Location: Hyderabad, India


Breaking News

New Supercomputer Claimed to be World's Fastest The builders of a new NASA supercomputer claim the 10,240-processor machine is the fastest in the world -- an exciting prospect for researchers even if the speed title has yet to be officially bestowed. Project Columbia, named for the space shuttle that was destroyed in early 2003, was built in less than 120 days at NASA's Ames Research Center. The cluster of 20 computers working as one will be used to speed up spacecraft design, environmental prediction and other research. At the $50 million machine's public unveiling Tuesday, the science shared the stage with claims of record-setting performance from system-builder Silicon Graphics Inc., processor-provider Intel Corp. and NASA. Using just 16 of Project Columbia's 20 installed systems, the computer achieved a sustained performance of 42.7 trillion calculations per second, or teraflops. "If you could do one calculation per second by hand, it would take you a million years to do what this machine does in a single second," said G. Scott Hubbard, Ames' director. By comparison, Earth Simulator's sustained performance is 35.86 teraflops. The competition for the top spot will be fierce. Last month, IBM announced the results of its Blue Gene supercomputer, which claimed its sustained performance was 36.01 teraflops. Because the machine is not yet finished, it could still come up on top. There may also be some improvement for Project Columbia. Its numbers were achieved using only four-fifths of its processors. Hackers Target Apple? Congratulations! The Apple community has—since its inception—been largely immune to nefarious hackers bent on spreading harm. If you are a Windows user, as I am, you know the routine. You complain about the latest spyware or virus attack, and Apple devotees respond with good-natured teasing—they don’t have worry about such nonsense. Well, now they do. That’s not true anymore. Predictably, posts on various Apple-related message boards have been offering varying levels of concern, ranging from mild disappointment to utter gloom. I think this reaction is fundamentally misguided. MAC users should not be upset about this malware news; they should rejoice. Huh? Why should the Apple community be celebrating the news? Before I explain, let me make one thing clear: I’m not advocating this kind of hacking, and certainly—as a victim of a virus attack myself not too long ago—I empathize with anyone who has been attacked. That said, this program is a milestone in computing history because the Apple community is finally large enough that it has drawn the attention of the hackers. Here’s what happened: Last week, astute Mac users discovered a program dubbed “Opener.” This piece of code embeds itself onto Macs running OS X, the latest Apple operating system, and disables the computer’s firewall. The malware also locates and collects any password information it can find on the infected system, leaving behind a password-cracking program called “John the Ripper.” It is believed that Opener can be called into action remotely utilizing a “bot net,” in which a remote hacker plants malware onto unsuspecting users’ computers and then calls that code into action


I am a Google fan!

There are thousands of Google related sites, services and features out there. Many are well known, some are not. I'd like to shed some light. The Original Google site of 1998 Google Nominated for 2004 Webby Awards Google has been nominated for the 2004 Webby Awards. The categories? "Services" and "Best Practices". Make sure to vote for our favorite website, Google! Drop everything and visit The site has official Google logos, fan-made logos, funny logos, etc. Make sure to check out the Google Stuff section. Google Employee Blogs If you have not seen these blogs, you need to check them out. Both are authored by Google employees! Fury 3.2 Our club The Unofficial Google Fan Club Google Calculators and Tools Explanation of Google Calculator Google 4x4 Surfer Google Dance Watch Tool Free Charts Generated from your Google Adsense Reports AdSense Tracker. Detailed AdSense reports for boosting your AdSense revenue!


No Excuses!

The Absolute Minimum Every Software Developer Absolutely, Positively Must Know About Unicode and Character Sets (No Excuses!) Hello guys here is one article i found which is a must for every developer. All that stuff about "plain text = ascii = characters are 8 bits" is not only wrong, it's hopelessly wrong, and if you're still programming that way, you're not much better than a medical doctor who doesn't believe in germs. Please do not write another line of code until you finish reading this article. Thank You Joel Spolsky.


Hard Drive Format Review

When a new hard drive was installed, the first thing need to be done is to create partitions and format the hard drive. Partitioning of the hard drive is always the same, but formatting it cause some confusion and problems. The common question is which file system format should I choose: FAT, FAT32, or NTFS? FAT or FAT16 file system FAT stands for "File Allocation Table", FAT and FAT16 are the same. This was widely used during the Under DOS and early versions of Windows 95 era when the hard drive capacity is generally small ( < 2 GB). Floppy drive is always formatted in this format. The good thing with FAT is that the data stored under this format is universally readable by any Windows PC, no matter it is DOS, Windows 2000, or Windows XP. FAT32 file system As the hard drive capacity goes beyond 2 GB, FAT32 was introduced in rush to allow for larger partitions and less waste, however Microsoft did not have enough foresight for fast development of storage technology, the partition size is still limited to 32 GB. FAT32 is mainly used in Windows 98 and Windows ME, but also supported by Windows 2000 and Windows XP. NTFS (New Technology File System) Finally Microsoft has moved a few steps head of storage industry. NTFS virtually removed limitation on the hard drive partition size, hence you use large hard drive by just use one primary partition. This is quite important for pure data storage products such as external had drive and portable hard drive. Windows NT can only be installed on a hard drive formatted in NTFS. Windows 2000 and Window XP support bother FAT32 and NTFS, you can choose to format the hard drive as NTFS or FAT32 before you install Windows OS. Which file system format to use? As mentioned, Windows 98 and Windows ME only support FAT32, so you have to create two or more partitions if your hard drive is more than 32 GB, and format all the partitions as FAT32. Similarly if you are going to use Windows NT, you have to format the hard drive as NTFS as this is the only format it supports. For Windows 2000 and XP user, it is a little bit complicated, you have to choose according to your situation: If all your computers have Windows 2000 or XP, NTFS is certainly the choice; If you wish to have two or more operation system on the same computer, such as Windows 98 in one partition and Windows XP in another partition; you'd better choose FAT32, otherwise you can not access the Windows 98 partition when you are running Windows XP, or access the Windows XP partition when you are running Windows 98. For those people who use portable hard drive or external hard drive: 1 If all your computers are in NTFS format, choose NTFS for your portable hard drive. 2 If your computer have both Window 98 and Windows XP, and the system hard drive where the Windows 98 and XP are installed) should be FAT32, and the portable hard drive should also be FAT32. 3 In situation of 2, if you are not going to use the portable hard drive under Windows 98, you may well choose NTFS, as this will allow you to use a 250GB hard drive under one drive letter.


Google's Desktop Search

Google's new Desktop Search software is a muscle car among search engines, racing through personal data stored inside your computer to instantly find things you can't easily locate.But it's also capable of skidding off the road when driven without the appropriate degree of caution. Introduced Thursday as a free download, Google Desktop Search ( keeps track of files on your computer's hard drive in much the same way that regular Google finds information you want on the Internet. When you go to the Google search page in your browser, after installing Desktop Search, the first results you see are your own files. If you're searching for information about Sunnyvale, for example, you get a list of e-mails, Word documents and plain-text documents on your computer that contain the word ``Sunnyvale.'' On my home PC, the first hit was an e-mail message from a friend about local politics, including a reference to that city. Below the Desktop Search results were the Web search results, starting with the city's official home page. Suddenly, I no longer have to ponder where I saw some piece of information: In an e-mail? On a Web page? In a document? A single Google query now covers everything I've seen on my computer since installing Desktop Search, as well as whatever is available on the Web. This is hugely valuable, yet occasionally creepy. Desktop Search does three things in particular that could compromise your privacy when someone else uses your computer: First, the software keeps a copy of all your AOL Instant Messenger conversations. AIM, for many users, is like talking over the water cooler at work -- you say things you don't want preserved for posterity. Until now, AIM conversations with your buddies disappeared from your computer the moment you closed the discussion window. Desktop Search, however, makes a copy of AIM conversations and keeps them forever. Second, the software keeps its own copy of all your Outlook and Outlook Express e-mail messages -- even after you delete them from within Outlook or Outlook Express. A confidential company memo, in other words, will still pop up during Google searches after you've emptied the Deleted Items folder in Outlook. Third, the software keeps a copy of every Web page you visit and lists those pages in search results with the date and time of your visit. This even includes Web pages that are supposed to be secure from prying eyes, such as those run by online banking sites. That means if someone else uses your PC and enters the word ``bank'' or ``brokerage'' in Desktop Search, they could uncover your confidential financial information. There are controls within Desktop Search to block each of these three search features, but it's not immediately obvious how to find them and many users will never bother to learn. On the other hand, many users will find these same features very useful. If you're getting important work or school information through IM, not just gossiping, the Desktop Search archive could be a lifesaver. Similarly, we've all had the experience of accidentally deleting an important e-mail, or being unable to find our way back to a crucial Web page. I called several experts on Internet security and privacy Friday to see if the far-reaching power of Desktop Search would stir up controversy. The consensus, for now at least, is no.The experts know, better than the rest of us, how many threats exist in malicious software that hides its intent to steal personal information. Google Desktop Search, at least, doesn't disguise itself. The program shows its presence with a small icon in the Windows system tray that looks like a child's swirly lollipop. My bottom line: I wouldn't recommend installing Desktop Search on any computer you don't own, such as PCs at work or school. If you think there's a risk of strangers using a machine you do own, disable the part of Desktop Search that keeps copies of secure Web pages -- but keep the other parts. Desktop Search is officially a ``beta,'' or unfinished pre-release program. Usually, software stays in beta for only a few weeks, but Google routinely runs beta programs for months or years. That gives the Mountain View company room to make improvements, and Google has already said it's working on password protection -- so only you or anyone you give your password could search your personal files. Despite the beta status, I would recommend Desktop Search now to anyone who's having a hard time keeping track of the many types of information that accumulates on a computer. You'll need a PC running Windows XP or Windows 2000 with 500 megabytes of free space on the hard drive. Desktop Search doesn't work with older versions of Windows or the Macintosh. You'll also need to be patient at the start. Desktop Search works in the background to keep an index of your personal files, and requires five to 24 hours of computer running time after installation to fully catalog your hard drive.


Google is Hiring!

Google Copernicus Center is hiring: Google is interviewing candidates for engineering positions at lunar hosting and research center, opening late in the spring of 2007. This unique opportunity is available only to highly-qualified individuals who are willing to relocate for an extended period of time, are in top physical condition and are capable of surviving with limited access to such modern conveniences as soy low-fat lattes, The Sopranos and a steady supply of oxygen. The Google Copernicus Hosting Environment and Experiment in Search Engineering (G.C.H.E.E.S.E.) is a fully integrated research, development and technology facility at which Google will be conducting experiments in entropized information filtering, high-density high-delivery hosting (HiDeHiDeHo) and de-oxygenated cubicle dwelling. This center will provide a unique platform from which Google will leapfrog current terrestrial-based technologies and bring information access to new heights of utility. Go to for more information and to apply go to


Great Stuff!

Free Legal 3D Computer Animation Software Used in Movies: Ever wonder what Hollywood uses tocreate 3D animations like Shrek and Ice Age. What do they use to renderthe stunts and visual effects in movies like Spiderman and Charlie'sAngels. They use the 3D computer animation software Maya from AliasSystems. Luckily, Alias provides a Personal Learning Edition of Mayafree! It only supports Mac and Windows 2000/XP. You can either order it on a CD or download it. I found an unofficial mirror at a messageboard. Visit it here: Try Linux Easily and Safely (You don't even need a hard disk!): Wanna try Linux but you just don't want the hassle of installing it? Toinstall it, you have to resize your Windows partition, create a newpartition, format it, add a boot manager, and much more! It?s so muchwork (not to mention the possible data loss). All you want to do is TRYLinux, not permanently use it! Well I heard about this thing fromTechTV. This Linux distribution is called Knoppix. It is a"live-on-cd" operating system. All you have to do is turn on thecomputer and pop in the CD. The operating system runs off the CD andRAM! You don't even need a hard disk! Just download the ISO image fromthe web site, burn it on a CD and reboot. Download Any Dynamic Link Library File (.dll) for Free: I came across a really useful site Of all the DLL download sites I've seen, this one was the most comprehensive and least annoying! Visit Watch out though! Since visitors make contributions, some DLLs may be virus infected! Use a virus scanner.


Computing the cosmos

One of the biggest computer simulations ever run is illuminating the deepest mysteries of the universe. To answer the fundamental questions in cosmology, an international group of scientists from Canada, Germany, the United Kingdom, and the United States has been working on an ambitious project whose goal is to simulate on a supercomputer the evolution of the entire universe, from just after the Big Bang until the present. The group, dubbed the Virgo Consortium—a name borrowed from the galaxy cluster closest to our own—is creating the largest and most detailed computer model of the universe ever made. While other groups have simulated chunks of the cosmos, the Virgo simulation is going for the whole thing. The cosmologists' best theories about the universe's matter distribution and galaxy formation will become equations, numbers, variables, and other parameters in simulations running on one of Germany's most powerful supercomputers, an IBM Unix cluster at the Max Planck Society's Computing Center in Garching, near Munich. 4 200 000 000 000: NUMBER OF CALCULATIONS PER SECOND THE VIRGO CONSORTIUM SUPERCOMPUTER CAN PERFORM . The machine specifically designed for simulation, a cluster of powerful IBM Unix computers, has a total of 812 processors and 2 terabytes of memory, for a peak performance of 4.2 teraflops, or trillions of calculations per second. It took 31st place late last year in the Top500 list, a ranking of the world's most powerful computers by Jack Dongarra, a professor of computer science at the University of Tennessee in Knoxville, and other supercomputer experts. But as it turns out, even the most powerful machine on Earth couldn't possibly replicate exactly the matter distribution conditions of the 380 000-year-old universe the Virgo group chose as the simulation's starting point. The number of particles is simply too large, and no computer now or in the foreseeable future could simulate the interaction of so many elements. So the fundamental challenge for the Virgo team is to approximate that reality in a way that is both feasible to compute and fine-grained enough to yield useful insights. The Virgo astrophysicists have tackled it by coming up with a representation of that epoch's distribution of matter using 10 billion mass points, many more than any other simulation has ever attempted to use. In June 2004, the first simulation of our universe was completed. The resulting data, which represents about 20 terabytes, will be available to everyone in the months to come, at least to people with a high-bandwidth connection.


Operating system Processes

Most of the sytems use Windows Operating system and you guys have you ever wondered what are those processes that we see in the windows Task Manager. csrss.exe: This is "Client Server Runtime Process" is part of the core of Windows. You cannot kill it and I am not sure why you would even want to. It is a 4k process that sucks up about 3 MB to 6 MB or so, but I do not support making it go away. Usually, if it is "difficult" to get rid of, it is needed. ctfmon.exe: This is your "Language Bar." Don't know what it is? I bet you do not need it. Head to Control Panel -> Regional and Language Options -> Languages TAB -> Details BUTTON -> Language Bar BUTTON (under "Preferences") -> select the "Turn off advanced text services" check box. This little detail will save you between 1.5 MB and 4 MB of RAM. If you are using a "non-US" version, you may be required to install the English localization to remove this "feature." CTHELPER.EXE: This is installed with the SoundBlaster Audigy2 drivers. It takes about 4 MB of RAM. CTDVDDET.exe: This is also installed with the SoundBlaster Audigy2 drivers. A "DVD Detection" application. It sucks up about 2.2 MB of memory. You can disable it by heading to the MediaSource DVD Audio Player, selecting Tools, then uncheck the "Auto Start" box. It should not start up automatically again. CTSysVol.exe: Yet another that is installed with the SoundBlaster Audigy2 Card. A "Volume Control" application that, by default, sits in the system tray. It takes about 3.8 to 5 MB of RAM doing nothing. Right click the tray icon and select "Close," then disable it via msconfig. devldr32.exe: This is installed if you have a Creative Sound Card (SBLive Series that I am aware of). It sucks up 2.3 MB to 2.6 MB, but I have not completed extensive testing with this NOT being there... After manually killing the process (this is not a service, it is listed as a driver in the hardware properties of the sound card) I loaded up a game of Dungeon Siege and all EAX features and 5.1 positional sound worked (with EAX on or off). Also, all Direct Sound tests completed without errors. Do not get excited, though. After renaming the process, the Windows File Protection dialog pops up. Upon reboot, devldr32.exe is not displayed in the active processes in Task Manager, but the Creative Mixer and AudioHQ applications fail to load. I also searched for a reference in the registry and found little to nothing... Kill it if you want to recover some memory, but I do not support such "drastic" measures... so you are on your own with it. Do not E-Mail me asking for help if you killed this process. :) explorer.exe: This is NOT related to Internet Explorer. There will ALWAYS be an explorer.exe running in the background. It is the user interface process/desktop/shell, etc. This is one of the many ways how Bill got away with "integrating" IE with Windows... If you load up "Windows Explorer" to rummage through files, you will see an additional explorer.exe in the background. This will fluctuate depending on what you have (fonts, background pics, active desktop) going at any given time. Usage of between 5.8 MB and 36 MB RAM is typical. IAAnotif.exe: This is installed with Intel's Application Accelerator software. It uses about 1.6 MB RAM. Idle: This is a generic process that is used when no other program or process is requiring CPU resources. It is not a bad thing if it is using 99% of your CPU! This process is a 16 k loop that the CPU processes while it is not doing "anything" else. If you computer is called upon to do any other task than nothing, the idle process allows that to happen and the % used will decrease accordingly. You can not disable the idle process. If it is using 97% CPU, which only means that the other 3% is used by real programs. If your idle process is constantly at a low rate (for example, 3%) something else, an application or process is using the CPU. IEXPLORE.EXE: This is the IE browser. Pops up only when you want to suck up 7.3 MB to ?? MB of memory to surf the web. I say ?? MB because every time you open an additional browser, you also start another one of these processes. If you close "all" browser windows, a IEXPLORE.EXE process will still be running. This is a "feature" to allow faster startup the next time you open IE. Unlike Mozilla, you cannot disable this "feature" other than directly killing the offending process. iTouch.exe: This process is installed with Logitech software for the "internet" key functions on keyboards and iTouch features on compatible mice. Plenty of functions remain with this software disabled, but some of the more "cool" stuff will not. This process takes from 3.6 MB to 12 MB of memory. "Generic Host Process for Win32 Services": This is what ZoneAlarm complains about while connected to the internet. "SVCHOST.EXE" is "Generic Service Host." What that means is it is a "host" for other processes or services. If your internet connection seems to "no longer work," it is due to you disallowing various "required" functions to no longer access the internet. A big one is "DNS Lookups." If you do not allow this to get through, you will no longer be able to type in "" but you will always be able to type in the IP address of the systems. The internet connection is still working, but you are blocking a "vital" part of the process for surfing web pages. mozilla.exe: This is the Mozilla browser executable. It uses between 14 MB and ?? MB of memory. Optionally, you can disable the system tray icon and not allow the "Quick Launch" feature to tell Mozilla to completely unload from memory when the final browser window is closed. This will, of course, increase the startup time when you fire up the browser window, again. msmsgs.exe: This is Microsoft Windows Messenger that comes with Windows XP Home and Pro. With some applications, namely, Outlook and MSN Explorer, this process will still run in the background to get all of those .NET alerts, etc, that Microsoft is saying will be so cool. msn6.exe: This is the Microsoft "MSN Explorer" bundled with Windows XP Home and Pro. While running this application, you will also have the previous process running. See msmsgs.exe for more information. Navapw32.exe: This is installed with Norton AntiVirus 2002 Software. Unless you want your Virus Scanner to no longer function, keep this process running. Do not "end" it. This process is also responsible for automatically updating the virus definitions and displaying that cute little icon in the system tray. point32.exe: This is installed with Microsoft Mouse Software, Intellimouse and the like. Most functions (if not all) are built into XP, so there is NO need to suck up 1.1 MB to 1.6 MB for a useless program also running in the background/system tray unless you require "specially mapped" key configurations for your buttons. promon.exe: This is installed with Intel Pro family graphics adapters. It controls the application that displays in your system tray. It uses about 656K to 1.1 MB just sitting there. I hate icons in the system tray... I have none. smss.exe: Dubbed "Windows NT Session Manager." Another process (see csrss.exe above) that is part of the core of Windows. It is a 45k process that uses about 300k to 2 MB. You cannot kill this process manually and I do not recommend trying other ways to get rid of it. Usually, if it is "difficult" to get rid of, it is needed. svchost.exe: A generic process that is "Service Host" for other processes. Yes, this is actually a service, but I am placing it here because I have no where else to put it. You may have 3 or 4 copies running in task manager (system, network, user, and ?) If you use my tweaking tips HERE, you can rid yourself of a couple of them. SWTrayV4.EXE: This is installed with the Microsoft SideWinder Version 4 Software. It takes between 4 MB and 5 MB of RAM. System IDLE Process: This is a generic process that is used when no other program or process is requiring CPU resources. It is not a bad thing if it is using 99% of your CPU! This process is a 16 k loop that the CPU processes while it is not doing "anything" else. If you computer is called upon to do any other task than nothing, the idle process allows that to happen and the % used will decrease accordingly. You can not disable the idle process. If it is using 97% CPU, which only means that the other 3% is used by real programs. If your idle process is constantly at a low rate (for example, 3%) something else, an application or process is using the CPU. taskmgr.exe: If you are looking at the processes running, this is the application that you are using to do it. "Windows Task Manager" is the full name. It uses about 3.2 MB of RAM, so take that into account when you are tweaking your system. TaskSwitch.exe: This is installed with PowerToys for XP. It uses 1.4 MB to 2 MB to display those cute icons when you hit Alt+tab. I can do without. vptray.exe: This is the cute Norton AV Tray application that displays in your system tray. It uses about 2.9 MB just sitting there. You may recover SOME memory by making the icon go away, but it is STILL running in the background. winlogon.exe: This takes care of login and logoff tasks. Really, you cannot get rid of this process. It is required as long as you are "logged in." I have saw this process fluctuate between 1.2 MB to 8.5 MB on a system that has been up for only an hour and 1.7 MB and 17 MB on a system that has been up for 40+ days. wowexec.exe: This is as process that is fired off to help "translate" interrupts, etc for 16 bit applications. If you see this process running, you are doing just that, running old applications or a DOS/command line/console window applications. Try and seek out "updated" software.


Secret of Google revealed!

In the world of World Wide Web, there can hardly be anyone who is unaware of the best and the fastest search engine, Google. It’s incredibly fast, showing search results with detailed information in milliseconds.Google is better than any of the search engines as it makes use of the link structure of the Web to calculate a quality ranking for each web page .This ranking is called PageRank. PageRank is also displayed on the toolbar of your browser if you’ve installed the Google toolbar. But the Toolbar PageRank only goes from 0 – 10 and seems to be something like a logarithmic scale. In short PageRank is a “vote”, by all the other pages on the Web, about how important a page is. A link to a page counts as a vote of support. Quoting from the original Google paper, PageRank is defined like this: We assume page A has pages T1...Tn which point to it (i.e., are citations). The parameter d is a damping factor which can be set between 0 and 1. We usually set d to 0.85. There are more details about d in the next section. Also C(A) is defined as the number of links going out of page A. The PageRank of a page A is given as follows: PR(A) = (1-d) + d (PR(T1)/C(T1) + ... + PR(Tn)/C(Tn)) Note that the PageRanks form a probability distribution over web pages, so the sum of all web pages' PageRanks will be one. PageRank or PR(A) can be calculated using a simple iterative algorithm, and corresponds to the principal eigenvector of the normalized link matrix of the web. But that’s not too helpful so let’s break it down into sections. 1. PR(Tn) - Each page has a notion of its own self-importance. That’s “PR(T1)” for the first page in the web all the way up to “PR(Tn)” for the last page 2. C(Tn) - Each page spreads its vote out evenly amongst all of it’s outgoing links. The count, or number, of outgoing links for page 1 is “C(T1)”, “C(Tn)” for page n, and so on for all pages. 3. PR(Tn)/C(Tn) - so if our page (page A) has a backlink from page “n” the share of the vote page A will get is “PR(Tn)/C(Tn)” 4. d(... - All these fractions of votes are added together but, to stop the other pages having too much influence, this total vote is “damped down” by multiplying it by 0.85 (the factor “d”) 5. (1 - d) - The (1 – d) bit at the beginning is a bit of probability math magic so the “sum of all web pages' PageRanks will be one”: it adds in the bit lost by the d(.... It also means that if a page has no links to it (no backlinks) even then it will still get a small PR of 0.15 (i.e. 1 – 0.85). (Aside: the Google paper says “the sum of all pages” but they mean the “the normalised sum” – otherwise known as “the average” to you and me. How is PageRank Calculated? This is where it gets tricky. The PR of each page depends on the PR of the pages pointing to it. But we won’t know what PR those pages have until the pages pointing to them have their PR calculated and so on… And when you consider that page links can form circles it seems impossible to do this calculation! But actually it’s not that bad. Remember this bit of the Google paper: PageRank or PR(A) can be calculated using a simple iterative algorithm, and corresponds to the principal eigenvector of the normalized link matrix of the web. What that means to us is that we can just go ahead and calculate a page’s PR without knowing the final value of the PR of the other pages. That seems strange but, basically, each time we run the calculation we’re getting a closer estimate of the final value. So all we need to do is remember the each value we calculate and repeat the calculations lots of times until the numbers stop changing much.