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45th Known Mersenne Prime Found?
An anonymous reader writes "The Great Internet Mersenne Prime Search (GIMPS) has apparently discovered a new world-record prime number. A GIMPS client computer reported the number on August 23rd, and verification is currently under way. The verification could take up to two weeks to complete. The last Mersenne prime discovered was over 9.8 million digits long, strongly suggesting that the new value may break the 10 million digit barrier — qualifying for the EFF's $100,000 prize!"
To what use will this long, long prime be put?
If video games influenced behavior the Pac Man generation would be eating pills and running away from their problems.
http://en.wikipedia.org/wiki/Mersenne_prime
Fun.
How we know is more important than what we know.
So there!
7. No, it doesn't make any sense.
And you only get 6 digits in prize money? What a rip off. That is only one $digit per 1.67 million prime digits.
Why do we waste CPU and energy to find these?
To what use will this long, long prime be put?
To pick up chicks!
"Hey babe! I just found the largest prime evar! Your place or mine?"
Hey, *I* discovered that prime, years ago.
I just never realized it was the 45th Mersenne Prime. Thanks for filling in that gap in its resume!
--
make install -not war
According to their own benchmark pages a newer Core 2 Duo E8500 process in less than 21 days. Just recently I know that password cracking programs were written to use GPU's which dramatically increased the performance. Wouldn't writing code to run this on the GPU's result in even faster processing times?
I was hoping it would be me. I have been using ./mprime on all my boxes for years now.
Congrats to the team and world.
"The price good men pay for indifference to public affairs is to be ruled by evil men." ~Plato (427-347 BC)
...he asks on slashdot.
Agreed. People should be using their extreme CPU cycles for things that matter, like helping the SETI program or running Microsoft Vista.
And work backwards, that will find the largest much faster than starting at zero.
You shouldn't think like that. Just think about your question, seriously. Whatever we do is pointless and useless and everything will be destroyed eventually through the heat death of the universe.
That being said, all that is important is that you have fun doing whatever you do. Believe it or not, some people really dig maths. Also, it's one more thing the species knows.
Sure, you are excited now, but I predict you will look back on this moment with indifference once the 46th is discovered. For now, I'm going to keep the champagne on ice.
I Heart Sorting Networks
...even!
... why the EFF considers it worth $100,000 of donated funds to pay someone for finding a 10,000,000-digit prime number. That is not what my donations were intended to do.
Go fix warrantless wiretapping, then go looking for prime numbers, kthxbye.
Since this is a particularly good prime, we should
standardize on it. That way we wouldn't have to
find our own ones every time we want to use RSA.
The submitter or editor could have at least typed the number into the summary. Lazy bastards.
I wonder how much electricity was used, and therefore coal and #6 burned, to find that prime - which will be used for what exactly?
Because doing it by hand is a real bitch and a half. Doing it by hand in moon or candle light sucks worse, I must add.
Navicula hydraulica plena anguilarum est. Omnes castelli tuus nostri sunt. Ed elli avea del cul fatto trombetta.
That's nothing. I found a prime number that is exactly twice as large as that one!
I think that should read 980,000 digits, not 9.8 million (see the list at Wikipedia), and 1 million digit mark, not 10 million (see linked EFF page).
...is a list of all the prime numbers whose length in number of digits is also a prime number as well. I wonder if anyone has found any really big ones of those.
I think big prime numbers are a clue. I just don't know what they are a clue to.
On slashdot, even the submitters don't RTFA apparently:
Story header: strongly suggesting that the new value may break the 10 million digit barrier
from TFA: However, the new prime falls short of the 10 million digits required
Seven puppies were harmed during the making of this post.
I wouldn't say the 45th known Mersenne prime has been found. I'd say the first unknown Mersenne prime has been found.
My friends and I wrote a unique prime number sieve, using previously unknown numerological techniques (exploiting digital roots).
You can find our sieve here:
http://jessicalogsdon.com/page5/page5.html
We are currently turning our sieve in a method for rapidly factoring semi-prime numbers. Digital root mechanics have certain properties that make it easy to identify semi-prime candidacy positions in a by-9 table of the natural numbers.
A PDF at the bottom of the above-linked site explains our latest investigation of solving for [p, q] where n = p*q. The source code on the page is our prime sieve implemented in Perl.
Big Money! No Whammy! You, too, could become a hundred-millionaire M.O.H.'ing RSA to the ground!!
-=/\- Jizzbug -/\=-
The summary is right. The parent is wrong and/or suffering from missing zero syndrome.
Well.. maybe. Or Maybe not. But Definitely not sort of.
I bet it'll be really exciting if one day they stumble upon a previously unknown Mersenne prime!
I think that should read 980,000 digits, not 9.8 million (see the list at Wikipedia), and 1 million digit mark, not 10 million (see linked EFF page).
No, both Wiki and the EFF agree it's 9.8 million. The 1 million digit prize was awarded back in 2000.
The real question is what have you been smoking and where can I get some?
So little time...
Sig this!
I do IT-support in the school district...let me tell you:
The kids were in a veritable state of mathematics riot today.
Smoking pot, getting laid, and blowing off responsibility is so not punk rock.
God...do these guys realize how embarrassing they make adulthood?
basically, they distribute the prize to contributors...currently $50,000 would go to you
One last thing: Sometimes I wonder; "Is that someone's signature? Or do they type that at the end of each post?"
doing it by hand would be like building the pyramids, by yourself.
it's not a weekend project, just writing down all the numbers from 1, to the number composed of at least 9 million but possibly ten or eleven million digits long... much less then dividing that number by every number from 1 to the number of the same length to make sure it is only evenly divisible by itself, and 1.
i repeat myself it's like trying to build they pyramids by yourself. or even better, trying to build a four lane highway by yourself. I remember hearing about a guy from Duluth Minnesota, who had been trying to build a highway the most direct route between Fargo, ND and Duluth, MN, and he actually started on the Duluth side, i know he didn't get far, but Duluth Minnesota is one of those 'rare' towns that was booming about 100 years ago, but then started shrinking (i forget when) and has never really completely recovered.
the guy started on his quest to get the highway built believing a direct route to Fargo would increase trade and tourism and what not (it would save on average an hours drive each way)
but i think he finally died, having completed somewhere between 12-40 miles of highway.
today's PCs are like having millions of number crunching slaves with never ending papyrus scrolls, there are things computers can do that a human being would never complete if they lived a million years. and even with those millions of number crunching slaves some things take a long time to compute.
the point being, the reason why people do these things with computers is because computers are the only thing that can do them, and to be the first to do something vastly unimaginable by normal standards. kinda like, 'why did we shoot a robot lander to mars?' instead of say, making beer free for everyone in the united states for a day.
https://www.gnu.org/philosophy/free-sw.html
Over a hundred comments posted and I see no ridicule of their silly silly self-deprecating name?
Have years of open source naming conventions desensitize you so?
2 + 1 = 3....both 2 and 3 are prime.
did I take the bait?
Thankfully the comic didn't imply a sense of humor.
I know a 100 Billion+ digit prime number....figured it out in my sleep about 10 years ago. But it would take me like 6 years speed writing 24/7 to write it out....not to mention the 500,000 trees it would take to make all the paper.
Becuase it is there and becuase we can. why bother to do anything at all? In a hundred years nobody will care or remember you for anything you have done at all during your lifetime, perhaps you should just go crawl back into bed and stay there for the rest of your life? You will have the exact same impact on the rest of the universe that you would have otherwise. While your doing that the rest of us will 'waste' out time discovering the universe around us, it may not server any purpose but we choose to do it and we feel better for it.
I may agree with what you say, but I will defend to the death your right to face the consequences of saying it.
why don't they just use a generator like this one:
http://mistupid.com/math/primes.htm
Maybe /. can take up a collection for the $31,071.
Knowledge is how to play a game, intelligence is how to win, wisdom is knowing what game to play.
I was looking for a good replacement password that would be easily memorized.
Accept any challenge, No matter the odds.
or sorting pr0n. Now that's important!
Can I get that in Roman Numerals pls?
Don't be apathetic. Procrastinate!
About 33 million bits ( ln(10)/ln(2) = 3.3219 ) or 4MB.
That depends on how you encode it, and how you compress it.
If you were to use a simple binary-coded decimal format.. you would need 10million*4bits = 40mil bits (4.8MB)
If you encoded as a floating point number, you couldn't raise it to a power since it's prime, so it would take about 33mil + 1 bits (3.9MB)
And more importantly:
Because it's a mersenne prime, this number can be expressed in the format (2^n)-1 where n is some integer greater than 33,219,260 and likely less than 41,000,000. So the value n is enough information to complete define the prime.
26 bits by your format.
24 bits by starting at an offset of 33,219,260.
And of course, you can write a custom compression program that can store that specific number in 1 bit.
I didn't see your response, so I wrote my own instead of moderating yours like I should have. If anything, laughing at yourself should be easiest of all since you are more likely to get the joke given an intimate knowledge of its subject matter. =)
Looking at this:
http://en.wikipedia.org/wiki/Image:Primes.png
We're still at the bottom of the exponential curve.
Another fun relationship is between Mersenne Primes and Perfect Numbers, numbers whose factors add up to themselves.
If 2^n-1 is prime, (2^n-1)(2^(n-1)) is perfect (and has a distinctive pattern of digits in binary, to boot...). The proof in this direction is easy. Proving that all even perfect numbers are of this form is a little harder, but doable.
The hard one is proving whether or not there are any odd perfect numbers, and, if so, what form they might take. Nobody has done this yet.
...laura
Knowing that it's gonna take a few weeks to check the veracity of the value...I wonder if they started their loop at 3 or 1? If they used 1...well... obviously they don't know shit about code optimization.
that will essentially map all the primes to n? akin to f(n)=prime number?
Quick! Someone write a program in Brainfuck to verify this! I'd punch in the program right here, but /.'s "junk" filter would tell me to go shove it where the sun don't shine!
McCain/Palin '08. Now THAT's hope and change!
Mathematician #1: How are we going to find the 46th Prime?
Mathematician #2: Bring out the GIMPS.
Mathematician #1: The GIMPS is sleeping.
Mathematician #2: I guess you're going to have to wake him up then.
The manifest absurdity of it is too obvious to require explanation
Yeah, you are damn right, large prime numbers have no use whatsoever!
/sarcasm
Least of all for us using The Internets!
For all things prime, I suggest you read Music of the primes. It's a good read and quite informative on the subject.
Dawkins Revisited: A person is shit's way of making more shit -- Steve Barnett, anthropologist.
Great idea! I love how you've obviously thought about how to prevent such a system being abused or gamed.
Oh wait, no you haven't.
I hate printers.
You don't understand, if you find the big prime, you get 10.000$! That's why I'm running it.
One donation? Who would hope to gain from something like this? I can think of at least two, 'letter agencies' that might hope to gain from this and have that kind of money to essentially (at least from the outside) throw away.
My bet is its one of these agencies or their counter parts in other parts of the world. Either that or a company researching crypto.
~AC
I always thought it would be 43. At least that is what Douglas Adams said.
Actually, if you have a possibly prime number N, you don't need to divide by every number from 1 to N to check whether it's prime.
A simple test is to test every odd from 1 to the square root of N. If 2 doesn't divide evenly into the number, then no other even number will. Also, if something can cleanly be factored out, it's not prime.
Wikipedia also suggests storing a list of primes to test first--If N can divide by any of those primes it is composite.
There are much better algorithms out there, but those are a few easy ways to speed up a primality test.
Eratosthenes? Is that you?
..Can I have it back please, then.
How many digits-per-minute can you type?
You know, there is a difference between trolling and pointing out the flaws in your reasoning. Just saying.
Any science news is good news, IMHO. But I do have to wonder what's going to come out of this discovery? Is the cure for cancer going to be found based on solving all the prime numbers out to like a gadzillion digits? Personally, I'd rather put my computers to more useful things -- like finding more drugs,... :-)
Yes, the information in this post is incorrect. But it's not Offtopic. It's not Redundant. It's not Overrated or Trolling or Flamebait. It's actually rather Insightful, even if the poster did make an error in his assumed understanding of the GP.
Please don't moderate it down further.
I know insight doesn't always need to come from truth, but I think this time it was only meant as a joke, but hey, what were the odds that >50% of the moderators were mathematicians? I guess that would depend on the base system used to count them.
Perhaps you could use a number-theoretic fft (using modular arithmetic instead of fp arithmetic) on a gpu to avoid the errors accumulation. Although old gpus only processed single precision fp, new gpus can process 24-bit integer multiplication at full speed as well (at least for nvidia's cuda). You probably gain a little bit of accuracy using NTTs vs single precision FP FFTs (where you probabaly need a few guard bits to avoid subtraction errors) which is likely an exponental speedup with these types of algorithms.
Of course the double precision arithmetic is only somewhat slower than single precision on GPUs, but consumes twice the register space (so on actual algorithms, it runs quite a bit slower because of this). Right now, GPU ffts are quite a bit faster than CPU ffts, but not yet 10x (unless you have a very large GPU and a fairly ordinary CPU) if you copy the data back to the CPU every time after an fft, but if you leave the data in the GPU and code the rest of the digit-convolution algorithm on the GPU, I'll bet it isn't that far off of 10x on average.
The aggregate intelligence of Slashdot must be very low if the parent is moderated +5, informative.
Digital roots do exist, and according to Wikipedia they're used in Western numerology.
The repeated addition of digits until you have only one digit has nothing to do with spirituality or mystic powers.
All magic is fake, especially paranormal and supernatural magic. None of these sorts of magic are used in prime number sieves.
What's the scientific significance of this?
He who can laugh at himself becomes invincible to insult.
Luckily you can easily see if the number is divisible by 2, 3 or 5[*] so you can start checking at 7 and work up to the square root of the number you're searching. You'll find that much faster.
* with 2 or 5 you can look at the last digit. with 3 you add all the digits together and see if they're divisible by 3.
-- Don't believe everything you read, hear or think
So, if there is a 10 million digit figure that exists as a prime number, but it's too long to write out such that we can see or behold it tangibly, do we really know if it exists?
52 52'23" W 47 32'07" N
dividing that number by every number from 1 to the number of the same length to make sure it is only evenly divisible by itself, and 1.
To be just a little bit picky... You can skip all of the even numbers, so really its only half as bad as you make it out to be ;)
Man, they had me thinking that that GIMP was primarily used for graphic design... Little did I know!
Now how do I locate this prime number plugin?
May I suggest you spend some of your time learning how to type typoless ?
I'm not a coward by any name.
"why did we shoot a robot lander to mars?"
Why did we?