Re: A couple of book questions...(one of them about Completeness)
hi, --- Jim Choate <[EMAIL PROTECTED]> wrote: > > On Sun, 1 Dec 2002, Sarad AV wrote: > > > We can't define completeness. > > We can define it, as has been done. okay,I get what you mean,thank you. How ever how do you 'precisely' define completeness? Regards Sarath. __ Do you Yahoo!? Yahoo! Mail Plus - Powerful. Affordable. Sign up now. http://mailplus.yahoo.com
Re: A couple of book questions...(one of them about Completeness)
On Sun, 1 Dec 2002, Sarad AV wrote: > We can't define completeness. We can define it, as has been done. What we can't do is -prove- any set of rules of arrangement that describe symbol manipulation as -complete- -within the rules of arrangement-. 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-. 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. It just hangs there in Limbo. There is no -I don't know- list. There is a parallel (but I don't think fully equivalent) situation with Geometry and Euclid's V Postulate. It turns out not to be so universal after all. One approach to dealing with this situation is Para-Consistent Logic. Time will tell how usefull that is. Personal Note: I don't believe that the value of Godel is really the utility of mathematics as much as demonstrating the imperfect reasoning of -all- human beings. Mankind, all mankind, is on a hunt for universality in a quest for transcending the mortal coil. It's the concept of 'transcendence' that keeps getting us in trouble. Intelligence isn't all it's cracked up to be. "We arrive at truth not by reason only, but also by the heart." Blaise Pascal "Intellectual brilliance is no guarantee against being dead wrong." David Fasold "It is not clear that intelligence has any long-term survival value." Stephen Hawkings -- 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)
"Photons are bosons, so they don't interact with each other. Photon detectors can and usually have anisotropic sensitivity. Sure you can never beat fiber, but line of sight is free..." 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. From: Eugen Leitl <[EMAIL PROTECTED]> To: Tyler Durden <[EMAIL PROTECTED]> CC: <[EMAIL PROTECTED]> Subject: Re: CNN.com - WiFi activists on free Web crusade - Nov. 29, 2002 (fwd) Date: Sun, 1 Dec 2002 11:39:37 +0100 (CET) On Sat, 30 Nov 2002, Tyler Durden wrote: > I just don't see how a single WiFi cloud will be able to scale very far. All > the WiFi users within "eyeshot" of each other are always going to contend > for bandwidth, no? It'll be just like the old half-duplex 10BaseT copper There is limited bandwidth within a cell, if you use omni radiators. How high is the limit? No one knows, but you can get 100 MBits/s with current ultrabroadband prototypes. Then you have stuff like http://www.mobileinfo.com/News_2002/Issue05/NTT_2.5gps.htm Wireless Transfer Rate of 10 Gbps Possible, NTT says Always stretching the boundaries of wireless communications is Japanese telecom NTT. The company?s most recent accomplishment was achieving a peak data transfer rate of 2.5 Gbps, breaking the recorded rate of 1 Gbps; NTT researchers now believe they will eventually break the 10 Gbps barrier. As the airwaves become increasingly congested, exploring uncharted airwaves could pay NTT high dividends in the future. As an article in ComputerWire explains, NTT's solution has been to harness new electronic and optical technologies to access the empty 120 GHz radio band. Optical systems are used to generate the original signal which is passed, using amplitude modulation to a 300 GHz photodiode, which creates an electrical signal that is passed to a direct slot antenna. The key to the whole process is the 300 GHz photodiode, which harnesses optical technology, in this case the Lithium Niobate substrate originally designed for light switching, to the business of generating an electrical signal. Commercial viability is still a ways off. At the moment, the sustained 1.25 Gbps signal generates a range of only 50 cm. Nevertheless, as demand for wireless services out strips available spectrum, NTT will no doubt find itself swarmed by partners and competitors alike. Then, you have funky stuff like antenna arrays. People have started tinkering on MEMS galvanometers lately, which would allow to use line of sight lasers across free space without need for manual alignment; possibly dynamically tracking moving objects. > LANs. And I still don't understand how a WiFi router will help you...if the Current routers use an omni to cover local area, and directional aeries to create a mesh with their peers. Directional aerials for long-range connections have both a longer range and are less sensitive to crosstalk from the omni. > different Layer2 LANs overlap in space at all, they'll interfere with each > other optically even if they are on different segments. (With copper you Photons are bosons, so they don't interact with each other. Photon detectors can and usually have anisotropic sensitivity. Sure you can never beat fiber, but line of sight is free... > didn't even have this problem.) Thus, aren't you stuck with zillions o > little WiFi islands that must not overlap without things getting very slow? No. > As for service providers not wanting freeloaders, I'd point out that DSL > "cares" much lessthe DSL connection is mapped over ATM and is basically If I have a P2P infrastructure run on end-user owned hardware (little boxes glued to windowpanes) across an urban area with ~100 MBps/cell there is not all that much use for an ISP. Things only become difficult if you want to crosslink cities. Here you have to use fiber, or similiar. > a dedicated connection to a router port, with fixed bandwidth in either > direction. Whether that port is processing lots of freeloader packets or > idle packets from a single dedicated user shouldn't matter much. > > Uh, but now that I think of it ATM does allow for some oversubscription, so > in order to maximize the conection between the DSLAM and the ATM switch > that's in front of the router (it might be in thesame box as the router, I > know!), maybe they'l discourage freeloading. BUT, DSL companies have been > touting that they're very happy for you to put a home-based LAN on your side > of the connection (Cable Modem providers don't normally like that). _ Help STOP SPAM with the new MSN 8 and get 2 months FREE* http://join.msn.com/?page=features/junkmail
Re: CNN.com - WiFi activists on free Web crusade - Nov. 29, 2002 (fwd)
Eugen Leitl wrote: > On Sat, 30 Nov 2002, Dave Howe wrote: > I believe I mentioned geographic routing (which is actually > switching, and not routing) so your packets get delivered, as the > crow flies. The question of name services. How often do you actually > use a domain name as an end user? Not very often. People typically > use a search engine. It doesn't matter how the URI looks like, as > long as it can be clicked on, or is short enough to be cut and > pasted, or written down on a piece of paper and entered manually, in > a pinch. 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. >> under ipv6 you can avoid having to have a explicit naming service - >> the > You obviously understand under naming service something other than > DNS. yup - I recognise anything as a naming service that allows you to associate a routable name with a node that otherwise has only a mac address; > Anything which relies on global routing tables and their refresh will > always has an issue. Which is why geographical local-knowledge routing > will dominate global networks. 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. > The best solution would seem to leave the multilingual node the > choice of means of delivery. It would be completely transparent to > the packet. 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 existing system is still ipv4, there are problems.
Question on P=NP
hi, Is the problem P=NP or not 'Decidable'. Regards Sarath. __ Do you Yahoo!? Yahoo! Mail Plus - Powerful. Affordable. Sign up now. http://mailplus.yahoo.com
Re: A couple of book questions...(one of them about Completeness)
On Sun, 1 Dec 2002, Sarad AV wrote: > --- Jim Choate <[EMAIL PROTECTED]> wrote: > > > > On Sun, 1 Dec 2002, Sarad AV wrote: > > > > > We can't define completeness. > > > > We can define it, as has been done. > > okay,I get what you mean,thank you. > 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. I intentionaly use the Dover books as much as possible because they are available all over, and they are very inexpensive but high quality. The best example I've seen is the 'Catalog' problem. Basically you have a bunch of books and two catalogs. One catalog has books which don't list themselves, and the other catalog only has books that do list themselves. How do you list the two catalogs? (You probably want to google it for a better description of the exact conditions and boundary values) -- 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 Sat, 30 Nov 2002, Tyler Durden wrote: > I just don't see how a single WiFi cloud will be able to scale very far. All > the WiFi users within "eyeshot" of each other are always going to contend > for bandwidth, no? It'll be just like the old half-duplex 10BaseT copper There is limited bandwidth within a cell, if you use omni radiators. How high is the limit? No one knows, but you can get 100 MBits/s with current ultrabroadband prototypes. Then you have stuff like http://www.mobileinfo.com/News_2002/Issue05/NTT_2.5gps.htm Wireless Transfer Rate of 10 Gbps Possible, NTT says Always stretching the boundaries of wireless communications is Japanese telecom NTT. The company?s most recent accomplishment was achieving a peak data transfer rate of 2.5 Gbps, breaking the recorded rate of 1 Gbps; NTT researchers now believe they will eventually break the 10 Gbps barrier. As the airwaves become increasingly congested, exploring uncharted airwaves could pay NTT high dividends in the future. As an article in ComputerWire explains, NTT's solution has been to harness new electronic and optical technologies to access the empty 120 GHz radio band. Optical systems are used to generate the original signal which is passed, using amplitude modulation to a 300 GHz photodiode, which creates an electrical signal that is passed to a direct slot antenna. The key to the whole process is the 300 GHz photodiode, which harnesses optical technology, in this case the Lithium Niobate substrate originally designed for light switching, to the business of generating an electrical signal. Commercial viability is still a ways off. At the moment, the sustained 1.25 Gbps signal generates a range of only 50 cm. Nevertheless, as demand for wireless services out strips available spectrum, NTT will no doubt find itself swarmed by partners and competitors alike. Then, you have funky stuff like antenna arrays. People have started tinkering on MEMS galvanometers lately, which would allow to use line of sight lasers across free space without need for manual alignment; possibly dynamically tracking moving objects. > LANs. And I still don't understand how a WiFi router will help you...if the Current routers use an omni to cover local area, and directional aeries to create a mesh with their peers. Directional aerials for long-range connections have both a longer range and are less sensitive to crosstalk from the omni. > different Layer2 LANs overlap in space at all, they'll interfere with each > other optically even if they are on different segments. (With copper you Photons are bosons, so they don't interact with each other. Photon detectors can and usually have anisotropic sensitivity. Sure you can never beat fiber, but line of sight is free... > didn't even have this problem.) Thus, aren't you stuck with zillions o > little WiFi islands that must not overlap without things getting very slow? No. > As for service providers not wanting freeloaders, I'd point out that DSL > "cares" much lessthe DSL connection is mapped over ATM and is basically If I have a P2P infrastructure run on end-user owned hardware (little boxes glued to windowpanes) across an urban area with ~100 MBps/cell there is not all that much use for an ISP. Things only become difficult if you want to crosslink cities. Here you have to use fiber, or similiar. > a dedicated connection to a router port, with fixed bandwidth in either > direction. Whether that port is processing lots of freeloader packets or > idle packets from a single dedicated user shouldn't matter much. > > Uh, but now that I think of it ATM does allow for some oversubscription, so > in order to maximize the conection between the DSLAM and the ATM switch > that's in front of the router (it might be in thesame box as the router, I > know!), maybe they'l discourage freeloading. BUT, DSL companies have been > touting that they're very happy for you to put a home-based LAN on your side > of the connection (Cable Modem providers don't normally like that).
Re: CNN.com - WiFi activists on free Web crusade - Nov. 29, 2002 (fwd)
On Sat, 30 Nov 2002, Morlock Elloi wrote: > Self-routing mesh networks have potential to sidestep this. Transistors are > small and cheap enough even today - the centralised communication > infrastructure is there so that you can be charged, not because technology > dictates that any more. With wireless there is a potential that everyone paves > (and marks street number) in front of their house. The only way to subvert this > would be to erase "santa monica" from minds of everyone. I don't see that > happening. The cool part about wireless meshes running geographic routing is that they're self-labelling, and create a grassroot positioning service. It can be coarse, like a node id'iing a cell, or really fine-resolution using relativistic ping to the end-user device (ideally, all nodes, even your handheld, are part of the ad hoc mesh). If your space is labelled, you can just publish a database which allows you to annotate arbitrary 3d coordinate regions with info. Could be proprietary, could be something like a Wiki. Of course, virtual graffiti will result in lot of database defacement, so you have to use prestige accounting to be able to filter out the twits. > The day that I can send a packet from LAX to SFO via non-ISP-ed network will be > the beginning of the end of telco/telecom monopolies. Or, should I say, > directory monopolies. The only way to make this low-latency is relativistic cut-through in the wireless domain with some serious local bandwidth, and some long-range links. Somebody needs to be motivated to haul boxes up the mountain ranges. This needs permits, and dedication, and some $$$s. High-latency low-QoS services should be dead easy, though. There goes SMS...
Re: CDR: Re: A couple of book questions...(one of them about Completeness)
hi, --- Jim Choate <[EMAIL PROTECTED]> wrote: hi, > > On Sat, 30 Nov 2002, Peter Fairbrother wrote: > > > > Godel didn't invent the term though, and may not > have said "this is the/my > > definition of completeness". I haven't read them > for some time, and can't > > remember. He may well have assumed his readers > would already know it. We can't define completeness. > > Of course he didn't, he just made it irrelevant > since you can't prove the > truthfullness of all the propositions requird to > prove completeness. > > Bottom line, mathematics may be complete but until > somebody invents a > meta-mathematics broader than mathematics it will > remain -an unprovable > proposition within mathematics, even in principle.- > Mathametics is always incomplete,always. Regards Sarath. > Adios. > > > -- > > > > 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 > > > > __ Do you Yahoo!? Yahoo! Mail Plus - Powerful. Affordable. Sign up now. http://mailplus.yahoo.com
Re: CNN.com - WiFi activists on free Web crusade - Nov. 29, 2002 (fwd)
On Sat, 30 Nov 2002, Dave Howe wrote: > without routing and name services, you have what amounts to a propriatory I believe I mentioned geographic routing (which is actually switching, and not routing) so your packets get delivered, as the crow flies. The question of name services. How often do you actually use a domain name as an end user? Not very often. People typically use a search engine. It doesn't matter how the URI looks like, as long as it can be clicked on, or is short enough to be cut and pasted, or written down on a piece of paper and entered manually, in a pinch. So you need (distributed) searching and document (not machine) address spaces, which current P2P suites create the architecture for. > NAT solution - no way to address an interior node on the cloud from the It depends on how large the network is. Wireless is potentially a much bigger node cloud, so the current Internet could became a 'proprietary niche' eventually. However, there is no reason why the nodes wouldn't have a second address, or the IPv6 address would double as a geographic coordinate. At least during the migration. > internet (and hence, peer to peer services or any other protocol that > requires an inbound connection not directly understood by the nat > translation - eg ftp on a non standard port or ssl-encrypted as ftps) Fear not. > under ipv6 you can avoid having to have a explicit naming service - the You obviously understand under naming service something other than DNS. > cloud id of the card (possibly with a network prefix to identify the cloud > as a whole) can *be* the unique name; routing is still an issue but that Anything which relies on global routing tables and their refresh will always has an issue. Which is why geographical local-knowledge routing will dominate global networks. > reduces to being able to route to a unique node inside the cloud - which > appears from a brief glance at the notes from Morlock Elloi (thanks again :) > to have at least a workable trial solution. if a IPv6 internet ever becomes > a reality, clouds would fit right in. It is a patch, not a solution. But wireless ad hoc meshes are really a first real reason to go IPv6. > TCP/IP tunnelling without a name service at at least one end isn't workable; > *static* NAT/PAT is of course a name service and can't be considered, but > SOCKS and socks aware p2p is a definite possibility. The best solution would seem to leave the multilingual node the choice of means of delivery. It would be completely transparent to the packet.
