Google Blogoscoped

Sunday, June 27, 2004

Mobile Communications and Collective Action by Howard Rheingold

“There are a number of gems in this presentation, which is overall very rousing about the possibilities of new technology and democratic empowerment. The one that made me think the most was the discussion of a UPC reader on a computer that looked the code up in a database and then did a Google search on that product, allowing you to know who things like whether the product was manufactured in an environmentally friendly way, if there was a store down the street that had it on sale, etc.”
– AKB, Howard Rheingold (Demand Media), April 19th, 2004

A talk by Howard Rheingold [RM].

More at the video blog.

Communicating with Computers by Alan Kay

You can view an inspiring talk by computer legend Alan Kay – inventor of the Dynabook, an early version of the laptop of today – on the history of software, computing, WYSIWYG, object-orientiation, and interface design. (Plus, Alan Kay is telling you why at Xerox PARC, bean bag chairs were used.)
It’s amazing to see Douglas Engelbart of the Augmentation Research Center at Stanford Research Institute (where close-by at Stanford University, Google was spawned later on) showing off mouse, collaborative desktop, windows, hypertext, hierarchical folders, and web cam – all in the 1960s. Also, you can find an introduction to Seymour Papert’s work; he’s the man who invented Logo and connected kids to computers.

The Google School

Google has become so important in everyday life, I was wondering what a Google school would look like. [Thanks to the free Prelinger film archives and their Duck and Cover.]

Watch the Google School for Understanding Google [WMV].


You can keep your HTML files small by putting layout details into a stylesheet. This approach can help search engines as well as your human visitors, but most of all it makes your web site highly maintainable.

View the introduction to writing HTML with CSS [WMV]*.

*I’m editing HTML and CSS using open-source freeware Netpadd.

Google PageRank Checksum Calculator

Alex Stapleton figured out the code to calculate the checksum to grab the PageRank for any URL. [Thanks Jesse.]

    This code is released unto the public domain 
header("Content-Type: text/plain; charset=utf-8"); 
define('GOOGLE_MAGIC', 0xE6359A60); 

//unsigned shift right 
function zeroFill($a, $b) 
    $z = hexdec(80000000); 
        if ($z & $a) 
            $a = ($a>>1); 
            $a &= (~$z); 
            $a |= 0x40000000; 
            $a = ($a>>($b-1)); 
            $a = ($a>>$b); 
        return $a; 

function mix($a,$b,$c) { 
  $a -= $b; $a -= $c; $a ^= (zeroFill($c,13)); 
  $b -= $c; $b -= $a; $b ^= ($a<<8); 
  $c -= $a; $c -= $b; $c ^= (zeroFill($b,13)); 
  $a -= $b; $a -= $c; $a ^= (zeroFill($c,12)); 
  $b -= $c; $b -= $a; $b ^= ($a<<16); 
  $c -= $a; $c -= $b; $c ^= (zeroFill($b,5)); 
  $a -= $b; $a -= $c; $a ^= (zeroFill($c,3));   
  $b -= $c; $b -= $a; $b ^= ($a<<10); 
  $c -= $a; $c -= $b; $c ^= (zeroFill($b,15)); 
  return array($a,$b,$c); 

function GoogleCH($url, $length=null, $init=GOOGLE_MAGIC) { 
    if(is_null($length)) { 
        $length = sizeof($url); 
    $a = $b = 0x9E3779B9; 
    $c = $init; 
    $k = 0; 
    $len = $length; 
    while($len >= 12) { 
        $a += ($url[$k+0] +($url[$k+1]<<8) +($url[$k+2]<<16) +($url[$k+3]<<24)); 
        $b += ($url[$k+4] +($url[$k+5]<<8) +($url[$k+6]<<16) +($url[$k+7]<<24)); 
        $c += ($url[$k+8] +($url[$k+9]<<8) +($url[$k+10]<<16)+($url[$k+11]<<24)); 
        $mix = mix($a,$b,$c); 
        $a = $mix[0]; $b = $mix[1]; $c = $mix[2]; 
        $k += 12; 
        $len -= 12; 

    $c += $length; 
    switch($len)              /* all the case statements fall through */ 
        case 11: $c+=($url[$k+10]<<24); 
        case 10: $c+=($url[$k+9]<<16); 
        case 9 : $c+=($url[$k+8]<<8); 
          /* the first byte of c is reserved for the length */ 
        case 8 : $b+=($url[$k+7]<<24); 
        case 7 : $b+=($url[$k+6]<<16); 
        case 6 : $b+=($url[$k+5]<<8); 
        case 5 : $b+=($url[$k+4]); 
        case 4 : $a+=($url[$k+3]<<24); 
        case 3 : $a+=($url[$k+2]<<16); 
        case 2 : $a+=($url[$k+1]<<8); 
        case 1 : $a+=($url[$k+0]); 
         /* case 0: nothing left to add */ 
    $mix = mix($a,$b,$c); 
    /*-------------------------------------------- report the result */ 
    return $mix[2]; 

//converts a string into an array of integers containing the numeric value of the char 
function strord($string) { 
    for($i=0;$i<strlen($string);$i++) { 
        $result[$i] = ord($string{$i}); 
    return $result; 
// - Checksum: 6540747202 
$url = 'info:'.$_GET['url']; 
$ch = GoogleCH(strord($url)); 

Once you calculated the checksum, you can dynamically find out the PageRank for a page by reading the values returned by the following URL: search?client=navclient-auto&ch=[checksum here] &features=Rank&q=info:


Blog  |  Forum     more >> Archive | Feed | Google's blogs | About


This site unofficially covers Google™ and more with some rights reserved. Join our forum!