austenandrews Posted February 28, 2006 Report Share Posted February 28, 2006 Technically speaking, anyway. http://www.aip.org/pnu/2006/split/767-1.html Physicists have built the world's thinnest gold necklaces, at just one atom wide. Quote Link to comment Share on other sites More sharing options...
Curufea Posted February 28, 2006 Report Share Posted February 28, 2006 Re: Monowire has arrived Hmm, I can see metal migration being a huge problem. Quote Link to comment Share on other sites More sharing options...
Dauntless Posted February 28, 2006 Report Share Posted February 28, 2006 Re: Monowire has arrived Call me a party-wrecker, but monomolecular wire (as a weapon) is just too implausible for me to suspend my disbelief. "but" you may say, "the article just proves that we can create it". Sure, but why would anyone think you can make a weapon out of it? A true monomolecular wire would just blow around in the wind. People think monomolecular wire will cut through anything....but that's assuming near infinite strength between the bonds holding the individual molecules together. Actually, most people blow lots of nanotechnology items way out of proportion. Nanites still have to obey thermodynamics, conservation of energy and momentum, and every other rule of (quantum) physics. Just because it's tiny doesn't mean it gets to break those rules. What monomolecular will be very interesting for is in building quantum circuits. As the article pointed out, the density pattern of the current flow of the electrons through the wire was actual a quantum wave function (which really is a probability function). An electron could leap into or out of a nanocircuit like that, which means the whole circuit itself becomes an indeterminate object until it's observed. What's the big deal about quantum computers? Well, for starters, a quantum computer that has 200 qubits (quantum bit registers) would be more powerful than all the computers in the world combined...and then some. It would be able to solve problems intractable by today's computers (for example, NP-complete problems). And lastly, it could simulate non-deterministic, non-local phenomena (such as perhaps, our own brain). That's what this stuff is cool for...not weapons. Quote Link to comment Share on other sites More sharing options...
austenandrews Posted February 28, 2006 Author Report Share Posted February 28, 2006 Re: Monowire has arrived Naturally, but it's a fun topic-starter. Quote Link to comment Share on other sites More sharing options...
Old Man Posted February 28, 2006 Report Share Posted February 28, 2006 Re: Monowire has arrived Anyone got some dental floss? Quote Link to comment Share on other sites More sharing options...
mirage Posted March 1, 2006 Report Share Posted March 1, 2006 Re: Monowire has arrived What monomolecular will be very interesting for is in building quantum circuits. As the article pointed out, the density pattern of the current flow of the electrons through the wire was actual a quantum wave function (which really is a probability function). An electron could leap into or out of a nanocircuit like that, which means the whole circuit itself becomes an indeterminate object until it's observed. How is this different from the "electron gas" in a dual hetro-junction? My solid state is a bit rust. Quote Link to comment Share on other sites More sharing options...
Jaxom Posted March 1, 2006 Report Share Posted March 1, 2006 Re: Monowire has arrived What monomolecular will be very interesting for is in building quantum circuits. As the article pointed out' date=' the density pattern of the current flow of the electrons through the wire was actual a quantum wave function (which really is a probability function). An electron could leap into or out of a nanocircuit like that, which means the whole circuit itself becomes an indeterminate object until it's observed. What's the big deal about quantum computers? Well, for starters, a quantum computer that has 200 qubits (quantum bit registers) would be more powerful than all the computers in the world combined...and then some.[/quote'] Not sure I see that step... [lots of techno-babble re: quantum wave collapse and uncertainty principles omitted for readability (and to save points instead of spending them on my HIBB)] Besides. We all know that buckytubes is where it is at for future weaponry anyway... Quote Link to comment Share on other sites More sharing options...
Zeropoint Posted March 1, 2006 Report Share Posted March 1, 2006 Re: Monowire has arrived The problem with "monowire" as a weapon is that the drag of the wire passing through the material being cut decreases linearly with the diameter of the wire, but the tensile strength of the wire decreases with the square of the diameter. It's quite possible to pull a piece of fine music wire through flesh, but if you walk through a spiderweb--which has about the same strength per cross-sectional area as steel--you don't get diced, the spiderweb breaks. Oh, and regarding quantum computers, it seems that they don't even have to actually run the program to give you the results. Check it out. Zeropoint Quote Link to comment Share on other sites More sharing options...
austenandrews Posted March 1, 2006 Author Report Share Posted March 1, 2006 Re: Monowire has arrived Yeah, that's totally freaky stuff. I still don't get how that works. Quote Link to comment Share on other sites More sharing options...
Dauntless Posted March 1, 2006 Report Share Posted March 1, 2006 Re: Monowire has arrived Mirage and Jaxom- I'm in computer science, not quantum physics, but I've been trying to learn the basics of quantum computation (a subset of QM). What I said is mostly conjecture, because today's qubits are mainly derived from the four technologies: ion traps, quantum dots, semiconductor impurities, and superconductors (there's a host of others, like single photon detection but these seem to be the most common). Of these, the one-molecule wide wire would most closely resemble a quantum dot, which is basically a semiconductor so small, it can contain a single electron. However, current research suggests that <20nm transistors will only be the first phase of quantum computers. They will essentially be classical computers using quantum mechanical principles to account for the quantum nature of the register. However, newer quantum logical structures will be derived that directly translate from the logic level to the quantum algorithms. There's a nice picture of what I'm trying to explain here. Also, zeropoint is right, it seems like quantum computers don't really have to run to solve equations. As I understand it, it has something to do with Schroedinger's wave equation being related to time. Feynman said that quantum Computers are essentially quantum simulators...and if reality is quantum mechanical, then it basically just simulates reality. Of course, you still have to encode the problem...and that's more than half the battle. Not to mention isolating the answer from quantum entanglement, which is the other really sticky problem. Ironically, it is the entanglement which provides the computational power by allowing the superposition of states to allow for multiple processing paths. But that's where some of Shannon's work on Information Theory comes to the rescue with what are essentially quantum versions of error correction codes (ECC). Without them, quantum computation would essentially be impossible even if we can build nanoscale transistors. If you're interested in this sort of stuff, check out the following links: http://www.theory.caltech.edu/~preskill/ph219/index.html#lecture http://www.csee.umbc.edu/~lomonaco/ams/Lecture_Notes.html Centre for Quantum Computation John Preskil's Site (he won the bet against Stephen Hawking about reversibility of information that's "destroyed" in Black Holes) David Deutsch's Video Lectures (David's considered by some to be the father of Quantum Computation for his pioneering work). Quote Link to comment Share on other sites More sharing options...
Publius Posted March 1, 2006 Report Share Posted March 1, 2006 Re: Monowire has arrived That's all Geek to me. I'd ask for an English translation but I'm afraid that would be beyond me as well. I'm just starting to get string and M-theory basics 'nailed down' (i.e. put into a format that the scientifically challenged can grasp basic understanding). Quote Link to comment Share on other sites More sharing options...
mirage Posted March 1, 2006 Report Share Posted March 1, 2006 Re: Monowire has arrived That's all Geek to me. I'd ask for an English translation but I'm afraid that would be beyond me as well. I'm just starting to get string and M-theory basics 'nailed down' (i.e. put into a format that the scientifically challenged can grasp basic understanding). As I've mentioned, I've been way out of the loop. I'm just starting actually look at M-theory, which wasn't even around when I was in school. I was going to give you a link to some basic, (no math pretty pictures), info, but my google-fu is failing me at the moment. I have a very basic paper, but I think the only copy I have is on my currently deceased Amiga and in a propriatary format. Long live .odt! Quote Link to comment Share on other sites More sharing options...
LordGhee Posted March 28, 2006 Report Share Posted March 28, 2006 Re: Monowire has arrived In simple terms what is NP-complete problems? thanks Lord Ghee Quote Link to comment Share on other sites More sharing options...
Captain Obvious Posted March 28, 2006 Report Share Posted March 28, 2006 Re: Monowire has arrived Call me a party-wrecker, but monomolecular wire (as a weapon) is just too implausible for me to suspend my disbelief. "but" you may say, "the article just proves that we can create it". Sure, but why would anyone think you can make a weapon out of it? A true monomolecular wire would just blow around in the wind. People think monomolecular wire will cut through anything....but that's assuming near infinite strength between the bonds holding the individual molecules together. A monomolecular wire would be as strong as diamond, given that a diamond is a monomolecular structure. The bonds holding it together would be way stronger than the bonds holding living cells together, so it could conceivably be made into a nasty cutting weapon (probably not a sword or a knife, but a garrote maybe). This thing is different, though. It's just a line of metallic atoms. And given how beat up my gold rings are (10k alloy for added strength), this wire would break just by looking at it. Quote Link to comment Share on other sites More sharing options...
Curufea Posted March 29, 2006 Report Share Posted March 29, 2006 Re: Monowire has arrived Has anyone worked out the maths of the strength of these molecular bonds? How much pressure or kinetic change/impact etc that this new materials science provides? Quote Link to comment Share on other sites More sharing options...
Captain Obvious Posted March 29, 2006 Report Share Posted March 29, 2006 Re: Monowire has arrived Nah. I can talk in generalities with the best of them, but when it gets down to specifics, I fall down like an old lady in a bathtub. Quote Link to comment Share on other sites More sharing options...
Curufea Posted March 29, 2006 Report Share Posted March 29, 2006 Re: Monowire has arrived Actually - I wouldn't mind seeing a good online reference for materials. I recall seeing one for the elements, which gave all the stats about them - weight, density, etc.. but not for materials. Quote Link to comment Share on other sites More sharing options...
Thia Halmades Posted March 30, 2006 Report Share Posted March 30, 2006 Re: Monowire has arrived You'll think it's silly, but trust me, it ain't: Suppose that you are organizing housing accommodations for a group of four hundred university students. Space is limited and only one hundred of the students will receive places in the dormitory. To complicate matters' date=' the Dean has provided you with a list of pairs of incompatible students, and requested that no pair from this list appear in your final choice. This is an example of what computer scientists call an NP-problem, since it is easy to check if a given choice of one hundred students proposed by a coworker is satisfactory (i.e., no pair from taken from your coworker's list also appears on the list from the Dean's office), however the task of generating such a list from scratch seems to be so hard as to be completely impractical. Indeed, the total number of ways of choosing one hundred students from the four hundred applicants is greater than the number of atoms in the known universe! Thus no future civilization could ever hope to build a supercomputer capable of solving the problem by brute force; that is, by checking every possible combination of 100 students. However, this apparent difficulty may only reflect the lack of ingenuity of your programmer. In fact, one of the outstanding problems in computer science is determining whether questions exist whose answer can be quickly checked, but which require an impossibly long time to solve by any direct procedure. Problems like the one listed above certainly seem to be of this kind, but so far no one has managed to prove that any of them really are so hard as they appear, i.e., that there really is no feasible way to generate an answer with the help of a computer. Stephen Cook and Leonid Levin formulated the P (i.e., easy to find) versus NP (i.e., easy to check) problem independently in 1971.[/quote'] That's P vs. NP. Quote Link to comment Share on other sites More sharing options...
Matt Frisbee Posted March 30, 2006 Report Share Posted March 30, 2006 Re: Monowire has arrived Compare monoatomic to monomolecular Gold wires -- monoatomic monowire -- monomolecular Most monowire has a weight bonded to one end of the line while the other is anchored. A sufficiently strong molecular bond keeps the entire strand together while irregularities in the molecular shape make the cutting edges of the wire. Not possible with current molecular theory, of course, but monowire in my Cyperpunk universe is probably about as big around as half a human hair. Just my two cents' worth, and now I'm out of pennies. Matt Frisbee Quote Link to comment Share on other sites More sharing options...
Dr. Anomaly Posted April 2, 2006 Report Share Posted April 2, 2006 Re: Monowire has arrived In simple terms what is NP-complete problems? thanks Lord Ghee In addition to what Thia Halmades said, let me add this: For many types of math problems, there are algorithms or procedures you can follow that will determine the answer without having to check out all possible answers...in other words, they have ways of narrowing down the set of possible answers fairly quickly. For some types of questions, you literally have to check every single possible answer (permutation of elements) before you can be sure you've got the best answer; there is no algorithm that provides a shortcut. nP Complete problems are of this latter type. "nP" stands for "(total) number of Permuations" -- in other words, however many possible permutations there are (n) you must check each and every permutation (P) to make sure you've got the best answer...you must check out the Complete set of possible answers. nP Complete = entire (complete) set of all (n) possible permutations (P) Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.