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The video showing refraction at at an air-metamaterial interface is highly enlightening. Is it an experimentally-acquired sequence of photographs, is it a plot of the numerical solution of Maxwell's equations, is it a plot of some approximate solution, or is it simply a cartoon painted up by a human artist? Whichever it is should be noted in the caption. 129.63.129.196 ( talk) 18:38, 18 October 2012 (UTC)
This article is a complete hotch-potch, and I think it would be completely useless for anyone who wanted to become familiar with this topic. By the look of things editors have been using this page to trumpet their own contributions to the field (which may or may not be relevant) rather than to provide a useful overview of the area. The problem is not helped by a lack of a good definition of a metamaterial - should it include the artificial dielectrics from the 1940's, left-handed tranmsission line media, and photonic crystals? ( No Worries 05:40, 25 September 2007 (UTC))
Is the diagram correct? It appears to contradict the later statement in the article "but rays are refracted away from the normal on entering the material" whereas the diagram has the rays being refracted closer to the normal, and more surprisingly, on the other side of the normal. If the diagram is wrong can someone delete it please.
Can/should we talk about superlenses here? Can someone at least answer some of the basic questions? Like do the concave/convex lenses work opposite from a regular lens?
Why is it that the only meta-material that is talked about is negative refractive index? Shouldn't that get its own page then?
Hi, I couldn't follow the connection between the 2nd and 3rd paragraphs. Could some one in the know edit this article and make these two paragraphs flow better ? Thanks -kg
The superlens created at Berkley did not have a negative index of refraction. All materials with a negative index of refraction are for microwave frequencies. See Superlens —This unsigned comment was added by 67.189.113.62 ( talk • contribs) on 03:04, 20 March 2006.
If it had a negative index of refraction for microwares, then it by defintion has a negative index of refrarction. I just does not have one for visible light, only microwave light. And don't make me explain how microwaves are light again.-- Scorpion451 02:46, 25 June 2007 (UTC)
It says that a 'C' ring with is axis in the propogation direction (I assume this means the ring is flat to oncoming radiation) would produce negative permeability. In fact, this only creates negative permitivitty. Negative permeability is created when propagation is in the plane of the ring and the B field then acts perpendicular to the loop. This is not possible if the axis of the ring is alined with the propogation vector of the light. See "Stefan Linden et. al., Magnetic Response of Metamaterials at 100 Terahertz, www.sciencemag.org, Vol 306, 19th Nov 2004, pg 1351-1353" for diagrams of permeability and permitivity with different orientations in respect to the incoming light.
Although it does say that "an induced current is created and the generated field is perpendicular to the magnetic field of the light. The magnetic resonance results in a negative permeability; the index is negative as well.", this is not magnetic resonsnace; the B field would have to be in the same direction of the normal of the loop (or have a component thereof) to create a current and then the induced field could not possibly be perpendicular to the driving field (just think Lenz's Law). If I'm missing something pleae feel free to enlighten me. —The preceding unsigned comment was added by 137.132.3.12 ( talk • contribs) on 07:48, 31 August 2006.
It's like a solenoid, the magnetic force is at a right angle to the current, but the looped shape distorts the field causing it to flow in the same direction as the current. The structure of the metamaterial sets up a similar situation, only it reverses the right hand rule, making it the left hand rule, and effectively making the induced field at a right angle to the driving field. Yes it's wierd, that's what makes metamaterials facinating. -- Scorpion451 02:50, 25 June 2007 (UTC)
According to the article "Unveiling the first invisibility shield" in Popular Science, light travels faster through a metamaterial than a vacuum. Was this a mistake? — Daniel 04:31, 21 September 2006 (UTC)
The phrase in the first line of the 2nd paragraph that reads "at least as small" is strange wording. Does that mean "at most as small"? In other words, as small or smaller? Please clarify. Unclepea 05:44, 20 October 2006 (UTC)
It means "as small as or smaller". "at most as small" would mean "as small as or larger". English doesn't make sense even if it is your first language.-- Scorpion451 02:58, 25 June 2007 (UTC)
Is the example at the end of the Nri paragraph correct?
"consider the following: a person submerged in a swimming pool filled with a hypothetical liquid with negative N would appear to float above the pool instead of appearing to be beneath the surface."
If the positive refraction index would make the submerged body look closer than it is, then the negative will make them appear "underneath" or even behind the view point.
I think you have the idea of the Plane and the Normal the wrong way around in this example. Otherwise it's been explained very well.
Daniel -- 80.195.237.107 22:18, 30 October 2006 (UTC)
I see that my example of the person in the swimming pool has been removed. It was from a Scientific American article, so I'm pretty sure it was right. Rotiro 11:02, 14 March 2007 (UTC)
The negative refractive index would indeed make the swimmer appear above the water, much like a concave mirror does, although by a different mechanism.-- Scorpion451 22:20, 26 June 2007 (UTC)
I'm still having trouble with the diagram showing negative refraction. My understanding, backed up by http://physicsworld.com/cws/article/news/2692 is that a positively refracting material bends light away from the normal, and a negatively refracting material bends light towards the normal. This diagram shows both materials bending the beam towards the normal, only that the negative material bends it so far that it goes past the normal. Either this is wrong, or the Wikipedia entry on "refraction" is wrong. ---posted by NobbyNobbs
Can somebody explain how Snell's Law holds for NRIs between minus one and zero?
If we take N1 to be 1 and Theta1 to be 45 degrees, then use a negative N2, say -0.2, then solving Sin(Theta2) = Sin(45) / (-0.2) = -3.53~ has no solutions for N2.
I ask because a metamaterial was recently produced with refractive index -0.6 for visible (780nm, red) light, and I'm still trying to figure out what it would 'look' like. The swimming pool discussions don't make much sense to me because, how on earth can something appear to be 'below me' when I'm standing on concrete. Wouldnt I just see concrete? 222.154.97.61 09:59, 19 December 2006 (UTC)
As for what it would look like, lay a mirror on the ground and look into it. The beams of light reflected from the mirror cover up the beams of light reflected from the concrete. It's hard to explain the way the equations apply to the wierd properties of metamaterials, because they violate fundamental assumptions of the equations. It's one of those cases of the equations say the data is wrong, but the universe says that the data is right. I'm leaning toward the universe. -- Scorpion451 03:07, 25 June 2007 (UTC)
When light moves from a dense to a less dense medium, such as from water to air, Snell's law cannot be used to calculate the refracted angle when the resolved sine value is higher than 1. At this point, light is reflected in the incident medium, known as internal reflection.
http://www.newscientisttech.com/article/dn10816.html 195.210.210.217 12:39, 19 December 2006 (UTC)
In the subsection "Negative refractive index", there's a list of some cool properties of metamaterials with negative n. The last point in the list is: "Higher frequencies have longer, not shorter, wavelengths in such a material ". I've added a citation needed flag to this, as I haven't encountered it in the literature on this topic, and I have the feeling it might be incorrect. (It runs contrary to the definition of frequency, which is phase velocity/wavelength.)
Can anyone find the proper reference for this fact? (Otherwise, I think it should be deleted as a precaution...) GameGod 02:26, 2 January 2007 (UTC)
18.95.7.45 20:58, 7 January 2007 (UTC) Matthieu
I'm not certain but I belive that the above fact is correct, even though it violates the C=F/W rule. I think this is due to the negative refraction index causing the particle to slow down. To put it this way, if C(phase speed)=1(just for simplicity), then in the metamaterial if it moved at half the speed it would be 1/2=F/W. If frequency is unchanged, then wavelength must double. Does this make sense? I can put it a little more clearly, I think.-- Scorpion451 03:04, 25 June 2007 (UTC)
I looked more into this. You are correct that the wavelength expands when frequency decreases and vice versa. The material, however, is not metamaterial. The expanded wavelength at slower speed is seen in materials with extremely high N, such as [[Bose Einstein condensates]. See the Slow Light article.-- Scorpion451 02:18, 8 July 2007 (UTC)
In the opening paragraph this sentence exists: "Such unusual properties could be a negative refractive index or infinite inertia (which are not found in naturally occurring materials)."
I've gotta say, "infinite inertia" sounds like dubious science to me - generally there's not much in science that is "infinite" and if some object possessed /infinite/ inertia then either its mass or velocity was infinite, both impossible AIUI.
There's no further mention of inertia in the article, nor here on the discussion and google didn't produce anything significant regarding this phrase ... so is this "infinite inertia" just buzzwordiness ... or outright nonsense or vandalism or ...???
Anyway, just a heads up about this fishy sounding phrase ... and thanks to all who contribute and edit to wikipedia!
-- wikifreeman 21:44, 17 October 2007 (UTC)
Also the statement that the doppler effect would be reversed is just hogwash. The doppler effect is a physical interaction between a signal moving through space and a receiver of that signal. A signal can only be expanded if the receiver is moving away from it, and can only be contracted if the reciever is moving towards it. The doppler effect is not effected any properties of the signal generator. Once a signal is moving through space, the doppler effect can only possibly work that way. Why is this article linked in "see also" from a real scientific article like "einstein-rosen-podolsky_bridge ? —Preceding unsigned comment added by 24.2.124.58 ( talk) 14:05, 28 September 2008 (UTC)
Agree about the BS Doppler claim as it violates special & general relativity, and conservation of energy. I tried asking for "proof" of this claim, but some idiot admin person yelled at me for "vandalizing the site." I like WIki, but if the admin censors trump scientific integrity, then this site is nothing more than a blog for some IT wannabe. — Preceding unsigned comment added by 72.66.109.243 ( talk) 02:55, 28 January 2012 (UTC)
Scorpion451, your Doppler counter-argument doesn't make any sense because the basic premise of the relativistic Doppler effect & gravitational red/blue shift resides with time dilation, which has nothing to do with materials (positive or negative index of refractions). However, I will be happy to eat my own words if you can cite peer reviewed/credible journal articles that prove me wrong. Until then, that bullet should be deleted from the article because it's unsupported. — Preceding unsigned comment added by 72.66.109.243 ( talk) 03:06, 28 January 2012 (UTC)
I am no expert in this field, but there does not appear to be any mention of the developments at Los Alamos National Laboratory by Hou-Tong Chen, Richard Averitt, Willie Padilla and others, which resulted in the fabrication of a controllable device. I would have thought this is very significant for the future use of metamaterials. http://www.lanl.gov/news/index.php/fuseaction/home.story/story_id/9935
parellic —Preceding unsigned comment added by Parellic ( talk • contribs) 17:52, 2 March 2008 (UTC)
I'm just an internet-educated dropout trying to make himself feel less stupid. If this is a stupid question, just delete it and I'll go away.
The page states that "A metamaterial (or meta material) is a material which gains its properties from its structure rather than directly from its composition." How are metamaterials different from allotropes? For example, graphite and diamond are both academically pure carbon, yet are literally as different as black and white. Diamond is one of the hardest materials in nature, but graphite rubs off on a sheet of paper. Graphite conducts electricity, diamond doesn’t. Could you say that metamaterials are allotropes that do not normally exist in nature? Or compounds with structures that do not normally exist in nature?
It is not for us to define them. We should cite a reliable source's definition. Lfstevens ( talk) 23:01, 25 April 2015 (UTC)
I'm new to this, but under External Links | Research groups (in order of importance), the number one spot is occupied by a site which appears to have nothing to do with Metamaterials. Maybe someone can correct this? 72.90.243.147 ( talk) 16:08, 5 April 2008 (UTC)
Yes, I agree. This appears to be vandalism. I have been going over the history of this page. There are a lot of changes by more than one anonymous IP address and so it is a little difficult to determine what is valid and what is not. From reading the "Oscar" dude's website, I do not believe he has anything to do with metamaterials. I am going to send him an email asking if he does. I am not sure if this "Oscar" guy is the source of the changes or not. He may not be aware of these edits at all. Anyway which way, the research groups should be listed alphabetically. The-tenth-zdog ( talk) 06:38, 6 April 2008 (UTC)
This entire article is hard for someone not already familiar with its concepts to understand. Although it has the virtue of having good spelling and of being grammatical, it could benefit from a complete rewrite due to its confusing and overly terse content and style. The final paragraph is particularly infelicitous. It and many others could also benefit from the addition of line drawings or other diagrams.
An example of an article of similar speciality and difficulty that is nevertheless easier for a nonspecialist to understand, due to its clear writing and its use of diagrams, is Block cipher modes of operation.
While it is certainly useful for an encyclopedia article to be accessible only by specialists in its field, it is even more useful if each article were understandable by a much wider audience. Then, besides being informative, the encyclopedia might also be tutorial, which greatly enhances its usefulness to society. David ( talk) 14:13, 16 August 2008 (UTC)
I have merged the section Metamaterial research from the article Cloaking device into the section Development and applications. I also split the section "Development and applications" into subsections to present the ideas in a more organized fashion. Please centralize discussion regarding this merge on this talk page, and feel free to change anything I merged. — OranL ( talk) 04:06, 21 August 2008 (UTC)
You're doing great job expanding that article. Just a bit of advice: (i) please check for duplicate references and replace them using <ref name=xxx> and then <ref name=xxx/> tags; (ii) please format references using {{cite journal}}, {{cite book}} , etc., templates; (iii) please avoid personal phrases ("Author X observed ..." in favor of "... was observed in"). Best wishes. Materialscientist ( talk) 01:45, 1 June 2009 (UTC)
I fixed the requested citation tag for Reference number 8. I also added the illustration (or whatever you call it). Ti-30X ( talk) 14:09, 7 June 2009 (UTC)
Editors of this article may be interested in the new article Negative index metamaterials and the discussion on its talk page. Note that the article really focuses on stealth applications, and there is a discussion in progress on whether to retitle the article, or to broaden its focus to cover negative index materials more broadly. There is some overlap with this article; some shuffling of material between the two articles may be beneficial.-- Srleffler ( talk) 19:18, 8 August 2009 (UTC)
The negative index metamaterial essay-like article has recently appeared has enormous overlap with this article, in a way that makes it completely synonymous with this one. This is the Wikipedia, an encyclopedia, which is where synonymous material is collected into one article.
The invisibility/cloaking discussion is covered in both places, as is the discussion of negative refractive index, and the lead of negative index metamaterial suggest that it covers all uses of negative index metamaterials; but almost the whole of this article covers that.
Unless a clear distinction can be made between these two articles or a clear subarticle relationship can be established then these two articles need to be merged.- ( User) Wolfkeeper ( Talk) 14:43, 16 August 2009 (UTC)
Understand but Strongly oppose and suggest focusing on writing and improving the articles rather than talking about that and moving articles forth and back. That metamaterials is in a poor state is an issue which is again to be fixed by editing that article rather than putting other material in its place. Today we move negative index metamaterials (NIM) article into metamaterials (only because it is better developed) and tomorrow say "whoops the article is too large, we should split it up". The way I see is to develop metamaterials in the general way, mentioning NIM, but also covering other directions. This topic has intrinsic tendency to grow, and the small current size is no argument to me. That metamaterials article needs cleanup I agree entirely, just couldn't find time for that. Materialscientist ( talk) 22:35, 16 August 2009 (UTC)
There is now a new section entitled "The six spokes of expanded metamaterial research." Please do not remove, move, or delete this section. One or two other editors and I will be editing the section, and hopefully use it as a base to expand the Metamaterial article. This gives a lot of basic information to start with. Thank you for your cooperation. Ti-30X ( talk) 18:21, 17 August 2009 (UTC)
I am thinking that the paragraphs in the introduction, beginning with "With a negative refractive index researchers have been able to create a device..." probably need to be thrown out. ( I am the previous author of these paragrpahs, too.) Just from my peliminary work on the other section and reading some new information, I can see that this is too narrow a definition. Metamaterials now have broader applications, if they didn't before. Come to think of it, it may be tough to pack all the new available information into one article. Also, I think this statement will have to be removed sooner rather than later: "Electromagnetics researchers often use the term metamaterials more narrowly, for materials which exhibit negative refraction". Again, this is too narrow a focus with the current information available. So if no one objects I will be removing these from the article, soon, to make room for a better introduction. Thanks. As usual this is open to discussion. Ti-30X ( talk) 19:46, 17 August 2009 (UTC)
Regarding the recent reference warring, per WP:RS in the context of science articles, I'd strongly suggest sticking to textbooks and peer-reviewed journal articles where possible. These definitely exist, and I'm pretty sure most of the parties involved have access to relevant online journal databases through your respective universities.
That, and the "electromagnetic vs. non-" dispute seems a bit like a mountain/molehill scenario to me. Why not just hedge and say that the term is usually used to refer to materials with strange electromagnetic properties? There's certainly a mountain of literature to support the claim that this is a very widespread use of the term. -- Christopher Thomas ( talk) 01:13, 20 August 2009 (UTC)
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help)To Wolfkeeper. (i) Please take it easy. Your criticism is more than appreciated, but slapping a newcomer on every mistake is not constructive. There could be a valid comment why are you bashing an active writer whereas there are thousands of abandoned articles with graver problems around. (ii) I think everybody would only welcome your writing (not only deletion) on this topic, including this article. (iii) I respect your opinion on the lead, but please understand that mine is simply an observation over many hundreds of WP articles on physics and materials science - they do not have a proper lead at all. (iv) Please appreciate different writing habits. Some people keep the story in the head and only when shaped, put it on paper. Very efficient and quick. That said, most guides on scientific writing advise to put up the abstract only after the whole text is finished, which I understand and respect too. (v) Just read your comment above. This is non-issue. Please propose your vision on defining metamaterials, with references. Materialscientist ( talk) 22:45, 20 August 2009 (UTC)
Chirality and bi-isotropic media: This section is currently being developed. Thanks Ti-30X ( talk) 14:24, 21 August 2009 (UTC)
Acoustic metamaterials is currently being development Ti-30X ( talk) 18:40, 24 August 2009 (UTC)
Based on the amount of material we seem to be able to access about metamaterials, we may want to dispense with the section entitled "Groups engaged in metamaterial research". Anybody agree with this? Ti-30X ( talk) 22:20, 24 August 2009 (UTC)
I know the section on Split ring cylinders has been sitting there for awhile. I was going through other material before I got to it. This section is still not finished. Ti-30X ( talk) 05:34, 31 August 2009 (UTC)
There are two separate section regarding negative index, Negative Refractive Index and Double Negative Metamaterials. One or the other should not exist since they're redundant and both refer the user to the negative index metamaterials page anyhow. 20:03, 15 March 2010 (UTC) —Preceding unsigned comment added by 152.3.196.93 ( talk)
I won't be doing anymore with acoustic metamaterials. I prefer research on other metamaterial types (probably EM). There may more that can be done with acoustic metamaterials if someone else wants to work on that area. Sorry. As much as I try the interest is just not there. Ti-30X ( talk) 21:05, 8 September 2009 (UTC)
I have been coming across this term a lot - the “THz gap”. No, it's not about capacitance. It appears to be partly about infrastructure that is not available to deliver Thz radiation which will advance our technologies or capablities in society. This includes a compact source that is proportional to the desired application.
"Many materials inherently do not respond to THz radiation and thus the tools necessary to construct devices operating within this range - sources, lenses, switches, modulators, detectors largely do not exist. Considerable efforts are underway to fill this “THz gap” in view of the wellknown potential applications using THz radiation." That is from one short article that I read regarding Thz-metamaterials. Objectives for Thz-metamaterials are
The above would be what I consider to be some of the infrastructure needed. Below, are some of the applications after the delivery systems are developed:
An intersting device that was mentioned briefly twice and in one journal article is the Quantum Cascade Laser as a Terahertz Local Oscillator . It said, "Although QCLs have been available at near infrared wavelengths for more than 10 years, the first THz QCL (at 4.4 THz) was only produced 2 years ago." This is being developed as a compact source to deliver Thz radiation. One article said these devices are the size of a baseball, which is pretty small. I am trying to find the article again, but that one said something about a source like this with previous laser technology would have to be huge - like the size of a house or something like that.
I am seeing that the research with metamterials is really important right now. I'll leave you all with another quote - "The design flexibility associated with metamaterials provides a promising approach — from a device perspective — towards filling this gap." These quotes are from the labratories (like Los Alamos). Ti-30X ( talk) 05:07, 14 September 2009 (UTC)
If no one objects I would like to do a whole article on THZ metamaterials. There appears to be enough material. In this way we could comfortably expand or expound on other categories. I will begin on a sub page using most of what is in this article on THz MM's to start with. And if there are then no objections I can move it out to Wikipedia. By the way, this will be straight science. It will be simply THz Metamaterials. I will see if I can add material to the Split-ring resonator article without taking away from the effectiveness of this article. Ti-30X ( talk) 15:07, 16 September 2009 (UTC)
I want to move this here for reference purposes. I will keep the first paragraph in the article because I think it is worth having the information in the article. I think it is noteable enough. Ti-30X ( talk) 15:15, 16 September 2009 (UTC)
The number of groups studying metamaterials is continuously increasing. For example, Duke University has initiated a Novel Electromagnetic Materials Program (NEMP) and became a leading metamaterials research center. The center is a part of an international team, which also includes California Institute of Technology, Harvard University, UCLA, Max Planck Institute of Germany, and the FOM Institute of the Netherlands. [1] In addition, there are currently six groups connected to this hub, which are conducting intense metamaterial research: [1]
References
I have found two references in the reference section that are incorrect, so far. These are references that I added for citations. They were correct when I entered them with the templates. Somehow they have been changed where they both have the wrong authors, and a PMID number that goes to an article entitled "Association of cytokine gene polymorphisms and liver fibrosis in chronic hepatitis B". The DOI numbers are correct (were correct?). I simply deleted and re-entered one reference with the correct information (see revision history).
Actually, it is a better reference than the first one. However, I would like this situation corrected. There is no reason to add a PMID number, especially if it is inaccurate, and especially if we end up with the wrong authors. Who knows what else was incorrect. Please don't add PMID numbers if the reference doesn't already have one. Any reference that didn't have one in the first place, is because the DOI led directly to the cite of the journal that published the article. I do supply a link to the PDF when I can. In any case a PMID number is not needed and changing the authors names is not in any way helpful. If someone is in doubt about a reference then address it here on this talk page, or on my talk page. Please, do not blantantly change information in the references. Of course, now, this just occured to me that this could be a case of vandalism. Ti-30X ( talk) 23:46, 22 September 2009 (UTC)
I am guessing this was just a good faith error. So, if adding a PMID number makes life easier for the reader or other interested party, then why not - go ahead. It is a good place to find journal articles. Stuff happens, and I am certainly not perfect. I apologize if I came across a little upset. This really isn't a big deal, because I doubt it was intentional. Ti-30X ( talk) 22:14, 23 September 2009 (UTC)
If no one objects, I think we could do a whole article on Metamaterial antennas. Of course we would have a summation in this article and a link to the "main" article. I have just barely scratched the surface with the material that is available in this area. The same is true for Terhertz metamaterials. There are also other categories that we haven't looked at yet. Also, I would like to add more to seismic metamaterials.
In any case, this has been really good. We have included many types of metamaterials, and created a much better article. Kudos, to Wolfkeeper for writing a great introduction which provides a focus (for me) for this article. There is so much material out there on metamaterials - it is amazing. Ti-30X ( talk) 03:07, 24 September 2009 (UTC)
I am thinking that it is best to go ahead and create a split for Acoustic metamaterials. This will give us more room in this article to expand into other areas, and this will give us more space to expand Acoustic metamaterials. Hopefully, no one objects. Here is the new article: Acoustic metamaterials Ti-30X ( talk) 04:01, 26 September 2009 (UTC)
There isn't much on metamaterials related to Avionics or Aerospace that I am able to find. So I am going to remove this as a section header. I will change it to "Tuneable metamaterials". And these are different because with previous NIMs discussed - in order to m get a negative refractive index (to operate at a different frequency) the periodicity and size of the elements would have to be changed. These type of "Tuneable metamaterials" appear to be tuneable in hand, so to speak. Ti-30X ( talk) 02:31, 1 October 2009 (UTC)
I am exapanding this section at the moment. I will be fleshing out the other sections that I have introduced these past few days. Apparently EBG's are photonic crystals (PC) and are also referred to as (PBG). I didn't realize this, and only noticed a similarity previously. I am thinking I will keep the opening line in this section say EBGs are PCs (and PBGs) and then just go ahead and use the nomenclature PC, interchangable with PBG thereafter. I also have research available on PCs that I can use for this section. Ti-30X ( talk) 10:20, 7 October 2009 (UTC)
I added a relevant image to this section. I felt that I had to make it 335 px in size so the words in the image are readable. It helps explain what the image is, besides the caption beneath the image. It seems to look OK. Ti-30X ( talk) 14:34, 8 October 2009 (UTC)
Because the Metamaterial article was going over 105 kilobytes, and becasue many subsections still need to be expanded I split Tunable metamaterials into a new article. There is still plenty of information and articles available on this topic. So, this will work out fine. Ti-30X ( talk) 15:15, 9 October 2009 (UTC)
I would like to add some information about the history of discovery, but was curtly reverted with comments that appear unrelated to the content of my edit: no names in the lead? or some such. Then move it, don't delete it. But, yes, it needed a reference, and I shouldn't expect everyone to know the key players by name, even if they are editing this article. I would like to insert a history of discovery section, dealing with the theoretical, first experimental result, different wavelengths.
Maybe editors could discuss problems, or bring problems to the talk page, after reversions. The article needs the history of the theoretical and then experimental discovery of metamaterials to be complete. -- 69.225.5.4 ( talk) 00:29, 11 October 2009 (UTC)
I have been wanting to a write a section like this, but it seems it will be a repeat of content that is already in the article in different places, including the other metamaterial articles. There are two sources that I intend to use for this. The general idea is to give a comprehensive overview of the progression toward the visible spectrum - which I don't think has been achieved. I say this because, I was reading something that seemed to say the visible blue-green capability was not repeatable (by other labs?). I will have to look into this and remove that section, if this is true. However, apparently one of the paramteters - desired permeability value(s) - has been achieved at blue-green frequencies, but negative refraction did not occur during this same experiment (demonstration).
I guess I can work on this section for awhile. If this seems redundant to you other editors please speak up, or go ahead make some edits in the section. One of the sources is referenced by citation 15 (this article is no longer referenced in Metamatrial. The sources are linked below) - and it is a good read by the way. I have to find the other article and I will note that here. Reference 16 is merely a web site, but it has a cited source and appears to be sponsored by the University of Sheffield, in England. Ti-30X ( talk) 18:26, 11 October 2009 (UTC)
Here is link to the first source: Optical negative-index metamaterials Ti-30X ( talk) 19:15, 11 October 2009 (UTC)
Here is the link for the second source: Perspectives on EM metamaterials
The statement "A recurrent issue with either naturally occurring, or conventional materials, is the lack of magnetic response." does not seem to be supported by its reference, which states that there is a magnetic resonance in an array of single nonmagnetic metallic split rings. It seems to me that a resonance is certainly a "response". In fact, the reference indicates that it is precisely this magnetic response that can create a negative index of refraction. David spector ( talk) 18:11, 14 October 2009 (UTC)
Google search results for "Novel Electromagnetic Materials Program" are zero, outside of wikipedia, so let's not perpetuate it to wiki mirrors. Why no hits? Because it's not the name of the program you are talking about. You can't just make up an acronym and assign it-well, you can and did, but that's OR and not part of wikipedia.
Don't return the statement about the program with the acronym you assigned it. And get its name correct. If the program is renamed in the future, feel free to use this. But, until then, use the real name, not a name and acronym of your choosing.
Notice the reference I used is referred to in the same way I and everyone refers to the paper, "Smith, Schultz et al." [3] Mine wasn't original research. OK, ask me to add a reference, but when I do, don't delete because you aren't familiar with the field.
This is a small complaint in light of the factual inaccuracy in the theoretical and technical aspects of this article, but, it's my bone. -- 69.225.5.183 ( talk) 19:23, 14 October 2009 (UTC)
I think the name changed to Novel Electromagnetic Media. http://people.ee.duke.edu/~drsmith/index.html YMMV. Rich Farmbrough, 04:31, 16 October 2009 (UTC).
The size of the "Metamaterial" article has nearly reached 104 kilobytes. Therefore I split the content of "Photonic metatmaterials" off to a new article entitled Photonic metamaterials.
In addition, I think it would be a good idea to somehow shrink the peliminary information in Seismic metamterials. I mean the general concepts such as S waves, P waves, Elasticity, etc., etc. Since this article could use the space, and since there are already good articles about these concepts, whittling this down, imho, is appropriate. Also, of course, I want to add more content about Seismic metamaterials.
I am wondering if it would be a good idea to move most of the material in the SRR section over to the SRR article. I would rather keep it in Metamaterial, but we could probably use the space.
I came across some research into a type of metamaterial that the army is working on, and I think this would certainly make a fine addition to the "Metamaterial" article. Ti-30X ( talk) 22:16, 15 October 2009 (UTC)
I restored the blurb about Novel Electromagnetic Materials without the "P". However, program is used in the section entitled "Current Programs and Overviews." There is also Programs, Collaborators, Funding, and "Research group" are all used on the top part of this page. Each section contains exciting work that is ongoing in metamaterials, in many organizations.
I never wrote "magnetism isn't a naturally occurring phenomenon" anywhere in this article. That would be ridiculous. This particular paragraph has been misunderstood. It is about "magnetic response". It is not about magnetism. I wrote "A recurrent issue with either naturally occurring, or conventional materials, is the lack of magnetic response. Such materials are particularly rare at Terahertz or optical frequencies. [1] However metamaterials are helping to fill this gap." I never wrote magnetism isn't a natural occuring phenomenon. A different meaning has been mistakenly read into this section. This happens all the time with people everywhere about anything. In any case, I can supply peer reviewed journal articles that reiterate what I wrote. It would not be in this article if I could not back it up. Ti-30X ( talk) 23:57, 15 October 2009 (UTC)
Not only is that not "basically what you wrote" it shows the problem with this article. You own the article and you won't allow others to correct your glaring errors.
Just because someone's page says the word "program" on it, does not mean that's part of the name of the research group, and doesn't make it the official acronym just because you made up an acronym.
Not even in quantum mechanics does none mean small. [6] You have dozens of problems of these types throughout the article. You're reading books and partially copying from them into this article without any understanding of what they say. Overall the information you've put in this article is factually inaccurate and internally inconsistent.
It took me a week to get you to stop fighting over your renaming of Smith's research group. Nothing, like the fact that wikipedia requires reliable secondary sources and none exists, could get you to see the reason the made up name you applied to the group isn't on the page or in any google searches or anywhere but on your page and copied from your article is that it isn't the name of the group.
Now we've learned from you that "magnetic response" has nothing to do with magnetism. [7] It is about "magnetic response". It is not about magnetism. See above.
There's no way anyone could spend two weeks for every physics error in this article while the article is being copied throughout cyberspace, and people are probably reading it, and its factual inaccuracy is not a concern to anyone, least of all its owner.
The article should be pared down to a stub, rewritten out of article space, and reposted when it has accurate physics.
Yes, no article is better than giving irresponsible made-up, and partially copied random pieces of information to the readers. Wikipedia has a responsibility for accuracy now that it dominates the search engine returns.
This is unbelievable. But, eventually the Essjays are all found out. He was at least embarrassed about it in the end.
When someone fights you for days to keep in a made-up acronym, and then returns that "lack of" is the same as "lack of large," and that "magnetic response" has nothing to do with magnetism, and is writing a wikipedia article that's being copied throughout cyberspace, it's time to stop AingGF and beyond time to start being concerned for the reader.
-- 69.225.5.183 ( talk) —Preceding undated comment added 15:53, 17 October 2009 (UTC).
Surprisingly, I haven't acutally found much more information than I have written for Seismic metamaterials. I could use the main peer reviewed article "Achieving control of in-plane elastic waves" and elaborate some of the articles that are numbered as references for the science involved. However, much more than this is really not available. I suspect it is because this is really new science. The last word that I have so far is this type of metamaterial is in the development stage. So, I can add more as more material becomes available. In the meantime this section is probably best merged with "Acoustic metamaterials", with a small summary left behind. Again, we can use the space. Thanks Ti-30X ( talk) 01:49, 19 October 2009 (UTC)
I recently split content from Metamaterial lens to the new article: Perfect lens. This will pretty much cover Metamaterial lenses up to the present, including microscopy. Steve Quinn (formerly Ti-30X) ( talk) 15:55, 1 November 2009 (UTC)
I couldn't find anything in wikipedia physics articles that acutally describe what an incident wave is. So here is a section with a brief, and simple description. Please feel free to add to it, or tighten it up if need be. Steve Quinn (formerly Ti-30X) ( talk) 01:28, 4 November 2009 (UTC)
I moved these two sections to the SRR article. It was the most available place at the moment. More than likely Nonlinear metamaterials will become an article, and the articles concerning controllable permeability might be moved to other articles. This merge allows "Metamaterial" to be a regular article once again. Other, future, metamaterial content can be linked to this article. Steve Quinn (formerly Ti-30X) ( talk) 04:58, 5 December 2009 (UTC)
I removed the section "Applications in paranormal research" as probable spam, and as suggested by - User:2over0. An appropriate suggestion imho. Steve Quinn (formerly Ti-30X) ( talk) 04:58, 5 December 2009 (UTC)
I appreciate good faith efforts. And the topic of the section where material was removed and then replaced by a blurb on Chiral metamaterials was apparently misunderstood. This section is not about only Chiral metamaterials. As a solution, I replaced the material, which is accurate, and created a section for Chiral metamaterials. In the future, please consult with the other editors involved with this article before removing material so we may achieve some kind of consensus. If this had been discussed first, the topic of the section would have been understood.
Having said, that please feel free to write an article on Chiral metamaterials. This is on my to do list, but, personally I don't know when I will write an article on Chiral metamaterials. Thanks again for the input, and knowledgable editors are always welcome. Steve Quinn (formerly Ti-30X) ( talk) 02:53, 23 December 2009 (UTC)
{{
cite journal}}
: Explicit use of et al. in: |first=
(
help)I am proposing to clean up negative index metamaterials, and move much of the negative index material to there. This includes the double and single negative stuff, which is a fairly in-depth distinction that is only relevant to negative index. However some negative index stuff should definitely still be left on this page, as it is one of the major areas of metamaterials work. ShiftyDave ( talk) 01:29, 25 December 2009 (UTC)
This page is now starting to look much better. However, the section titled "Incident Wave" seems very bizarre and unnecessary. Firstly, this term is used widely in microwaves/optics etc and is not specific to metamaterials. Secondly, this section is just duplicating material from Electromagnetic Spectrum. So I am proposing to delete it and add a link somewhere in the introductory paragraphs to Electromagnetic Spectrum. ShiftyDave ( talk) 23:55, 28 December 2009 (UTC)
I noticed that the continuum mechanics (CM) navbox ( Template:Continuum mechanics) was used on this article; but when I read the section it was used in, the connection / relationship to CM seemed pretty tenuous (I am a casual reader of this article only - maybe it would be obvious to experts). The section ( [8]) was the summary for Acoustic metamaterials. Normally, the navbox is used in a fairly prominent position in an article to set the broader context for the topic. It is unusual for it to be placed so far down in a relatively minor section within the broader article, and without explanation.
I think it is important both to make sure the navbox is well used and that the broader context for the article within CM is set.
Fluid mechanics might be a good example of how the navbox is typically used. (Note there is a section which specifically defines its relationship to CM, which is particularly helpful in that instance).
The navbox is also used in the acoustic metamaterials article, but again it isn't very prominent ( [9]) and the connection is only made in a vague way in another section ( [10]).
I was however kindly informed by user Steve Quinn that there is a definite relevance of continuum mechanics topics to (acoustic) metamaterials, and so to me as a new reader it seems important to set that context more explicitly. I also think consistency with other articles is sensible, where it makes sense.
So I had a few suggestions:
The same points should be considered for acoustic metamaterials.
Thoughts?
Thanks!
David Hollman ( Talk) 08:53, 24 August 2010 (UTC)
Strong critiques have been made in the literature on the subject of metamaterials. To this day, some of these critiques have not been answered, and a reader of this page might benefit from knowing that not everyone accepts the current views on metamaterials, and in particular on negative index.
Relevant resources include:
1- Vadim A. Markel, "Correct definition of the Poynting vector in electrically and magnetically polarizable medium reveals that negative refraction is impossible," Opt. Express 16, 19152-19168 (2008)
2- Benedikt A. Munk, "Metamaterials: Critique and Alternatives." —Preceding unsigned comment added by Baptiste.auguie ( talk • contribs) 16:55, 30 October 2010 (UTC)
Just to let those of you who edit this article, that a team at St. Andrews University in Scotland have developed Metamaterials on to fabrics. Before ths they were only found on flat hard surfaces. link here [ [11]]. Krásné nápady ( talk) 10:53, 4 November 2010 (UTC)
http://www.lockheedmartin.com/news/press_releases/2011/0215_ss_Metamaterials.html “We are extremely excited about the outcome of this collaboration, which represents a game change in the field of metamaterials,” said Werner. “In particular, we have succeeded in designing metamaterials that considerably improve conventional horn antennas by more than an octave bandwidth with negligible loss, and advanced the state-of-the-art in the process.”
Q; Speaking as a non-expert, is this superior to a corrugated horn by virtue of the metamaterial being thinner than corrugations? — Preceding unsigned comment added by 134.223.230.153 ( talk) 18:48, 9 September 2014 (UTC)
Taking a run at this. Feedback welcomed. Comments:
Cheers! Lfstevens ( talk) 04:58, 2 January 2014 (UTC)
Wikipedia is an online encyclopedia for the general public. That is why Wikipedia policy requires that, wherever possible, non-technical language be used in parallel with technical language in its articles (translating and clarifying as much as possible for the lay reader).
This is also good practice for scientists who need, for many reasons, to know how to communicate about their field to non-scientists.
It is also good manners not to communicate in a cryptic, self-absorbed way to people who are not scientists.
2602:306:BDA0:97A0:466D:57FF:FE90:AC45 ( talk) 16:07, 25 February 2014 (UTC)
I wonder if someone could say over what freq band the structure in the intro section exhibits negative index? Also, what's the difference between a metamaterial and a photonic crystal? — Preceding unsigned comment added by 134.223.230.153 ( talk) 18:26, 9 September 2014 (UTC)
I am afraid the (electromagnetic) metamaterial physics are much more complicated than the article implies. It should be substantially rewritten, or at least a warning about its approximate nature should be added! Please take a look on the related discussion under Talk:Negative_index_metamaterials - it applies to this article as well. -- FDominec ( talk) 18:07, 5 December 2014 (UTC)
I wondered if the research promulgated by Roderic Lakes (and appearing variously in Nature etc.. ) on designed materials and structure - some with emergent properties (and natural analogues too) should be included. The terminology is in terms of the cellular structure of materials but I feel that for thermal, mechanical and acoustic structures - and even extreme behaviours this is all very relevant.
Lakes, R. S., "Materials with structural hierarchy", Nature, 361, 511-515 (1993). Cover issue and Lakes, R. S., "Cellular solid structures with unbounded thermal expansion", Journal of Materials Science Letters, 15,475-477 (1996). http://silver.neep.wisc.edu/~lakes/lakescvbrief.html My own interest is how structured materials might best be made and, as lakes mentions, manufacturing (since the time of Eiffel) has been a major issue. — Preceding unsigned comment added by JulianSpence ( talk • contribs) 14:54, 14 May 2015 (UTC)
It would be a good idea to mention Auxetic metamaterials in the section on elastic materials. There are other types of metamaterials discussed elsewhere ( Mechanical_metamaterials), but this article on the whole seems to give an extremely high weight to negative-index materials (in all contexts) and almost no mention of other types. I was very surprised to not see Auxetics mentioned at all. — Preceding unsigned comment added by 198.144.208.23 ( talk) 19:01, 11 June 2015 (UTC)
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The comment(s) below were originally left at Talk:Metamaterial/Comments, and are posted here for posterity. Following several discussions in past years, these subpages are now deprecated. The comments may be irrelevant or outdated; if so, please feel free to remove this section.
The first metamaterials were developed by W.E. Kock in the late 1940's
Metal-lens antennas, IRE Proc., 34 November 1946, pp. 828-836 and Metallic delay lenses, Bell. Sys. Tech. Jour.,27, January 1948, pp. 58-82. The book Antennas Theory and Practice by Sergi A. Schelkunoff copyright 1952 by Bell Labs describes metal lens antennas in chapters 19.9 through 19.12. |
Last edited at 16:34, 29 March 2007 (UTC). Substituted at 23:46, 29 April 2016 (UTC)
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There is no single academic source which doesn't define metamaterials as only the 'optic metamaterials'. All existing literature I have encountered during my PhD on the topic would not use the term metamaterial to signify mechanical metamaterials. So if we follow the definitions that are commonly used in academia there shouldn't be an article which contains both optical metamaterials and mechanical metamaterials. Optical metamaterials are called "metamaterials" in academia, while the term mechanical metamaterials has been introduced to talk about non-optical aspects. It therefore makes sense forr the wikipedia article called "metamaterials" to only talk about electromagnetic phenomena.
However, in my honest opinion the term 'metamaterial' should never have been defined in the literature as only pertaining to optics. The fact that there is literature which discusses the concept of mechanical metamaterials presumes that the term 'metamaterials' isn't confined to optics only. One can logically deduce that the term 'metamaterial' should not be confined to optic metamaterials only.
The question is whether Wikipedia should define the term metamaterial in the logical way, or whether it should follow academia. Please discuss.
Like: electric-material, electromagnetic-material, optic-material, philosophy-material(materialism), add infimum...sorry forgot my password again... 75.82.19.242 ( talk) 19:19, 18 June 2022 (UTC)
The field of material is to well established and broad-in use everyday-for one article... ...Many Subjects in this field like: electric-material, electromagnetic-material, optic-material, philosophic-material(materialism), add infimum... 75.82.19.242 ( talk) 19:35, 18 June 2022 (UTC)
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The video showing refraction at at an air-metamaterial interface is highly enlightening. Is it an experimentally-acquired sequence of photographs, is it a plot of the numerical solution of Maxwell's equations, is it a plot of some approximate solution, or is it simply a cartoon painted up by a human artist? Whichever it is should be noted in the caption. 129.63.129.196 ( talk) 18:38, 18 October 2012 (UTC)
This article is a complete hotch-potch, and I think it would be completely useless for anyone who wanted to become familiar with this topic. By the look of things editors have been using this page to trumpet their own contributions to the field (which may or may not be relevant) rather than to provide a useful overview of the area. The problem is not helped by a lack of a good definition of a metamaterial - should it include the artificial dielectrics from the 1940's, left-handed tranmsission line media, and photonic crystals? ( No Worries 05:40, 25 September 2007 (UTC))
Is the diagram correct? It appears to contradict the later statement in the article "but rays are refracted away from the normal on entering the material" whereas the diagram has the rays being refracted closer to the normal, and more surprisingly, on the other side of the normal. If the diagram is wrong can someone delete it please.
Can/should we talk about superlenses here? Can someone at least answer some of the basic questions? Like do the concave/convex lenses work opposite from a regular lens?
Why is it that the only meta-material that is talked about is negative refractive index? Shouldn't that get its own page then?
Hi, I couldn't follow the connection between the 2nd and 3rd paragraphs. Could some one in the know edit this article and make these two paragraphs flow better ? Thanks -kg
The superlens created at Berkley did not have a negative index of refraction. All materials with a negative index of refraction are for microwave frequencies. See Superlens —This unsigned comment was added by 67.189.113.62 ( talk • contribs) on 03:04, 20 March 2006.
If it had a negative index of refraction for microwares, then it by defintion has a negative index of refrarction. I just does not have one for visible light, only microwave light. And don't make me explain how microwaves are light again.-- Scorpion451 02:46, 25 June 2007 (UTC)
It says that a 'C' ring with is axis in the propogation direction (I assume this means the ring is flat to oncoming radiation) would produce negative permeability. In fact, this only creates negative permitivitty. Negative permeability is created when propagation is in the plane of the ring and the B field then acts perpendicular to the loop. This is not possible if the axis of the ring is alined with the propogation vector of the light. See "Stefan Linden et. al., Magnetic Response of Metamaterials at 100 Terahertz, www.sciencemag.org, Vol 306, 19th Nov 2004, pg 1351-1353" for diagrams of permeability and permitivity with different orientations in respect to the incoming light.
Although it does say that "an induced current is created and the generated field is perpendicular to the magnetic field of the light. The magnetic resonance results in a negative permeability; the index is negative as well.", this is not magnetic resonsnace; the B field would have to be in the same direction of the normal of the loop (or have a component thereof) to create a current and then the induced field could not possibly be perpendicular to the driving field (just think Lenz's Law). If I'm missing something pleae feel free to enlighten me. —The preceding unsigned comment was added by 137.132.3.12 ( talk • contribs) on 07:48, 31 August 2006.
It's like a solenoid, the magnetic force is at a right angle to the current, but the looped shape distorts the field causing it to flow in the same direction as the current. The structure of the metamaterial sets up a similar situation, only it reverses the right hand rule, making it the left hand rule, and effectively making the induced field at a right angle to the driving field. Yes it's wierd, that's what makes metamaterials facinating. -- Scorpion451 02:50, 25 June 2007 (UTC)
According to the article "Unveiling the first invisibility shield" in Popular Science, light travels faster through a metamaterial than a vacuum. Was this a mistake? — Daniel 04:31, 21 September 2006 (UTC)
The phrase in the first line of the 2nd paragraph that reads "at least as small" is strange wording. Does that mean "at most as small"? In other words, as small or smaller? Please clarify. Unclepea 05:44, 20 October 2006 (UTC)
It means "as small as or smaller". "at most as small" would mean "as small as or larger". English doesn't make sense even if it is your first language.-- Scorpion451 02:58, 25 June 2007 (UTC)
Is the example at the end of the Nri paragraph correct?
"consider the following: a person submerged in a swimming pool filled with a hypothetical liquid with negative N would appear to float above the pool instead of appearing to be beneath the surface."
If the positive refraction index would make the submerged body look closer than it is, then the negative will make them appear "underneath" or even behind the view point.
I think you have the idea of the Plane and the Normal the wrong way around in this example. Otherwise it's been explained very well.
Daniel -- 80.195.237.107 22:18, 30 October 2006 (UTC)
I see that my example of the person in the swimming pool has been removed. It was from a Scientific American article, so I'm pretty sure it was right. Rotiro 11:02, 14 March 2007 (UTC)
The negative refractive index would indeed make the swimmer appear above the water, much like a concave mirror does, although by a different mechanism.-- Scorpion451 22:20, 26 June 2007 (UTC)
I'm still having trouble with the diagram showing negative refraction. My understanding, backed up by http://physicsworld.com/cws/article/news/2692 is that a positively refracting material bends light away from the normal, and a negatively refracting material bends light towards the normal. This diagram shows both materials bending the beam towards the normal, only that the negative material bends it so far that it goes past the normal. Either this is wrong, or the Wikipedia entry on "refraction" is wrong. ---posted by NobbyNobbs
Can somebody explain how Snell's Law holds for NRIs between minus one and zero?
If we take N1 to be 1 and Theta1 to be 45 degrees, then use a negative N2, say -0.2, then solving Sin(Theta2) = Sin(45) / (-0.2) = -3.53~ has no solutions for N2.
I ask because a metamaterial was recently produced with refractive index -0.6 for visible (780nm, red) light, and I'm still trying to figure out what it would 'look' like. The swimming pool discussions don't make much sense to me because, how on earth can something appear to be 'below me' when I'm standing on concrete. Wouldnt I just see concrete? 222.154.97.61 09:59, 19 December 2006 (UTC)
As for what it would look like, lay a mirror on the ground and look into it. The beams of light reflected from the mirror cover up the beams of light reflected from the concrete. It's hard to explain the way the equations apply to the wierd properties of metamaterials, because they violate fundamental assumptions of the equations. It's one of those cases of the equations say the data is wrong, but the universe says that the data is right. I'm leaning toward the universe. -- Scorpion451 03:07, 25 June 2007 (UTC)
When light moves from a dense to a less dense medium, such as from water to air, Snell's law cannot be used to calculate the refracted angle when the resolved sine value is higher than 1. At this point, light is reflected in the incident medium, known as internal reflection.
http://www.newscientisttech.com/article/dn10816.html 195.210.210.217 12:39, 19 December 2006 (UTC)
In the subsection "Negative refractive index", there's a list of some cool properties of metamaterials with negative n. The last point in the list is: "Higher frequencies have longer, not shorter, wavelengths in such a material ". I've added a citation needed flag to this, as I haven't encountered it in the literature on this topic, and I have the feeling it might be incorrect. (It runs contrary to the definition of frequency, which is phase velocity/wavelength.)
Can anyone find the proper reference for this fact? (Otherwise, I think it should be deleted as a precaution...) GameGod 02:26, 2 January 2007 (UTC)
18.95.7.45 20:58, 7 January 2007 (UTC) Matthieu
I'm not certain but I belive that the above fact is correct, even though it violates the C=F/W rule. I think this is due to the negative refraction index causing the particle to slow down. To put it this way, if C(phase speed)=1(just for simplicity), then in the metamaterial if it moved at half the speed it would be 1/2=F/W. If frequency is unchanged, then wavelength must double. Does this make sense? I can put it a little more clearly, I think.-- Scorpion451 03:04, 25 June 2007 (UTC)
I looked more into this. You are correct that the wavelength expands when frequency decreases and vice versa. The material, however, is not metamaterial. The expanded wavelength at slower speed is seen in materials with extremely high N, such as [[Bose Einstein condensates]. See the Slow Light article.-- Scorpion451 02:18, 8 July 2007 (UTC)
In the opening paragraph this sentence exists: "Such unusual properties could be a negative refractive index or infinite inertia (which are not found in naturally occurring materials)."
I've gotta say, "infinite inertia" sounds like dubious science to me - generally there's not much in science that is "infinite" and if some object possessed /infinite/ inertia then either its mass or velocity was infinite, both impossible AIUI.
There's no further mention of inertia in the article, nor here on the discussion and google didn't produce anything significant regarding this phrase ... so is this "infinite inertia" just buzzwordiness ... or outright nonsense or vandalism or ...???
Anyway, just a heads up about this fishy sounding phrase ... and thanks to all who contribute and edit to wikipedia!
-- wikifreeman 21:44, 17 October 2007 (UTC)
Also the statement that the doppler effect would be reversed is just hogwash. The doppler effect is a physical interaction between a signal moving through space and a receiver of that signal. A signal can only be expanded if the receiver is moving away from it, and can only be contracted if the reciever is moving towards it. The doppler effect is not effected any properties of the signal generator. Once a signal is moving through space, the doppler effect can only possibly work that way. Why is this article linked in "see also" from a real scientific article like "einstein-rosen-podolsky_bridge ? —Preceding unsigned comment added by 24.2.124.58 ( talk) 14:05, 28 September 2008 (UTC)
Agree about the BS Doppler claim as it violates special & general relativity, and conservation of energy. I tried asking for "proof" of this claim, but some idiot admin person yelled at me for "vandalizing the site." I like WIki, but if the admin censors trump scientific integrity, then this site is nothing more than a blog for some IT wannabe. — Preceding unsigned comment added by 72.66.109.243 ( talk) 02:55, 28 January 2012 (UTC)
Scorpion451, your Doppler counter-argument doesn't make any sense because the basic premise of the relativistic Doppler effect & gravitational red/blue shift resides with time dilation, which has nothing to do with materials (positive or negative index of refractions). However, I will be happy to eat my own words if you can cite peer reviewed/credible journal articles that prove me wrong. Until then, that bullet should be deleted from the article because it's unsupported. — Preceding unsigned comment added by 72.66.109.243 ( talk) 03:06, 28 January 2012 (UTC)
I am no expert in this field, but there does not appear to be any mention of the developments at Los Alamos National Laboratory by Hou-Tong Chen, Richard Averitt, Willie Padilla and others, which resulted in the fabrication of a controllable device. I would have thought this is very significant for the future use of metamaterials. http://www.lanl.gov/news/index.php/fuseaction/home.story/story_id/9935
parellic —Preceding unsigned comment added by Parellic ( talk • contribs) 17:52, 2 March 2008 (UTC)
I'm just an internet-educated dropout trying to make himself feel less stupid. If this is a stupid question, just delete it and I'll go away.
The page states that "A metamaterial (or meta material) is a material which gains its properties from its structure rather than directly from its composition." How are metamaterials different from allotropes? For example, graphite and diamond are both academically pure carbon, yet are literally as different as black and white. Diamond is one of the hardest materials in nature, but graphite rubs off on a sheet of paper. Graphite conducts electricity, diamond doesn’t. Could you say that metamaterials are allotropes that do not normally exist in nature? Or compounds with structures that do not normally exist in nature?
It is not for us to define them. We should cite a reliable source's definition. Lfstevens ( talk) 23:01, 25 April 2015 (UTC)
I'm new to this, but under External Links | Research groups (in order of importance), the number one spot is occupied by a site which appears to have nothing to do with Metamaterials. Maybe someone can correct this? 72.90.243.147 ( talk) 16:08, 5 April 2008 (UTC)
Yes, I agree. This appears to be vandalism. I have been going over the history of this page. There are a lot of changes by more than one anonymous IP address and so it is a little difficult to determine what is valid and what is not. From reading the "Oscar" dude's website, I do not believe he has anything to do with metamaterials. I am going to send him an email asking if he does. I am not sure if this "Oscar" guy is the source of the changes or not. He may not be aware of these edits at all. Anyway which way, the research groups should be listed alphabetically. The-tenth-zdog ( talk) 06:38, 6 April 2008 (UTC)
This entire article is hard for someone not already familiar with its concepts to understand. Although it has the virtue of having good spelling and of being grammatical, it could benefit from a complete rewrite due to its confusing and overly terse content and style. The final paragraph is particularly infelicitous. It and many others could also benefit from the addition of line drawings or other diagrams.
An example of an article of similar speciality and difficulty that is nevertheless easier for a nonspecialist to understand, due to its clear writing and its use of diagrams, is Block cipher modes of operation.
While it is certainly useful for an encyclopedia article to be accessible only by specialists in its field, it is even more useful if each article were understandable by a much wider audience. Then, besides being informative, the encyclopedia might also be tutorial, which greatly enhances its usefulness to society. David ( talk) 14:13, 16 August 2008 (UTC)
I have merged the section Metamaterial research from the article Cloaking device into the section Development and applications. I also split the section "Development and applications" into subsections to present the ideas in a more organized fashion. Please centralize discussion regarding this merge on this talk page, and feel free to change anything I merged. — OranL ( talk) 04:06, 21 August 2008 (UTC)
You're doing great job expanding that article. Just a bit of advice: (i) please check for duplicate references and replace them using <ref name=xxx> and then <ref name=xxx/> tags; (ii) please format references using {{cite journal}}, {{cite book}} , etc., templates; (iii) please avoid personal phrases ("Author X observed ..." in favor of "... was observed in"). Best wishes. Materialscientist ( talk) 01:45, 1 June 2009 (UTC)
I fixed the requested citation tag for Reference number 8. I also added the illustration (or whatever you call it). Ti-30X ( talk) 14:09, 7 June 2009 (UTC)
Editors of this article may be interested in the new article Negative index metamaterials and the discussion on its talk page. Note that the article really focuses on stealth applications, and there is a discussion in progress on whether to retitle the article, or to broaden its focus to cover negative index materials more broadly. There is some overlap with this article; some shuffling of material between the two articles may be beneficial.-- Srleffler ( talk) 19:18, 8 August 2009 (UTC)
The negative index metamaterial essay-like article has recently appeared has enormous overlap with this article, in a way that makes it completely synonymous with this one. This is the Wikipedia, an encyclopedia, which is where synonymous material is collected into one article.
The invisibility/cloaking discussion is covered in both places, as is the discussion of negative refractive index, and the lead of negative index metamaterial suggest that it covers all uses of negative index metamaterials; but almost the whole of this article covers that.
Unless a clear distinction can be made between these two articles or a clear subarticle relationship can be established then these two articles need to be merged.- ( User) Wolfkeeper ( Talk) 14:43, 16 August 2009 (UTC)
Understand but Strongly oppose and suggest focusing on writing and improving the articles rather than talking about that and moving articles forth and back. That metamaterials is in a poor state is an issue which is again to be fixed by editing that article rather than putting other material in its place. Today we move negative index metamaterials (NIM) article into metamaterials (only because it is better developed) and tomorrow say "whoops the article is too large, we should split it up". The way I see is to develop metamaterials in the general way, mentioning NIM, but also covering other directions. This topic has intrinsic tendency to grow, and the small current size is no argument to me. That metamaterials article needs cleanup I agree entirely, just couldn't find time for that. Materialscientist ( talk) 22:35, 16 August 2009 (UTC)
There is now a new section entitled "The six spokes of expanded metamaterial research." Please do not remove, move, or delete this section. One or two other editors and I will be editing the section, and hopefully use it as a base to expand the Metamaterial article. This gives a lot of basic information to start with. Thank you for your cooperation. Ti-30X ( talk) 18:21, 17 August 2009 (UTC)
I am thinking that the paragraphs in the introduction, beginning with "With a negative refractive index researchers have been able to create a device..." probably need to be thrown out. ( I am the previous author of these paragrpahs, too.) Just from my peliminary work on the other section and reading some new information, I can see that this is too narrow a definition. Metamaterials now have broader applications, if they didn't before. Come to think of it, it may be tough to pack all the new available information into one article. Also, I think this statement will have to be removed sooner rather than later: "Electromagnetics researchers often use the term metamaterials more narrowly, for materials which exhibit negative refraction". Again, this is too narrow a focus with the current information available. So if no one objects I will be removing these from the article, soon, to make room for a better introduction. Thanks. As usual this is open to discussion. Ti-30X ( talk) 19:46, 17 August 2009 (UTC)
Regarding the recent reference warring, per WP:RS in the context of science articles, I'd strongly suggest sticking to textbooks and peer-reviewed journal articles where possible. These definitely exist, and I'm pretty sure most of the parties involved have access to relevant online journal databases through your respective universities.
That, and the "electromagnetic vs. non-" dispute seems a bit like a mountain/molehill scenario to me. Why not just hedge and say that the term is usually used to refer to materials with strange electromagnetic properties? There's certainly a mountain of literature to support the claim that this is a very widespread use of the term. -- Christopher Thomas ( talk) 01:13, 20 August 2009 (UTC)
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help)To Wolfkeeper. (i) Please take it easy. Your criticism is more than appreciated, but slapping a newcomer on every mistake is not constructive. There could be a valid comment why are you bashing an active writer whereas there are thousands of abandoned articles with graver problems around. (ii) I think everybody would only welcome your writing (not only deletion) on this topic, including this article. (iii) I respect your opinion on the lead, but please understand that mine is simply an observation over many hundreds of WP articles on physics and materials science - they do not have a proper lead at all. (iv) Please appreciate different writing habits. Some people keep the story in the head and only when shaped, put it on paper. Very efficient and quick. That said, most guides on scientific writing advise to put up the abstract only after the whole text is finished, which I understand and respect too. (v) Just read your comment above. This is non-issue. Please propose your vision on defining metamaterials, with references. Materialscientist ( talk) 22:45, 20 August 2009 (UTC)
Chirality and bi-isotropic media: This section is currently being developed. Thanks Ti-30X ( talk) 14:24, 21 August 2009 (UTC)
Acoustic metamaterials is currently being development Ti-30X ( talk) 18:40, 24 August 2009 (UTC)
Based on the amount of material we seem to be able to access about metamaterials, we may want to dispense with the section entitled "Groups engaged in metamaterial research". Anybody agree with this? Ti-30X ( talk) 22:20, 24 August 2009 (UTC)
I know the section on Split ring cylinders has been sitting there for awhile. I was going through other material before I got to it. This section is still not finished. Ti-30X ( talk) 05:34, 31 August 2009 (UTC)
There are two separate section regarding negative index, Negative Refractive Index and Double Negative Metamaterials. One or the other should not exist since they're redundant and both refer the user to the negative index metamaterials page anyhow. 20:03, 15 March 2010 (UTC) —Preceding unsigned comment added by 152.3.196.93 ( talk)
I won't be doing anymore with acoustic metamaterials. I prefer research on other metamaterial types (probably EM). There may more that can be done with acoustic metamaterials if someone else wants to work on that area. Sorry. As much as I try the interest is just not there. Ti-30X ( talk) 21:05, 8 September 2009 (UTC)
I have been coming across this term a lot - the “THz gap”. No, it's not about capacitance. It appears to be partly about infrastructure that is not available to deliver Thz radiation which will advance our technologies or capablities in society. This includes a compact source that is proportional to the desired application.
"Many materials inherently do not respond to THz radiation and thus the tools necessary to construct devices operating within this range - sources, lenses, switches, modulators, detectors largely do not exist. Considerable efforts are underway to fill this “THz gap” in view of the wellknown potential applications using THz radiation." That is from one short article that I read regarding Thz-metamaterials. Objectives for Thz-metamaterials are
The above would be what I consider to be some of the infrastructure needed. Below, are some of the applications after the delivery systems are developed:
An intersting device that was mentioned briefly twice and in one journal article is the Quantum Cascade Laser as a Terahertz Local Oscillator . It said, "Although QCLs have been available at near infrared wavelengths for more than 10 years, the first THz QCL (at 4.4 THz) was only produced 2 years ago." This is being developed as a compact source to deliver Thz radiation. One article said these devices are the size of a baseball, which is pretty small. I am trying to find the article again, but that one said something about a source like this with previous laser technology would have to be huge - like the size of a house or something like that.
I am seeing that the research with metamterials is really important right now. I'll leave you all with another quote - "The design flexibility associated with metamaterials provides a promising approach — from a device perspective — towards filling this gap." These quotes are from the labratories (like Los Alamos). Ti-30X ( talk) 05:07, 14 September 2009 (UTC)
If no one objects I would like to do a whole article on THZ metamaterials. There appears to be enough material. In this way we could comfortably expand or expound on other categories. I will begin on a sub page using most of what is in this article on THz MM's to start with. And if there are then no objections I can move it out to Wikipedia. By the way, this will be straight science. It will be simply THz Metamaterials. I will see if I can add material to the Split-ring resonator article without taking away from the effectiveness of this article. Ti-30X ( talk) 15:07, 16 September 2009 (UTC)
I want to move this here for reference purposes. I will keep the first paragraph in the article because I think it is worth having the information in the article. I think it is noteable enough. Ti-30X ( talk) 15:15, 16 September 2009 (UTC)
The number of groups studying metamaterials is continuously increasing. For example, Duke University has initiated a Novel Electromagnetic Materials Program (NEMP) and became a leading metamaterials research center. The center is a part of an international team, which also includes California Institute of Technology, Harvard University, UCLA, Max Planck Institute of Germany, and the FOM Institute of the Netherlands. [1] In addition, there are currently six groups connected to this hub, which are conducting intense metamaterial research: [1]
References
I have found two references in the reference section that are incorrect, so far. These are references that I added for citations. They were correct when I entered them with the templates. Somehow they have been changed where they both have the wrong authors, and a PMID number that goes to an article entitled "Association of cytokine gene polymorphisms and liver fibrosis in chronic hepatitis B". The DOI numbers are correct (were correct?). I simply deleted and re-entered one reference with the correct information (see revision history).
Actually, it is a better reference than the first one. However, I would like this situation corrected. There is no reason to add a PMID number, especially if it is inaccurate, and especially if we end up with the wrong authors. Who knows what else was incorrect. Please don't add PMID numbers if the reference doesn't already have one. Any reference that didn't have one in the first place, is because the DOI led directly to the cite of the journal that published the article. I do supply a link to the PDF when I can. In any case a PMID number is not needed and changing the authors names is not in any way helpful. If someone is in doubt about a reference then address it here on this talk page, or on my talk page. Please, do not blantantly change information in the references. Of course, now, this just occured to me that this could be a case of vandalism. Ti-30X ( talk) 23:46, 22 September 2009 (UTC)
I am guessing this was just a good faith error. So, if adding a PMID number makes life easier for the reader or other interested party, then why not - go ahead. It is a good place to find journal articles. Stuff happens, and I am certainly not perfect. I apologize if I came across a little upset. This really isn't a big deal, because I doubt it was intentional. Ti-30X ( talk) 22:14, 23 September 2009 (UTC)
If no one objects, I think we could do a whole article on Metamaterial antennas. Of course we would have a summation in this article and a link to the "main" article. I have just barely scratched the surface with the material that is available in this area. The same is true for Terhertz metamaterials. There are also other categories that we haven't looked at yet. Also, I would like to add more to seismic metamaterials.
In any case, this has been really good. We have included many types of metamaterials, and created a much better article. Kudos, to Wolfkeeper for writing a great introduction which provides a focus (for me) for this article. There is so much material out there on metamaterials - it is amazing. Ti-30X ( talk) 03:07, 24 September 2009 (UTC)
I am thinking that it is best to go ahead and create a split for Acoustic metamaterials. This will give us more room in this article to expand into other areas, and this will give us more space to expand Acoustic metamaterials. Hopefully, no one objects. Here is the new article: Acoustic metamaterials Ti-30X ( talk) 04:01, 26 September 2009 (UTC)
There isn't much on metamaterials related to Avionics or Aerospace that I am able to find. So I am going to remove this as a section header. I will change it to "Tuneable metamaterials". And these are different because with previous NIMs discussed - in order to m get a negative refractive index (to operate at a different frequency) the periodicity and size of the elements would have to be changed. These type of "Tuneable metamaterials" appear to be tuneable in hand, so to speak. Ti-30X ( talk) 02:31, 1 October 2009 (UTC)
I am exapanding this section at the moment. I will be fleshing out the other sections that I have introduced these past few days. Apparently EBG's are photonic crystals (PC) and are also referred to as (PBG). I didn't realize this, and only noticed a similarity previously. I am thinking I will keep the opening line in this section say EBGs are PCs (and PBGs) and then just go ahead and use the nomenclature PC, interchangable with PBG thereafter. I also have research available on PCs that I can use for this section. Ti-30X ( talk) 10:20, 7 October 2009 (UTC)
I added a relevant image to this section. I felt that I had to make it 335 px in size so the words in the image are readable. It helps explain what the image is, besides the caption beneath the image. It seems to look OK. Ti-30X ( talk) 14:34, 8 October 2009 (UTC)
Because the Metamaterial article was going over 105 kilobytes, and becasue many subsections still need to be expanded I split Tunable metamaterials into a new article. There is still plenty of information and articles available on this topic. So, this will work out fine. Ti-30X ( talk) 15:15, 9 October 2009 (UTC)
I would like to add some information about the history of discovery, but was curtly reverted with comments that appear unrelated to the content of my edit: no names in the lead? or some such. Then move it, don't delete it. But, yes, it needed a reference, and I shouldn't expect everyone to know the key players by name, even if they are editing this article. I would like to insert a history of discovery section, dealing with the theoretical, first experimental result, different wavelengths.
Maybe editors could discuss problems, or bring problems to the talk page, after reversions. The article needs the history of the theoretical and then experimental discovery of metamaterials to be complete. -- 69.225.5.4 ( talk) 00:29, 11 October 2009 (UTC)
I have been wanting to a write a section like this, but it seems it will be a repeat of content that is already in the article in different places, including the other metamaterial articles. There are two sources that I intend to use for this. The general idea is to give a comprehensive overview of the progression toward the visible spectrum - which I don't think has been achieved. I say this because, I was reading something that seemed to say the visible blue-green capability was not repeatable (by other labs?). I will have to look into this and remove that section, if this is true. However, apparently one of the paramteters - desired permeability value(s) - has been achieved at blue-green frequencies, but negative refraction did not occur during this same experiment (demonstration).
I guess I can work on this section for awhile. If this seems redundant to you other editors please speak up, or go ahead make some edits in the section. One of the sources is referenced by citation 15 (this article is no longer referenced in Metamatrial. The sources are linked below) - and it is a good read by the way. I have to find the other article and I will note that here. Reference 16 is merely a web site, but it has a cited source and appears to be sponsored by the University of Sheffield, in England. Ti-30X ( talk) 18:26, 11 October 2009 (UTC)
Here is link to the first source: Optical negative-index metamaterials Ti-30X ( talk) 19:15, 11 October 2009 (UTC)
Here is the link for the second source: Perspectives on EM metamaterials
The statement "A recurrent issue with either naturally occurring, or conventional materials, is the lack of magnetic response." does not seem to be supported by its reference, which states that there is a magnetic resonance in an array of single nonmagnetic metallic split rings. It seems to me that a resonance is certainly a "response". In fact, the reference indicates that it is precisely this magnetic response that can create a negative index of refraction. David spector ( talk) 18:11, 14 October 2009 (UTC)
Google search results for "Novel Electromagnetic Materials Program" are zero, outside of wikipedia, so let's not perpetuate it to wiki mirrors. Why no hits? Because it's not the name of the program you are talking about. You can't just make up an acronym and assign it-well, you can and did, but that's OR and not part of wikipedia.
Don't return the statement about the program with the acronym you assigned it. And get its name correct. If the program is renamed in the future, feel free to use this. But, until then, use the real name, not a name and acronym of your choosing.
Notice the reference I used is referred to in the same way I and everyone refers to the paper, "Smith, Schultz et al." [3] Mine wasn't original research. OK, ask me to add a reference, but when I do, don't delete because you aren't familiar with the field.
This is a small complaint in light of the factual inaccuracy in the theoretical and technical aspects of this article, but, it's my bone. -- 69.225.5.183 ( talk) 19:23, 14 October 2009 (UTC)
I think the name changed to Novel Electromagnetic Media. http://people.ee.duke.edu/~drsmith/index.html YMMV. Rich Farmbrough, 04:31, 16 October 2009 (UTC).
The size of the "Metamaterial" article has nearly reached 104 kilobytes. Therefore I split the content of "Photonic metatmaterials" off to a new article entitled Photonic metamaterials.
In addition, I think it would be a good idea to somehow shrink the peliminary information in Seismic metamterials. I mean the general concepts such as S waves, P waves, Elasticity, etc., etc. Since this article could use the space, and since there are already good articles about these concepts, whittling this down, imho, is appropriate. Also, of course, I want to add more content about Seismic metamaterials.
I am wondering if it would be a good idea to move most of the material in the SRR section over to the SRR article. I would rather keep it in Metamaterial, but we could probably use the space.
I came across some research into a type of metamaterial that the army is working on, and I think this would certainly make a fine addition to the "Metamaterial" article. Ti-30X ( talk) 22:16, 15 October 2009 (UTC)
I restored the blurb about Novel Electromagnetic Materials without the "P". However, program is used in the section entitled "Current Programs and Overviews." There is also Programs, Collaborators, Funding, and "Research group" are all used on the top part of this page. Each section contains exciting work that is ongoing in metamaterials, in many organizations.
I never wrote "magnetism isn't a naturally occurring phenomenon" anywhere in this article. That would be ridiculous. This particular paragraph has been misunderstood. It is about "magnetic response". It is not about magnetism. I wrote "A recurrent issue with either naturally occurring, or conventional materials, is the lack of magnetic response. Such materials are particularly rare at Terahertz or optical frequencies. [1] However metamaterials are helping to fill this gap." I never wrote magnetism isn't a natural occuring phenomenon. A different meaning has been mistakenly read into this section. This happens all the time with people everywhere about anything. In any case, I can supply peer reviewed journal articles that reiterate what I wrote. It would not be in this article if I could not back it up. Ti-30X ( talk) 23:57, 15 October 2009 (UTC)
Not only is that not "basically what you wrote" it shows the problem with this article. You own the article and you won't allow others to correct your glaring errors.
Just because someone's page says the word "program" on it, does not mean that's part of the name of the research group, and doesn't make it the official acronym just because you made up an acronym.
Not even in quantum mechanics does none mean small. [6] You have dozens of problems of these types throughout the article. You're reading books and partially copying from them into this article without any understanding of what they say. Overall the information you've put in this article is factually inaccurate and internally inconsistent.
It took me a week to get you to stop fighting over your renaming of Smith's research group. Nothing, like the fact that wikipedia requires reliable secondary sources and none exists, could get you to see the reason the made up name you applied to the group isn't on the page or in any google searches or anywhere but on your page and copied from your article is that it isn't the name of the group.
Now we've learned from you that "magnetic response" has nothing to do with magnetism. [7] It is about "magnetic response". It is not about magnetism. See above.
There's no way anyone could spend two weeks for every physics error in this article while the article is being copied throughout cyberspace, and people are probably reading it, and its factual inaccuracy is not a concern to anyone, least of all its owner.
The article should be pared down to a stub, rewritten out of article space, and reposted when it has accurate physics.
Yes, no article is better than giving irresponsible made-up, and partially copied random pieces of information to the readers. Wikipedia has a responsibility for accuracy now that it dominates the search engine returns.
This is unbelievable. But, eventually the Essjays are all found out. He was at least embarrassed about it in the end.
When someone fights you for days to keep in a made-up acronym, and then returns that "lack of" is the same as "lack of large," and that "magnetic response" has nothing to do with magnetism, and is writing a wikipedia article that's being copied throughout cyberspace, it's time to stop AingGF and beyond time to start being concerned for the reader.
-- 69.225.5.183 ( talk) —Preceding undated comment added 15:53, 17 October 2009 (UTC).
Surprisingly, I haven't acutally found much more information than I have written for Seismic metamaterials. I could use the main peer reviewed article "Achieving control of in-plane elastic waves" and elaborate some of the articles that are numbered as references for the science involved. However, much more than this is really not available. I suspect it is because this is really new science. The last word that I have so far is this type of metamaterial is in the development stage. So, I can add more as more material becomes available. In the meantime this section is probably best merged with "Acoustic metamaterials", with a small summary left behind. Again, we can use the space. Thanks Ti-30X ( talk) 01:49, 19 October 2009 (UTC)
I recently split content from Metamaterial lens to the new article: Perfect lens. This will pretty much cover Metamaterial lenses up to the present, including microscopy. Steve Quinn (formerly Ti-30X) ( talk) 15:55, 1 November 2009 (UTC)
I couldn't find anything in wikipedia physics articles that acutally describe what an incident wave is. So here is a section with a brief, and simple description. Please feel free to add to it, or tighten it up if need be. Steve Quinn (formerly Ti-30X) ( talk) 01:28, 4 November 2009 (UTC)
I moved these two sections to the SRR article. It was the most available place at the moment. More than likely Nonlinear metamaterials will become an article, and the articles concerning controllable permeability might be moved to other articles. This merge allows "Metamaterial" to be a regular article once again. Other, future, metamaterial content can be linked to this article. Steve Quinn (formerly Ti-30X) ( talk) 04:58, 5 December 2009 (UTC)
I removed the section "Applications in paranormal research" as probable spam, and as suggested by - User:2over0. An appropriate suggestion imho. Steve Quinn (formerly Ti-30X) ( talk) 04:58, 5 December 2009 (UTC)
I appreciate good faith efforts. And the topic of the section where material was removed and then replaced by a blurb on Chiral metamaterials was apparently misunderstood. This section is not about only Chiral metamaterials. As a solution, I replaced the material, which is accurate, and created a section for Chiral metamaterials. In the future, please consult with the other editors involved with this article before removing material so we may achieve some kind of consensus. If this had been discussed first, the topic of the section would have been understood.
Having said, that please feel free to write an article on Chiral metamaterials. This is on my to do list, but, personally I don't know when I will write an article on Chiral metamaterials. Thanks again for the input, and knowledgable editors are always welcome. Steve Quinn (formerly Ti-30X) ( talk) 02:53, 23 December 2009 (UTC)
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help)I am proposing to clean up negative index metamaterials, and move much of the negative index material to there. This includes the double and single negative stuff, which is a fairly in-depth distinction that is only relevant to negative index. However some negative index stuff should definitely still be left on this page, as it is one of the major areas of metamaterials work. ShiftyDave ( talk) 01:29, 25 December 2009 (UTC)
This page is now starting to look much better. However, the section titled "Incident Wave" seems very bizarre and unnecessary. Firstly, this term is used widely in microwaves/optics etc and is not specific to metamaterials. Secondly, this section is just duplicating material from Electromagnetic Spectrum. So I am proposing to delete it and add a link somewhere in the introductory paragraphs to Electromagnetic Spectrum. ShiftyDave ( talk) 23:55, 28 December 2009 (UTC)
I noticed that the continuum mechanics (CM) navbox ( Template:Continuum mechanics) was used on this article; but when I read the section it was used in, the connection / relationship to CM seemed pretty tenuous (I am a casual reader of this article only - maybe it would be obvious to experts). The section ( [8]) was the summary for Acoustic metamaterials. Normally, the navbox is used in a fairly prominent position in an article to set the broader context for the topic. It is unusual for it to be placed so far down in a relatively minor section within the broader article, and without explanation.
I think it is important both to make sure the navbox is well used and that the broader context for the article within CM is set.
Fluid mechanics might be a good example of how the navbox is typically used. (Note there is a section which specifically defines its relationship to CM, which is particularly helpful in that instance).
The navbox is also used in the acoustic metamaterials article, but again it isn't very prominent ( [9]) and the connection is only made in a vague way in another section ( [10]).
I was however kindly informed by user Steve Quinn that there is a definite relevance of continuum mechanics topics to (acoustic) metamaterials, and so to me as a new reader it seems important to set that context more explicitly. I also think consistency with other articles is sensible, where it makes sense.
So I had a few suggestions:
The same points should be considered for acoustic metamaterials.
Thoughts?
Thanks!
David Hollman ( Talk) 08:53, 24 August 2010 (UTC)
Strong critiques have been made in the literature on the subject of metamaterials. To this day, some of these critiques have not been answered, and a reader of this page might benefit from knowing that not everyone accepts the current views on metamaterials, and in particular on negative index.
Relevant resources include:
1- Vadim A. Markel, "Correct definition of the Poynting vector in electrically and magnetically polarizable medium reveals that negative refraction is impossible," Opt. Express 16, 19152-19168 (2008)
2- Benedikt A. Munk, "Metamaterials: Critique and Alternatives." —Preceding unsigned comment added by Baptiste.auguie ( talk • contribs) 16:55, 30 October 2010 (UTC)
Just to let those of you who edit this article, that a team at St. Andrews University in Scotland have developed Metamaterials on to fabrics. Before ths they were only found on flat hard surfaces. link here [ [11]]. Krásné nápady ( talk) 10:53, 4 November 2010 (UTC)
http://www.lockheedmartin.com/news/press_releases/2011/0215_ss_Metamaterials.html “We are extremely excited about the outcome of this collaboration, which represents a game change in the field of metamaterials,” said Werner. “In particular, we have succeeded in designing metamaterials that considerably improve conventional horn antennas by more than an octave bandwidth with negligible loss, and advanced the state-of-the-art in the process.”
Q; Speaking as a non-expert, is this superior to a corrugated horn by virtue of the metamaterial being thinner than corrugations? — Preceding unsigned comment added by 134.223.230.153 ( talk) 18:48, 9 September 2014 (UTC)
Taking a run at this. Feedback welcomed. Comments:
Cheers! Lfstevens ( talk) 04:58, 2 January 2014 (UTC)
Wikipedia is an online encyclopedia for the general public. That is why Wikipedia policy requires that, wherever possible, non-technical language be used in parallel with technical language in its articles (translating and clarifying as much as possible for the lay reader).
This is also good practice for scientists who need, for many reasons, to know how to communicate about their field to non-scientists.
It is also good manners not to communicate in a cryptic, self-absorbed way to people who are not scientists.
2602:306:BDA0:97A0:466D:57FF:FE90:AC45 ( talk) 16:07, 25 February 2014 (UTC)
I wonder if someone could say over what freq band the structure in the intro section exhibits negative index? Also, what's the difference between a metamaterial and a photonic crystal? — Preceding unsigned comment added by 134.223.230.153 ( talk) 18:26, 9 September 2014 (UTC)
I am afraid the (electromagnetic) metamaterial physics are much more complicated than the article implies. It should be substantially rewritten, or at least a warning about its approximate nature should be added! Please take a look on the related discussion under Talk:Negative_index_metamaterials - it applies to this article as well. -- FDominec ( talk) 18:07, 5 December 2014 (UTC)
I wondered if the research promulgated by Roderic Lakes (and appearing variously in Nature etc.. ) on designed materials and structure - some with emergent properties (and natural analogues too) should be included. The terminology is in terms of the cellular structure of materials but I feel that for thermal, mechanical and acoustic structures - and even extreme behaviours this is all very relevant.
Lakes, R. S., "Materials with structural hierarchy", Nature, 361, 511-515 (1993). Cover issue and Lakes, R. S., "Cellular solid structures with unbounded thermal expansion", Journal of Materials Science Letters, 15,475-477 (1996). http://silver.neep.wisc.edu/~lakes/lakescvbrief.html My own interest is how structured materials might best be made and, as lakes mentions, manufacturing (since the time of Eiffel) has been a major issue. — Preceding unsigned comment added by JulianSpence ( talk • contribs) 14:54, 14 May 2015 (UTC)
It would be a good idea to mention Auxetic metamaterials in the section on elastic materials. There are other types of metamaterials discussed elsewhere ( Mechanical_metamaterials), but this article on the whole seems to give an extremely high weight to negative-index materials (in all contexts) and almost no mention of other types. I was very surprised to not see Auxetics mentioned at all. — Preceding unsigned comment added by 198.144.208.23 ( talk) 19:01, 11 June 2015 (UTC)
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The first metamaterials were developed by W.E. Kock in the late 1940's
Metal-lens antennas, IRE Proc., 34 November 1946, pp. 828-836 and Metallic delay lenses, Bell. Sys. Tech. Jour.,27, January 1948, pp. 58-82. The book Antennas Theory and Practice by Sergi A. Schelkunoff copyright 1952 by Bell Labs describes metal lens antennas in chapters 19.9 through 19.12. |
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There is no single academic source which doesn't define metamaterials as only the 'optic metamaterials'. All existing literature I have encountered during my PhD on the topic would not use the term metamaterial to signify mechanical metamaterials. So if we follow the definitions that are commonly used in academia there shouldn't be an article which contains both optical metamaterials and mechanical metamaterials. Optical metamaterials are called "metamaterials" in academia, while the term mechanical metamaterials has been introduced to talk about non-optical aspects. It therefore makes sense forr the wikipedia article called "metamaterials" to only talk about electromagnetic phenomena.
However, in my honest opinion the term 'metamaterial' should never have been defined in the literature as only pertaining to optics. The fact that there is literature which discusses the concept of mechanical metamaterials presumes that the term 'metamaterials' isn't confined to optics only. One can logically deduce that the term 'metamaterial' should not be confined to optic metamaterials only.
The question is whether Wikipedia should define the term metamaterial in the logical way, or whether it should follow academia. Please discuss.
Like: electric-material, electromagnetic-material, optic-material, philosophy-material(materialism), add infimum...sorry forgot my password again... 75.82.19.242 ( talk) 19:19, 18 June 2022 (UTC)
The field of material is to well established and broad-in use everyday-for one article... ...Many Subjects in this field like: electric-material, electromagnetic-material, optic-material, philosophic-material(materialism), add infimum... 75.82.19.242 ( talk) 19:35, 18 June 2022 (UTC)