Subwoofer Makes Cornstarch Dance


People tend not to think about the non-Newtonian properties of foodstuffs, but we’re glad at least one person did. When it comes to cornstarch, it’s indeterminate viscosity when mixed with water made it the perfect solution for a pretty neat trick: making a liquid move in reaction to a subwoofer. The unique motion can be attributed to the physical properties of the solution: when enough force is applied quickly, it acts as a solid. Otherwise, it flows like a liquid. The erratic bouncing of the sound waves combined with a little tactile manipulation create varying degrees and speeds of applied pressure, which in turn create a mass of flowing shapes that almost appear to be alive.

We’ve covered weird fluids before, but this is perhaps most similar to SnOil, a game that uses ferrofluids to achieve a similar result. SnOil, however, does not depend of vibrations to create shapes in the fluid, it uses small electromagnets and magnetically charges liquid instead. We love the ordered appearance of the SnOil unit, but the chaotic motion of the cornstarch and it’s non-Newtonian properties make it appear almost otherworldly. We wonder how ferrofluids would react in a situation similar to the cornstarch above, since it would respond to both the vibration and the voice coil’s magnetic field.

[via Neatorama]

Map Abstraction API In Javascript


Maybe you’ve tinkered a bit with the Google Maps API. Most of the software produced with it is not all that useful or entertaining, but a few gem have shone through. Still, wouldn’t it be better if applications produced with it could be easily ported to other online mapping services like Mapquest or Yahoo! Maps?

This is possible with Mapstraction, a Javascript API that works with nine mapping services and plans to incorporate more into the fold. Mapstraction has open-source features that normalize functions across the biggest services, which makes searching for map data a consistent, predictable experience no matter which service you use.

Some of Mapstraction’s current features are what you would expect: point, line, and polygon support, image overlay, GeoRSS and KML feed importing, and several others. We’re really looking forward to future versions with OpenStreetMap support. Currently Mapstraction works with only commercial mapping services, but OpenStreetMap combined with Mapstraction directly hits the sweet spot; a customizable, open source map.

[via Hackszine]

Breath Controlled LED Candles


Instructables user [cedtlab] has posted an interesting LED project that simulates birthday candles. The circuit runs on an AVR ATTiny45, and is powered by 4 AA or AAA batteries. By using a Charliplexing technique, they are able to drive all 20 LEDs with only 5 pins of the ATTiny. A thermistor is used for detecting breath by measuring temperature changes, and then blocks of LEDs turn off depending on the change detected. They have provided schematics and source code for everything. Make sure to check out the video of the “ficticious birthday party” after the break.

Continue reading “Breath Controlled LED Candles”

Portable Air Conditioner


The dog days of Summer are looming just over the horizon like a hot sticky wave of impending doom, but you don’t have to take it lying down. Building a portable air conditioner is cheap easy, and we daresay refreshing.

You’ll need the following materials: a condenser, heater core, or radiator, a styrofoam cooler, a submersible water pump, a few case fans, some adapters to power the works, and a few other materials. The pump circulates cold water through the condenser as the fan pushes air through it and the rest of the box.

We’ve never been huge fans of swamp coolers like this one since they offer no true refrigeration cycle. What’s more, they pump a good deal of humidity into the air, which makes the heat worse in the long run, or creates a vicious cycle of cooling and humidifying. Still, when the heat is scrambling our brains, it’s hard to say no to any relief, however ephemeral.

Magnetic Movie


Magnetic field lines may be invisible to the naked eye, but they behave in ways that would amaze us if only we could see them. [Ruth Jarman] and [Joe Gerhardt] from Semiconductor wanted to make them visible for everyone, so they produced Magnetic Movie, a film that combines animations, theoretical models, and actual VLF recordings of the entire Earth’s magetic forces to create a film that shows magnetic fields moving and jumping through the air in living color.

The film is part art project and part scientific experiment, but we can enjoy it on both levels, as watching the path and motion of magnetic field lines is both beautiful and informative. Get a glimpse for yourself after the break.

Continue reading “Magnetic Movie”

Taser Ammo For Your Spud Gun


We definitely don’t recommend trying this one, but [Tony] sent in this odd twist on the old potato launcher. A pair of physics students put together a Taser like potato sized bullet. On impact, two metal pins are inserted into the target, delivering an electric shock. Depending on the size of the capacitor and amount of charge delivered, it can be a (sort of) non-lethal or lethal shock. We’d prefer not to be shot with either one.

[via pspmod]

Live Full Motion Video On A Peggy

[Windell] was stoked enough to send us [Jay]’s sweet hack on [Windell]’s Evil Mad Scientist Laboratories Peggy 2.0 kit. [Jay] added serial input and hacked quartz composer on his mac to light up all 625 LEDs with live motion video. If you were jealous of the Metalab’s giant LED display, now you can have your own – smaller and cheaper.

EMSL has recently supplemented this awesome device with their Arduino Library for Peggy 2.0. It is a program library that contains various animations and demonstrations of how to draw on a Peggy. Download and enjoy them as they are or tweak them to test out some of Peggy 2.0’s capabilities.