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A team from the the University of California in Los Angeles (UCLA) found the new prime – meaning it can be divided only by itself and one - by connecting 75 computers and harnessing their power. The number is the largest "Mersenne prime" to have been discovered. Mersenne primes are numbers expressed as two to the power of "P" minus one - where P is itself a prime number. In the UCLA team's new prime, P is 43,112,609. Their number is the 46th known Mersenne prime and the eighth to have been discovered at UCLA. Mersenne primes are named after their discoverer, Marin Mersenne, who was a 17th century French mathematician. "We're delighted," said UCLA's Edson Smith, the team's leader. "Now we're looking for the next one, despite the odds." The $100,000 prize was offered by the Electronic Frontier Foundation for anyone discovering the first Mersenne prime with more than 10 million digits. The foundation set up the prime number prize to promote co-operative computing on the internet. Their offer saw thousands of people around the world have participating in the "Great Internet Mersenne Prime Search", or Gimps - in which they devoted some of their computer's unused power to performing the calculations needed to find huge Mersenne primes.
Originally posted by Anonymous ATS
reply to post by sir_chancealot
Hi sir_chancelot,
your way to find prime numbers is relevant (for a human brain and for small numbers) but it's not working for computers and high numbers and you have one misconception about computers, like many ohter people : you mistake frequency (aka "CPU speed") and the "power" of a CPU, i.e. 32 or 64 bits for the most recent home PCs.
Let's start with number coding. The highest signed number a 64 bits CPU can code is (2^63)-1 : 1 bit for the sign (+ or -), 63 bits for the power of 2, and -1 because you have to count out 0.
So the highest signed number for a 64 bits CPU is 9,223,372,036,854,775,807. The highest unsigned number is (2^64)-1.
Of course, if you try on your Windows calculator, you'll see you can go much higher (to about 2^100,000) but it's using some programming tricks.
Now, let's get back to your "algorythm". It's the way human brain works, simple, effective but very long. Let me show you with a similar algorythm :
Imagine you want to count from 1 to (2^63)-1, by adding 1 every 1x10^-9 second, approx. corresponding to a 1Ghz CPU. It would take [(2^63)-1] / [(10^9)x60*60*24*30*12] = 296 years (if I didn't make a mistake in my calculation). But you get the picture.
Now Imagine for a number like 2^43,112,609 ... You see now it IS quite a feat and finding such high prime numbers is not that simple.
I hope I shed some light on this achievement. As for the use of finding such a high number ... glory I guess
Originally posted by VIKINGANT
reply to post by sir_chancealot
OK then,
With wanting to sound like a smart A... I would like you to post here the next prime number beyond 43,112,609.
Let us know how you get on...