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Your Words Can Be Recovered From a Video of a Chip Bag Next to You

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When you speak, your voice makes sound waves. Sound waves are just tiny movements in the air around you, so when you speak, the objects around you also move, ever so slightly. A potted plant, a glass of water, or a bag of chips will vibrate in response to the pressure changes caused by your voice. Might it be possible to reconstruct what someone was saying from video of nearby objects alone? A team of MIT computer scientists have figured out how to do just that, turning a chip bag into a “visual microphone.”

This amazing video shows three demonstrations of sound being recovered through video: one where a melody is captured in the vibrations of leaves on a plant, another where speech is captured in the vibration of a chip bag, and a third where a song is identified solely through a video of the ear buds through which the song was playing.

The technique involves computations on pixel-to-pixel differences over time that effectively magnify small movements. Those worried about the potential eavesdropping or spying applications of the technique can take comfort in the fact that it works best with very high rate, memory intensive video capture—but not too much comfort. As shown in the video, it is possible to get a much better than expected result with a regular consumer camera by taking advantage of artifacts resulting from a “rolling shutter” capture. So watch what you say if the cameras are rolling, or at least clean up your snack wrappers before you say it.

There’s more at the pages of lead researchers Abe Davis and Michael Rubenstein. Rubenstein also has a fascinating TEDx talk about the motion magnifying technique that shows how regular video can be transformed to show blood pumping behind skin, a baby’s breathing, or a wine glass pulsating to a singer’s voice.

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Animals
Where Do Birds Get Their Songs?
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Birds display some of the most impressive vocal abilities in the animal kingdom. They can be heard across great distances, mimic human speech, and even sing using distinct dialects and syntax. The most complex songs take some practice to learn, but as TED-Ed explains, the urge to sing is woven into songbirds' DNA.

Like humans, baby birds learn to communicate from their parents. Adult zebra finches will even speak in the equivalent of "baby talk" when teaching chicks their songs. After hearing the same expressions repeated so many times and trying them out firsthand, the offspring are able to use the same songs as adults.

But nurture isn't the only factor driving this behavior. Even when they grow up without any parents teaching them how to vocalize, birds will start singing on their own. These innate songs are less refined than the ones that are taught, but when they're passed down through multiple generations and shaped over time, they start to sound similar to the learned songs sung by other members of their species.

This suggests that the drive to sing as well as the specific structures of the songs themselves have been ingrained in the animals' genetic code by evolution. You can watch the full story from TED-Ed below, then head over here for a sample of the diverse songs produced by birds.

[h/t TED-Ed]

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Animals
Watch the First-Ever Footage of a Baby Dumbo Octopus
NOAA, Wikimedia Commons // Public Domain
NOAA, Wikimedia Commons // Public Domain

Dumbo octopuses are named for the elephant-ear-like fins they use to navigate the deep sea, but until recently, when and how they developed those floppy appendages were a mystery. Now, for the first time, researchers have caught a newborn Dumbo octopus on tape. As reported in the journal Current Biology, they discovered that the creatures are equipped with the fins from the moment they hatch.

Study co-author Tim Shank, a researcher at the Woods Hole Oceanographic Institution in Massachusetts, spotted the octopus in 2005. During a research expedition in the North Atlantic, one of the remotely operated vehicles he was working with collected several coral branches with something strange attached to them. It looked like a bunch of sandy-colored golf balls at first, but then he realized it was an egg sac.

He and his fellow researchers eventually classified the hatchling that emerged as a member of the genus Grimpoteuthis. In other words, it was a Dumbo octopus, though they couldn't determine the exact species. But you wouldn't need a biology degree to spot its resemblance to Disney's famous elephant, as you can see in the video below.

The octopus hatched with a set of functional fins that allowed it to swim around and hunt right away, and an MRI scan revealed fully-developed internal organs and a complex nervous system. As the researchers wrote in their study, Dumbo octopuses enter the world as "competent juveniles" ready to jump straight into adult life.

Grimpoteuthis spends its life in the deep ocean, which makes it difficult to study. Scientists hope the newly-reported findings will make it easier to identify Grimpoteuthis eggs and hatchlings for future research.

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