here is a definition none of you have enough experimental basis to understand,” the teacher would say as their dreams of being a true educator were crushed a little more.

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The Potowitzer: A Rapid Fire Potato Cannon

If you’ve ever fired a potato cannon, you’ll know that they are a raucous good time, but are somewhat clumsy to reload after each shot. Seeing an opportunity to improve on the design and minimize the delay between launches, [Danger First] have concocted a fast reloading potato cannon — or should I say — Potowitzer.

The key here is that they’ve gone through the extra effort of designing and building honest-to-goodness artillery rounds for their Potowitzer’s manual breech-loading mechanism. Foregoing the inconsistency of potatoes, they’ve 3D printed a bevy of bullets and sealed them with propane gas into PVC pipe cartridges. Metal contacts around the base to carry current from a BBQ lighter to the inside of the cartridge to ignite the propellant. Seeing it fire at about 18 rounds per minute is something special.

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Reverse Engineering the McDonald’s French Fry

McDonald’s is serious about their fries. When they were forced by shifting public opinion (drunkenly swaggering around as it always does) to switch from their beef tallow and cottonseed oil mixture to a vegetable oil mixture; they spent millions to find a solution that retained the taste. How they make the fries is not the worlds most closely guarded secret, but they do have a unique flavor, texture, and appearance which is a product of lots of large scale industrial processes. [J. Kenji López-Alt] decided to reverse engineer the process.

His first problem was of procurement. He could easily buy cooked fries, but he needed the frozen fries from McDonald’s to begin his reverse engineering. McDonald’s refused to sell him uncooked fries, “They just don’t do that,” one employee informed him. He reached out to his audience, and one of them had access to a charlatan. The mountebank made quick work of the McDonald’s employees and soon [J. Kenji] had a few bags of the frozen potato slivers to work with.

What follows next was both entertaining and informative. At one point he actually brought out a Starrett dial caliper to measure the fries; they were 0.25in squares in cross section. Lots of research and experimentation was done to get that texture. For example, McDonald’s fries aren’t just frozen raw potatoes. They are, in fact; blanched, flash fried, frozen and then fried again. Getting this process right was a challenge, but he arrived at similar fries by employing his sous vide cooker.

He then wanted to see if he could come up with a french fry recipe that not only allowed the home chef to make their own McDonald’s fries, but improve on them as well. It gets into some food chemistry here. For example he found that the same effect as blanching could be produced by boiling the fries; if you added vinegar to keep the cell walls from disintegrating.

The article certainly shows how knowledge of the chemistry behind cooking can improve the results.

Satellite dish solar cooker bakes potatoes and more

baked-potatoes-in-a-dish-solar-cooker

Hone your survival skills by harnessing the sun’s rays to cook your meals. [Robert] and his daughter turned an old satellite dish into a solar cooker. The image above shows them baking some potatoes, but the temperatures inside the cast iron vessel are high enough to let you cook most foods.

The dish was originally used for satellite television but has been collecting dust in the shed for quite some time. When [Robert] came across a roll of foil tape in his workshop he decided to give the project a whirl. His daughter helped out by peeling away the tape backing (this can be much harder than it sounds) while he applied the reflective material trying to keep it free of wrinkles. After a close call [Robert] donned a pair of welding goggles when positioning the dish. If the light intensity can get the pot up as high as 428 degree Fahrenheit we’re sure it can cause flash blindness.

Unlike other dish cookers we’ve seen, [Robert] didn’t use the original mount for holding the dish in place. He just set it on three bricks and directed it by hand. To keep the intensity focused on the kettle he had to reposition it every 15 minutes.

We wonder if the heat is too much for building a sun tracking solar power harvester?

This GLaDOS potato is a lie

Why settle for virtual reality when you can make the digital world into reality? [Josh] wanted to have a GLaDOS potato accompany him through life when not playing Portal 2. He set to work to see what kind of replica prop he could come up with. Judging from the image above, and demo video after the break, he nailed it right in the spud.

There’s no worrying about rot. The potato and a few parts were molded from Sculpey and baked in the oven. Since the fake spud is hollow in the center it’s easy to hide the bits that make it talk. An old MP3 player was loaded with quotes from the game, and plays them back via an LM386 audio amplifier circuit and a speaker hidden below the electronic eye. The eye is lit by five yellow LEDs which are also tied into the amplifier to make them blink and fade with the intensity of the audio signal.

A paint job and the nails and wire really make the build look just right. Now [Josh] needs to host a geek-themed Halloween party so he can really show this off.

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Double barreled air cannon

[Jeremy] wrote in to show off his latest creation. he has built a two barrel pneumatic air cannon. Eschewing the traditional approach of having a single barrel and pressure chamber for his spud gun, [Jeremy] wanted to have a double barreled version. Since he was doing this pneumatically, he had to rig up a way to maintain pressure in each barrel independently of each other, as well as trigger them independently. While we can all agree that one way valves and sprinkler valves aren’t ground breaking, it is nice to see it all laid out and tested. We now have the blueprints if we were so inclined to create our own version.  You can see him testing it out by filling the chambers with water and sploooshing that all over the place after the break.

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