ElectromagneticWaves
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Time Machines - Wireless wonder
Welcome to Time Machines, where we offer up a selection of mechanical oddities, milestone gadgets, and unique inventions to test out your tech-history skills. This device famously exhibited the potential of tuned radio waves and their ability to wirelessly convey a signal. In 1899, it transmitted a message successfully from Britain, across the English Channel's 32-mile expanse, to a receiver in France. Its business-minded inventor went on to pioneer an industry in communication that changed the world. Tune in past the break for more about this breakthrough gadget.
Man illuminates electromagnetic waves using coffee cans and LEDs, Christmas-colored science ensues
Electromagnetic radiation is all around us, but we're largely unaware that our bodies are constantly bathed in waves of the stuff because our eyes aren't equipped to see most of it. Dr. Gregory Chavat decided to give us a glimpse of an EM waveform, however, by using a coffee can radar system, a couple of LEDs, and long-exposure photography. The setup consisted of a radar emitter made out of one coffee can and a second can with a couple of LEDs attached to serve as a tethered receiver antenna. Those LEDs were then set to that light up red or green to illuminate the EM wave peaks and valleys. By moving the receiver closer and further away from the emitter while taking a long exposure photo, the good doctor was able to capture the wavefront radiating on film, and let you see the unseen with a bit of Christmas-colored flair. Check the video below for a fuller explanation, and hit the more coverage link to learn how to build a coffee-can radar and perform some basement black magic yourself.
Electromagnetic invisibility a precursor to the real thing?
This could either be that one giant leap, or just another in a long sequence of multidirectional small steps on the Quixotic quest for undetectability. So-called dc metamaterials are the chief culprit for inciting our interest anew, as researchers from Universitat Autònoma de Barcelona have found a way to use them to render metallic objects invisible to low frequency electromagnetic waves. Composed of irregular networks of superconductors, the metamaterials are capable of granting superpowers altering the magnetic field of materials, and in theory, this advance could aid magnetic imaging in medical settings and also help cloak military vessels from magnetic detection. Of course, there's still the whole "oh, now we need a working prototype" conundrum, but hey, at least we've got the gears turning in the right direction.[Via PhysOrg]
Cellphones are dangerous/not dangerous, baby daddy edition
Dudes, if you're into cellphone carryin' on that belt or anywhere else in that -- ahem -- vacinity, you'd better watch out if you plan on being a proud pop in the future. Research by the Cleveland Clinic concludes that men in a study who used a wireless phone for more than four hours per day had the biggest drop in fertility. Are those electromagnetic waves really to blame here? There are studies that show cellular radiation does indeed heat up human tissue, but the level is so low that any health impact is non-existent or negligible. Still, we're going to start keeping those phones on the counter or desk and cuddle up for a nice conversation with that trusty Bluetooth headset from now on.[Via textually.org]
