From...

INTERACTIVE Are you interested in volunteering your PC to hunt for prime numbers (and netting the $50,000 prize)? Yes No View Results

May 13, 1999
Web posted at: 8:38 a.m. EDT (1238 GMT)

In this story: Home PCs do their bit Big rewards Effort's the thing RELATED STORIES, SITES

by Jennifer Pelz

(IDG) -- Somewhere near the edge of human imagination, there's a million-digit number with a rare distinction. It is the biggest prime number ever known--and it's waiting to be discovered.

And a San Francisco Internet group wants you to find it.

Don't worry, you don't have to do the math. Your computer will do it for you in its spare time, experts say.

To demonstrate how personal computers can cooperate for the common good, the Electronic Frontier Foundation is offering a $50,000 prize to the first person to find a million-digit prime number (the mathematical term for numbers like 2, 3, or 7027 that can't be divided evenly). The rewards rise for the first ten-million-digit prime number and beyond.

This is one of a growing number of efforts to put the world's millions of computers together to work for progress and profit.

Home PCs do their bit

All it takes to try for the prime-number prize is a standard home computer. A free program, available at Mersenne.org, will assign a number to test and start the computer on its way.

Designed to be unobtrusive, the software works with power left over from whatever else the computer is doing, explains George Woltman, the program's author. If the computer is grappling with a big database, the number testing will go slowly. If the machine is idling, the program will crank away as fast as it can.

But even when the computer is working, "most of the time, you're really not using your computer very hard," says Woltman, a retired computer programmer living in Orlando, Florida.

A PC with a 200-MHz Pentium processor can check out a number in about three weeks, if it's running the entire time, he says. There are also versions of the software for Macintosh and Linux operating systems.

Although it will work unnoticed, the software installs an icon that allows the user to easily check its progress. If it finds the assigned number is prime, "it'll go crazy and beep," Woltman says. "It'll let you know you've gotten lucky."

MORE COMPUTING INTELLIGENCE
	IDG.net home page
PC World home page
FileWorld find free software fast
Make your PC work harder with these tips
Reviews & in-depth info at IDG.net
		IDG.net's desktop PC page
		IDG.net's portable PC page
IDG.net's Windows software page
IDG.net's personal news page
Year 2000 World
Questions about computers? Let IDG.net's editors help you
Subscribe to IDG.net's free daily newsletter for computer geniuses (& newbies)
Search IDG.net in 12 languages
News Radio
	Fusion audio primers
	Computerworld Minute

Big rewards

Roland Clarkson, a California college sophomore, got lucky this January. Running Woltman's program, Clarkson's two 200-MHz computers found the current record holder, a prime number with 909,526 digits.

Clarkson's find is a number so huge that, written in a line of 12-point type, it would stretch for nearly two and a half miles, according to University of Tennessee math professor Chris Caldwell. And that's without commas.

Except for 1, not a single other number can divide it without leaving a remainder.

While such prime numbers are useful for code writing, mathematicians admire them for themselves. These rarities are the building blocks that make all other numbers. And there's no formula for finding them all, said Caldwell, keeper of the Prime Pages, a Web list of all known prime numbers.

To Caldwell, hunting prime numbers is like collecting gems, ancient coins, or first editions. "In all human endeavor, the more rare something is, the more we value it," he explains.

About 8000 computers are now working on the Internet prime-number project, Woltman said. They have joined the distinguished company of major mathematicians and philosophers like Euclid and Descartes, who pondered prime numbers, Caldwell said.

Effort's the thing

But for the Electronic Frontier Foundation, the point is the effort, not the potential find.

For one thing, the foundation wants idle computers to do something more productive than running screen savers. The project also showcases the social benefits and commercial potential of cobbling computers together, says John Gilmore, one of the organization's founders.

"The way computers are linked now makes it possible to build supercomputers out of ordinary ones ... with some social cooperation," he says.

The prime-number hunters aren't alone in realizing this. Distributed.net, a group of computer users around the globe, has worked on various code-testing projects since 1997 in the interest of improving computer security. The current project promises prizes of $1000 to $2000.

Meanwhile, astronomers at the University of California at Berkeley want help scanning the skies for signs of intelligent life, as part of their Search for Extraterrestrial Intelligence at Home project. The necessary software--a screen saver that will analyze data from a giant telescope in Puerto Rico--is scheduled to become available May 17 from the SETI at Home Web site.

Ultimately, Gilmore suggests, there could even be a market for these piecemeal supercomputers. He envisions businesses paying to have a network of small computers work on big projects like animation, economic modeling, or testing product designs.