First black hole for light created on Earth
First, before we start talking about the article, I want to point out what the "black hole" I had in mind was. A black hole occurs when you take something- anything, really,- and squish it down until it's really, really, really (really) small. For instance, I might be wrong, but I believe if you wanted to squish yourself that small, you'd have to be as small as a molecule- which is really small. Once it collapses down to a certain radius (there's a name for it, but I don't know how to spell or say it), it becomes so dense that it's gravity is really strong- so strong that light cannot escape the pull of it. Let's take an example that is almost certainly wrong, but gets the general gist of it. Let's say that I have a very big sheet of unbreakable fabric, which would be the space-time continuum. Now, put a school-bus on it. It creates a sag in the fabric, right? The sag is the gravity (according to Einstein) because if you were a marble on it, you'd roll down, or be "attracted to" the school bus. Next, you have to put on some muscle and compress the entire school bus into a tiny ball the size of a pinhead- no, not taking a little piece, but actually stuffing all that matter into a little ball. Put that little ball on the fabric, and voila! you see that it creates a "hole" that your marble self would just roll into and never come out again. That is a black hole. Such a thing on earth that, even it was a size of an atom, would suck us all up into oblivion if I have it correct, although the good thing would be that we wouldn't even know it (people were worrying about that when they launched the LHC Collider, which smashes atoms to find things like evaporating mini black holes and weird elementary particles. Complicated stuff). Anyway, it's fascinating to think about, but not a good thing to have.
The article is says they have made a "black hole for light." Is it a black hole that will suck us all up? No!! It's almost completely different than what a cosmic black hole is. It is meant to trap electromagnetic radiation (light, microwaves, etc.), not people, so rest easy. It is supposed to work on the principle of black holes in the sense that light spirals towards the center. I think of it more like a labyrinth that forces you to go a certain way. Back to the article- when they do start talking about the device, they say, "The key to making light curve inwards is to make the shell's permittivity – which affects the electric component of an electromagnetic wave – increase smoothly from the outer to the inner surface." If you are having one of those What's that? faces, then you know what I'm thinking. Permittivity, according to to dictionary.com, is "A measure of the ability of a material to resist the formation of an electric field within it." So, I'm guessing that that the outside attracts the light or microwave and the inside, well, keeps it inside- although it all transitions smoothly, of course. Two scientists, Tie Jun Cui and Qiang Cheng at the Southeast University of Nanjing made one of these "black holes" for microwaves (the radiation used to heat up your hot cocoa) with 60 round strips made out of a special material called "meta-materials." Meta-material's acclaim to fame, so to speak, is that they are used to make things invisible. (Quick lesson on invisibility: you bend the rays around the object you want to make invisible so the rays don't bounce off and go into your eye, making you "see" it. Don't count on it too soon though, I'm pretty sure they still have a long way to go. All the good stuff you'll probably have to wait a long time for) The outer 40 rings form the shell that the light/microwaves enter, and the inner 20 actually absorb it. Each of the rings apparently look like a circuit board. In the first version, the absorber converts the microwaves (or is it light? I'm confused) into heat.
Now that the version for microwaves is done, they are hoping to do the same for light. However, since light has smaller wavelengths than microwaves (the electromagnetic spectrum!), they have to make the circuitry on the boards a lot smaller. The purpose for this is that they could hopefully put a solar cell in the middle of the absorber, converting the light into electricity. If so, they could use this black-holeish thing instead of huge mirrors to focus enough sunlight on the cells. (Yes, you need sunlight for solar cells to work, you can't put it in half-shade and expect it to produce a whole bunch of electricity).
In my opinion, this is definitely impressive, but it is not exactly the biggest thing that ever happened. After all, with the ability to bend light and all those smart people (not me, I'm just the critic) out there, somebody probably would have come up with it sooner or later. However, the speed that they work and the neatness is definitely a big accomplishment. Also, I think that they (I don't know who gave the name, so I'm saying they) completely misnamed it. Black holes will make people jump, you know! Couldn't they have named it something like the "light-trapper" or "sun-collector" or "light labyrinth" or even "a device that simulates the effects of a black hole on space-time with meta-materials in order to bend light into a compact thingamajig." Making a black hole in any headline would definitely make people read it, but still, when it's in Chinese (English too) it's hard to get the real scoop without using dictionaries and a lot of prior knowledge that's there because of luck! (Actually, you could argue it's my fault for not learning Chinese properly and that I shouldn't be on a Chinese website in the first place, but it still makes people jump to weird conclusions). Wow, I just realized there are a lot of comments, and a treasure trove of information as well. I like how one person said "it is more of a lens made of meta-materials" because that makes more sense and is not nearly as extreme as a black hole! Plus, some people interpret it as sucking in light, while others think that the light has to hit the thing first, then it navigates its way to the middle. I agree with the latter more, because it says nothing about attracting anything other than the reference to black holes. There are also a lot of people pointing out that meta-materials aren't exactly cheap, so whether this light-trap (as people call it) would be more expensive or cheaper than mirrors is also something to consider. Others point out that this could have other uses. The one that I think was the most interesting (and probably practical) would be to create cheaper versions of this in order to trap excess radio waves and other radiation types from cell phones and wireless devices in the office to reduce exposure. There are also a lot of comments (you can see the varying degrees of "it's a black hole" vs. it's not) that actually take the idea of a black hole literally (one started talking about a black hole bomb! I don't think that would be possible with a light-trap). Overall a good discussion of the article in the comments- and there's a link to another version of the article! Here it is! http://blogs.discovery.com/space_disco/2009/10/first-ever-black-hole-created-on-earth.html Don't read the comments on that one, though, since it's a somewhat nasty discussion. Otherwise, it's definitely a good discovery, but they could have been clearer on the actual device, not just going "it's like a black hole!" because that isn't a good analogy at all- and certainly not good for innocent schoolkids to read, since they can get mixed up.
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