mersenneforum.org

mersenneforum.org (https://www.mersenneforum.org/index.php)
-   News (https://www.mersenneforum.org/forumdisplay.php?f=151)
-   -   Lucky 13 (M51 related) (https://www.mersenneforum.org/showthread.php?t=23877)

Madpoo 2018-12-10 03:27

[QUOTE=ixfd64;502223]Silly question: now that new Mersenne primes are no longer marked as a "success" until they are verified, does this mean that there is no way to spot them early unless George tells us?[/QUOTE]

The guessing game has a long history. In a way, it's half the fun. I think we've done a fair job of keeping details hidden on the server itself. In years past it was pretty obvious that a prime was found because the report page would show a success in a particular 1M range. LOL

The details of hiding the discovery until it was verified and ready to be announced has evolved to the point where nowadays most of the clues have come from people who know the exponent (because they're doing validation runs or whatever) and leak out enough info that guessing the exponent has become almost trivial.

I suppose the best clues for me would be the ones that require people to do a little mathy-stuff to figure it out, but are also general enough that it's not actually giving it away, but rather just narrows it down a bit. Like knowing whether exponent mod 4 is a 1 or a 3 ... narrows it down by half. LOL Or knowing that it's also exponent mod 8 = 5.

Of the known Mersenne primes, those 2 factoids account for 11 of the 50 (51 if we count the new one) ... 21.6%. For the entire set of prime exponent candidates from 2 through 1e9 there are 25% meeting that criteria so we're underperforming a bit there. :smile:

Of course we'll still get the people who complain that it takes too long between initial discovery and the press release going out, but whatever. :smile: These things take time...it has to be verified, George has to put together the PR stuff and use his contacts to get the word out, plus there is the timing of making the announcement when it's optimal and won't be buried in other news.

The aim of the PR is not only to announce it but also draw some attention to the project to get more participation, hopefully. After previous discoveries, there's a sharp uptick in people using the software although it tends to taper back down. Still, there are some who hear about it, think it's cool, and stick around at least long enough to do some solid tests.

With all the recent improvements in the code in just the past year, I think the extra attention would be great for people who may not be aware of those additions (PRP, the new error checking methods like Gerbicz and Jacobi, enhancements for newer CPUs and multithreading benchmarks, etc)

Madpoo 2018-12-10 04:00

[QUOTE=Madpoo;502236]...Of the known Mersenne primes, those 2 factoids account for 11 of the 50 (51 if we count the new one) ... 21.6%. For the entire set of prime exponent candidates from 2 through 1e9 there are 25% meeting that criteria so we're underperforming a bit there...[/QUOTE]

I realized that if I narrowed it down even more and mentioned what the result is mod 18, and if you knew an approximate range (within 5M) of where the exponent is, and account for known factors and tests already reported in, you could narrow it down to a pool of 933 exponents, so that's a little too specific.

From there you might be able to narrow it down to assignments made within the past XX days (bearing in mind, some exponents are assigned well in advance and just take a while to even start, much less the time it takes to complete). But still, you might get it narrowed to a few hundred.

Anyway, so, you kind of see how the game is played. :smile:

moebius 2018-12-10 04:31

Congratulations, hopefully it is also the largest currently known prime number:toot::toot::toot::toot:

axn 2018-12-10 04:47

[QUOTE=Madpoo;502236]The guessing game has a long history.[/QUOTE]

That was not the point. The point is, nobody will look for a prime, because there are no more indications on the server that a prime was reported. You can't guess something, if you don't know that there is a "something" to guess.

Madpoo 2018-12-10 04:55

[QUOTE=axn;502240]That was not the point. The point is, nobody will look for a prime, because there are no more indications on the server that a prime was reported. You can't guess something, if you don't know that there is a "something" to guess.[/QUOTE]

George started this thread, so there's your clue. :smile:

The reason it's hidden on the server from the start is because we've had a history of false positives. Most of them lately have been from a funny version of cudalucas 2.05.1 but there have been others. Couple years back a user was reporting quite a few of them from one of his machines, and earlier this year there was a false positive from a double-check in the 47-48M range or something like that.

By waiting until we've at least made sure it's not bogus, we cut down the noise. If people saw all of the false alarms it wouldn't be nearly as fun when the real thing happens. You're welcome. LOL

axn 2018-12-10 05:00

[QUOTE=Madpoo;502241]George started this thread, so there's your clue. :smile:[/QUOTE]
Right. Which led to...
[QUOTE=ixfd64;502223]Silly question: now that new Mersenne primes are no longer marked as a "success" until they are verified, does this mean that there is no way to spot them early unless George tells us?[/QUOTE]

So, the answer to that is a "yes", I guess.

Madpoo 2018-12-10 05:28

[QUOTE=axn;502242]So, the answer to that is a "yes", I guess.[/QUOTE]

Yeah, I suppose so. And now we also know the reason why it's done that way. False positives.

a1call 2018-12-10 05:45

I found the detective work very satisfying last time.
Thank you for making math fun.
BTW Anyone looking for Twins this time around?
That could end up being a clue.:smile:

henryzz 2018-12-10 09:04

Is it prime or prp currently? This could the first using the new testing methodology

LaurV 2018-12-10 10:17

Sorry I lost the "start" of the thread. Congrats to the finder.

If the offer for DC still stands, I can put one card on it (say ~120 GHzD/D card).

(Edit: contrary to other "competitors" here, people know that I [U]always[/U] run CL in [U]two[/U] cards in parallel, with different shifts, so any mismatch or false residue is excluded).

(Edit 2: and yes, that is ~240 GHzD/D totally).

axn 2018-12-10 13:13

What is the progress/ETA on the verification runs?

And, what is the plan on the press release? Pre-christmas or post new year?


All times are UTC. The time now is 08:03.

Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2020, Jelsoft Enterprises Ltd.