Don’t Trust Your Ears For The Freshest Chips

May 20, 2020 by Brian McEvoy 11 Comments

We hear fables of how to restore the crispness to your crisp and the crackle to your crackers, but they are more hot air than some of the methods. We found one solution that has some teeth though, and it doesn’t require any kitchen appliances, just a pair of headphones. Keep reading before you mash potato chips into your Beats. [Charles Spence] co-authors a paper with [Massimiliano Zampini] titled The Role of Auditory Cues in Modulating the Perceived Crispness and Staleness of Potato Chips. It’s a mouthful, so folks refer to it as the “Sonic Chip Experiment,” which rolls off the tongue. The paper is behind paywalls, but you can find it if you know where to look.

The experiment puts participants in some headphones while they eat Pringles, and researchers feed them different sound waves. Sometimes the sound file is a recording of crackly chewing, and other times it is muffled mastication. The constant was the Pringles, which are a delight for testing because they are uniform. Participants report that some chips are fresher than others. This means we use our ears to help judge consumable consistency. Even people who knew all about the experiment report they can willingly fool themselves with the recordings.

What other foods would benefit from the augmented crunch, and which ones would suffer? If shapely food is your jam, we have a holy cookie which is probably best enjoyed with your eyes. If you prefer your Skittles organized by color, we have you covered.

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Dancing Arrows To Break Your Brain

March 20, 2019 by Brian Benchoff 8 Comments

Last year, mathematician and professional optical illusionist [Kokichi Sugihara] came up with an arrow that only points one way. Technically, it’s ‘anomalous mirror symmetry’, but if you print this arrow and look at it juuuussst right, it appears this arrow only points one way.

[Ali] had the idea to turn this arrow illusion into something motorized, and for that he turned to 3D printing. The models for the illusion arrows were already available, but there had to be a way to turn a single arrow into an art installation. For that, you just need a few 9g servos. [Ali] slightly modified his servos so they would turn a full 180 degrees, and designed a magnetic mount to allow easy swap-out of these arrows.

The servos are attached to a 3D printed frame with heat-staked threaded inserts, and driven by a Pololu servo driver. The effect is great, with multiple arrows twisting and turning but still only appearing to point to the right. [Ali] put together two videos of this arrow illusion, one that’s effectively a build guide, and of course all the STLs are available in a link in the description.

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Inexpensive Display Jumps To Life

January 13, 2018 by Bryan Cockfield 19 Comments

If you’ve ever been to a local fair or amusement park, chances are you’ve seen an illusion known as Pepper’s Ghost. To perform the illusion, essentially all that’s needed is a thin sheet of plastic or one-way mirror and a light source. Get it right, and you’ll have apparitions popping up in all kinds of interesting places. With just the right software, though, one of those places could be in your own 3D display.

Using just a tablet and a sheet of plastic rolled into a cone, a three-person team was able to create a 3D display using the Pepper’s Ghost illusion. Using special software that the team developed, an image is altered so that when it reflects off of the plastic cone the image appears as a 3D rendering of the original picture. The rendering is perspective-correct and offers a novel way to interact with a 3D model without needing expensive equipment or special glasses.

If you do have some fancy equipment sitting around, like a computer monitor and some plexiglass, similar 3D displays have been made which utilize similar effects. Right now the team that developed this one haven’t made their code open yet, but have promised to release it soon so that others can build their own displays.

Thanks to [bmsleight] for the tip!

Star Wars Speeder’s Finishing Touch: Mirrors

November 8, 2017 by Donald Papp 19 Comments

[Super 73] make electric scooters, and they made some Star Wars Speeder Bikes with a twist for Halloween; adding some mirrored panels around the bottoms of the bikes made for a decent visual effect that requires no upkeep or fancy workings. Having amazed everyone with the bikes, they followed them up with a video of the build process.

The speeders are shells built around their Super 73 electric scooter, with bases of what looks like MDF sitting on anchor points. Onto the base platforms goes cardboard and expanding foam to create the correct shapes, which are then sanded then coated in fiberglass and bondo. Then it’s time for paint, weathering, and all the assorted bits and pieces needed to make the speeders as screen-accurate as possible. The real finishing touch are the mirrored panels to conceal the wheels and create a levitation illusion. As long as the mirrors are angled so that they reflect the pavement when viewed by a pedestrian, it works fairly well.

Top it off with costumes and a ride around town (with plenty of cameras of course, they naturally wanted to grab some eyeballs) and we have to say, the end result looks nifty. Both the showcase and making-of videos are embedded below.

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Gravity Defying Drips Of A Bike Pump Controlled Fountain

May 22, 2017 by Mike Szczys 9 Comments

People love to see a trick that fools their senses. This truism was in play at the Crash Space booth this weekend as [Steve Goldstein] and [Kevin Jordan] showed off a drip fountain controlled by a bike pump.

These optical illusion drip fountains use strobing light to seemingly freeze dripping water in mid-air. We’ve seen this before several times (the work of Hackaday alum [Mathieu Stephan] comes to mind) but never with a user input quite as delightful as a bike pump. It’s connected to an air pressure sensor that is monitored by the Arduino that strobes the lights. As someone works the pump, the falling droplets appear to slow, stop, and then begin flowing against gravity.

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All Your Displays Are Belong To Us

September 26, 2016 by Elliot Williams 23 Comments

Artist and Hackaday reader [Blair Neal] wrote in with his incredible compendium of “alternative” displays. (Here as PDF.) From Pepper’s Ghost to POV, he’s got it all covered, with emphasis on their uses in art.

There’s an especially large focus on 3D displays. Projecting onto screens, droplets of water, spinning objects, and even plasma combustion are covered. But so are the funny physical displays: flip-dots, pin-cushions, and even servo-driven “pixels”.

We really liked the section on LCDs with modified polarization layers — we’ve seen some cool hacks using that gimmick, but the art pieces he dredged up look even better. Makes us want to take a second look at that busted LCD screen in the basement.

We’re big fans of the bright and blinky, so it’s no surprise that [Blair] got a bunch of his examples from these very pages. And we’ve covered [Blair]’s work as well: both his Wobbulator and his “Color a Sound” projects. Hackaday: your one-stop-shop for freaky pixels.

[Blair]’s list looks pretty complete to us, but there’s always more out there. What oddball displays are missing? What’s the strangest or coolest display you’ve ever seen?

Making The Dune “Pain Box” A Reality

February 21, 2015 by Rick Osgood 57 Comments

If you are unfamiliar with Dune, then you may not know what the pain box is. The pain box is a fictional device that produces an excruciating burning sensation without causing any actual damage. [Bryan] has been working on a project to duplicate this effect in the real world. It sounds like he may be on the right path by using the “thermal grill illusion”.

The thermal grill illusion is a sensory trick originally demonstrated back in 1896. The trick is made up of two interlaced grills. One is cool to the touch, and the other is warm. If the user touches a single grill, they won’t experience any pain because neither temperature is very extreme. However if the user places their hand over the interlaced grills simultaneously they will immediately experience a burning heat. This usually causes the person to pull their hand away immediately. It’s a fun trick and you can sometimes see examples of it at science museums.

The thermal grill illusion sounded like the perfect way to make the pain box a reality. [Bryan] has set specific constraints on this build to make it more true to the Dune series. He wants to ensure the entire package fits into a small box, just big enough to place an adult hand inside. He also wants to keep safety in mind, since it has the potential to actually cause harm if it were to overheat.

[Bryan] has so far tried two methods with varying success. The first attempt involved using several thermoelectric coolers (TECs). [Bryan] had seen PCBs etched a certain way allowing them to radiate heat. We’ve seen this before in 3D printer surfaces. He figured if they could become hot, then why couldn’t they become cold too? His idea was very simple. He etched a PCB that had just two large copper pours. Each one branched out into “fingers” making up the grill.

Each side of the grill ultimately lead to a flat surface to which a TEC was mounted. One side was cold and the other was hot. Heat sinks we attached to the open side of the TECs to help with performance. Unfortunately this design didn’t work. The temperature was not conducted down to the fingers at all. The back side of the PCB did get hot and cold directly under the TECs, but that wouldn’t work for this illusion.

The latest version of the project scraps the PCB idea and uses small diameter copper tubing for the grill. [Bryan] is working with two closed loop water systems. One is for warm water and the other is for cold. He’s using an aquarium pump to circulate the water and the TECs to actually heat or cool the water. The idea is that the water will change the temperature of the copper tubing as it flows through.

While the results so far are better than the previous revision, unfortunately this version is having problems of its own. The hot water eventually gets too hot, and it takes over an hour for it to heat up in the first place. On top of that, the cold water never quite gets cold enough. Despite these problems, [Bryan] is hopefully he can get this concept working. He has several ideas for improvements listed on his blog. Maybe some Hackaday readers can come up with some clever solutions to help this project come to fruition.