Taking their cues from science-fiction and fantasy tales, scientists have made a major breakthrough in invisibility technology by developing a thin, potentially wearable invisibility cloak that could shield objects from detection.
Unlike earlier invisibility projects that relied on light-bending metamaterials, physicists at the University of Texas recently unveiled an ultra-thin “metascreen,” composed of a 60-micrometer-thick copper tape attached to a 100-micrometer-thick polycarbonate sheet. The cloak can be made to perfectly conform around an object and the copper is patterned in a way that causes light from the cloak and light from the cloaked object to negate each other, resulting in invisibility.
“When the scattered fields from the cloak and the object interfere, they cancel each other out, and the overall effect is transparency and invisibility at all angles of observation,” Andrea Alú, one of the project’s leaders and an assistant professor at UT’s Department of Electrical and Computer Engineering, noted. “The advantages of the mantle cloaking over existing techniques are its conformability, ease of manufacturing, and improved bandwidth. We have shown that you don’t need a bulk metamaterial to cancel the scattering from an object – a simple patterned surface that is conformal to the object may be sufficient and, in many regards, even better than a bulk metamaterial.”
At present, the cloak can only hide objects from microwaves, effectively rendering them undetectable to radar, but in theory it could be used to hide things from the human eye, since microwaves, visible light, and infrared are essentially physically identical waves that simply oscillate at different frequencies.
“The one problem is that their patterned material scattering technique inversely scales with wavelength – so, while it’s possible to hide an 18cm cylinder from 3.6GHz microwave radiation, they can only hide micrometer-scale objects from 400-800THz visible light. One micrometer is 0.001 millimeters; the width of a red blood cell is about six micrometers,” ExtremeTech explains. “Still, it’s yet another exciting invisibility cloak proof of concept. With the amount of money being poured into invisibility R&D, and the myriad of military (and consumer) uses, it’s really only a matter of time until an actual invisibility cloak is realized.”
Bluetooth in Your Body
The day of using a syringe for blood tests may soon be over. A group of scientists at École Polytechnique Fédérale de Lausane in Switzerland have developed a small implant that can perform tests on a subject’s blood when activated via Bluetooth. The 14mm x 2mm device can rest under the skin and conducts the tests for patients remotely, sidestepping the regular need for needles and doctor visits or hospital stays.
The implant can test for up to five different substances in the blood at a time and can last for months before needing to be replaced or removed. The developers hope to begin testing the Bluetooth-enabled device on patients who require a high amount of close monitoring, such as those in intensive care.
The following video explains how the machine works:
The Science of Mosh Pits
The chaos of the mosh pit may actually be more orderly and instructive than anyone imagined.
Cornell physics grad student Jesse Silverberg witnessed a mosh pit at a heavy-metal concert and realized he was seeing motions similar to those found in schools of fish, according to Popular Science. Silverberg and two compatriots began studying YouTube videos of the phenomenon and developing models to observe the movements of the individual actors. They realized that moshers operate like atoms in a gas.
The team built the Moshpits Simulations tool to demonstrate how moshers operate during shows. The user can toggle crowd size, noise level, location, and other elements to see the similarities between gas atoms or birds working in larger groups and responding to outside stimuli. The red dots represent moshers who engage in “self-propelled, experience flocking interactions…subject to random fluctuations in the forces they experience,” according to the Atlantic.
If you’d like to try the simulator yourself, check out the research group’s website HERE.
Easter Candy by the Numbers
With Easter coming up this Sunday, families across the country are stocking up on candy, chocolate, and other treats for children (and adults) to enjoy. America has a sizable sweet tooth, and snack purchases are likely to boom this weekend, but you may be amazed at the scale of the coming candy frenzy.
An infographic from DegreeSearch highlights just how severe our candy habit is. For example, did you know that Americans buy about 120 million lbs. of candy for Easter, enough to fill 4,615 dump trucks?
Have a great weekend, folks.