Interesting science stuff

[mike777]

http://www.telegraph.co.uk/news/main.jhtml...levitate106.xml

[luke warm]

amazing... how much do we not know?

[helene_t]

Sorry, but why is this interesting? I may have missed something but to me it's just the usual giberish by a journalist who thinks it's cool to talk about "quantum fields" and other buzz-words the meaning of which he has no clue about.

 

Physical Reviews Online requires a paid subscription and apx seems to be down at the moment. Fortunately the Smithsonian/NASA Astrophysics Data System adsabs.harvard.edu has cached a copy of the abstract. It reads:

Left-handed metamaterials make perfect lenses that image classical electromagnetic fields with significantly higher resolution than the diffraction limit. Here we consider the quantum physics of such devices. We show that the Casimir force of two conducting plates may turn from attraction to repulsion if a perfect lens is sandwiched between them. For optical left-handed metamaterials this repulsive force of the quantum vacuum may levitate ultra-thin mirrors.

The reference is arXiv:quant-ph/0608115

[Al_U_Card]

Even the Van der Waal's force has a repulsive component. Science is a terrible thing to waste....

[luke warm]

going by al's and helene's statements, there's nothing to that article... al even implies that the science used is 'wasted' in such pursuits... i'll stand by my original post, there is no limit to the (even scientific) things we don't know

[helene_t]

The original article might be interesting. If someone could translate it into a language I can understand (and put it on a webserver I have access to) I might be able to judge. But the story is one year old and I haven't noticed anything in Scientific American, or other media. I could have missed it, of course.

[keylime]

I read it, and immediately resumed eating lunch. Blah blah.

[Al_U_Card]

A bit along the lines of the quantum evaporation of black holes....only important if you are falling into one and have to be home in time for eternity....

[hotShot]

I read a more scientific article about it and it might become interesting for nano machines one day, but it won't have an effect to the macroscopic world.

[mike777]

University of Koblenz physicists

are claiming they have propelled

photons faster than the speed of

light, using quantum tunneling

across a barrier gap of up to a

meter. New Scientist article

 

http://www.kurzweilai.net/news/frame.html?....html?id%3D7147

[Gerben42]

Again bad wording. I am getting the feeling that this mr. Kurzweil is just a populist, making bad quotes like this.

 

The simple explanation is: When a particle encounters a barrier, there is a finite chance that it actually is on the other side. This "tunneling" does not cost time and thus the particle will have gotten some distance for free. Unfortunately we cannot make this probablity 1 so if we send information through the barrier, we get incomplete information back. But we get the incomplete information very quickly :angry:

[barmar]

It's a direct quote from one of the scientists:

 

"For the time being," he says, "this is the only violation [of special relativity] that I know of."

 

But later in the article, another scientist chimes in:

 

Aephraim Steinberg, a quantum optics expert at the University of Toronto, Canada, doesn't dispute Nimtz and Stahlhofen's results. However, Einstein can rest easy, he says. The photons don't violate relativity: it's just a question of interpretation.

[mike777]

Space.com, August 23, 2007

 

 

The universe has a huge hole in it, nearly a billion light-years across, that dwarfs anything else of its kind. Astronomers don't know why the hole is there.

 

http://www.kurzweilai.net/news/frame.html?....html?id%3D7182