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2018-12-27, 07:49   #232
Mark Rose

"/X$$‘-‘)/X\" Jan 2013 23·359 Posts Quote:  Originally Posted by GP2 I blame that website, and good thing I didn't post 20996011. unwise bob chose death?  2018-12-27, 18:30 #233 Dr Sardonicus Feb 2017 Nowhere 2·1,787 Posts Huh. There are kinds of information I would like to retain, but I just can't seem to memorize -- at least not by rote -- and maybe a mnemonic is just the thing for that. But with a lot of things -- like numbers -- I generally find it much harder to remember the mnemonic, than the thing it's supposed to help me remember, like in this case the actual number 82589933. Of course, once the mnemonic is memorized, and (somehow) associated with the thing it's helping me remember, it can really help, by giving my mind another "handle" on it. So, ROYGB(I)V, or, "Roar out, you great big (or bIg) voice" helps me keep the rainbow colors straight. Or, at any rate, a lot faster than visualizing the spectrum as going from lower to higher frequencies (red to blue; I also remember infrared and ultraviolet). Alas, remembering the way in which the mnemonic is associated with the thing to be remembered can also be problematic for me. With the phone number scheme, at least converting the mnemonic word into a number seems to be unambiguous. I'm not sure what to do to form a word from a number that has 1's or 0's in it. With the latest Mersenne prime exponent, I remember the "9933" ending without apparent effort. I remember the initial "82" which leaves two digits. One of them is a five. The first one -- I remember now! OK, the other one's an 8... Got it! And if I'm not sure, I remember that for this p, p-1 is divisible by 103 :-D Last fiddled with by Dr Sardonicus on 2018-12-27 at 18:37  2018-12-27, 20:35 #234 masser Jul 2003 wear a mask 101101001002 Posts Looking at the "method used" list on Wikipedia's Mersenne Prime page, I'm struck by how successful GIMPS has been on commodity cpus. I know that GIMPS has users with access to awesome hardware. Also, I wouldn't be surprised if, in the near future, GIMPS finds a Mersenne primes with a GPU or an interesting cloud chip. So, questions for the old-timers on the forum. Looking over the chips that found Mersenne primes (for GIMPS), which processor was the "highest end" for its time? Which processor was the least capable for its time?  2018-12-27, 21:32 #235 kriesel "TF79LL86GIMPS96gpu17" Mar 2017 US midwest 2·2,309 Posts What hardware, what OS, etc? In the GIMPS era (1996 and forward): Cray: 1 Intel cpus: 16; AMD cpu: 1; NVIDIA gpu: 0 AMD gpu; 0; Intel integrated graphics processor, 0, not even in the running Other (ARM, Motorola, etc); 0 I'm guessing most of the Intel cpus were running Windows at the time, but have no data handy. (If linux, would it say mprime instead on https://www.mersenne.org/primes/ ?) nonGIMPS 1, GIMPS 17 Primality test: LL 18 PRP 0 Last fiddled with by kriesel on 2018-12-27 at 21:33 2018-12-28, 03:10 #236 Madpoo Serpentine Vermin Jar Jul 2014 327710 Posts Quote:  Originally Posted by kriesel I'm guessing most of the Intel cpus were running Windows at the time, but have no data handy. (If linux, would it say mprime instead on https://www.mersenne.org/primes/ ?) I could be mistaken but I think all of the Prime95 finds were done in Windows; no Linux winners yet. I'll chalk that up to the smaller pool of Linux systems out there.  2018-12-28, 03:43 #237 LaurV Romulan Interpreter Jun 2011 Thailand 3×2,957 Posts Re: mnemonics, when in high school, teachers forced us to learn poetry which was supposed to help us remember the digits of \(e$$ and $$\pi$$. On the same idea shown on wolfram (see the end of the article), but the Romanian versions were more "on the subject", for example, for e, the poetry was something like "a Scottish guy invented it, a Swiss guy introduced it in computing..." (Ro: un scoțian a inventat, un elvețian a introdus în calcule... = 2.71828182) - the "Scottish" part most probably refers to Napier, even if his contribution wasn't so great, and just now I see that the mnemonic I remember is getting the last digit wrong (7 instead of 8) - maybe I am remembering it wrong... Anyhow, the idea is, as you said, I used to know the mnemonics for 40 or 50 digits for both e and pi, but it was not useful, and right now, I know the (most of) the digits, but I forgot the mnemonics long time ago... for the hack of me, I can't remember at all what the "pi" mnemonic was about...
2018-12-28, 22:50   #238
ewmayer
2ω=0

Sep 2002
República de California

9,791 Posts

Quote:
 Originally Posted by Dr Sardonicus With the phone number scheme, at least converting the mnemonic word into a number seems to be unambiguous. I'm not sure what to do to form a word from a number that has 1's or 0's in it.
That issue is why I usually prefer a so-called "modifed phone keypad mnemonic", in which the letters of the alphabet are divvied up amongst all 10 digits. A fun way of doing this, and one entirely apt for the present context, is to use the Mersenne-mod IBDWT mix-of-2-wordsizes scheme to do said divvying. Such an enhancement was simply unnecessary for the latest M-prime exponent, is all, and the modifed scheme has the drawback that one can no longer whip out one's mobile as a visual aid when working the numbers.

2018-12-29, 21:27   #239
retina
Undefined

"The unspeakable one"
Jun 2006
My evil lair

23×727 Posts

Quote:
 Originally Posted by ewmayer ... and the modifed scheme has the drawback that one can no longer whip out one's mobile as a visual aid when working the numbers.
Hehe, those poor folk with those crappy "smart" phones with touch screens can't see any visual aid.

2018-12-29, 22:09   #240
ewmayer
2ω=0

Sep 2002
República de California

979110 Posts

Quote:
 Originally Posted by retina Hehe, those poor folk with those crappy "smart" phones with touch screens can't see any visual aid.
Since their phones are so smart, surely they need no such help!

 2018-12-29, 22:33 #241 Batalov     "Serge" Mar 2008 Phi(4,2^7658614+1)/2 23·7·163 Posts Isn't this a strawman? A google search for images of keypads shows those little letters on each variant. I am pretty sure that many people still call mnemonic numbers, such as "800.Go.FedEx" or "800-SF-CLAIM" etc
 2019-01-01, 23:06 #242 bhelmes     Mar 2016 52·11 Posts second article about M51 on german https://www.nzz.ch/wissenschaft/prim...ekt-ld.1447651

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