Optical setup helps researchers hide an event from time. Cloaking devices are one of the inventions of science fiction that have made a few tentative steps towards the real world in recent years. Now, researchers have moved the concept into the fourth dimension, creating a setup that hides a specific point in time from being perceived by observers. But if you want to make an event disappear, you have to act fast: right now, we can only hide a few picoseconds worth of time. The cloaking devices we've made all work based on a similar principle: light that enters the device is bent in such a way that when it exits, its location and direction make it appear that the device itself, and anything within it, were not present.
In other words, while within the device, light travels as if it were present. It's just that, once it exits the other side, there's no evidence that anything unusual has taken place. The same general idea governs the action of a temporal cloaking device. Fifty picoseconds isn't a lot to work with. So, what is a “temporal cloak”, anyway? I’ve been saying for a few years that optical science has entered a truly remarkable new era: instead of asking the question, “What are the physical limitations on what light can do?” , we are now asking, “How can we make light do whatever we want it to do?” Among other things, we can make light travel “faster than light“, we can focus light through a highly scattering material, we can take high-resolution pictures with low-resolution sensors, and even make particles “fly” on a “wind” of light!
Inevitably, though, many of these discoveries get misinterpreted in popular news accounts to the point that their real significance is lost in a haze of science fictional, or even supernatural, hype. A good example of this is the “picosecond camera” that I described last week, which is an amazing achievement but also possesses a number of technical limitations that make it not quite a “camera” in the ordinary sense of the word. The picture looks the same, but represents something very different! From the 'X-Files': Radical Technology Creates a "Hole in Time" to Mask Real Events.
Cornell University scientists demonstrate how they have have created, a new invisibility technique that masks an entire event by briefly bending the speed of light around an event. This 2011 illustration above shows art thief can walking into a museum and stealing a painting without setting of laser beam alarms or even showing up on surveillance cameras--not only is the thief is invisible - his whole event is. Think of it as a hole in the fabric of time. The time cloak created by scientists at Cornell University lasts an incredibly tiny fraction of a fraction of a second, hiding an event for 40 picoseconds (trillionths of a second), according to a study appearing in Thursday's edition of the journal Nature.
The Cornell team alters not where the light flows but how fast it moves, changing in the dimension of time, not space. The scientists created a lens of not just light, but time by spliting light and speeding up one part of light and slowing down another, creating a gap. 'Space-time cloak' to conceal events revealed in new study. Public release date: 15-Nov-2010 [ Print | E-mail Share ] [ Close Window ] Contact: Katherine Barnesc.temp2@imperial.ac.uk 44-207-594-6702Imperial College London The study, by researchers from Imperial College London, involves a new class of materials called metamaterials, which can be artificially engineered to distort light or sound waves. With conventional materials, light typically travels along a straight line, but with metamaterials, scientists can exploit a wealth of additional flexibility to create undetectable blind spots.
By deflecting certain parts of the electromagnetic spectrum, an image can be altered or made to look like it has disappeared. Previously, a team led by Professor Sir John Pendry at Imperial College London showed that metamaterials could be used to make an optical invisibility cloak. Such a space-time cloak would open up a temporary corridor through which energy, information and matter could be manipulated or transported undetected. Notes to editors: 1. " 2. 3. 4. Is thorium energy’s silver bullet? | Guest Work. By George Dracoulis, Professor, Department of Nuclear Physics at Australian National University. You have probably heard at least a little about thorium. There are certainly advocates out there who strongly believe it could help solve the world’s energy problems.
The idea is that thorium-based nuclear energy (it is nuclear) would have all the advantages of a uranium-based system — producing large-scale electricity with low emissions — without any of the disadvantages, real and imagined. Of course, life is a little more complicated than that, otherwise we would have thorium based systems already. In fact, thorium technology in various guises has been around since the start of the nuclear age. But the threat of climate change has thrown the technological challenges facing all energy production into sharp relief. Spruiking thorium I recently attended a meeting at Parliament House in Canberra entitled ’Thorium, a Base Load Power Source?’. Thorium and molten-salt reactors A thorium-rich future?
“Zombie” Fly Parasite Killing Honeybees. A parasitic fly landing on a honeybee. Courtesy of Christopher Quock A heap of dead bees was supposed to become food for a newly captured praying mantis. Instead, the pile ended up revealing a previously unrecognized suspect in colony collapse disorder—a mysterious condition that for several years has been causing declines in U.S. honeybee populations, which are needed to pollinate many important crops.
This new potential culprit is a bizarre—and potentially devastating—parasitic fly that has been taking over the bodies of honeybees (Apis mellifera) in Northern California. John Hafernik, a biology professor at San Francisco State University, had collected some belly-up bees from the ground underneath lights around the University’s biology building. The team performed a genetic analysis of the fly and found that it is the same species that has previously been documented to parasitize bumblebee as well as paper wasp populations. Parasitic fly larva emerging from a dead bee's neck. 104: The colony-collapse blues. The entire TWiV family reviews the latest ideas about colony collapse disorder of honeybees, and resurgence of monkeypox in Africa.
Click the arrow above to play, or right-click to download TWiV #104 (70 MB .mp3, 97 minutes) Subscribe to TWiV (free) in iTunes , at the Zune Marketplace , by the RSS feed , or by email , or listen on your mobile device with Stitcher Radio . The Harvey Lectures Iridovirus and microsporidian linked to colony collapse disorder C CD discussed previously on TWiV 64 , 49 , and 46 Why are they called iridoviruses ? Iridoviruses at ViralZone Scientists and soldiers solve a bee mystery (NY Times, pdf) Edgewood research center involvement in CCD Resurgence of monkeypox in Africa (PNAS) Orthopoxvirus in Ghana Outbreak of monkeypox in US (MMWR) Goodbye smallpox vaccination, hello monkeypox Letters read on TWiV 104 {*style:<b>Dickson – <i>Four Fish </i> by Paul Greenberg </b>*}Nikon Small World contest , 2010 winners {*style:<b>Rich – Encyclopedia of Life.
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