Online

Plastic that tracks your balance in real time?

Plastic that tracks your balance in real time?

This “Live Checking Card” concept design from Yoon Jin-Young, Lee Jun-Kyo, Lee Young-Ho, and Kim Jin-Yi has been getting a lot of bandwidth around the tubes, lately. Ignoring the details of technical implementation, the notion itself is straightforward: Your check card shows you exactly how much money you have available to spend and tracks that amount, essentially in real time. This idea won the prestigious red dot design concept award for 2009.

VOIP ideal for hiding secret messages?

VOIP ideal for hiding secret messages?

The 50-cent word here is “steganography,” which per Wikipedia is “the art and science of writing hidden messages in such a way that no one, apart from the sender and intended recipient, suspects the existence of the message.” You may have heard, for instance, that you can encode a hidden message in, say, an image file, in such a way that no one who wasn’t looking for it would know that it’s there.

Well, this morning Danger Room linked to a post at IEEE Spectrum to the effect that Voice Over Internet Protocol (VOIP) is particularly susceptible to steganographic hijinks. Wired’s David Pierce put it this way:

Mercury “beating heart” works with gallium, too

So it turns out, happily, that the mercury beating heart demo I wrote about a couple days ago can also be done with molten gallium, which is vastly less toxic than mercury and requires only slightly higher temperatures. The chemists at the University of Nottingham who produce The Periodic Table of Videos made this very informative video demonstrating the process, which is slightly different from the mercury beating heart demo in that there is no iron nail present. The gallium blob “beats” anyway, but much slower than the mercury with the nail. I bet using a nail would make the gallium version beat just as fast. [Thanks Filip!]

How-To: Make a giant octopus

YouTuber bluworm took on the task of making a great big octopus puppet for stop-motion animation in a film by his friend Daniel Lennéer. Along the way he produced this informative and entertaining video describing the casting, sculpting, and armature-work that went into it, as well as showing off some of the finished animation (starting around 5:00). Besides the cool propcasting info, I gotta give it up to bluworm for his video editing chops–this is definitely one of the most watchable how-to videos I’ve ever seen, and I’ve seen a bunch of them. [via Propnomicon]

Briggs-Rauscher oscillating chemical reaction

There are, however, other oscillating chemical reactions. None of them result in mechanical action, but the cyclical color changes of, for instance, the Briggs-Rauscher reaction (shown above) are pretty cool in and of themselves. The prototype chemical oscillator is the Belousov-Zhabotinsky reaction (Wikipedia) which was only discovered in the 1950s. For years, no respectable journal would print reports of oscillating chemical reactions because many editors could not reconcile their understandings of thermodynamics with the notion of an oscillating reaction. Guess who had to eat crow?

Mercury “beating heart” demo video

This classic chemistry demo involves the use of toxic metallic mercury, so it’s one of those that is best to just watch on YouTube instead of trying yourself. The pulsing action is caused by surface tension effects–metallic mercury is oxidized at the surface of the drop to form a film of mercury (I) sulfate, which lowers the drop’s surface tension and causes it to flatten under its own weight. The flattening brings the drop into contact with the tip of a carefully-positioned iron nail, which reduces the mercury (I) sulfate back to metallic mercury, which in turn increases the drop’s surface tension and causes it to contract away from the nail. Thanks to YouTuber sciencevidds for sharing it with us. [via Boing and then some more Boing]