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Physicists Devise Magnetic Shield
sciencehabit writes "The sneaky science of 'cloaking' just keeps getting richer. Physicists and engineers had already demonstrated rudimentary invisibility cloaks that can hide objects from light, sound, and water waves. Now, they've devised an 'antimagnet' cloak that can shield an object from a constant magnetic field without disturbing that field. If realized, such a cloak could have medical applications, researchers say."
Would this not cause a security nightmare?
From reading the headline I was almost expecting a shield a la Star Trek. All we would have left would be to find a way to make the Alcubierre warp drive something more than a theoretical possibility and I'd be donning Vulcan ears. Oh, well, I guess the waiting is not almost over yet.
I like my dinosaurs feathery, and my pterosaurs hairy (or is it pycnofibery?)
Forget the actual medical applications. The applications for pseudo medicine are just as good. There are already a ton of people sleeping on magnetic mats. They would eat this up. Maybe even literally.
A better headline would be, Physicists Come up with Idea to Build Perfect Magnetic Shield. As the article states, the device itself is hypothetical no proof of concept has been built.
Put my fist through my alarm clock with its ding-dong death inside my ear. - The Blackjacks.
Okaaaaaay. I hate to break it to you guys, but passive and active magnetic shielding has been around for a long time now. This is simply a new spin on old tech, adapting it and slightly enhancing it.
Shielding an object from external fields is not difficult provided you have money to spend. Hospitals do it all the time for their MRI suites. The shielding may be either passive (LOTS of steel plates in the floor, walls and ceiling), or actively by installing 3-axis helmholtz coils in the walls, floor and ceiling. The coils are then driven by a set of very large and fast amplifiers. The amplifiers are driven by correction signal from a computer that has at least one 3-axis magnetometer. Obviously, the active solution is better as it can correct for things like elevators, automobiles and other things that influence the local magnetic field. The passive shielding is only good is the external field does not change.
I remember one such shielding job in San Francisco that gave trouble because of the volume of *WATER* flow in the city water main running under the MRI suite. Yes, even water can affect magnetic fields. Passive shielding would not work, so the site had to switch to the more expensive active shielding.
I also have had trouble calibrating magnetic instrumentation because of cars in the car park moving around. I'd have to wait for a window where there was no activity outside the building. I'm talking about smallish cars more than 50' away, and large trucks could change the fields from more than 100' away...
Why is it that most of the people that I encounter seem to have been shat from the Sphincter of Mediocrity?
MRI suites are already shielded.
And no, you can not shield the specific volume (inside the magnet) to be imaged.
Why is it that most of the people that I encounter seem to have been shat from the Sphincter of Mediocrity?
Wow. An electromagnetic shield to get "something" by TSA scanners? I'm pretty sure I could just hire a baggage handler to put "something" on board, without ever seeing a scanner. If money doesn't work, threatening his loved ones would.
Yeah, that was evil, and I went there. Other people would, too.
When you want something built, come see me. If you want correct grammar and spelling, get a F*ing liberal arts student.
Landmines. Right now, they use a bare minimum of metal to evade metal detectors, so everything is mechanical. This would allow a processor and such to be in the mine so you could have it not detonate on friendlies, and deactivate itself/start beeping after a couple years. Heck, you could even have the mines networked so the whole field detonates simultaneously when it detects large number of troops are half-way across. I'm not sure if it's in the best interest of humanity to revisit this technology, but at least some of their tactical and humanitarian problems can be addressed.
Personally, I'd prefer not to have a pacemaker with a large, cryogenically cooled shield around it. Walking around with a liquid nitrogen can and hoses going into my chest would seriously cramp my lifestyle.
I'm not even sure it would work properly - most of the danger to metallic implants, particularly sensitive electronic ones, in an MRI is from RF signals, not the magnetic field.