Re: A couple of book questions...(one of them about Completeness)
That any particular string can be -precisely- defined as truth or false as required by the definition of completeness, is what is not possible. Here we come down to what appears to be at the heart of the confusion as far as I see it. "True", depending on who's saying it (even in a discussion of Godelian Completeness), may be different. Mathematical types may define "true" as being "provably true", meaning something like "this statement can be derived from the other statements in my system by building up from logic plus the fundamental axioms". In Godel, in any formal system there are statements that are true but unprovable in that system. This would seem to render the notion of "true" above meaningless. But what it means in a "practical" sense is that there may be truisms (such as, "there exists no solution to the problem of a^n + b^n = c^n, where a,b,c and n are integers and n>2"), which are true (and let's face it, this statement is either true or false) but which can not be proven given the fundamental axioms of the system. Thus, in order to build more mathematics with this "truth", it must be incoroprated as an axiom. (Godel also says that after this "incoporation" is done, there will now be new unprovable statements.) I originally mentioned Godel in the context of the notion of the dificulty of factoring large numbers. My point was that its possible that... 1) Factoring is inherently difficult to do, and no mathematical advances will ever change that. and 2) We may never be able to PROVE 1 above. Thus, we may have to forever live with the uncertainty of the difficulty of factorization. _ The new MSN 8: smart spam protection and 2 months FREE* http://join.msn.com/?page=features/junkmail
Re: Anyone heard about the Berkeley college student?
At 8:05 -0800 2002/12/02, Major Variola (ret) wrote: >The folks in the next cube over discuss "boms" all the time ---meaning >Bill of Materials. I can't wait for them to make a work call from an >airport. We have "software boms", "bom targets", "per-ism boms", etc. When I see your coworkers in detention, we will all have a big laugh. -- J. Eric Townsend -- jet spies com buy stuff, damnit: http://www.spies.com/jet/store.html
Re: CNN.com - WiFi activists on free Web crusade - Nov. 29, 2002
On Mon, 2 Dec 2002, Peter Fairbrother wrote: > What I don't understand is how a node knows the location of a person > who moves about in the first place. The node spans a cell. Similiar to your cellular phone, you can link an ID to a cell. Within the cell you can use relativistic ping and/or signal strength (that's how mobile phone localization is done today). Since cells overlap you've got a lot of constraints to get a position fix. > Also, I don't like the idea that my location is known by the location > of my equipment. But I know very little about geographical routing. Your location is already known, whether you're using wire or wireless. Wireless has limited range, cables are expensive enough so that their lenght is being minimized. Traceroutes and signal pings and already existing IP location databases make anonymity a myth. The only way to address it is to use anonymizing proxies/traffic remixing. Geographic routing is intrinsically resistant to address spoofing (neighbours will refuse routing packets from obviously bogus origin). If you want to avoid disclosing your physical location, use a higher, anonymizing protocol layer.
Re: CNN.com - WiFi activists on free Web crusade - Nov. 29, 2002 (fwd)
On Mon, 2 Dec 2002, David Howe wrote: > I think what I am trying to say is - given a "normal" internet user > using IPv4 software that wants to connect to someone "in the cloud", how > does he identify *to his software* the machine in the cloud if that > machine is not given a unique IP address? few if any IPv4 packages can Of course it should be given an unique IP address. IPv6 is pretty popular with the ad hoc mesh crowd, btw. It's the only address space where you can still get large address slices for free or nearly so. (The space is probably large enough so that one could really map WGS 84 -> IPv6, and have very few direct collisions -- if it wasn't for small well-populated address slices and addresses and networks with magical meaning). But it should also get a geographic address, preferrably one refinable to ~~um scale, if needed. Bits are cheap, right? > address anything more complex than a IPv4 dotted quad (or if given a DNS > name, will resolve same to a dotted quad) > > odds are good that "cloud" nodes will be fully aware of geographic > routing (there are obviously issues there though; given a node that is Hopefully, > geographically "closer" to the required destination, but does not have a > valid path to it, purely geographic routing will fail and fail badly; it Geographic routing stands and falls with some (simple) connectivity assumptions. These are present in wireless dense node clouds in urban areas. > may also be that the optimum route is a longer but less congested (and > therefore higher bandwidth) path than the direct one. The connectivity in a line of sight network is not very high, and it is perfectly feasible to maintain a quality metric (latency, bandwidth) for each link. Given short range and high bandwidth within each cell that's not worth the trouble. > For a mental image, imagine a circular "cloud" with a H shaped hole in > it; think about routing between the "pockets" at top and bottom of the > H, now imagine a narrow (low bandwidth) bridge across the crossbar > (which is a "high cost" path for traffic). How do you handle these two > cases? High-dimensional networks don't block (map a high-dimensional network to Earth surface to see why). But that doesn't help much with current networks, where no satellite clouds are available. It hurts, but for nodes at and nearby the edge one would need to use special case treatment (implementing backpropagating pressure flow, so there would be less incentive to send packets to nodes at a wall).
Re: CNN.com - WiFi activists on free Web crusade - Nov. 29, 2002
Eugen Leitl wrote: > On Mon, 2 Dec 2002, Peter Fairbrother wrote: > >> What I don't understand is how a node knows the location of a person >> who moves about in the first place. > > The node spans a cell. Similiar to your cellular phone, you can link an ID > to a cell. Within the cell you can use relativistic ping and/or signal > strength (that's how mobile phone localization is done today). Since cells > overlap you've got a lot of constraints to get a position fix. Sure, I understand that. Maybe I wasn't clear. What I want to know is how an end-user can know where another end-user, who moves from cell to cell, is? A cellphone network uses a constantly-updated central database. What is a cell here? Is it just the nodes that one node can reach directly, or a geographical area? I thought a mesh wasn't structured at that level. -- Peter Fairbrother
Re: CNN.com - WiFi activists on free Web crusade
At 02:57 PM 12/2/02 +, Peter Fairbrother wrote: > >What I don't understand is how a node knows the location of a person who >moves about in the first place. > >Also, I don't like the idea that my location is known by the location of my >equipment. But I know very little about geographical routing. Look, knowledge that you can receive *any* wireless system is going to provide info about your location. This includes nets with huge 'cells', like a 100,000 watt commercial broadcast station, and nets with smaller cells, like the 'cellular' phones and 802.11foo meshes. The only difference (albeit a significant one) is the size of the cell. Of course if you're needing to transmit, you give your location. Now if you're needing to receive, and you roam beyond the diameter of a single 'cell', you are going to have to transmit your location (think cell phones) XOR the system has to broadcast to all cells (think pagers).
Wireless Routing, Position Inference (was Re: CNN.com - WiFi activists on free Web crusade)
At 02:57 PM 12/2/02 +, Peter Fairbrother wrote: > >What I don't understand is how a node knows the location of a person who >moves about in the first place. > >Also, I don't like the idea that my location is known by the location of my >equipment. But I know very little about geographical routing. I'll bite. Lets think about fundamentals, and play the adversary game. If I know that you can receive in *any wireless* system, then I know something about your location. This includes nets with huge 'cells', like a 100,000 watt commercial broadcast station (are you listening to KFOO or WFOO?), and nets with smaller cells, like the 'cellular' phones and 802.11foo meshes. The only difference (albeit a significant one) is the size of the cell ---the smaller your cells the more bits I get about your location. (Barring cypherpunk jokesters who make cell calls from the foci of dishes to hit another base station...) Of course if you're needing to transmit, you give your location. If you're needing to receive, and you roam beyond the diameter of a single 'cell', you are going to have to transmit your location (think cell phones) for routing XOR the system has no routing and must broadcast to all cells (think pagers) (you might consider the physical cells merged into a large single virtual cell in this case.). This latter doesn't scale. Got Yagis?
Re: CNN.com - WiFi activists on free Web crusade - Nov. 29, 2002
Eugen Leitl wrote: > On Sun, 1 Dec 2002, Dave Howe wrote: > >> ah. Sorry, I don't think of dns as a name service (apart from once >> removed) - we are talking DHCP or similar routable-address assignment. > > You can use GPS as naming service (name collisions are then equivalent to > physical space collisions). You can actually label the nodes > automagically, once you know that it's a nearest-neighbour mesh spanned > over patches of Earth surface. You can use signal strenght and > relativistic ping to make mutual time of flight triangulation. It is a > good idea to use a few GPS anchor nodes, so that all domains are > consistent. What I don't understand is how a node knows the location of a person who moves about in the first place. Also, I don't like the idea that my location is known by the location of my equipment. But I know very little about geographical routing. -- Peter Fairbrother
Re: Anyone heard about the Berkeley college student?
At 12:06 PM 11/29/02 -0500, Tyler Durden wrote: >In the Chinese papers over the last few days they've been reporting an >incident that happened to a Chinese UC Berkeley college student, who was >using her cell phone to discuss playing some sort of videogame. The >videogame involves placing "explosives" in various places in the game. > The folks in the next cube over discuss "boms" all the time ---meaning Bill of Materials. I can't wait for them to make a work call from an airport.
Re: ...(one of them about Completeness)
On Sun, 1 Dec 2002, Sarad AV wrote: > By principle of what? By the principles of mathematics. Godel used Principia Mathematica as a starting point. You might also. > Isn't that the reason we call it 'undecidable',put it > in an undeciable list which is the truth. The problem description doesn't allow a third list, to create a third list ouf of thin air would change mathematics from what we use today to something else. The assumption of basic mathematics to be complete (see definition) is that -all- strings will be either true or false. Godel's does -not- say mathematics is incomplete, it says we can't prove completeness -within- mathematics proper. To do so requires a meta-mathematics of some sort. > We can actually write these symbols down,it will be > true for some and false for some To write a string down to feed to your truth engine is one thing, to be able to write it in either the 'true' or 'false' list is something entirely different. Nobody cares about the first part, they care a great deal about the second. And no it won't be 'true for some, false for some'. The actual content of the symbols is of -no interst-. We are trying to determine if the string is legitimate within the axioms and their grammer, not it's absolute context sensitive result. Godel covers this in the first two (2) pages of his incompleteness work. It's cheap, try it. > eg: If we say-For a context free grammar G, L(G) is > ambigious. Then you've changed the rules in the middle of the game, and apparently without realizing it. What you are creating with that assertion is para-consistent logic. A different beasty. -- We don't see things as they are, [EMAIL PROTECTED] we see them as we are. www.ssz.com [EMAIL PROTECTED] Anais Nin www.open-forge.org
Re: A couple of book questions...(one of them about Completeness)
hi, > How ever how do you 'precisely' define > completeness? > > There were a couple of examples in the message > you replied to. There > are different sorts of completeness as well. You > might also look into some > of the references I provided. Okay,I ask a legitimate question,how do you argue it is correct and precise,we can't,thats why it is undefinable. Regards Sarath. __ Do you Yahoo!? Yahoo! Mail Plus - Powerful. Affordable. Sign up now. http://mailplus.yahoo.com
Re: ...(one of them about Completeness)
hi, Thanks for the replies,a few more queries. > Complete means that we can take any and all -legal- > strings within that > formalism and assign them -one of only two- truth > values; True v False. > > The fundamental problem is axiomatic. The rules > define -all- statements as > being -either true or false-, no other possibility > is allowed -by > principle-. By principle of what? > > We create two lists 'true' and 'false', we are > -required- to put -any- > string (or formula in Godel-speak, or 'sequence' and > 'inside or outside' > with regard to Cauchy Completeness) we write in one > of these two, and > only these two lists. > > However, as Godel shows, we -can- write strings > (some of them are quite > simple which is what makes it so shocking) that we > can't put in -either- > of these lists. > > There is -no- place to write it down. Isn't that the reason we call it 'undecidable',put it in an undeciable list which is the truth. We can actually write these symbols down,it will be true for some and false for some eg: If we say-For a context free grammar G, L(G) is ambigious.This is true for some G and false for G,If we ask a turing machine to solve this question,it can't because there is no algorithm to determine the statement is true or false. A function is turing computable only if for every element in the domain,the function's value can be computed with a Turing machine. The domain is important,for sime G we get True and some G we get false.By the defenition of turing complenetess,since we cannot show it is true or false for every element in the domain,it is not turing computable and hence undecidable.We can write down the symbols but it does n't mean any thing. Regards Sarath. __ Do you Yahoo!? Yahoo! Mail Plus - Powerful. Affordable. Sign up now. http://mailplus.yahoo.com
Re: CDR: Re: A couple of book questions...(one of them aboutCompleteness)
On Sun, 1 Dec 2002, Sarad AV wrote: > hi, > > > How ever how do you 'precisely' define > > completeness? > > > > There were a couple of examples in the message > > you replied to. There > > are different sorts of completeness as well. You > > might also look into some > > of the references I provided. > > Okay,I ask a legitimate question,how do you argue it > is correct and precise,we can't,thats why it is > undefinable. No. Completeness is -not- what is being 'argued'. The definitions are quite clear and straight forward; precise. I provided both Godel and Cauchy completeness definitions with references for deeper study. A Godel completeness -requires- all strings to be either true or false. There is -zero- room for confusion there. There is no confusion as to what complete means. That any particular string can be -precisely- defined as truth or false , as required by the definition of completeness, is what is not possible. -- We don't see things as they are, [EMAIL PROTECTED] we see them as we are. www.ssz.com [EMAIL PROTECTED] Anais Nin www.open-forge.org
Re: The CDR as a Cliological experiment
On Sat, 30 Nov 2002, Tyler Durden wrote: > Quite a statement.Obviously too much here to discuss in any detail, but I > would say this may be over-pessimistic. A trip out to Elmhurst Queens may be > very eye-opening. Elmhurst has over 120 languages and 150 nations > represented. It's a chaotic, dirty mess but it's also a hell of alot of > fun...authentic cheap foods of the various immigrant groups are available > (with few or no Americans in sight). > > But the point is, there's so much diversity, and everyone is pretty much > focused on grabbing some chunk of the perceived American dream, there's > never a chance for any real ethnic strife to get going. Muslims live next to > Christians, Hindus, Jews and distinctly "other", and there's no problem at Your example proves my point. They (and you) are still thinking of themselves as Muslim, Christian, Hindu, etc. Now ask yourself, how deeply do they 'get along' if they are still staying so seperated? Simply because two cultures occupy the same space doesn't mean they are one culture. -- We don't see things as they are, [EMAIL PROTECTED] we see them as we are. www.ssz.com [EMAIL PROTECTED] Anais Nin www.open-forge.org
Re: Question on P=NP
At 8:55 AM -0800 12/1/02, Sarad AV wrote: hi, Is the problem P=NP or not 'Decidable'. I don't even think we know. I vaguely remember someone saying that it would be really fascinating if it turned out not to be decidable. -Peter
Re: CNN.com - WiFi activists on free Web crusade - Nov. 29, 2002 (fwd)
On Sun, 1 Dec 2002, Dave Howe wrote: > ah. Sorry, I don't think of dns as a name service (apart from once > removed) - we are talking DHCP or similar routable-address assignment. You can use GPS as naming service (name collisions are then equivalent to physical space collisions). You can actually label the nodes automagically, once you know that it's a nearest-neighbour mesh spanned over patches of Earth surface. You can use signal strenght and relativistic ping to make mutual time of flight triangulation. It is a good idea to use a few GPS anchor nodes, so that all domains are consistent. > Indeed so - but of course the current internet *does* work that way, > so any new solution that advertises itself as "Free Internet access" > *must* fit into the current scheme or it is worthless. I think it can fit. > Unfortunately, such abstraction fails unless the *sender* knows how to > push the packet in the right direction, and each hop knows how to get > it a little nearer; this more or less requires that each node be given > a unique identifier compatable with the existing system, and given the No, an orthogonal identifier is sufficient. In fact, DNS loc would be a good start. The system can negotiate whatever routing method it uses. If the node doesn't understand geographic routing, it falls back to legacy methods. > existing system is still ipv4, there are problems.
Re: CNN.com - WiFi activists on free Web crusade - Nov. 29, 2002 (fwd)
at Monday, December 02, 2002 8:42 AM, Eugen Leitl <[EMAIL PROTECTED]> was seen to say: > No, an orthogonal identifier is sufficient. In fact, DNS loc would be > a good start. I think what I am trying to say is - given a "normal" internet user using IPv4 software that wants to connect to someone "in the cloud", how does he identify *to his software* the machine in the cloud if that machine is not given a unique IP address? few if any IPv4 packages can address anything more complex than a IPv4 dotted quad (or if given a DNS name, will resolve same to a dotted quad) > The system can negotiate whatever routing method it uses. If the node > doesn't understand geographic routing, it falls back to legacy > methods. odds are good that "cloud" nodes will be fully aware of geographic routing (there are obviously issues there though; given a node that is geographically "closer" to the required destination, but does not have a valid path to it, purely geographic routing will fail and fail badly; it may also be that the optimum route is a longer but less congested (and therefore higher bandwidth) path than the direct one. For a mental image, imagine a circular "cloud" with a H shaped hole in it; think about routing between the "pockets" at top and bottom of the H, now imagine a narrow (low bandwidth) bridge across the crossbar (which is a "high cost" path for traffic). How do you handle these two cases?
Re: CDR: Re: CNN.com - WiFi activists on free Web crusade - Nov.29, 2002 (fwd)
On Sat, 30 Nov 2002, Dave Howe wrote: > Jim Choate wrote: > > On Sat, 30 Nov 2002, Dave Howe wrote: > > The scaling problem is a valid one up to a point. The others are not. > > The biggest problem is people trying to do distributed computing using > > non-distributed os'es (eg *nix clones and Microsloth). > not as such, no. the vast majority of "free internet cloud" users couldn't > care less about computer resources and/or distributed computing They don't careYet! see... Smart Mobs: The next social revolution H. Rheingold ISBN 0-7386-0608-3 Leonardo's Laptop: Human needs and the computing technologies B. Shneiderman ISDN 0-262-19476-7 As to the other points you make, they are all addressible and are in fact being implemented now using existing technology. -- We don't see things as they are, [EMAIL PROTECTED] we see them as we are. www.ssz.com [EMAIL PROTECTED] Anais Nin www.open-forge.org
Re: The CDR as a Cliological experiment
On Sat, 30 Nov 2002, Tim May wrote: > On Saturday, November 30, 2002, at 07:05 PM, Tyler Durden wrote: > > > "(Tyler Durden, _please_ learn to trim your replies. Your "quote the > > entire thing" top posting is getting tiresome. I hear there are night > > school classes which teach Outlook Express or whichever braindead > > mailer you are using.)" > > > > Damn are you grumpy Tim May. Whaddya usin', carrier pigeon to download > > messages? (Or does some form of carpal tunnel make it excruciatingly > > painful to scroll down?) > > It doesn't matter what I am using. Top posting and bottom posting are > both bad. Tim, fuck off and die. If you don't like it edit it to suit yourself. Quit acting like a fascist pig who wants everyone to do it 'your way'. Sigh, CACL hypocrisy as usual. Next thing you know you'll be wanting to throw people off because they kiss in your presence...have you considered subscribing to Igor's node? You'd fit right in. -- We don't see things as they are, [EMAIL PROTECTED] we see them as we are. www.ssz.com [EMAIL PROTECTED] Anais Nin www.open-forge.org
Re: Question on P=NP
On Sun, 1 Dec 2002, Sarad AV wrote: > Is the problem P=NP or not 'Decidable'. It's certainly an open question, so the answer is 'nobody knows'. I personaly don't think it is true (ie P<>NP), YMMV. -- We don't see things as they are, [EMAIL PROTECTED] we see them as we are. www.ssz.com [EMAIL PROTECTED] Anais Nin www.open-forge.org
Re: CNN.com - WiFi activists on free Web crusade - Nov. 29, 2002(fwd)
On Sun, 1 Dec 2002, Tyler Durden wrote: > "Photons are bosons, so they don't interact with each other. Generally, don't forget 'entanglement' which is clearly interacting with each other ;) > Well, by interfere I meant in the detectors of course. So are you telling me > that two WiFi receivers pointed in different directions will not receive the > same information? I don't think WiFi (IR) is all that directional is it? If > it is, then maybe we CAN have a new LAN segment. It all depends on the antenna. If you use a Pringle Can kludge they are quite directional. There is at least a couple of the Austin Wireless group who have worked with other groups to build a phased array assembly that allows 801.11b to reach several miles instead of several hundred feet. It claims to be able to handle multiple connections. Haven't had a chance to look at it and see if it really works as advertised. Several of Hangar 18 are currently working on 'Open Air Optical Network' serial adapters that will work with Linux, Plan 9, Winblows, etc. Just about anything that will do SLIP or PPP over a serial port and has line of sight for he lasers. Our next project along these lines is to start using 900MHz radios to increase the 'backbone' range. The idea here is to expand the current 'regular Internet' backbone for open-forge.org (two sites seperated by about six miles using ISDN, with one site using a T1 to access the regular network). When we get this up we should have about six to eight major 'backbone' sites scattered around Austin using 900MHz to connect to the T1. Our current backbone project is created by several commercial entitites and individuals using non-consumer AUP's (for 'free', we use Tit-for-Tat, we only interact with other 'producers' not 'consumers' - the idea is to promote others to handle the fan-out to a larger user community). We've got nodes in several states. We're currently looking at setting up the auth servers so that we can better manage resources and access. We've got somewhere in the neighborhood of about 40 machines in the pool. We'll be using not only the traditional DNS but also custom namespaces (accessed through VPN Gateways). We're also building a pool of 'community accessible' process servers (ala Plan 9). -- We don't see things as they are, [EMAIL PROTECTED] we see them as we are. www.ssz.com [EMAIL PROTECTED] Anais Nin www.open-forge.org
Re: CDR: Re: The CDR as a Cliological experiment
On Sat, 30 Nov 2002, Tim May wrote: > On Saturday, November 30, 2002, at 05:23 PM, Tyler Durden wrote: > > As far as I'm concerned, most strife boils down to the perceived > > economic interests of the concerned parties, and apparently > > ehtnic/religious/whatever differences are just a mask for these > > simpler problems. As a big for instance, racism during the slavery > > days was really a way to allow for economic explouitation of "human > > resources"...slavetraders of course searched for Biblical and > > Darwinian justification of their actions, and codified them into their > > "religion". > > The slave trade was centered around some negroes capturing and selling > some other negroes. Simplistic oversimplification as usual. Why were the negroes selling other negroes? So they wouldn't become slaves themselves. Further, don't confuse the mechanism of slave trade with the -reason- for slave trade, cheap labor. -- We don't see things as they are, [EMAIL PROTECTED] we see them as we are. www.ssz.com [EMAIL PROTECTED] Anais Nin www.open-forge.org